path: root/libgweather/gweather-weather.c

/* gweather-weather.c - Overall weather server functions
 *
 * SPDX-FileCopyrightText: The GWeather authors
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"

#include "gweather-weather.h"

#include "gweather-enum-types.h"
#include "gweather-private.h"

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <langinfo.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include <gio/gio.h>

#define MOON_PHASES 36

/**
 * GWeatherInfo:
 *
 * `GWeatherInfo` provides a handy way to access weather conditions
 * and forecasts from a [struct@GWeather.Location], aggregating multiple
 * different web services.
 *
 * It includes also astronomical data such as sunrise times and
 * moon phases.
 */

#define TEMPERATURE_UNIT "temperature-unit"
#define DISTANCE_UNIT    "distance-unit"
#define SPEED_UNIT       "speed-unit"
#define PRESSURE_UNIT    "pressure-unit"
#define DEFAULT_LOCATION "default-location"

enum
{
    PROP_0,
    PROP_LOCATION,
    PROP_ENABLED_PROVIDERS,
    PROP_APPLICATION_ID,
    PROP_CONTACT_INFO,
    PROP_LAST
};

enum
{
    SIGNAL_UPDATED,
    SIGNAL_LAST
};

static guint gweather_info_signals[SIGNAL_LAST];

G_DEFINE_TYPE (GWeatherInfo, gweather_info, G_TYPE_OBJECT);

void
_gweather_gettext_init (void)
{
    static gsize gweather_gettext_initialized = FALSE;

    if (G_UNLIKELY (g_once_init_enter (&gweather_gettext_initialized))) {
        bindtextdomain (GETTEXT_PACKAGE, GNOMELOCALEDIR);
#ifdef HAVE_BIND_TEXTDOMAIN_CODESET
        bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
#endif

        bindtextdomain (LOCATIONS_GETTEXT_PACKAGE, GNOMELOCALEDIR);
#ifdef HAVE_BIND_TEXTDOMAIN_CODESET
        bind_textdomain_codeset (LOCATIONS_GETTEXT_PACKAGE, "UTF-8");
#endif

        g_once_init_leave (&gweather_gettext_initialized, TRUE);
    }
}

static void
_weather_location_free (WeatherLocation *location)
{
    g_free (location->name);
    g_free (location->code);
    g_free (location->zone);
    g_free (location->radar);
    g_free (location->country_code);
    g_free (location->tz_hint);
}

static gboolean
should_use_caps (GWeatherFormatOptions options)
{
    return options == GWEATHER_FORMAT_OPTION_DEFAULT ||
           (options & GWEATHER_FORMAT_OPTION_SENTENCE_CAPITALIZATION);
}

/* clang-format off */
static const gchar *wind_direction_str[] = {
    N_("variable"),
    N_("north"), N_("north — northeast"), N_("northeast"), N_("east — northeast"),
    N_("east"), N_("east — southeast"), N_("southeast"), N_("south — southeast"),
    N_("south"), N_("south — southwest"), N_("southwest"), N_("west — southwest"),
    N_("west"), N_("west — northwest"), N_("northwest"), N_("north — northwest")
};

static const gchar *wind_direction_caps_str[] = {
    N_("Variable"),
    N_("North"), N_("North — Northeast"), N_("Northeast"), N_("East — Northeast"),
    N_("East"), N_("East — Southeast"), N_("Southeast"), N_("South — Southeast"),
    N_("South"), N_("South — Southwest"), N_("Southwest"), N_("West — Southwest"),
    N_("West"), N_("West — Northwest"), N_("Northwest"), N_("North — Northwest")
};
/* clang-format on */

const gchar *
gweather_wind_direction_to_string_full (GWeatherWindDirection wind,
                                        GWeatherFormatOptions options)
{
    gboolean use_caps = should_use_caps (options);

    if (wind <= GWEATHER_WIND_INVALID || wind >= GWEATHER_WIND_LAST)
        return use_caps ? C_ ("wind direction", "Invalid")
                        : C_ ("wind direction", "invalid");

    return use_caps ? _ (wind_direction_caps_str[(int) wind])
                    : _ (wind_direction_str[(int) wind]);
}

const gchar *
gweather_wind_direction_to_string (GWeatherWindDirection wind)
{
    return gweather_wind_direction_to_string_full (wind, GWEATHER_FORMAT_OPTION_DEFAULT);
}

static const gchar *sky_str[] = {
    N_ ("clear sky"),
    N_ ("broken clouds"),
    N_ ("scattered clouds"),
    N_ ("few clouds"),
    N_ ("overcast")
};

static const gchar *sky_caps_str[] = {
    N_ ("Clear sky"),
    N_ ("Broken clouds"),
    N_ ("Scattered clouds"),
    N_ ("Few clouds"),
    N_ ("Overcast")
};

const char *
gweather_sky_to_string (GWeatherSky sky)
{
    return gweather_sky_to_string_full (sky, GWEATHER_FORMAT_OPTION_DEFAULT);
}

const gchar *
gweather_sky_to_string_full (GWeatherSky sky,
                             GWeatherFormatOptions options)
{
    gboolean use_caps = should_use_caps (options);

    if (sky <= GWEATHER_SKY_INVALID || sky >= GWEATHER_SKY_LAST)
        return use_caps ? C_ ("sky conditions", "Invalid")
                        : C_ ("sky conditions", "invalid");

    return use_caps ? _ (sky_caps_str[(int) sky])
                    : _ (sky_str[(int) sky]);
}

/*
 * Even though tedious, I switched to a 2D array for weather condition
 * strings, in order to facilitate internationalization, esp. for languages
 * with genders.
 */

/*
 * Almost all reportable combinations listed in
 * http://www.crh.noaa.gov/arx/wx.tbl.php are entered below, except those
 * having 2 qualifiers mixed together [such as "Blowing snow in vicinity"
 * (VCBLSN), "Thunderstorm in vicinity" (VCTS), etc].
 * Combinations that are not possible are filled in with "??".
 * Some other exceptions not handled yet, such as "SN BLSN" which has
 * special meaning.
 */

/* clang-format off */

/*
 * Note, magic numbers, when you change the size here, make sure to change
 * the below function so that new values are recognized
 */
/*                   NONE                         VICINITY                             LIGHT                      MODERATE                      HEAVY                      SHALLOW                      PATCHES                         PARTIAL                      THUNDERSTORM                    BLOWING                      SHOWERS                         DRIFTING                      FREEZING                      */
/*               *******************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************/
static const gchar *conditions_str[24][13] = {
/* TRANSLATOR: If you want to know what "blowing" "shallow" "partial"
 * etc means, you can go to http://www.weather.com/glossary/ and
 * http://www.crh.noaa.gov/arx/wx.tbl.php */
    /* NONE          */ {"??",                        "??",                                "??",                      "??",                         "??",                      "??",                        "??",                           "??",                        N_("thunderstorm"),             "??",                        "??",                           "??",                         "??"                         },
    /* DRIZZLE       */ {N_("drizzle"),               "??",                                N_("light drizzle"),       N_("moderate drizzle"),       N_("heavy drizzle"),       "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         N_("freezing drizzle")       },
    /* RAIN          */ {N_("rain"),                  "??",                                N_("light rain"),          N_("moderate rain"),          N_("heavy rain"),          "??",                        "??",                           "??",                        N_("thunderstorm"),             "??",                        N_("rain showers"),             "??",                         N_("freezing rain")          },
    /* SNOW          */ {N_("snow"),                  "??",                                N_("light snow"),          N_("moderate snow"),          N_("heavy snow"),          "??",                        "??",                           "??",                        N_("snowstorm"),                N_("blowing snowfall"),      N_("snow showers"),             N_("drifting snow"),          "??"                         },
    /* SNOW_GRAINS   */ {N_("snow grains"),           "??",                                N_("light snow grains"),   N_("moderate snow grains"),   N_("heavy snow grains"),   "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* ICE_CRYSTALS  */ {N_("ice crystals"),          "??",                                "??",                      N_("ice crystals"),           "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* ICE_PELLETS   */ {N_("sleet"),           "??",                                N_("little sleet"),     N_("moderate sleet"),   N_("heavy sleet"),   "??",                        "??",                           "??",                        N_("sleet storm"),         "??",                        N_("showers of sleet"),   "??",                         "??"                         },
    /* HAIL          */ {N_("hail"),                  "??",                                "??",                      N_("hail"),                   "??",                      "??",                        "??",                           "??",                        N_("hailstorm"),                "??",                        N_("hail showers"),             "??",                         "??",                        },
    /* SMALL_HAIL    */ {N_("small hail"),            "??",                                "??",                      N_("small hail"),             "??",                      "??",                        "??",                           "??",                        N_("small hailstorm"),          "??",                        N_("showers of small hail"),    "??",                         "??"                         },
    /* PRECIPITATION */ {N_("unknown precipitation"), "??",                                "??",                      "??",                         "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* MIST          */ {N_("mist"),                  "??",                                "??",                      N_("mist"),                   "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* FOG           */ {N_("fog"),                   N_("fog in the vicinity") ,          "??",                      N_("fog"),                    "??",                      N_("shallow fog"),           N_("patches of fog"),           N_("partial fog"),           "??",                           "??",                        "??",                           "??",                         N_("freezing fog")           },
    /* SMOKE         */ {N_("smoke"),                 "??",                                "??",                      N_("smoke"),                  "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* VOLCANIC_ASH  */ {N_("volcanic ash"),          "??",                                "??",                      N_("volcanic ash"),           "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* SAND          */ {N_("sand"),                  "??",                                "??",                      N_("sand"),                   "??",                      "??",                        "??",                           "??",                        "??",                           N_("blowing sand"),          "",                             N_("drifting sand"),          "??"                         },
    /* HAZE          */ {N_("haze"),                  "??",                                "??",                      N_("haze"),                   "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* SPRAY         */ {"??",                        "??",                                "??",                      "??",                         "??",                      "??",                        "??",                           "??",                        "??",                           N_("blowing sprays"),        "??",                           "??",                         "??"                         },
    /* DUST          */ {N_("dust"),                  "??",                                "??",                      N_("dust"),                   "??",                      "??",                        "??",                           "??",                        "??",                           N_("blowing dust"),          "??",                           N_("drifting dust"),          "??"                         },
    /* SQUALL        */ {N_("squall"),                "??",                                "??",                      N_("squall"),                 "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* SANDSTORM     */ {N_("sandstorm"),             N_("sandstorm in the vicinity") ,    "??",                      N_("sandstorm"),              N_("heavy sandstorm"),     "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* DUSTSTORM     */ {N_("duststorm"),             N_("duststorm in the vicinity") ,    "??",                      N_("duststorm"),              N_("heavy duststorm"),     "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* FUNNEL_CLOUD  */ {N_("funnel cloud"),          "??",                                "??",                      "??",                         "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* TORNADO       */ {N_("tornado"),               "??",                                "??",                      "??",                         "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* DUST_WHIRLS   */ {N_("dust whirls"),           N_("dust whirls in the vicinity") ,  "??",                      N_("dust whirls"),            "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         }
};

/*
 * Note, magic numbers, when you change the size here, make sure to change
 * the below function so that new values are recognized
 */
/*                   NONE                         VICINITY                             LIGHT                      MODERATE                      HEAVY                      SHALLOW                      PATCHES                         PARTIAL                      THUNDERSTORM                    BLOWING                      SHOWERS                         DRIFTING                      FREEZING                      */
/*               *******************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************/
static const gchar *conditions_caps_str[24][13] = {
/* TRANSLATOR: If you want to know what "blowing" "shallow" "partial"
 * etc means, you can go to http://www.weather.com/glossary/ and
 * http://www.crh.noaa.gov/arx/wx.tbl.php */
    /* NONE          */ {"??",                        "??",                                "??",                      "??",                         "??",                      "??",                        "??",                           "??",                        N_("Thunderstorm"),             "??",                        "??",                           "??",                         "??"                         },
    /* DRIZZLE       */ {N_("Drizzle"),               "??",                                N_("Light drizzle"),       N_("Moderate drizzle"),       N_("Heavy drizzle"),       "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         N_("Freezing drizzle")       },
    /* RAIN          */ {N_("Rain"),                  "??",                                N_("Light rain"),          N_("Moderate rain"),          N_("Heavy rain"),          "??",                        "??",                           "??",                        N_("Thunderstorm"),             "??",                        N_("Rain showers"),             "??",                         N_("Freezing rain")          },
    /* SNOW          */ {N_("Snow"),                  "??",                                N_("Light snow"),          N_("Moderate snow"),          N_("Heavy snow"),          "??",                        "??",                           "??",                        N_("Snowstorm"),                N_("Blowing snowfall"),      N_("Snow showers"),             N_("Drifting snow"),          "??"                         },
    /* SNOW_GRAINS   */ {N_("Snow grains"),           "??",                                N_("Light snow grains"),   N_("Moderate snow grains"),   N_("Heavy snow grains"),   "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* ICE_CRYSTALS  */ {N_("Ice crystals"),          "??",                                "??",                      N_("Ice crystals"),           "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* ICE_PELLETS   */ {N_("Sleet"),           "??",                                N_("Little sleet"),     N_("Moderate sleet"),   N_("Heavy sleet"),   "??",                        "??",                           "??",                        N_("Sleet storm"),         "??",                        N_("Showers of sleet"),   "??",                         "??"                         },
    /* HAIL          */ {N_("Hail"),                  "??",                                "??",                      N_("Hail"),                   "??",                      "??",                        "??",                           "??",                        N_("Hailstorm"),                "??",                        N_("Hail showers"),             "??",                         "??",                        },
    /* SMALL_HAIL    */ {N_("Small hail"),            "??",                                "??",                      N_("Small hail"),             "??",                      "??",                        "??",                           "??",                        N_("Small hailstorm"),          "??",                        N_("Showers of small hail"),    "??",                         "??"                         },
    /* PRECIPITATION */ {N_("Unknown precipitation"), "??",                                "??",                      "??",                         "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* MIST          */ {N_("Mist"),                  "??",                                "??",                      N_("Mist"),                   "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* FOG           */ {N_("Fog"),                   N_("Fog in the vicinity") ,          "??",                      N_("Fog"),                    "??",                      N_("Shallow fog"),           N_("Patches of fog"),           N_("Partial fog"),           "??",                           "??",                        "??",                           "??",                         N_("Freezing fog")           },
    /* SMOKE         */ {N_("Smoke"),                 "??",                                "??",                      N_("Smoke"),                  "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* VOLCANIC_ASH  */ {N_("Volcanic ash"),          "??",                                "??",                      N_("Volcanic ash"),           "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* SAND          */ {N_("Sand"),                  "??",                                "??",                      N_("Sand"),                   "??",                      "??",                        "??",                           "??",                        "??",                           N_("Blowing sand"),          "",                             N_("Drifting sand"),          "??"                         },
    /* HAZE          */ {N_("Haze"),                  "??",                                "??",                      N_("Haze"),                   "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* SPRAY         */ {"??",                        "??",                                "??",                      "??",                         "??",                      "??",                        "??",                           "??",                        "??",                           N_("Blowing sprays"),        "??",                           "??",                         "??"                         },
    /* DUST          */ {N_("Dust"),                  "??",                                "??",                      N_("Dust"),                   "??",                      "??",                        "??",                           "??",                        "??",                           N_("Blowing dust"),          "??",                           N_("Drifting dust"),          "??"                         },
    /* SQUALL        */ {N_("Squall"),                "??",                                "??",                      N_("Squall"),                 "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* SANDSTORM     */ {N_("Sandstorm"),             N_("Sandstorm in the vicinity") ,    "??",                      N_("Sandstorm"),              N_("Heavy sandstorm"),     "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* DUSTSTORM     */ {N_("Duststorm"),             N_("Duststorm in the vicinity") ,    "??",                      N_("Duststorm"),              N_("Heavy duststorm"),     "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* FUNNEL_CLOUD  */ {N_("Funnel cloud"),          "??",                                "??",                      "??",                         "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* TORNADO       */ {N_("Tornado"),               "??",                                "??",                      "??",                         "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         },
    /* DUST_WHIRLS   */ {N_("Dust whirls"),           N_("Dust whirls in the vicinity") ,  "??",                      N_("Dust whirls"),            "??",                      "??",                        "??",                           "??",                        "??",                           "??",                        "??",                           "??",                         "??"                         }
};

/* clang-format on */

const gchar *
gweather_conditions_to_string_full (GWeatherConditions *cond,
                                    GWeatherFormatOptions options)
{
    gboolean use_caps = should_use_caps (options);

    const gchar *str;

    if (!cond->significant) {
        return "-";
    } else {
        if (cond->phenomenon > GWEATHER_PHENOMENON_INVALID &&
            cond->phenomenon < GWEATHER_PHENOMENON_LAST &&
            cond->qualifier > GWEATHER_QUALIFIER_INVALID &&
            cond->qualifier < GWEATHER_QUALIFIER_LAST)
            str = use_caps ? _ (conditions_caps_str[(int) cond->phenomenon][(int) cond->qualifier])
                           : _ (conditions_str[(int) cond->phenomenon][(int) cond->qualifier]);
        else
            str = use_caps ? C_ ("sky conditions", "Invalid")
                           : C_ ("sky conditions", "invalid");
        return (strlen (str) > 0) ? str : "-";
    }
}

const gchar *
gweather_conditions_to_string (GWeatherConditions *cond)
{
    return gweather_conditions_to_string_full (cond, GWEATHER_FORMAT_OPTION_DEFAULT);
}

static gboolean
requests_init (GWeatherInfo *info)
{
    if (info->requests_pending)
        return FALSE;

    return TRUE;
}

void
_gweather_info_begin_request (GWeatherInfo *info,
                              SoupMessage *message)
{
    info->requests_pending = g_slist_prepend (info->requests_pending, message);
    g_object_ref (message);
}

static void
copy_weather_data (GWeatherInfo *src,
                   GWeatherInfo *dest)
{
    dest->hasHumidity = src->hasHumidity;
    dest->update = src->update;
    dest->current_time = src->current_time;
    dest->sky = src->sky;
    dest->cond = src->cond;
    dest->temp = src->temp;
    dest->temp_min = src->temp_min;
    dest->temp_max = src->temp_max;
    dest->dew = src->dew;
    dest->humidity = src->humidity;
    dest->wind = src->wind;
    dest->windspeed = src->windspeed;
    dest->pressure = src->pressure;
    dest->visibility = src->visibility;
}

static void
fixup_current_conditions (GWeatherInfo *info)
{
    GWeatherInfo *first_forecast;

    /* Current conditions already available */
    if (info->update != 0) {
        g_debug ("Not fixing up current conditions, already valid");
        return;
    } else if (!info->forecast_list ||
               !info->forecast_list->data) {
        g_debug ("No forecast list available, not fixing up");
        return;
    }

    first_forecast = info->forecast_list->data;
    /* Add current conditions from forecast if close enough */
    if (first_forecast->update - time (NULL) > 60 * 60) {
        g_debug ("Forecast is too far in the future, ignoring");
        return;
    }

    copy_weather_data (first_forecast, info);
    g_debug ("Fixed up missing current weather with first forecast data");
}

void
_gweather_info_request_done (GWeatherInfo *info,
                             SoupMessage *message)
{
    info->requests_pending = g_slist_remove (info->requests_pending, message);
    g_object_unref (message);

    if (info->requests_pending == NULL) {
        fixup_current_conditions (info);
        g_signal_emit (info, gweather_info_signals[SIGNAL_UPDATED], 0);
    } else {
        g_debug ("Not emitting 'updated' as there are still %d requests pending",
                 g_slist_length (info->requests_pending));
    }
}

#if SOUP_CHECK_VERSION (2, 99, 2)
void
_gweather_info_queue_request (GWeatherInfo *info,
                              SoupMessage *msg,
                              GAsyncReadyCallback callback)
{
    GCancellable *cancellable = g_cancellable_new ();
    g_object_set_data_full (G_OBJECT (msg), "request-cancellable",
                            cancellable, g_object_unref);
    soup_session_send_and_read_async (info->session, msg, G_PRIORITY_DEFAULT,
                                      cancellable, callback, info);
    g_object_unref (msg);
}
#else
void
_gweather_info_queue_request (GWeatherInfo *info,
                              SoupMessage *msg,
                              SoupSessionCallback callback)
{
    soup_session_queue_message (info->session, msg, callback, info);
}
#endif

/* it's OK to pass in NULL */
void
free_forecast_list (GWeatherInfo *info)
{
    if (!info)
        return;

    g_slist_free_full (info->forecast_list, g_object_unref);
    info->forecast_list = NULL;
}

/* Relative humidity computation - thanks to <Olof.Oberg@modopaper.modogroup.com>
   calc_dew is simply the inverse of calc_humidity */

static inline gdouble
calc_dew (gdouble temp, gdouble humidity)
{
    gdouble esat, esurf, tmp;

    if (temp > -500.0 && humidity > -1.0) {
        temp = TEMP_F_TO_C (temp);

        esat = 6.11 * pow (10.0, (7.5 * temp) / (237.7 + temp));
        esurf = (humidity / 100) * esat;
    } else {
        esurf = -1.0;
        esat = 1.0;
    }

    tmp = log10 (esurf / 6.11);
    return TEMP_C_TO_F (tmp * 237.7 / (tmp + 7.5));
}

static inline gdouble
calc_humidity (gdouble temp, gdouble dewp)
{
    gdouble esat, esurf;

    if (temp > -500.0 && dewp > -500.0) {
        temp = TEMP_F_TO_C (temp);
        dewp = TEMP_F_TO_C (dewp);

        esat = 6.11 * pow (10.0, (7.5 * temp) / (237.7 + temp));
        esurf = 6.11 * pow (10.0, (7.5 * dewp) / (237.7 + dewp));
    } else {
        esurf = -1.0;
        esat = 1.0;
    }
    return ((esurf / esat) * 100.0);
}

static inline gdouble
calc_apparent (GWeatherInfo *info)
{
    gdouble temp = info->temp;
    gdouble wind = WINDSPEED_KNOTS_TO_MPH (info->windspeed);
    gdouble apparent = -1000.;
    gdouble dew = info->dew;
    gdouble humidity;

    if (info->hasHumidity)
        humidity = info->humidity;
    else
        humidity = calc_humidity (temp, dew);

    /*
     * Wind chill calculations as of 01-Nov-2001
     * http://www.nws.noaa.gov/om/windchill/index.shtml
     * Some pages suggest that the formula will soon be adjusted
     * to account for solar radiation (bright sun vs cloudy sky)
     */
    if (temp <= 50.0) {
        if (wind > 3.0) {
            gdouble v = pow (wind, 0.16);
            apparent = 35.74 + 0.6215 * temp - 35.75 * v + 0.4275 * temp * v;
        } else if (wind >= 0.) {
            apparent = temp;
        }
    }
    /*
     * Heat index calculations:
     * http://www.srh.noaa.gov/fwd/heatindex/heat5.html
     */
    else if (temp >= 80.0) {
        if (temp >= -500. && humidity >= 0) {
            gdouble t2, h2;
            gdouble t3, h3;

            t2 = temp * temp;
            h2 = humidity * humidity;

#if 1
            /*
	     * A really precise formula.  Note that overall precision is
	     * constrained by the accuracy of the instruments and that the
	     * we receive the temperature and dewpoints as integers.
	     */

            t3 = t2 * temp;
            h3 = h2 * temp;

            apparent = 16.923 + 0.185212 * temp + 5.37941 * humidity - 0.100254 * temp * humidity + 9.41695e-3 * t2 + 7.28898e-3 * h2 + 3.45372e-4 * t2 * humidity - 8.14971e-4 * temp * h2 + 1.02102e-5 * t2 * h2 - 3.8646e-5 * t3 + 2.91583e-5 * h3 + 1.42721e-6 * t3 * humidity + 1.97483e-7 * temp * h3 - 2.18429e-8 * t3 * h2 + 8.43296e-10 * t2 * h3 - 4.81975e-11 * t3 * h3;
#else
            /*
	     * An often cited alternative: values are within 5 degrees for
	     * most ranges between 10% and 70% humidity and to 110 degrees.
	     */
            apparent = -42.379 + 2.04901523 * temp + 10.14333127 * humidity - 0.22475541 * temp * humidity - 6.83783e-3 * t2 - 5.481717e-2 * h2 + 1.22874e-3 * t2 * humidity + 8.5282e-4 * temp * h2 - 1.99e-6 * t2 * h2;
#endif
        }
    } else {
        apparent = temp;
    }

    return apparent;
}

static void
gweather_info_reset (GWeatherInfo *info)
{
    g_clear_pointer (&info->forecast_attribution, g_free);

    free_forecast_list (info);

    info->update = 0;
    info->current_time = time (NULL);
    info->sky = -1;
    info->cond.significant = FALSE;
    info->cond.phenomenon = GWEATHER_PHENOMENON_NONE;
    info->cond.qualifier = GWEATHER_QUALIFIER_NONE;
    info->temp = -1000.0;
    info->tempMinMaxValid = FALSE;
    info->temp_min = -1000.0;
    info->temp_max = -1000.0;
    info->dew = -1000.0;
    info->humidity = -1.0;
    info->wind = -1;
    info->windspeed = -1;
    info->pressure = -1.0;
    info->visibility = -1.0;
    info->sunriseValid = FALSE;
    info->sunsetValid = FALSE;
    info->moonValid = FALSE;
    info->sunrise = 0;
    info->sunset = 0;
    info->moonphase = 0;
    info->moonlatitude = 0;
    info->forecast_list = NULL;
}

static void
settings_changed_cb (GSettings *settings,
                     const char *key,
                     GWeatherInfo *info)
{
    /* Only emit the signal if no network requests are pending.
       Otherwise just wait for the update that will happen at
       the end
    */
    if (info->requests_pending == NULL)
        g_signal_emit (info, gweather_info_signals[SIGNAL_UPDATED], 0);
}

void
gweather_info_init (GWeatherInfo *info)
{
    info->providers = GWEATHER_PROVIDER_METAR | GWEATHER_PROVIDER_IWIN;
    info->settings = g_settings_new ("org.gnome.GWeather4");

    g_signal_connect_object (info->settings, "changed", G_CALLBACK (settings_changed_cb), info, 0);

    gweather_info_reset (info);
}

static SoupCache *
get_cache (void)
{
    SoupCache *cache;
    char *filename;

    filename = g_build_filename (g_get_user_cache_dir (),
                                 "libgweather",
                                 NULL);

    if (g_mkdir_with_parents (filename, 0700) < 0) {
        g_warning ("Failed to create libgweather cache directory: %s. Check your XDG_CACHE_HOME setting!", strerror (errno));
        g_free (filename);
        return NULL;
    }

    cache = soup_cache_new (filename, SOUP_CACHE_SINGLE_USER);

    g_free (filename);
    return cache;
}

static void
dump_and_unref_cache (SoupCache *cache)
{
    soup_cache_dump (cache);
    g_object_unref (cache);
}

static SoupSession *static_session;

static SoupSession *
ref_session (GWeatherInfo *info)
{
    SoupSession *session;
    SoupCache *cache;
    g_autofree char *user_agent = NULL;

    session = static_session;

    if (session != NULL)
        return g_object_ref (session);

    session = soup_session_new ();
    user_agent = g_strdup_printf ("libgweather/%s %s (%s)",
                                  LIBGWEATHER_VERSION,
                                  info->application_id,
                                  info->contact_info);
    g_object_set (G_OBJECT (session), "user-agent", user_agent, NULL);

    cache = get_cache ();
    if (cache != NULL) {
        soup_session_add_feature (session, SOUP_SESSION_FEATURE (cache));
        g_object_set_data_full (G_OBJECT (session), "libgweather-cache", g_object_ref (cache), (GDestroyNotify) dump_and_unref_cache);

        soup_cache_load (cache);
        g_object_unref (cache);
    }

    static_session = session;
    g_object_add_weak_pointer (G_OBJECT (session), (void **) &static_session);

    return session;
}

/**
 * gweather_info_store_cache:
 *
 * Ensures that any data cached from the network is stored to disk.
 * Calling this is not necessary, as the cache will be saved when
 * the last reference to a #GWeatherInfo will be dropped.
 * On the other hand, it must be called if there is any chance that
 * the application will be closed without unreffing all objects, such
 * as when using a language binding that employs a GC.
 */
void
gweather_info_store_cache (void)
{
    SoupCache *cache;

    if (static_session == NULL)
        return;

    cache = g_object_get_data (G_OBJECT (static_session), "libgweather-cache");
    soup_cache_dump (cache);
}

/**
 * gweather_info_update:
 * @info: a #GWeatherInfo
 *
 * Requests a reload of weather conditions and forecast data from
 * enabled network services.
 * This call does no synchronous IO: rather, the result is delivered
 * by emitting the #GWeatherInfo::updated signal.
 * Note that if no network services are enabled, the signal will not
 * be emitted. See #GWeatherInfo:enabled-providers for details.
 */
void
gweather_info_update (GWeatherInfo *info)
{
    gboolean ok;

    if (info->providers == GWEATHER_PROVIDER_NONE)
        return;

    g_return_if_fail (info->application_id != NULL);
    g_return_if_fail (g_application_id_is_valid (info->application_id));
    g_return_if_fail (info->contact_info != NULL);

    /* Update in progress */
    if (!requests_init (info))
        return;

    gweather_info_reset (info);

    if (!info->session)
        info->session = ref_session (info);

    if (info->providers & GWEATHER_PROVIDER_METAR)
        metar_start_open (info);

    ok = FALSE;
    /* Try national forecast services first */
    if (info->providers & GWEATHER_PROVIDER_IWIN)
        ok = iwin_start_open (info);
    if (ok)
        return;

    /* Try met.no next */
    if (info->providers & GWEATHER_PROVIDER_MET_NO)
        ok = metno_start_open (info);
    if (ok)
        return;

    /* Try OpenWeatherMap next */
    if (info->providers & GWEATHER_PROVIDER_OWM)
        owm_start_open (info);
}

void
gweather_info_abort (GWeatherInfo *info)
{
    GSList *list, *iter;
    GSList dummy = { NULL, NULL };

    g_return_if_fail (GWEATHER_IS_INFO (info));

    if (info->session == NULL) {
        g_assert (info->requests_pending == NULL);
        return;
    }

    list = info->requests_pending;
    /* to block updated signals */
    info->requests_pending = &dummy;

    for (iter = list; iter; iter = iter->next) {
#if SOUP_CHECK_VERSION (2, 99, 2)
        g_cancellable_cancel (g_object_get_data (iter->data, "request-cancellable"));
#else
        soup_session_cancel_message (info->session, iter->data, SOUP_STATUS_CANCELLED);
#endif
    }

    g_slist_free (list);

    info->requests_pending = NULL;
}

static void
gweather_info_dispose (GObject *object)
{
    GWeatherInfo *info = GWEATHER_INFO (object);

    gweather_info_abort (info);

    g_clear_object (&info->session);

    free_forecast_list (info);

    info->valid = FALSE;

    G_OBJECT_CLASS (gweather_info_parent_class)->dispose (object);
}

static void
gweather_info_finalize (GObject *object)
{
    GWeatherInfo *info = GWEATHER_INFO (object);

    _weather_location_free (&info->location);
    g_clear_object (&info->settings);

    if (info->glocation)
        gweather_location_unref (info->glocation);

    g_clear_pointer (&info->application_id, g_free);
    g_clear_pointer (&info->contact_info, g_free);

    g_free (info->forecast_attribution);

    G_OBJECT_CLASS (gweather_info_parent_class)->finalize (object);
}

gboolean
gweather_info_is_valid (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    return info->valid;
}

gboolean
gweather_info_network_error (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    return info->network_error;
}

const GWeatherLocation *
gweather_info_get_location (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);
    return info->glocation;
}

gchar *
gweather_info_get_location_name (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    return g_strdup (info->location.name);
}

gchar *
gweather_info_get_update (GWeatherInfo *info)
{
    char *out;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid)
        return g_strdup ("-");

    if (info->update != 0) {
        GDateTime *now = g_date_time_new_from_unix_local (info->update);

        out = g_date_time_format (now, _ ("%a, %b %d / %H∶%M"));
        if (!out)
            out = g_strdup ("???");

        g_date_time_unref (now);
    } else
        out = g_strdup (_ ("Unknown observation time"));

    return out;
}

gchar *
gweather_info_get_sky (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);
    if (!info->valid)
        return g_strdup ("-");
    if (info->sky < 0)
        return g_strdup (C_ ("sky conditions", "Unknown"));
    return g_strdup (gweather_sky_to_string (info->sky));
}

gchar *
gweather_info_get_conditions (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);
    if (!info->valid)
        return g_strdup ("-");
    return g_strdup (gweather_conditions_to_string (&info->cond));
}

static gboolean
is_locale_metric (void)
{
    /* Translate to the default units to use for presenting
     * lengths to the user. Translate to default:inch if you
     * want inches, otherwise translate to default:mm.
     * Do *not* translate it to "predefinito:mm", if it
     * it isn't default:mm or default:inch it will not work
     */
    gchar *e = _ ("default:mm");

#ifdef HAVE__NL_MEASUREMENT_MEASUREMENT
    const char *fmt;
    fmt = nl_langinfo (_NL_MEASUREMENT_MEASUREMENT);

    if (fmt && *fmt == 2)
        return FALSE;
    else
        return TRUE;
#endif

    if (strcmp (e, "default:inch") == 0)
        return FALSE;
    else if (strcmp (e, "default:mm"))
        g_warning ("Whoever translated default:mm did so wrongly.\n");

    return TRUE;
}

/**
 * gweather_temperature_unit_to_real:
 * @unit: a tempeature unit, or %GWEATHER_TEMP_UNIT_DEFAULT
 *
 * Resolve @unit into a real temperature unit, potentially considering
 * locale defaults.
 */
GWeatherTemperatureUnit
gweather_temperature_unit_to_real (GWeatherTemperatureUnit unit)
{
    if (G_UNLIKELY (unit == GWEATHER_TEMP_UNIT_INVALID)) {
        g_critical ("Conversion to invalid temperature unit");
        unit = GWEATHER_TEMP_UNIT_DEFAULT;
    }

    if (unit == GWEATHER_TEMP_UNIT_DEFAULT)
        return is_locale_metric () ? GWEATHER_TEMP_UNIT_CENTIGRADE : GWEATHER_TEMP_UNIT_FAHRENHEIT;

    return unit;
}

static gchar *
temperature_string (gfloat temp_f, GWeatherTemperatureUnit to_unit, gboolean want_round)
{
    to_unit = gweather_temperature_unit_to_real (to_unit);

    switch (to_unit) {
        case GWEATHER_TEMP_UNIT_FAHRENHEIT:
            if (!want_round) {
                /* TRANSLATOR: This is the temperature in degrees Fahrenheit
                 * with a non-break space (U+00A0) between the digits and the
                 * degrees sign (U+00B0), followed by the letter F
                 */
                return g_strdup_printf (_ ("%.1f\u00A0\u00B0F"), temp_f);
            } else {
                /* TRANSLATOR: This is the temperature in degrees Fahrenheit
                 * with a non-break space (U+00A0) between the digits and the
                 * degrees sign (U+00B0), followed by the letter F
                 */
                return g_strdup_printf (_ ("%d\u00A0\u00B0F"), (int) floor (temp_f + 0.5));
            }
            break;
        case GWEATHER_TEMP_UNIT_CENTIGRADE:
            if (!want_round) {
                /* TRANSLATOR: This is the temperature in degrees Celsius
                 * with a non-break space (U+00A0) between the digits and
                 * the degrees sign (U+00B0), followed by the letter C
                 */
                return g_strdup_printf (_ ("%.1f\u00A0\u00B0C"), TEMP_F_TO_C (temp_f));
            } else {
                /* TRANSLATOR: This is the temperature in degrees Celsius
                 * with a non-break space (U+00A0) between the digits and
                 * the degrees sign (U+00B0), followed by the letter C
                 */
                return g_strdup_printf (_ ("%d\u00A0\u00B0C"), (int) floor (TEMP_F_TO_C (temp_f) + 0.5));
            }
            break;
        case GWEATHER_TEMP_UNIT_KELVIN:
            if (!want_round) {
                /* TRANSLATOR: This is the temperature in kelvin (U+212A KELVIN SIGN)
                 * with a non-break space (U+00A0) between the digits and the degrees
                 * sign
                 */
                return g_strdup_printf (_ ("%.1f\u00A0\u212A"), TEMP_F_TO_K (temp_f));
            } else {
                /* TRANSLATOR: This is the temperature in kelvin (U+212A KELVIN SIGN)
                 * with a non-break space (U+00A0) between the digits and the degrees
                 * sign
                 */
                return g_strdup_printf (_ ("%d\u00A0\u212A"), (int) floor (TEMP_F_TO_K (temp_f)));
            }
            break;

        case GWEATHER_TEMP_UNIT_INVALID:
        case GWEATHER_TEMP_UNIT_DEFAULT:
            g_assert_not_reached ();
    }

    return NULL;
}

gchar *
gweather_info_get_temp (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid)
        return g_strdup ("-");
    if (info->temp < -500.0)
        return g_strdup (C_ ("temperature", "Unknown"));

    return temperature_string (info->temp, g_settings_get_enum (info->settings, TEMPERATURE_UNIT), FALSE);
}

gchar *
gweather_info_get_temp_min (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid || !info->tempMinMaxValid)
        return g_strdup ("-");
    if (info->temp_min < -500.0)
        return g_strdup (C_ ("temperature", "Unknown"));

    return temperature_string (info->temp_min, g_settings_get_enum (info->settings, TEMPERATURE_UNIT), FALSE);
}

gchar *
gweather_info_get_temp_max (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid || !info->tempMinMaxValid)
        return g_strdup ("-");
    if (info->temp_max < -500.0)
        return g_strdup (C_ ("temperature", "Unknown"));

    return temperature_string (info->temp_max, g_settings_get_enum (info->settings, TEMPERATURE_UNIT), FALSE);
}

gchar *
gweather_info_get_dew (GWeatherInfo *info)
{
    gdouble dew;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid)
        return g_strdup ("-");

    if (info->hasHumidity)
        dew = calc_dew (info->temp, info->humidity);
    else
        dew = info->dew;
    if (dew < -500.0)
        return g_strdup (C_ ("dew", "Unknown"));

    return temperature_string (info->dew, g_settings_get_enum (info->settings, TEMPERATURE_UNIT), FALSE);
}

gchar *
gweather_info_get_humidity (GWeatherInfo *info)
{
    gdouble humidity;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid)
        return g_strdup ("-");

    if (info->hasHumidity)
        humidity = info->humidity;
    else
        humidity = calc_humidity (info->temp, info->dew);
    if (humidity < 0.0)
        return g_strdup (C_ ("humidity", "Unknown"));

    /* TRANSLATOR: This is the humidity in percent */
    return g_strdup_printf (_ ("%.f%%"), humidity);
}

gchar *
gweather_info_get_apparent (GWeatherInfo *info)
{
    gdouble apparent;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid)
        return g_strdup ("-");

    apparent = calc_apparent (info);
    if (apparent < -500.0)
        return g_strdup (C_ ("temperature", "Unknown"));

    return temperature_string (apparent, g_settings_get_enum (info->settings, TEMPERATURE_UNIT), FALSE);
}

static GWeatherSpeedUnit
speed_unit_to_real (GWeatherSpeedUnit unit)
{
    if (G_UNLIKELY (unit == GWEATHER_SPEED_UNIT_INVALID)) {
        g_critical ("Conversion to invalid speed unit");
        unit = GWEATHER_SPEED_UNIT_DEFAULT;
    }

    if (unit == GWEATHER_SPEED_UNIT_DEFAULT)
        return is_locale_metric () ? GWEATHER_SPEED_UNIT_KPH : GWEATHER_SPEED_UNIT_MPH;

    return unit;
}

static gchar *
windspeed_string (gfloat knots, GWeatherSpeedUnit to_unit)
{
    to_unit = speed_unit_to_real (to_unit);

    switch (to_unit) {
        case GWEATHER_SPEED_UNIT_KNOTS:
            /* TRANSLATOR: This is the wind speed in knots */
            return g_strdup_printf (_ ("%0.1f knots"), knots);
        case GWEATHER_SPEED_UNIT_MPH:
            /* TRANSLATOR: This is the wind speed in miles per hour */
            return g_strdup_printf (_ ("%.1f mph"), WINDSPEED_KNOTS_TO_MPH (knots));
        case GWEATHER_SPEED_UNIT_KPH:
            /* TRANSLATOR: This is the wind speed in kilometers per hour */
            return g_strdup_printf (_ ("%.1f km/h"), WINDSPEED_KNOTS_TO_KPH (knots));
        case GWEATHER_SPEED_UNIT_MS:
            /* TRANSLATOR: This is the wind speed in meters per second */
            return g_strdup_printf (_ ("%.1f m/s"), WINDSPEED_KNOTS_TO_MS (knots));
        case GWEATHER_SPEED_UNIT_BFT:
            /* TRANSLATOR: This is the wind speed as a Beaufort force factor
	 * (commonly used in nautical wind estimation).
	 */
            return g_strdup_printf (_ ("Beaufort force %.1f"), WINDSPEED_KNOTS_TO_BFT (knots));
        case GWEATHER_SPEED_UNIT_INVALID:
        case GWEATHER_SPEED_UNIT_DEFAULT:
            g_assert_not_reached ();
    }

    return NULL;
}

gchar *
gweather_info_get_wind (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid)
        return g_strdup ("-");
    if (info->windspeed < 0.0 || info->wind < 0)
        return g_strdup (C_ ("wind speed", "Unknown"));
    if (info->windspeed == 0.00) {
        return g_strdup (_ ("Calm"));
    } else {
        gchar *speed_string;
        gchar *wind_string;

        speed_string = windspeed_string (info->windspeed, g_settings_get_enum (info->settings, SPEED_UNIT));

        /* TRANSLATOR: This is 'wind direction' / 'wind speed' */
        wind_string = g_strdup_printf (_ ("%s / %s"), gweather_wind_direction_to_string (info->wind), speed_string);

        g_free (speed_string);
        return wind_string;
    }
}

/**
 * gweather_speed_unit_to_string:
 * @unit: a speed unit, or %GWEATHER_SPEED_UNIT_DEFAULT
 *
 * Creates a human-readable, localized representation of @unit
 */
const gchar *
gweather_speed_unit_to_string (GWeatherSpeedUnit unit)
{
    unit = speed_unit_to_real (unit);

    switch (unit) {
        case GWEATHER_SPEED_UNIT_KNOTS:
            /* TRANSLATOR: This is the wind speed in knots */
            return _ ("knots");
        case GWEATHER_SPEED_UNIT_MPH:
            /* TRANSLATOR: This is the wind speed in miles per hour */
            return _ ("mph");
        case GWEATHER_SPEED_UNIT_KPH:
            /* TRANSLATOR: This is the wind speed in kilometers per hour */
            return _ ("km/h");
        case GWEATHER_SPEED_UNIT_MS:
            /* TRANSLATOR: This is the wind speed in meters per second */
            return _ ("m/s");
        case GWEATHER_SPEED_UNIT_BFT:
            /* TRANSLATOR: This is the wind speed as a Beaufort force factor
	 * (commonly used in nautical wind estimation).
	 */
            return _ ("Beaufort force");
        case GWEATHER_SPEED_UNIT_INVALID:
        case GWEATHER_SPEED_UNIT_DEFAULT:
            g_assert_not_reached ();
    }

    return NULL;
}

static GWeatherPressureUnit
pressure_unit_to_real (GWeatherPressureUnit unit)
{
    if (G_UNLIKELY (unit == GWEATHER_PRESSURE_UNIT_INVALID)) {
        g_critical ("Conversion to invalid pressure unit");
        unit = GWEATHER_PRESSURE_UNIT_DEFAULT;
    }

    if (unit == GWEATHER_PRESSURE_UNIT_DEFAULT)
        return is_locale_metric () ? GWEATHER_PRESSURE_UNIT_MM_HG : GWEATHER_PRESSURE_UNIT_INCH_HG;

    return unit;
}

gchar *
gweather_info_get_pressure (GWeatherInfo *info)
{
    GWeatherPressureUnit unit;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid)
        return g_strdup ("-");
    if (info->pressure < 0.0)
        return g_strdup (C_ ("pressure", "Unknown"));

    unit = pressure_unit_to_real (g_settings_get_enum (info->settings, PRESSURE_UNIT));
    switch (unit) {
        case GWEATHER_PRESSURE_UNIT_INCH_HG:
            /* TRANSLATOR: This is pressure in inches of mercury */
            return g_strdup_printf (_ ("%.2f inHg"), info->pressure);
        case GWEATHER_PRESSURE_UNIT_MM_HG:
            /* TRANSLATOR: This is pressure in millimeters of mercury */
            return g_strdup_printf (_ ("%.1f mmHg"), PRESSURE_INCH_TO_MM (info->pressure));
        case GWEATHER_PRESSURE_UNIT_KPA:
            /* TRANSLATOR: This is pressure in kiloPascals */
            return g_strdup_printf (_ ("%.2f kPa"), PRESSURE_INCH_TO_KPA (info->pressure));
        case GWEATHER_PRESSURE_UNIT_HPA:
            /* TRANSLATOR: This is pressure in hectoPascals */
            return g_strdup_printf (_ ("%.2f hPa"), PRESSURE_INCH_TO_HPA (info->pressure));
        case GWEATHER_PRESSURE_UNIT_MB:
            /* TRANSLATOR: This is pressure in millibars */
            return g_strdup_printf (_ ("%.2f mb"), PRESSURE_INCH_TO_MB (info->pressure));
        case GWEATHER_PRESSURE_UNIT_ATM:
            /* TRANSLATOR: This is pressure in atmospheres */
            return g_strdup_printf (_ ("%.3f atm"), PRESSURE_INCH_TO_ATM (info->pressure));

        case GWEATHER_PRESSURE_UNIT_INVALID:
        case GWEATHER_PRESSURE_UNIT_DEFAULT:
            g_assert_not_reached ();
    }

    return NULL;
}

static GWeatherDistanceUnit
distance_unit_to_real (GWeatherDistanceUnit unit)
{
    if (G_UNLIKELY (unit == GWEATHER_DISTANCE_UNIT_INVALID)) {
        g_critical ("Conversion to invalid distance unit");
        unit = GWEATHER_DISTANCE_UNIT_DEFAULT;
    }

    if (unit == GWEATHER_DISTANCE_UNIT_DEFAULT)
        return is_locale_metric () ? GWEATHER_DISTANCE_UNIT_METERS : GWEATHER_DISTANCE_UNIT_MILES;

    return unit;
}

gchar *
gweather_info_get_visibility (GWeatherInfo *info)
{
    GWeatherDistanceUnit unit;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid)
        return g_strdup ("-");
    if (info->visibility < 0.0)
        return g_strdup (C_ ("visibility", "Unknown"));

    unit = distance_unit_to_real (g_settings_get_enum (info->settings, DISTANCE_UNIT));
    switch (unit) {
        case GWEATHER_DISTANCE_UNIT_MILES:
            /* TRANSLATOR: This is the visibility in miles */
            return g_strdup_printf (_ ("%.1f miles"), info->visibility);
        case GWEATHER_DISTANCE_UNIT_KM:
            /* TRANSLATOR: This is the visibility in kilometers */
            return g_strdup_printf (_ ("%.1f km"), VISIBILITY_SM_TO_KM (info->visibility));
        case GWEATHER_DISTANCE_UNIT_METERS:
            /* TRANSLATOR: This is the visibility in meters */
            return g_strdup_printf (_ ("%.0fm"), VISIBILITY_SM_TO_M (info->visibility));

        case GWEATHER_DISTANCE_UNIT_INVALID:
        case GWEATHER_DISTANCE_UNIT_DEFAULT:
            g_assert_not_reached ();
    }

    return NULL;
}

gchar *
gweather_info_get_sunrise (GWeatherInfo *info)
{
    GDateTime *sunrise;
    gchar *buf;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    _gweather_info_ensure_sun (info);

    if (!info->sunriseValid)
        return g_strdup ("-");

    sunrise = g_date_time_new_from_unix_local (info->sunrise);

    buf = g_date_time_format (sunrise, _ ("%H∶%M"));
    if (!buf)
        buf = g_strdup ("-");

    g_date_time_unref (sunrise);
    return buf;
}

gchar *
gweather_info_get_sunset (GWeatherInfo *info)
{
    GDateTime *sunset;
    gchar *buf;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    _gweather_info_ensure_sun (info);

    if (!info->sunsetValid)
        return g_strdup ("-");

    sunset = g_date_time_new_from_unix_local (info->sunset);
    buf = g_date_time_format (sunset, _ ("%H∶%M"));
    if (!buf)
        buf = g_strdup ("-");

    g_date_time_unref (sunset);
    return buf;
}

/**
 * gweather_info_get_forecast_list:
 * @info: a #GWeatherInfo
 *
 * Returns: (transfer none) (element-type GWeather.Info): list
 * of GWeatherInfo* objects for the forecast.
 * The list is owned by the 'info' object thus is alive as long
 * as the 'info'. The 'update' property is the date/time when the
 * forecast info is used for.
 **/
GSList *
gweather_info_get_forecast_list (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid)
        return NULL;

    return info->forecast_list;
}

/**
 * gweather_info_get_attribution:
 * @info: a #GWeatherInfo
 *
 * Some weather services require the application showing the
 * data to include an attribution text, possibly including links
 * to the service website.
 * This must be shown prominently toghether with the data.
 *
 * Returns: (transfer none): the required attribution text, in Pango
 *          markup form, or %NULL if not required
 */
const gchar *
gweather_info_get_attribution (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    return info->forecast_attribution;
}

gchar *
gweather_info_get_temp_summary (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid || info->temp < -500.0)
        return g_strdup ("--");

    return temperature_string (info->temp, g_settings_get_enum (info->settings, TEMPERATURE_UNIT), TRUE);
}

/**
 * gweather_info_get_weather_summary:
 * @info: a #GWeatherInfo
 *
 * Returns: (transfer full): a summary for current weather conditions.
 */
gchar *
gweather_info_get_weather_summary (GWeatherInfo *info)
{
    gchar *buf;
    gchar *out;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    if (!info->valid)
        return g_strdup (_ ("Retrieval failed"));
    buf = gweather_info_get_conditions (info);
    if (g_str_equal (buf, "-")) {
        g_free (buf);
        buf = gweather_info_get_sky (info);
    }

    out = g_strdup_printf ("%s: %s", info->location.name, buf);

    g_free (buf);
    return out;
}

/**
 * gweather_info_is_daytime:
 * @info: a #GWeatherInfo
 *
 * Returns: Whether it is daytime (that is, if the sun is visible)
 *   or not at the location and the point of time referred by @info.
 *   This is mostly equivalent to comparing the return value
 *   of gweather_info_get_value_sunrise() and
 *   gweather_info_get_value_sunset(), but it accounts also
 *   for midnight sun and polar night, for locations within
 *   the Artic and Antartic circles.
 */
gboolean
gweather_info_is_daytime (GWeatherInfo *info)
{
    time_t current_time;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);

    _gweather_info_ensure_sun (info);

    if (info->polarNight)
        return FALSE;
    if (info->midnightSun)
        return TRUE;

    current_time = info->current_time;
    return (!info->sunriseValid || (current_time >= info->sunrise)) &&
           (!info->sunsetValid || (current_time < info->sunset));
}

const gchar *
gweather_info_get_icon_name (GWeatherInfo *info)
{
    GWeatherConditions cond;
    GWeatherSky sky;
    gboolean daytime;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    cond = info->cond;
    sky = info->sky;

    if (cond.significant) {
        if (cond.phenomenon != GWEATHER_PHENOMENON_NONE &&
            cond.qualifier == GWEATHER_QUALIFIER_THUNDERSTORM)
            return "weather-storm";

        switch (cond.phenomenon) {
            case GWEATHER_PHENOMENON_INVALID:
            case GWEATHER_PHENOMENON_LAST:
            case GWEATHER_PHENOMENON_NONE:
                break;

            case GWEATHER_PHENOMENON_DRIZZLE:
            case GWEATHER_PHENOMENON_RAIN:
            case GWEATHER_PHENOMENON_UNKNOWN_PRECIPITATION:
            case GWEATHER_PHENOMENON_HAIL:
            case GWEATHER_PHENOMENON_SMALL_HAIL:
                return "weather-showers";

            case GWEATHER_PHENOMENON_SNOW:
            case GWEATHER_PHENOMENON_SNOW_GRAINS:
            case GWEATHER_PHENOMENON_ICE_PELLETS:
            case GWEATHER_PHENOMENON_ICE_CRYSTALS:
                return "weather-snow";

            case GWEATHER_PHENOMENON_TORNADO:
            case GWEATHER_PHENOMENON_SQUALL:
                return "weather-storm";

            case GWEATHER_PHENOMENON_MIST:
            case GWEATHER_PHENOMENON_FOG:
            case GWEATHER_PHENOMENON_SMOKE:
            case GWEATHER_PHENOMENON_VOLCANIC_ASH:
            case GWEATHER_PHENOMENON_SAND:
            case GWEATHER_PHENOMENON_HAZE:
            case GWEATHER_PHENOMENON_SPRAY:
            case GWEATHER_PHENOMENON_DUST:
            case GWEATHER_PHENOMENON_SANDSTORM:
            case GWEATHER_PHENOMENON_DUSTSTORM:
            case GWEATHER_PHENOMENON_FUNNEL_CLOUD:
            case GWEATHER_PHENOMENON_DUST_WHIRLS:
                return "weather-fog";
        }
    }

    daytime = gweather_info_is_daytime (info);

    switch (sky) {
        case GWEATHER_SKY_INVALID:
        case GWEATHER_SKY_LAST:
        case GWEATHER_SKY_CLEAR:
            if (daytime)
                return "weather-clear";
            else
                return "weather-clear-night";

        case GWEATHER_SKY_BROKEN:
        case GWEATHER_SKY_SCATTERED:
        case GWEATHER_SKY_FEW:
            if (daytime)
                return "weather-few-clouds";
            else
                return "weather-few-clouds-night";

        case GWEATHER_SKY_OVERCAST:
            return "weather-overcast";

        default: /* unrecognized */
            return NULL;
    }
}

const gchar *
gweather_info_get_symbolic_icon_name (GWeatherInfo *info)
{
    GWeatherConditions cond;
    GWeatherSky sky;
    gboolean daytime;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    cond = info->cond;
    sky = info->sky;

    if (cond.significant) {
        if (cond.phenomenon != GWEATHER_PHENOMENON_NONE &&
            cond.qualifier == GWEATHER_QUALIFIER_THUNDERSTORM)
            return "weather-storm-symbolic";

        switch (cond.phenomenon) {
            case GWEATHER_PHENOMENON_INVALID:
            case GWEATHER_PHENOMENON_LAST:
            case GWEATHER_PHENOMENON_NONE:
                break;

            case GWEATHER_PHENOMENON_DRIZZLE:
            case GWEATHER_PHENOMENON_RAIN:
            case GWEATHER_PHENOMENON_UNKNOWN_PRECIPITATION:
            case GWEATHER_PHENOMENON_HAIL:
            case GWEATHER_PHENOMENON_SMALL_HAIL:
                return "weather-showers-symbolic";

            case GWEATHER_PHENOMENON_SNOW:
            case GWEATHER_PHENOMENON_SNOW_GRAINS:
            case GWEATHER_PHENOMENON_ICE_PELLETS:
            case GWEATHER_PHENOMENON_ICE_CRYSTALS:
                return "weather-snow-symbolic";

            case GWEATHER_PHENOMENON_TORNADO:
            case GWEATHER_PHENOMENON_SQUALL:
                return "weather-storm-symbolic";

            case GWEATHER_PHENOMENON_MIST:
            case GWEATHER_PHENOMENON_FOG:
            case GWEATHER_PHENOMENON_SMOKE:
            case GWEATHER_PHENOMENON_VOLCANIC_ASH:
            case GWEATHER_PHENOMENON_SAND:
            case GWEATHER_PHENOMENON_HAZE:
            case GWEATHER_PHENOMENON_SPRAY:
            case GWEATHER_PHENOMENON_DUST:
            case GWEATHER_PHENOMENON_SANDSTORM:
            case GWEATHER_PHENOMENON_DUSTSTORM:
            case GWEATHER_PHENOMENON_FUNNEL_CLOUD:
            case GWEATHER_PHENOMENON_DUST_WHIRLS:
                return "weather-fog-symbolic";
        }
    }

    daytime = gweather_info_is_daytime (info);

    switch (sky) {
        case GWEATHER_SKY_INVALID:
        case GWEATHER_SKY_LAST:
        case GWEATHER_SKY_CLEAR:
            if (daytime)
                return "weather-clear-symbolic";
            else
                return "weather-clear-night-symbolic";

        case GWEATHER_SKY_BROKEN:
        case GWEATHER_SKY_SCATTERED:
        case GWEATHER_SKY_FEW:
            if (daytime)
                return "weather-few-clouds-symbolic";
            else
                return "weather-few-clouds-night-symbolic";

        case GWEATHER_SKY_OVERCAST:
            return "weather-overcast-symbolic";

        default: /* unrecognized */
            return NULL;
    }
}

static gboolean
temperature_value (gdouble temp_f,
                   GWeatherTemperatureUnit to_unit,
                   gdouble *value,
                   GSettings *settings)
{
    gboolean ok = TRUE;

    *value = 0.0;
    if (temp_f < -500.0)
        return FALSE;

    if (to_unit == GWEATHER_TEMP_UNIT_DEFAULT)
        to_unit = g_settings_get_enum (settings, TEMPERATURE_UNIT);
    to_unit = gweather_temperature_unit_to_real (to_unit);

    switch (to_unit) {
        case GWEATHER_TEMP_UNIT_FAHRENHEIT:
            *value = temp_f;
            break;
        case GWEATHER_TEMP_UNIT_CENTIGRADE:
            *value = TEMP_F_TO_C (temp_f);
            break;
        case GWEATHER_TEMP_UNIT_KELVIN:
            *value = TEMP_F_TO_K (temp_f);
            break;
        case GWEATHER_TEMP_UNIT_INVALID:
        case GWEATHER_TEMP_UNIT_DEFAULT:
            g_assert_not_reached ();
    }

    return ok;
}

static gboolean
speed_value (gdouble knots,
             GWeatherSpeedUnit to_unit,
             gdouble *value,
             GSettings *settings)
{
    gboolean ok = TRUE;

    *value = -1.0;

    if (knots < 0.0)
        return FALSE;

    if (to_unit == GWEATHER_SPEED_UNIT_DEFAULT)
        to_unit = g_settings_get_enum (settings, SPEED_UNIT);
    to_unit = speed_unit_to_real (to_unit);

    switch (to_unit) {
        case GWEATHER_SPEED_UNIT_KNOTS:
            *value = knots;
            break;
        case GWEATHER_SPEED_UNIT_MPH:
            *value = WINDSPEED_KNOTS_TO_MPH (knots);
            break;
        case GWEATHER_SPEED_UNIT_KPH:
            *value = WINDSPEED_KNOTS_TO_KPH (knots);
            break;
        case GWEATHER_SPEED_UNIT_MS:
            *value = WINDSPEED_KNOTS_TO_MS (knots);
            break;
        case GWEATHER_SPEED_UNIT_BFT:
            *value = WINDSPEED_KNOTS_TO_BFT (knots);
            break;
        case GWEATHER_SPEED_UNIT_INVALID:
        case GWEATHER_SPEED_UNIT_DEFAULT:
            g_assert_not_reached ();
    }

    return ok;
}

static gboolean
pressure_value (gdouble inHg,
                GWeatherPressureUnit to_unit,
                gdouble *value,
                GSettings *settings)
{
    gboolean ok = TRUE;

    *value = -1.0;

    if (inHg < 0.0)
        return FALSE;

    if (to_unit == GWEATHER_PRESSURE_UNIT_DEFAULT)
        to_unit = g_settings_get_enum (settings, PRESSURE_UNIT);
    to_unit = pressure_unit_to_real (to_unit);

    switch (to_unit) {
        case GWEATHER_PRESSURE_UNIT_INCH_HG:
            *value = inHg;
            break;
        case GWEATHER_PRESSURE_UNIT_MM_HG:
            *value = PRESSURE_INCH_TO_MM (inHg);
            break;
        case GWEATHER_PRESSURE_UNIT_KPA:
            *value = PRESSURE_INCH_TO_KPA (inHg);
            break;
        case GWEATHER_PRESSURE_UNIT_HPA:
            *value = PRESSURE_INCH_TO_HPA (inHg);
            break;
        case GWEATHER_PRESSURE_UNIT_MB:
            *value = PRESSURE_INCH_TO_MB (inHg);
            break;
        case GWEATHER_PRESSURE_UNIT_ATM:
            *value = PRESSURE_INCH_TO_ATM (inHg);
            break;
        case GWEATHER_PRESSURE_UNIT_INVALID:
        case GWEATHER_PRESSURE_UNIT_DEFAULT:
            g_assert_not_reached ();
    }

    return ok;
}

static gboolean
distance_value (gdouble miles,
                GWeatherDistanceUnit to_unit,
                gdouble *value,
                GSettings *settings)
{
    gboolean ok = TRUE;

    *value = -1.0;

    if (miles < 0.0)
        return FALSE;

    if (to_unit == GWEATHER_DISTANCE_UNIT_DEFAULT)
        to_unit = g_settings_get_enum (settings, DISTANCE_UNIT);
    to_unit = distance_unit_to_real (to_unit);

    switch (to_unit) {
        case GWEATHER_DISTANCE_UNIT_MILES:
            *value = miles;
            break;
        case GWEATHER_DISTANCE_UNIT_KM:
            *value = VISIBILITY_SM_TO_KM (miles);
            break;
        case GWEATHER_DISTANCE_UNIT_METERS:
            *value = VISIBILITY_SM_TO_M (miles);
            break;
        case GWEATHER_DISTANCE_UNIT_INVALID:
        case GWEATHER_DISTANCE_UNIT_DEFAULT:
            g_assert_not_reached ();
    }

    return ok;
}

/**
 * gweather_info_get_value_sky:
 * @info: a #GWeatherInfo
 * @sky: (out): a location for a #GWeatherSky.
 *
 * Fills out @sky with current sky conditions.
 * Returns: TRUE is @sky is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_sky (GWeatherInfo *info, GWeatherSky *sky)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (sky != NULL, FALSE);

    if (!info->valid)
        return FALSE;

    if (info->sky <= GWEATHER_SKY_INVALID || info->sky >= GWEATHER_SKY_LAST)
        return FALSE;

    *sky = info->sky;

    return TRUE;
}

/**
 * gweather_info_get_value_conditions:
 * @info: a #GWeatherInfo
 * @phenomenon: (out): a location for a #GWeatherConditionPhenomenon.
 * @qualifier: (out): a location for a #GWeatherConditionQualifier.
 *
 * Fills out @phenomenon and @qualifier with current weather conditions.
 * Returns: TRUE is out arguments are valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_conditions (GWeatherInfo *info, GWeatherConditionPhenomenon *phenomenon, GWeatherConditionQualifier *qualifier)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (phenomenon != NULL, FALSE);
    g_return_val_if_fail (qualifier != NULL, FALSE);

    if (!info->valid)
        return FALSE;

    if (!info->cond.significant)
        return FALSE;

    if (!(info->cond.phenomenon > GWEATHER_PHENOMENON_INVALID &&
          info->cond.phenomenon < GWEATHER_PHENOMENON_LAST &&
          info->cond.qualifier > GWEATHER_QUALIFIER_INVALID &&
          info->cond.qualifier < GWEATHER_QUALIFIER_LAST))
        return FALSE;

    *phenomenon = info->cond.phenomenon;
    *qualifier = info->cond.qualifier;

    return TRUE;
}

/**
 * gweather_info_get_value_temp:
 * @info: a #GWeatherInfo
 * @unit: the desired unit, as a #GWeatherTemperatureUnit
 * @value: (out): the temperature value
 *
 * Returns: TRUE is @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_temp (GWeatherInfo *info, GWeatherTemperatureUnit unit, gdouble *value)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);

    if (!info->valid)
        return FALSE;

    return temperature_value (info->temp, unit, value, info->settings);
}

/**
 * gweather_info_get_value_temp_min:
 * @info: a #GWeatherInfo
 * @unit: the desired unit, as a #GWeatherTemperatureUnit
 * @value: (out): the minimum temperature value
 *
 * Returns: TRUE is @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_temp_min (GWeatherInfo *info, GWeatherTemperatureUnit unit, gdouble *value)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);

    if (!info->valid || !info->tempMinMaxValid)
        return FALSE;

    return temperature_value (info->temp_min, unit, value, info->settings);
}

/**
 * gweather_info_get_value_temp_max:
 * @info: a #GWeatherInfo
 * @unit: the desired unit, as a #GWeatherTemperatureUnit
 * @value: (out): the maximum temperature value
 *
 * Returns: TRUE is @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_temp_max (GWeatherInfo *info, GWeatherTemperatureUnit unit, gdouble *value)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);

    if (!info->valid || !info->tempMinMaxValid)
        return FALSE;

    return temperature_value (info->temp_max, unit, value, info->settings);
}

/**
 * gweather_info_get_value_dew:
 * @info: a #GWeatherInfo
 * @unit: the desired unit, as a #GWeatherTemperatureUnit
 * @value: (out): the dew point
 *
 * Returns: TRUE is @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_dew (GWeatherInfo *info, GWeatherTemperatureUnit unit, gdouble *value)
{
    gdouble dew;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);

    if (!info->valid)
        return FALSE;

    if (info->hasHumidity)
        dew = calc_dew (info->temp, info->humidity);
    else
        dew = info->dew;

    return temperature_value (dew, unit, value, info->settings);
}

/**
 * gweather_info_get_value_apparent:
 * @info: a #GWeatherInfo
 * @unit: the desired unit, as a #GWeatherTemperatureUnit
 * @value: (out): the apparent temperature
 *
 * Returns: TRUE is @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_apparent (GWeatherInfo *info, GWeatherTemperatureUnit unit, gdouble *value)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);

    if (!info->valid)
        return FALSE;

    return temperature_value (calc_apparent (info), unit, value, info->settings);
}

/**
 * gweather_info_get_value_update:
 * @info: a #GWeatherInfo
 * @value: (out) (type glong): the time @info was last updated
 *
 * Note that @value may be 0 if @info has not yet been updated.
 *
 * Returns: TRUE is @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_update (GWeatherInfo *info, time_t *value)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);

    if (!info->valid)
        return FALSE;

    *value = info->update;

    return TRUE;
}

/**
 * gweather_info_get_value_sunrise:
 * @info: a #GWeatherInfo
 * @value: (out) (type gulong): the time of sunrise
 *
 * Returns: TRUE is @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_sunrise (GWeatherInfo *info, time_t *value)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);

    _gweather_info_ensure_sun (info);

    if (!info->sunriseValid)
        return FALSE;

    *value = info->sunrise;

    return TRUE;
}

/**
 * gweather_info_get_value_sunset:
 * @info: a #GWeatherInfo
 * @value: (out) (type gulong): the time of sunset
 *
 * Returns: TRUE is @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_sunset (GWeatherInfo *info, time_t *value)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);

    _gweather_info_ensure_sun (info);

    if (!info->sunsetValid)
        return FALSE;

    *value = info->sunset;

    return TRUE;
}

/**
 * gweather_info_get_value_moonphase:
 * @info: a #GWeatherInfo
 * @value: (out): the current moon phase
 * @lat: (out): the moon declension
 *
 * Returns: TRUE is @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_moonphase (GWeatherInfo *info,
                                   GWeatherMoonPhase *value,
                                   GWeatherMoonLatitude *lat)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);
    g_return_val_if_fail (lat != NULL, FALSE);

    _gweather_info_ensure_moon (info);

    if (!info->moonValid)
        return FALSE;

    *value = info->moonphase;
    *lat = info->moonlatitude;

    return TRUE;
}

/**
 * gweather_info_get_value_wind:
 * @info: a #GWeatherInfo
 * @unit: the desired unit, as a #GWeatherSpeedUnit
 * @speed: (out): forecasted wind speed
 * @direction: (out): forecasted wind direction
 *
 * Returns: TRUE if @speed and @direction are valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_wind (GWeatherInfo *info,
                              GWeatherSpeedUnit unit,
                              gdouble *speed,
                              GWeatherWindDirection *direction)
{
    gboolean res = FALSE;

    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (speed != NULL, FALSE);
    g_return_val_if_fail (direction != NULL, FALSE);

    if (!info->valid)
        return FALSE;

    if (info->windspeed < 0.0 || info->wind <= GWEATHER_WIND_INVALID || info->wind >= GWEATHER_WIND_LAST)
        return FALSE;

    res = speed_value (info->windspeed, unit, speed, info->settings);
    *direction = info->wind;

    return res;
}

/**
 * gweather_info_get_value_pressure:
 * @info: a #GWeatherInfo
 * @unit: the desired unit, as a #GWeatherPressureUnit
 * @value: (out): forecasted pressure, expressed in @unit
 *
 * Returns: TRUE if @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_pressure (GWeatherInfo *info,
                                  GWeatherPressureUnit unit,
                                  gdouble *value)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);

    if (!info->valid)
        return FALSE;

    return pressure_value (info->pressure, unit, value, info->settings);
}

/**
 * gweather_info_get_value_visibility:
 * @info: a #GWeatherInfo
 * @unit: the desired unit, as a #GWeatherDistanceUnit
 * @value: (out): forecasted visibility, expressed in @unit
 *
 * Returns: TRUE if @value is valid, FALSE otherwise.
 */
gboolean
gweather_info_get_value_visibility (GWeatherInfo *info,
                                    GWeatherDistanceUnit unit,
                                    gdouble *value)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), FALSE);
    g_return_val_if_fail (value != NULL, FALSE);

    if (!info->valid)
        return FALSE;

    return distance_value (info->visibility, unit, value, info->settings);
}

static void
gweather_info_set_location_internal (GWeatherInfo *info,
                                     GWeatherLocation *location)
{
    GVariant *default_loc = NULL;
    const gchar *name = NULL;
    gboolean latlon_override = FALSE;
    gdouble lat, lon;

    if (info->glocation == location)
        return;

    if (info->glocation)
        gweather_location_unref (info->glocation);

    info->glocation = location;

    if (info->glocation) {
        gweather_location_ref (location);
    } else {
        g_autoptr (GWeatherLocation) world = NULL;
        const gchar *station_code;

        default_loc = g_settings_get_value (info->settings, DEFAULT_LOCATION);

        g_variant_get (default_loc, "(&s&sm(dd))", &name, &station_code, &latlon_override, &lat, &lon);

        if (strcmp (name, "") == 0)
            name = NULL;

        world = gweather_location_get_world ();
        info->glocation = gweather_location_find_by_station_code (world, station_code);
    }

    if (info->glocation) {
        _weather_location_free (&info->location);
        _gweather_location_update_weather_location (info->glocation,
                                                    &info->location);
    }

    if (name) {
        g_free (info->location.name);
        info->location.name = g_strdup (name);
    }

    if (latlon_override) {
        info->location.latlon_valid = TRUE;
        info->location.latitude = DEGREES_TO_RADIANS (lat);
        info->location.longitude = DEGREES_TO_RADIANS (lon);
    }

    if (default_loc)
        g_variant_unref (default_loc);
}

/**
 * gweather_info_set_location:
 * @info: a #GWeatherInfo
 * @location: (allow-none): a location for which weather is desired
 *
 * Changes @info to report weather for @location.
 * Note that this will clear any forecast or current conditions from
 * @info, you must call gweather_info_update() to obtain the new data.
 */
void
gweather_info_set_location (GWeatherInfo *info,
                            GWeatherLocation *location)
{
    g_return_if_fail (GWEATHER_IS_INFO (info));

    gweather_info_set_location_internal (info, location);
    gweather_info_reset (info);
}

/**
 * gweather_info_get_enabled_providers:
 * @info: a #GWeatherInfo
 *
 * Gets the bitmask of enabled #GWeatherProvider weather
 * providers.
 */
GWeatherProvider
gweather_info_get_enabled_providers (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info),
                          GWEATHER_PROVIDER_NONE);

    return info->providers;
}

/**
 * gweather_info_set_enabled_providers:
 * @info: a #GWeatherInfo
 * @providers: a bitmask of #GWeatherProvider
 *
 * Sets the enabled providers for fetching the weather. Note
 * that it is up to the application developer to make sure that
 * the terms of use for each service are respected.
 *
 * Online providers will not be enabled if the application ID is
 * not set to a valid value.
 */
void
gweather_info_set_enabled_providers (GWeatherInfo *info,
                                     GWeatherProvider providers)
{
    g_return_if_fail (GWEATHER_IS_INFO (info));

    if (providers != GWEATHER_PROVIDER_NONE) {
        g_return_if_fail (info->application_id != NULL);
        g_return_if_fail (g_application_id_is_valid (info->application_id));
    }

    if (info->providers == providers)
        return;

    info->providers = providers;

    gweather_info_abort (info);
    g_object_notify (G_OBJECT (info), "enabled-providers");
}

/**
 * gweather_info_get_application_id:
 * @info: a #GWeatherInfo
 *
 * Get the [application ID](https://docs.flatpak.org/en/latest/conventions.html#application-ids)
 * of the application fetching the weather.
 *
 * Returns: the application ID
 */
const char *
gweather_info_get_application_id (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    return info->application_id;
}

/**
 * gweather_info_set_application_id:
 * @info: a #GWeatherInfo
 * @application_id: the application ID to set
 *
 * Sets the [application ID](https://docs.flatpak.org/en/latest/conventions.html#application-ids)
 * of the application fetching the weather. It is a requirement
 * for using any of the online weather providers.
 *
 * If the application uses #GApplication, then the application ID
 * will be automatically filled in.
 */
void
gweather_info_set_application_id (GWeatherInfo *info,
                                  const char *application_id)
{
    g_return_if_fail (GWEATHER_IS_INFO (info));
    g_return_if_fail (g_application_id_is_valid (application_id));

    g_clear_pointer (&info->application_id, g_free);
    info->application_id = g_strdup (application_id);

    if (info->session) {
        g_clear_object (&info->session);
        info->session = ref_session (info);
    }
}

/**
 * gweather_info_get_contact_info:
 * @info: a #GWeatherInfo
 *
 * Get the contact information of the application fetching the weather.
 *
 * Returns: the contact information
 */
const char *
gweather_info_get_contact_info (GWeatherInfo *info)
{
    g_return_val_if_fail (GWEATHER_IS_INFO (info), NULL);

    return info->contact_info;
}

/**
 * gweather_info_set_contact_info:
 * @info: a #GWeatherInfo
 * @contact_info: the contact information for the application
 *
 * Sets the contact information for the application fetching the
 * weather. It is a requirement for using any of the online
 * weather providers as it allows API providers to contact application
 * developers in case of terms of use breaches.
 *
 * The contact information should be an email address, or the full
 * URL to an online contact form which weather providers can use
 * to contact the application developer. Avoid using bug tracker
 * URLs which require creating accounts.
 */
void
gweather_info_set_contact_info (GWeatherInfo *info,
                                const char *contact_info)
{
    g_return_if_fail (GWEATHER_IS_INFO (info));
    g_return_if_fail (contact_info != NULL);

    g_clear_pointer (&info->contact_info, g_free);
    info->contact_info = g_strdup (contact_info);

    if (info->session) {
        g_clear_object (&info->session);
        info->session = ref_session (info);
    }
}

static void
gweather_info_set_property (GObject *object,
                            guint property_id,
                            const GValue *value,
                            GParamSpec *pspec)
{
    GWeatherInfo *self = GWEATHER_INFO (object);

    switch (property_id) {
        case PROP_LOCATION:
            gweather_info_set_location_internal (self, (GWeatherLocation *) g_value_get_boxed (value));
            break;
        case PROP_ENABLED_PROVIDERS:
            gweather_info_set_enabled_providers (self, g_value_get_flags (value));
            break;
        case PROP_APPLICATION_ID:
            gweather_info_set_application_id (self, g_value_get_string (value));
            break;
        case PROP_CONTACT_INFO:
            gweather_info_set_contact_info (self, g_value_get_string (value));
            break;
        default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
    }
}

static void
gweather_info_get_property (GObject *object,
                            guint property_id,
                            GValue *value,
                            GParamSpec *pspec)
{
    GWeatherInfo *self = GWEATHER_INFO (object);

    switch (property_id) {
        case PROP_LOCATION:
            g_value_set_boxed (value, self->glocation);
            break;
        case PROP_ENABLED_PROVIDERS:
            g_value_set_flags (value, self->providers);
            break;
        case PROP_APPLICATION_ID:
            g_value_set_string (value, self->application_id);
            break;
        case PROP_CONTACT_INFO:
            g_value_set_string (value, self->contact_info);
            break;
        default:
            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
    }
}

static void
gweather_info_constructed (GObject *object)
{
    GWeatherInfo *info = GWEATHER_INFO (object);
    GApplication *app;

    if (info->application_id != NULL)
        return;
    app = g_application_get_default ();
    if (!app)
        return;

    gweather_info_set_application_id (info,
                                      g_application_get_application_id (app));
}

void
gweather_info_class_init (GWeatherInfoClass *klass)
{
    GParamSpec *pspec;
    GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

    gobject_class->dispose = gweather_info_dispose;
    gobject_class->finalize = gweather_info_finalize;
    gobject_class->set_property = gweather_info_set_property;
    gobject_class->get_property = gweather_info_get_property;
    gobject_class->constructed = gweather_info_constructed;

    pspec = g_param_spec_boxed ("location",
                                "Location",
                                "The location this info represents",
                                GWEATHER_TYPE_LOCATION,
                                G_PARAM_STATIC_STRINGS | G_PARAM_READWRITE | G_PARAM_CONSTRUCT);
    g_object_class_install_property (gobject_class, PROP_LOCATION, pspec);

    pspec = g_param_spec_flags ("enabled-providers",
                                "Enabled providers",
                                "A bitmask of enabled weather service providers",
                                GWEATHER_TYPE_PROVIDER,
                                GWEATHER_PROVIDER_NONE,
                                G_PARAM_STATIC_STRINGS | G_PARAM_READWRITE);
    g_object_class_install_property (gobject_class, PROP_ENABLED_PROVIDERS, pspec);

    pspec = g_param_spec_string ("application-id",
                                 "Application ID",
                                 "An unique reverse-DNS application ID",
                                 NULL,
                                 G_PARAM_STATIC_STRINGS | G_PARAM_READWRITE);
    g_object_class_install_property (gobject_class, PROP_APPLICATION_ID, pspec);

    pspec = g_param_spec_string ("contact-info",
                                 "Contact information",
                                 "An email address or contact form URL",
                                 NULL,
                                 G_PARAM_STATIC_STRINGS | G_PARAM_READWRITE);
    g_object_class_install_property (gobject_class, PROP_CONTACT_INFO, pspec);

    /**
     * GWeatherInfo::updated:
     * @object: the emitter of the signal.
     *
     * This signal is emitted after the initial fetch of the weather
     * data from upstream services, and after every successful call
     * to @gweather_info_update().
     */
    gweather_info_signals[SIGNAL_UPDATED] = g_signal_new ("updated",
                                                          GWEATHER_TYPE_INFO,
                                                          G_SIGNAL_RUN_FIRST,
                                                          0,
                                                          NULL, /* accumulator */
                                                          NULL, /* accu_data */
                                                          g_cclosure_marshal_VOID__VOID,
                                                          G_TYPE_NONE,
                                                          0);

    _gweather_gettext_init ();
}

/**
 * gweather_info_new:
 * @location: (allow-none): the desidered #GWeatherLocation (%NULL for default)
 *
 * Builds a new #GWeatherInfo that will provide weather information about
 * @location.
 *
 * Since version 40, this does not automatically call gweather_info_update().
 * gweather_info_update() must be called manually once all the necessary set up
 * has been made, such as setting the enabled providers.
 *
 * Returns: (transfer full): a new #GWeatherInfo
 */
GWeatherInfo *
gweather_info_new (GWeatherLocation *location)
{
    if (location != NULL)
        return g_object_new (GWEATHER_TYPE_INFO, "location", location, NULL);
    return g_object_new (GWEATHER_TYPE_INFO, NULL);
}

GWeatherInfo *
_gweather_info_new_clone (GWeatherInfo *original)
{
    return g_object_new (GWEATHER_TYPE_INFO,
                         "application-id",
                         original->application_id,
                         "contact-info",
                         original->contact_info,
                         "enabled-providers",
                         original->providers,
                         "location",
                         original->glocation,
                         NULL);
}