/*
 * Copyright (C) 2004-2005 Nokia Corporation.
 * Copyright (C) 2008 Bastien Nocera <hadess@hadess.net>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; version 2 of the
 * License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include <config.h>
#include <stdlib.h>
#include <string.h>
#include <glib.h>
#include <expat.h>

#include "gvfsbackendobexftp-cap-parser.h"

#define d(x)

struct _OvuCaps {
	GList *memory_entries;

	/* FIXME: Add "Services" and "Inbox" data here later. */
};

struct _OvuCapsMemory {
        gchar   *type;
        goffset  free;
        goffset  used;
        guint    has_free : 1;
	guint    has_used : 1;
        guint    case_sensitive : 1;
};

typedef enum {
	PARSER_STATE_INVALID,

	PARSER_STATE_START,
	PARSER_STATE_CAPABILITY,

	PARSER_STATE_GENERAL,

	PARSER_STATE_MEMORY,
	PARSER_STATE_MEMORY_TYPE,
	PARSER_STATE_MEMORY_LOCATION,
	PARSER_STATE_MEMORY_FREE,
	PARSER_STATE_MEMORY_USED,
	PARSER_STATE_MEMORY_SHARED,
	PARSER_STATE_MEMORY_FILESIZE,
	PARSER_STATE_MEMORY_FOLDERSIZE,
	PARSER_STATE_MEMORY_FILELEN,
	PARSER_STATE_MEMORY_FOLDERLEN,
	PARSER_STATE_MEMORY_CASE,
	PARSER_STATE_MEMORY_EXT,

	PARSER_STATE_INBOX,
	PARSER_STATE_SERVICE,

	PARSER_STATE_SKIP
} ParserState;


typedef struct {
	GList             *state;

	GList             *memory_entries;

	gchar             *memory_type;
	goffset   memory_free;
	goffset   memory_used;
	gboolean           memory_has_free;
	gboolean           memory_has_used;
	gboolean           memory_case_sensitive;

	GError           **error;
} ParserData;

static void    cap_parser_start_node_cb   (void                 *user_data,
					   const char           *node_name,
					   const char          **attr);

static void    cap_parser_end_node_cb     (void                 *user_data,
					   const char           *node_name);
static void    cap_parser_text_cb         (void                 *user_data,
					   const XML_Char       *s,
                                           int                   len);
static XML_Parser
cap_parser_create_parser                  (ParserData           *data);


static void
cap_parser_push_state (ParserData *data, ParserState state)
{
	data->state = g_list_prepend (data->state,
				      GINT_TO_POINTER (state));
}

static ParserState
cap_parser_pop_state (ParserData *data)
{
	ParserState state;

	if (!data->state) {
		return PARSER_STATE_INVALID;
	}

	state = GPOINTER_TO_INT (data->state->data);
	data->state = g_list_delete_link (data->state, data->state);

	return state;
}

static ParserState
cap_parser_peek_state (ParserData *data)
{
	if (!data->state) {
		return PARSER_STATE_START;
	}

	return GPOINTER_TO_INT (data->state->data);
}

static const char *
cap_parser_get_attribute_value (const char  *name, const char **attr)
{
	gint i = 0;

	while (attr[i]) {
		if (strcmp (name, attr[i]) == 0) {
			return attr[i + 1];
		}
		i += 2;
	}

	return "";
}

static void
cap_parser_start_node_cb (void        *user_data,
			  const char  *node_name,
			  const char **attr)
{
	ParserData  *data;
	ParserState  state;
	const gchar *version;

	data = (ParserData *) user_data;

	state = cap_parser_peek_state (data);

	switch (state) {
	case PARSER_STATE_START:
		if (strcmp (node_name, "Capability") != 0) {
			g_set_error (data->error,
				     G_MARKUP_ERROR,
				     G_MARKUP_ERROR_INVALID_CONTENT,
				     "Outermost element must be a <Capability>, not <%s>",
				     node_name);
			return;
		}

		version = cap_parser_get_attribute_value ("version", attr);
		/* Assume an empty version is fine */
		if (strcmp (version, "1.0") != 0 && version[0] != '\0') {
			g_warning ("Version expected is '1.0', not '%s'\n", version);
		}

		cap_parser_push_state (data, PARSER_STATE_CAPABILITY);
		break;

	case PARSER_STATE_CAPABILITY:
		if (strcmp (node_name, "General") == 0) {
			cap_parser_push_state (data, PARSER_STATE_GENERAL);
		}
		else if (strcmp (node_name, "Inbox") == 0) {
			cap_parser_push_state (data, PARSER_STATE_INBOX);
		}
		else if (strcmp (node_name, "Service") == 0) {
			cap_parser_push_state (data, PARSER_STATE_SERVICE);
		} else {
			g_set_error (data->error,
				     G_MARKUP_ERROR,
				     G_MARKUP_ERROR_INVALID_CONTENT,
				     "Don't expect node '%s' as child of 'Cap'",
				     node_name);
			return;
		}
		break;

	case PARSER_STATE_GENERAL:
		if (strcmp (node_name, "Memory") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY);
		}
		else if (strcmp (node_name, "Manufacturer") == 0 ||
			 strcmp (node_name, "Model") == 0 ||
			 strcmp (node_name, "SN") == 0 ||
			 strcmp (node_name, "OEM") == 0 ||
			 strcmp (node_name, "SW") == 0 ||
			 strcmp (node_name, "FW") == 0 ||
			 strcmp (node_name, "HW") == 0 ||
			 strcmp (node_name, "Language") == 0 ||
			 strcmp (node_name, "Ext") == 0) {

			/* Skip these for now. */
			cap_parser_push_state (data, PARSER_STATE_SKIP);
		} else {
			g_set_error (data->error,
				     G_MARKUP_ERROR,
				     G_MARKUP_ERROR_INVALID_CONTENT,
				     "Don't expect node '%s' as child of 'General'",
				     node_name);
			return;
		}

		break;

	case PARSER_STATE_MEMORY:
		if (strcmp (node_name, "MemType") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_TYPE);
		}
		else if (strcmp (node_name, "Location") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_LOCATION);
		}
		else if (strcmp (node_name, "Free") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_FREE);
		}
		else if (strcmp (node_name, "Used") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_USED);
		}
		else if (strcmp (node_name, "Shared") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_SHARED);
		}
		else if (strcmp (node_name, "FileSize") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_FILESIZE);
		}
		else if (strcmp (node_name, "FolderSize") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_FOLDERSIZE);
		}
		else if (strcmp (node_name, "FileNLen") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_FILELEN);
		}
		else if (strcmp (node_name, "FolderNLen") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_FOLDERLEN);
		}
		else if (strcmp (node_name, "CaseSenN") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_CASE);
			data->memory_case_sensitive = TRUE;
		}
		else if (strcmp (node_name, "Ext") == 0) {
			cap_parser_push_state (data, PARSER_STATE_MEMORY_EXT);
		} else {
			g_set_error (data->error,
				     G_MARKUP_ERROR,
				     G_MARKUP_ERROR_INVALID_CONTENT,
				     "Don't expect node '%s' as child of 'Memory'",
				     node_name);
			return;
		}
		break;

	case PARSER_STATE_INBOX:
	case PARSER_STATE_SERVICE:
		/* Skip these for now. */
		cap_parser_push_state (data, PARSER_STATE_SKIP);
		break;

	case PARSER_STATE_SKIP:
		cap_parser_push_state (data, PARSER_STATE_SKIP);
		break;

	default:
		g_warning ("Node not handled: '%s'\n", node_name);
		cap_parser_push_state (data, PARSER_STATE_SKIP);
		break;
	}
}

static void
cap_parser_reset_memory (ParserData *data)
{
	g_free (data->memory_type);
	data->memory_type = NULL;
	data->memory_free = 0;
	data->memory_used = 0;
	data->memory_has_free = FALSE;
	data->memory_has_used = FALSE;
	data->memory_case_sensitive = FALSE;
}

static void
cap_parser_end_node_cb (void *user_data, const char *node_name)
{
	ParserData    *data;
	ParserState    state;
	OvuCapsMemory *memory;

	data = (ParserData *) user_data;

	state = cap_parser_pop_state (data);

	switch (state) {
	case PARSER_STATE_INVALID:
		return;

	case PARSER_STATE_MEMORY:
		memory = ovu_caps_memory_new (data->memory_type,
					      data->memory_free,
					      data->memory_used,
					      data->memory_has_free,
					      data->memory_has_used,
					      data->memory_case_sensitive);

		data->memory_entries = g_list_prepend (data->memory_entries,
						       memory);
		cap_parser_reset_memory (data);
		break;

	case PARSER_STATE_CAPABILITY:
		data->memory_entries = g_list_reverse (data->memory_entries);
		break;

	default:
		break;
	}
}

/* Parse a long, return -1 if input is not strictly valid or null. */
static goffset
parse_long (const gchar *str, gboolean *success)
{
	gchar *endptr;
	glong  l;

	*success = TRUE;

	if (!str) {
		*success = FALSE;
		return 0;
	}

	l = strtol (str, &endptr, 10);
	if (endptr[0] != '\0' || l < 0) {
		*success = FALSE;
		l = 0;
	}

	return l;
}

static void
cap_parser_text_cb (void           *user_data,
		    const XML_Char *s,
		    int             len)
{
	ParserData  *data;
	ParserState  state;
	gchar       *tmp;

	data = (ParserData *) user_data;

	/* text is not null terminated. */
	tmp = g_strndup (s, len);

	state = cap_parser_peek_state (data);

	switch (state) {
	case PARSER_STATE_MEMORY_TYPE:
		data->memory_type = g_strdup (tmp);
		break;
	case PARSER_STATE_MEMORY_FREE:
		data->memory_free = parse_long (tmp, &data->memory_has_free);
		break;
	case PARSER_STATE_MEMORY_USED:
		data->memory_used = parse_long (tmp, &data->memory_has_used);
		break;

	default:
		break;
	}

	g_free (tmp);
}

static XML_Parser
cap_parser_create_parser (ParserData *data)
{
	XML_Parser parser;

	parser = XML_ParserCreate (NULL);

	XML_SetElementHandler (parser,
			       cap_parser_start_node_cb,
			       cap_parser_end_node_cb);

	XML_SetCharacterDataHandler (parser, cap_parser_text_cb);

	XML_SetUserData (parser, data);

	return parser;
}

static void
cap_parser_free (ParserData *data, gboolean free_data)
{
	cap_parser_reset_memory (data);

	if (free_data) {
		g_list_foreach (data->memory_entries,
				(GFunc) ovu_caps_memory_free, NULL);
	}

	g_free (data);
}

OvuCaps *
ovu_caps_parser_parse (const gchar  *buf,
		       gint          len,
		       GError      **error)
{
	ParserData *data;
	XML_Parser  parser;
	OvuCaps    *caps;

	data = g_new0 (ParserData, 1);

	data->error = error;
	parser = cap_parser_create_parser (data);

	if (XML_Parse (parser, buf, len, TRUE) == 0) {
		caps = NULL;

		if (*error == NULL) {
			g_set_error_literal (error,
					     G_MARKUP_ERROR,
					     G_MARKUP_ERROR_INVALID_CONTENT,
					     "Couldn't parse the incoming data");
		}

		cap_parser_free (data, TRUE);
	} else {
		caps = g_new0 (OvuCaps, 1);
		caps->memory_entries = data->memory_entries;
		
		cap_parser_free (data, FALSE);
	}

	XML_ParserFree (parser);

	return caps;
}

OvuCapsMemory *
ovu_caps_memory_new (const gchar      *type,
		     goffset  free,
		     goffset  used,
		     gboolean          has_free,
		     gboolean          has_used,
		     gboolean          case_sensitive)
{
	OvuCapsMemory *memory;

	memory = g_new0 (OvuCapsMemory, 1);

	memory->type = g_strdup (type);
	memory->free = free;
	memory->used = used;
	memory->has_free = has_free;
	memory->has_used = has_used;
	memory->case_sensitive = case_sensitive;

	return memory;
}

void
ovu_caps_memory_free (OvuCapsMemory *memory)
{
	g_free (memory->type);
	g_free (memory);
}

gboolean
ovu_caps_memory_equal (OvuCapsMemory *m1, OvuCapsMemory *m2)
{
	if (strcmp (m1->type, m2->type) != 0) {
		d(g_print ("type mismatch: %s %s\n",
			   m1->type, m2->type));
		return FALSE;
	}

	if (m1->free != m2->free) {
		d(g_print ("free mismatch: %d %d\n",
			   (int) m1->free, (int) m2->free));
		return FALSE;
	}

	if (m1->used != m2->used) {
		d(g_print ("used mismatch: %d %d\n",
			   (int) m1->used, (int) m2->used));
		return FALSE;
	}

	if (m1->case_sensitive != m2->case_sensitive) {
		d(g_print ("case mismatch: %d %d\n",
			   m1->case_sensitive,
			   m2->case_sensitive));
		return FALSE;
	}

	return TRUE;
}

void
ovu_caps_free (OvuCaps *caps)
{
	g_list_free_full (caps->memory_entries, (GDestroyNotify) ovu_caps_memory_free);

	g_free (caps);
}

GList *
ovu_caps_get_memory_entries (OvuCaps *caps)
{
	g_return_val_if_fail (caps != NULL, NULL);

	return caps->memory_entries;
}

OvuCapsMemory *
ovu_caps_get_memory_type (OvuCaps     *caps,
			  const gchar *mem_type)
{
	GList *tmp;

	g_return_val_if_fail (caps != NULL, NULL);

	for (tmp = caps->memory_entries; tmp != NULL; tmp = tmp->next) {
		OvuCapsMemory *memory = tmp->data;

		/* treat a NULL memory type as matching anything */
		if (mem_type == NULL || (memory->type != NULL &&
					 !strcmp(mem_type, memory->type)))
			return memory;
	}
	return NULL;
}

const gchar *
ovu_caps_memory_get_type (OvuCapsMemory *memory)
{
	return memory->type;
}

goffset
ovu_caps_memory_get_used (OvuCapsMemory *memory)
{
	return memory->used;
}

goffset
ovu_caps_memory_get_free (OvuCapsMemory *memory)
{
	return memory->free;
}

gboolean
ovu_caps_memory_has_used (OvuCapsMemory *memory)
{
	return memory->has_used;
}

gboolean
ovu_caps_memory_has_free (OvuCapsMemory *memory)
{
	return memory->has_free;
}

gboolean
ovu_caps_memory_get_case_sensitive (OvuCapsMemory *memory)
{
	return memory->case_sensitive;
}