/*
 * This file is part of GtkSourceView
 *
 * Copyright (C) 2010 - Ignacio Casal Quinteiro
 * Copyright (C) 2014 - Sébastien Wilmet
 *
 * GtkSourceView 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; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * GtkSourceView 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 library; if not, see <http://www.gnu.org/licenses/>.
 */

#include <glib.h>
#include <glib/gprintf.h>
#include <gtk/gtk.h>
#include <stdlib.h>
#include <string.h>
#include <gtksourceview/gtksource.h>
#include "gtksourceview/gtksourcebufferoutputstream-private.h"

static void
test_consecutive_write (const gchar          *inbuf,
                        const gchar          *outbuf,
                        gsize                 write_chunk_len,
                        GtkSourceNewlineType  newline_type)
{
	GtkSourceBuffer *source_buffer;
	GtkSourceBufferOutputStream *out;
	gsize len;
	gssize n, w;
	GError *err = NULL;
	gchar *b;
	GtkSourceNewlineType type;
	GSList *encodings = NULL;

	source_buffer = gtk_source_buffer_new (NULL);
	encodings = g_slist_prepend (encodings, (gpointer)gtk_source_encoding_get_utf8 ());
	out = gtk_source_buffer_output_stream_new (source_buffer, encodings, TRUE);

	n = 0;

	do
	{
		len = MIN (write_chunk_len, strlen (inbuf + n));
		w = g_output_stream_write (G_OUTPUT_STREAM (out), inbuf + n, len, NULL, &err);
		g_assert_cmpint (w, >=, 0);
		g_assert_no_error (err);

		n += w;
	} while (w != 0);

	g_output_stream_flush (G_OUTPUT_STREAM (out), NULL, &err);

	g_assert_no_error (err);

	type = gtk_source_buffer_output_stream_detect_newline_type (out);
	g_assert_cmpint (type, ==, newline_type);

	g_output_stream_close (G_OUTPUT_STREAM (out), NULL, &err);
	g_assert_no_error (err);

	g_object_get (G_OBJECT (source_buffer), "text", &b, NULL);

	g_assert_cmpstr (outbuf, ==, b);
	g_free (b);

	g_assert_false (gtk_text_buffer_get_modified (GTK_TEXT_BUFFER (source_buffer)));

	g_object_unref (source_buffer);
	g_object_unref (out);
}

static void
test_empty (void)
{
	test_consecutive_write ("", "", 10, GTK_SOURCE_NEWLINE_TYPE_DEFAULT);
	test_consecutive_write ("\r\n", "", 10, GTK_SOURCE_NEWLINE_TYPE_CR_LF);
	test_consecutive_write ("\r", "", 10, GTK_SOURCE_NEWLINE_TYPE_CR);
	test_consecutive_write ("\n", "", 10, GTK_SOURCE_NEWLINE_TYPE_LF);
}

static void
test_consecutive (void)
{
	test_consecutive_write ("hello\nhow\nare\nyou", "hello\nhow\nare\nyou", 2,
				GTK_SOURCE_NEWLINE_TYPE_LF);
	test_consecutive_write ("hello\rhow\rare\ryou", "hello\rhow\rare\ryou", 2,
				GTK_SOURCE_NEWLINE_TYPE_CR);
	test_consecutive_write ("hello\r\nhow\r\nare\r\nyou", "hello\r\nhow\r\nare\r\nyou", 2,
				GTK_SOURCE_NEWLINE_TYPE_CR_LF);
}

static void
test_consecutive_tnewline (void)
{
	test_consecutive_write ("hello\nhow\nare\nyou\n", "hello\nhow\nare\nyou", 2,
				GTK_SOURCE_NEWLINE_TYPE_LF);
	test_consecutive_write ("hello\rhow\rare\ryou\r", "hello\rhow\rare\ryou", 2,
				GTK_SOURCE_NEWLINE_TYPE_CR);
	test_consecutive_write ("hello\r\nhow\r\nare\r\nyou\r\n", "hello\r\nhow\r\nare\r\nyou", 2,
				GTK_SOURCE_NEWLINE_TYPE_CR_LF);
}

static void
test_big_char (void)
{
	test_consecutive_write ("\343\203\200\343\203\200", "\343\203\200\343\203\200", 2,
				GTK_SOURCE_NEWLINE_TYPE_LF);
}

static void
test_boundary (void)
{
	GtkSourceBuffer *source_buffer;
	GtkSourceBufferOutputStream *out;
	gint line_count;
	GError *err = NULL;
	GSList *encodings = NULL;

	source_buffer = gtk_source_buffer_new (NULL);
	encodings = g_slist_prepend (encodings, (gpointer)gtk_source_encoding_get_utf8 ());
	out = gtk_source_buffer_output_stream_new (source_buffer, encodings, TRUE);

	g_output_stream_write (G_OUTPUT_STREAM (out), "\r", 1, NULL, NULL);
	g_output_stream_write (G_OUTPUT_STREAM (out), "\n", 1, NULL, NULL);

	g_output_stream_flush (G_OUTPUT_STREAM (out), NULL, &err);
	g_assert_no_error (err);

	line_count = gtk_text_buffer_get_line_count (GTK_TEXT_BUFFER (source_buffer));

	g_assert_cmpint (line_count, ==, 2);

	g_output_stream_close (G_OUTPUT_STREAM (out), NULL, &err);
	g_assert_no_error (err);

	g_object_unref (source_buffer);
	g_object_unref (out);
}

#if 0
static void
test_invalid_utf8 (void)
{
	test_consecutive_write ("foobar\n\xef\xbf\xbe", "foobar\n\\EF\\BF\\BE", 10,
	                        GTK_SOURCE_NEWLINE_TYPE_LF);
	test_consecutive_write ("foobar\n\xef\xbf\xbezzzzzz\n", "foobar\n\\EF\\BF\\BEzzzzzz", 10,
	                        GTK_SOURCE_NEWLINE_TYPE_LF);
	test_consecutive_write ("\xef\xbf\xbezzzzzz\n", "\\EF\\BF\\BEzzzzzz", 10,
	                        GTK_SOURCE_NEWLINE_TYPE_LF);
}
#endif

/* SMART CONVERSION */

#define TEXT_TO_CONVERT "this is some text to make the tests"
#define TEXT_TO_GUESS "hello \xe6\x96\x87 world"

static gchar *
get_encoded_text (const gchar             *text,
                  gint                     nread,
                  const GtkSourceEncoding *to,
                  const GtkSourceEncoding *from,
                  gsize                   *bytes_written_aux,
                  gboolean                 care_about_error)
{
	GCharsetConverter *converter;
	gchar *out, *out_aux;
	gsize bytes_read, bytes_read_aux;
	gsize bytes_written;
	GConverterResult res;
	GError *err;

	converter = g_charset_converter_new (gtk_source_encoding_get_charset (to),
					     gtk_source_encoding_get_charset (from),
					     NULL);

	out = g_malloc (200);
	out_aux = g_malloc (200);
	err = NULL;
	bytes_read_aux = 0;
	*bytes_written_aux = 0;

	if (nread == -1)
	{
		nread = strlen (text);
	}

	do
	{
		res = g_converter_convert (G_CONVERTER (converter),
		                           text + bytes_read_aux,
		                           nread,
		                           out_aux,
		                           200,
		                           G_CONVERTER_INPUT_AT_END,
		                           &bytes_read,
		                           &bytes_written,
		                           &err);
		memcpy (out + *bytes_written_aux, out_aux, bytes_written);
		bytes_read_aux += bytes_read;
		*bytes_written_aux += bytes_written;
		nread -= bytes_read;
	} while (res != G_CONVERTER_FINISHED && res != G_CONVERTER_ERROR);

	if (care_about_error)
	{
		g_assert_no_error (err);
	}
	else if (err)
	{
		g_printf ("** You don't care, but there was an error: %s", err->message);
		return NULL;
	}

	out[*bytes_written_aux] = '\0';

	if (!g_utf8_validate (out, *bytes_written_aux, NULL) && !care_about_error)
	{
		if (!care_about_error)
		{
			return NULL;
		}
		else
		{
			g_assert_not_reached ();
		}
	}

	return out;
}

static gchar *
do_test (const gchar              *inbuf,
         const gchar              *enc,
         GSList                   *encodings,
         gsize                     len,
         gsize                     write_chunk_len,
         const GtkSourceEncoding **guessed)
{
	GtkSourceBuffer *source_buffer;
	GtkSourceBufferOutputStream *out;
	GError *err = NULL;
	GtkTextIter start, end;
	gchar *text;
	gsize to_write;
	gssize n, w;

	if (enc != NULL)
	{
		encodings = NULL;
		encodings = g_slist_prepend (encodings, (gpointer)gtk_source_encoding_get_from_charset (enc));
	}

	source_buffer = gtk_source_buffer_new (NULL);
	out = gtk_source_buffer_output_stream_new (source_buffer, encodings, TRUE);

	n = 0;

	do
	{
		to_write = MIN (len, write_chunk_len);
		w = g_output_stream_write (G_OUTPUT_STREAM (out), inbuf + n, to_write, NULL, &err);
		g_assert_cmpint (w, >=, 0);
		g_assert_no_error (err);

		len -= w;
		n += w;
	} while (len != 0);

	g_output_stream_flush (G_OUTPUT_STREAM (out), NULL, &err);
	g_assert_no_error (err);

	g_output_stream_close (G_OUTPUT_STREAM (out), NULL, &err);
	g_assert_no_error (err);

	if (guessed != NULL)
	{
		*guessed = gtk_source_buffer_output_stream_get_guessed (out);
	}

	gtk_text_buffer_get_bounds (GTK_TEXT_BUFFER (source_buffer), &start, &end);
	text = gtk_text_buffer_get_text (GTK_TEXT_BUFFER (source_buffer),
	                                 &start,
	                                 &end,
	                                 FALSE);

	g_object_unref (source_buffer);
	g_object_unref (out);

	return text;
}

static void
test_utf8_utf8 (void)
{
	gchar *aux;

	aux = do_test (TEXT_TO_CONVERT, "UTF-8", NULL, strlen (TEXT_TO_CONVERT), strlen (TEXT_TO_CONVERT), NULL);
	g_assert_cmpstr (aux, ==, TEXT_TO_CONVERT);
	g_free (aux);

	aux = do_test ("foobar\xc3\xa8\xc3\xa8\xc3\xa8zzzzzz", "UTF-8", NULL, 18, 18, NULL);
	g_assert_cmpstr (aux, ==, "foobar\xc3\xa8\xc3\xa8\xc3\xa8zzzzzz");
	g_free (aux);

	/* small chunk */
	aux = do_test ("foobar\xc3\xa8\xc3\xa8\xc3\xa8zzzzzz", "UTF-8", NULL, 18, 2, NULL);
	g_assert_cmpstr (aux, ==, "foobar\xc3\xa8\xc3\xa8\xc3\xa8zzzzzz");
	g_free (aux);
}

static void
test_empty_conversion (void)
{
	const GtkSourceEncoding *guessed;
	gchar *out;
	GSList *encodings = NULL;

	/* testing the case of an empty file and list of encodings with no
	   utf-8. In this case, the smart converter cannot determine the right
	   encoding (because there is no input), but should still default to
	   utf-8 for the detection */
	encodings = g_slist_prepend (encodings, (gpointer)gtk_source_encoding_get_from_charset ("UTF-16"));
	encodings = g_slist_prepend (encodings, (gpointer)gtk_source_encoding_get_from_charset ("ISO-8859-15"));

	out = do_test ("", NULL, encodings, 0, 0, &guessed);

	g_assert_cmpstr (out, ==, "");
	g_free (out);

	g_assert_true (guessed == gtk_source_encoding_get_utf8 ());
}

static void
test_guessed (void)
{
	GSList *encs = NULL;
	gchar *aux, *aux2, *fail;
	gsize aux_len, fail_len;
	const GtkSourceEncoding *guessed;

	aux = get_encoded_text (TEXT_TO_GUESS, -1,
	                        gtk_source_encoding_get_from_charset ("UTF-16"),
	                        gtk_source_encoding_get_from_charset ("UTF-8"),
	                        &aux_len,
	                        TRUE);

	fail = get_encoded_text (aux, aux_len,
	                         gtk_source_encoding_get_from_charset ("UTF-8"),
	                         gtk_source_encoding_get_from_charset ("ISO-8859-15"),
	                         &fail_len,
	                         FALSE);

	g_assert_null (fail);

	/* ISO-8859-15 should fail */
	encs = g_slist_append (encs, (gpointer)gtk_source_encoding_get_from_charset ("ISO-8859-15"));
	encs = g_slist_append (encs, (gpointer)gtk_source_encoding_get_from_charset ("UTF-16"));

	aux2 = do_test (aux, NULL, encs, aux_len, aux_len, &guessed);
	g_free (aux);
	g_free (aux2);

	g_assert_true (guessed == gtk_source_encoding_get_from_charset ("UTF-16"));
}

static void
test_utf16_utf8 (void)
{
	gchar *text, *aux;
	gsize aux_len;

	text = get_encoded_text ("\xe2\xb4\xb2", -1,
	                         gtk_source_encoding_get_from_charset ("UTF-16"),
	                         gtk_source_encoding_get_from_charset ("UTF-8"),
	                         &aux_len,
	                         TRUE);

	aux = do_test (text, "UTF-16", NULL, aux_len, aux_len, NULL);
	g_assert_cmpstr (aux, ==, "\xe2\xb4\xb2");
	g_free (aux);

	aux = do_test (text, "UTF-16", NULL, aux_len, 1, NULL);
	g_assert_cmpstr (aux, ==, "\xe2\xb4\xb2");
	g_free (aux);
}

gint
main (gint   argc,
      gchar *argv[])
{
	g_test_init (&argc, &argv, NULL);

	g_test_add_func ("/buffer-output-stream/empty", test_empty);

	g_test_add_func ("/buffer-output-stream/consecutive", test_consecutive);
	g_test_add_func ("/buffer-output-stream/consecutive_tnewline", test_consecutive_tnewline);
	g_test_add_func ("/buffer-output-stream/big-char", test_big_char);
	g_test_add_func ("/buffer-output-stream/test-boundary", test_boundary);


	/* This broke after https://bugzilla.gnome.org/show_bug.cgi?id=694669 We
	 * need to revisit the test to pick something that is actually invalid
	 * utf8.
	 */
#if 0
	g_test_add_func ("/buffer-output-stream/test-invalid-utf8", test_invalid_utf8);
#endif
	g_test_add_func ("/buffer-output-stream/smart conversion: utf8-utf8", test_utf8_utf8);
	g_test_add_func ("/buffer-output-stream/smart conversion: empty", test_empty_conversion);
	g_test_add_func ("/buffer-output-stream/smart conversion: guessed", test_guessed);
	g_test_add_func ("/buffer-output-stream/smart conversion: utf16-utf8", test_utf16_utf8);

	return g_test_run ();
}