/*
 * Copyright (C) 2011 Red Hat Inc.
 *
 * Author:
 *      Benjamin Otte <otte@redhat.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#undef GTK_DISABLE_DEPRECATED

#include <string.h>
#include <glib/gstdio.h>
#include <gtk/gtk.h>

#ifdef G_OS_WIN32
# include <io.h>
#endif

static char *
test_get_reference_file (const char *css_file)
{
  GString *file = g_string_new (NULL);

  if (g_str_has_suffix (css_file, ".css"))
    g_string_append_len (file, css_file, strlen (css_file) - 4);
  else
    g_string_append (file, css_file);
  
  g_string_append (file, ".ref.css");

  if (!g_file_test (file->str, G_FILE_TEST_EXISTS))
    {
      g_string_free (file, TRUE);
      return g_strdup (css_file);
    }

  return g_string_free (file, FALSE);
}

static char *
test_get_errors_file (const char *css_file)
{
  GString *file = g_string_new (NULL);

  if (g_str_has_suffix (css_file, ".css"))
    g_string_append_len (file, css_file, strlen (css_file) - 4);
  else
    g_string_append (file, css_file);
  
  g_string_append (file, ".errors");

  if (!g_file_test (file->str, G_FILE_TEST_EXISTS))
    {
      g_string_free (file, TRUE);
      return NULL;
    }

  return g_string_free (file, FALSE);
}

static GBytes *
diff_with_file (const char  *file1,
                char        *text,
                gssize       len,
                GError     **error)
{
  GSubprocess *process;
  GBytes *input, *output;

  process = g_subprocess_new (G_SUBPROCESS_FLAGS_STDIN_PIPE
                              | G_SUBPROCESS_FLAGS_STDOUT_PIPE,
                              error,
                              "diff", "-u", file1, "-", NULL);
  if (process == NULL)
    return NULL;

  input = g_bytes_new_static (text, len >= 0 ? len : strlen (text));
  if (!g_subprocess_communicate (process,
                                 input,
                                 NULL,
                                 &output,
                                 NULL,
                                 error))
    {
      g_object_unref (process);
      g_bytes_unref (input);
      return NULL;
    }

  if (!g_subprocess_get_successful (process) &&
      /* this is the condition when the files differ */
      !(g_subprocess_get_if_exited (process) && g_subprocess_get_exit_status (process) == 1))
    {
      g_clear_pointer (&output, g_bytes_unref);
      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
                   "The `diff' process exited with error status %d",
                   g_subprocess_get_exit_status (process));
    }

  g_object_unref (process);
  g_bytes_unref (input);

  return output;
}

static void
append_error_value (GString *string,
                    GType    enum_type,
                    guint    value)
{
  GEnumClass *enum_class;
  GEnumValue *enum_value;

  enum_class = g_type_class_ref (enum_type);
  enum_value = g_enum_get_value (enum_class, value);

  g_string_append (string, enum_value->value_name);

  g_type_class_unref (enum_class);
}

static void
parsing_error_cb (GtkCssProvider *provider,
                  GtkCssSection  *section,
                  const GError   *error,
                  GString        *errors)
{
  char *section_string;

  section_string = gtk_css_section_to_string (section);

  g_string_append_printf (errors,
                          "%s: error: ",
                          section_string);
  g_free (section_string);

  if (error->domain == GTK_CSS_PARSER_ERROR)
    append_error_value (errors, GTK_TYPE_CSS_PARSER_ERROR, error->code);
  else if (error->domain == GTK_CSS_PARSER_WARNING)
    append_error_value (errors, GTK_TYPE_CSS_PARSER_WARNING, error->code);
  else
    g_string_append_printf (errors, 
                            "%s %u\n",
                            g_quark_to_string (error->domain),
                            error->code);

  g_string_append_c (errors, '\n');
}

static void
parse_css_file (GFile *file, gboolean generate)
{
  GtkCssProvider *provider;
  char *css, *css_file, *reference_file, *errors_file;
  GString *errors;
  GBytes *diff;
  GError *error = NULL;

  css_file = g_file_get_path (file);
  errors = g_string_new ("");

  provider = gtk_css_provider_new ();
  g_signal_connect (provider, 
                    "parsing-error",
                    G_CALLBACK (parsing_error_cb),
                    errors);
  gtk_css_provider_load_from_path (provider, css_file);

  css = gtk_css_provider_to_string (provider);

  if (generate)
    {
      g_print ("%s", css);
      goto out;
    }

  reference_file = test_get_reference_file (css_file);

  diff = diff_with_file (reference_file, css, -1, &error);
  g_assert_no_error (error);

  if (diff && g_bytes_get_size (diff) > 0)
    {
      g_test_message ("Resulting CSS doesn't match reference:\n%s",
                      (const char *) g_bytes_get_data (diff, NULL));
      g_test_fail ();
    }
  g_free (reference_file);
  g_clear_pointer (&diff, g_bytes_unref);

  errors_file = test_get_errors_file (css_file);

  if (errors_file)
    {
      diff = diff_with_file (errors_file, errors->str, errors->len, &error);
      g_assert_no_error (error);

      if (diff && g_bytes_get_size (diff) > 0)
        {
          g_test_message ("Errors don't match expected errors:\n%s",
                          (const char *) g_bytes_get_data (diff, NULL));
          g_test_fail ();
        }
      g_clear_pointer (&diff, g_bytes_unref);
    }
  else if (errors->str[0])
    {
      g_test_message ("Unexpected errors:\n%s", errors->str);
      g_test_fail ();
    }

  g_free (errors_file);
  g_string_free (errors, TRUE);

out:
  g_free (css_file);
  g_free (css);
}

static void
test_css_file (GFile *file)
{
  parse_css_file (file, FALSE);
}

static void
add_test_for_file (GFile *file)
{
  char *path;

  path = g_file_get_path (file);

  g_test_add_vtable (path,
                     0,
                     g_object_ref (file),
                     NULL,
                     (GTestFixtureFunc) test_css_file,
                     (GTestFixtureFunc) g_object_unref);

  g_free (path);
}

static int
compare_files (gconstpointer a, gconstpointer b)
{
  GFile *file1 = G_FILE (a);
  GFile *file2 = G_FILE (b);
  char *path1, *path2;
  int result;

  path1 = g_file_get_path (file1);
  path2 = g_file_get_path (file2);

  result = strcmp (path1, path2);

  g_free (path1);
  g_free (path2);

  return result;
}

static void
add_tests_for_files_in_directory (GFile *dir)
{
  GFileEnumerator *enumerator;
  GFileInfo *info;
  GList *files;
  GError *error = NULL;

  enumerator = g_file_enumerate_children (dir, G_FILE_ATTRIBUTE_STANDARD_NAME, 0, NULL, &error);
  g_assert_no_error (error);
  files = NULL;

  while ((info = g_file_enumerator_next_file (enumerator, NULL, &error)))
    {
      const char *filename;

      filename = g_file_info_get_name (info);

      if (!g_str_has_suffix (filename, ".css") ||
          g_str_has_suffix (filename, ".out.css") ||
          g_str_has_suffix (filename, ".ref.css"))
        {
          g_object_unref (info);
          continue;
        }

      files = g_list_prepend (files, g_file_get_child (dir, filename));

      g_object_unref (info);
    }
  
  g_assert_no_error (error);
  g_object_unref (enumerator);

  files = g_list_sort (files, compare_files);
  g_list_foreach (files, (GFunc) add_test_for_file, NULL);
  g_list_free_full (files, g_object_unref);
}

int
main (int argc, char **argv)
{
  gtk_test_init (&argc, &argv);

  if (argc < 2)
    {
      const char *basedir;
      GFile *dir;

      basedir = g_test_get_dir (G_TEST_DIST);
      dir = g_file_new_for_path (basedir);
      add_tests_for_files_in_directory (dir);

      g_object_unref (dir);
    }
  else if (strcmp (argv[1], "--generate") == 0)
    {
      if (argc >= 3)
        {
          GFile *file = g_file_new_for_commandline_arg (argv[2]);

          parse_css_file (file, TRUE);

          g_object_unref (file);
        }
    }
  else
    {
      guint i;

      for (i = 1; i < argc; i++)
        {
          GFile *file = g_file_new_for_commandline_arg (argv[i]);

          add_test_for_file (file);

          g_object_unref (file);
        }
    }

  return g_test_run ();
}