/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2014 Richard Hughes <richard@hughsie.com>
 *
 * Licensed under the GNU General Public License Version 2
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU 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>

#define _GNU_SOURCE
#include <string.h>

#include <gnome-software.h>

/*
 * SECTION:
 * Loads remote icons and converts them into local cached ones.
 *
 * It is provided so that each plugin handling icons does not
 * have to handle the download and caching functionality.
 */

struct GsPluginData {
	GtkIconTheme		*icon_theme;
	GMutex			 icon_theme_lock;
	GHashTable		*icon_theme_paths;
};

void
gs_plugin_initialize (GsPlugin *plugin)
{
	GsPluginData *priv = gs_plugin_alloc_data (plugin, sizeof(GsPluginData));
	priv->icon_theme = gtk_icon_theme_new ();
	priv->icon_theme_paths = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
	g_mutex_init (&priv->icon_theme_lock);

	/* needs remote icons downloaded */
	gs_plugin_add_rule (plugin, GS_PLUGIN_RULE_RUN_AFTER, "appstream");
	gs_plugin_add_rule (plugin, GS_PLUGIN_RULE_RUN_AFTER, "epiphany");
}

void
gs_plugin_destroy (GsPlugin *plugin)
{
	GsPluginData *priv = gs_plugin_get_data (plugin);
	g_object_unref (priv->icon_theme);
	g_hash_table_unref (priv->icon_theme_paths);
	g_mutex_clear (&priv->icon_theme_lock);
}

static gboolean
gs_plugin_icons_download (GsPlugin *plugin,
			  const gchar *uri,
			  const gchar *filename,
			  GError **error)
{
	guint status_code;
	g_autoptr(GdkPixbuf) pixbuf_new = NULL;
	g_autoptr(GdkPixbuf) pixbuf = NULL;
	g_autoptr(GInputStream) stream = NULL;
	g_autoptr(SoupMessage) msg = NULL;

	/* create the GET data */
	msg = soup_message_new (SOUP_METHOD_GET, uri);
	if (msg == NULL) {
		g_set_error (error,
			     GS_PLUGIN_ERROR,
			     GS_PLUGIN_ERROR_NOT_SUPPORTED,
			     "%s is not a valid URL", uri);
		return FALSE;
	}

	/* set sync request */
	status_code = soup_session_send_message (gs_plugin_get_soup_session (plugin), msg);
	if (status_code != SOUP_STATUS_OK) {
		g_set_error (error,
			     GS_PLUGIN_ERROR,
			     GS_PLUGIN_ERROR_DOWNLOAD_FAILED,
			     "Failed to download icon %s: %s",
			     uri, soup_status_get_phrase (status_code));
		return FALSE;
	}

	/* we're assuming this is a 64x64 png file, resize if not */
	stream = g_memory_input_stream_new_from_data (msg->response_body->data,
						      msg->response_body->length,
						      NULL);
	pixbuf = gdk_pixbuf_new_from_stream (stream, NULL, error);
	if (pixbuf == NULL)
		return FALSE;
	if (gdk_pixbuf_get_height (pixbuf) == 64 &&
	    gdk_pixbuf_get_width (pixbuf) == 64) {
		pixbuf_new = g_object_ref (pixbuf);
	} else {
		pixbuf_new = gdk_pixbuf_scale_simple (pixbuf, 64, 64,
						      GDK_INTERP_BILINEAR);
	}

	/* write file */
	return gdk_pixbuf_save (pixbuf_new, filename, "png", error, NULL);
}

static GdkPixbuf *
gs_plugin_icons_load_local (GsPlugin *plugin, AsIcon *icon, GError **error)
{
	gint size;
	if (as_icon_get_filename (icon) == NULL) {
		g_set_error_literal (error,
				     GS_PLUGIN_ERROR,
				     GS_PLUGIN_ERROR_NOT_SUPPORTED,
				     "icon has no filename");
		return NULL;
	}
	size = (gint) (64 * gs_plugin_get_scale (plugin));
	return gdk_pixbuf_new_from_file_at_size (as_icon_get_filename (icon),
						 size, size, error);
}

static gchar *
gs_plugin_icons_get_cache_fn (AsIcon *icon)
{
	g_autofree gchar *basename = NULL;
	g_autofree gchar *checksum = NULL;
	checksum = g_compute_checksum_for_string (G_CHECKSUM_SHA1,
						  as_icon_get_url (icon),
						  -1);
	basename = g_path_get_basename (as_icon_get_url (icon));
	return g_strdup_printf ("%s-%s", checksum, basename);
}

static GdkPixbuf *
gs_plugin_icons_load_remote (GsPlugin *plugin, AsIcon *icon, GError **error)
{
	const gchar *fn;
	gchar *found;

	/* not applicable for remote */
	if (as_icon_get_url (icon) == NULL) {
		g_set_error_literal (error,
				     GS_PLUGIN_ERROR,
				     GS_PLUGIN_ERROR_NOT_SUPPORTED,
				     "icon has no URL");
		return NULL;
	}

	/* set cache filename if not already set */
	if (as_icon_get_filename (icon) == NULL) {
		g_autofree gchar *fn_cache = NULL;
		g_autofree gchar *fn_basename = NULL;

		/* use a hash-prefixed filename to avoid cache clashes */
		fn_basename = gs_plugin_icons_get_cache_fn (icon);
		fn_cache = gs_utils_get_cache_filename ("icons",
							fn_basename,
							GS_UTILS_CACHE_FLAG_WRITEABLE,
							error);
		if (fn_cache == NULL)
			return NULL;
		as_icon_set_filename (icon, fn_cache);
	}

	/* already in cache */
	if (g_file_test (as_icon_get_filename (icon), G_FILE_TEST_EXISTS))
		return gs_plugin_icons_load_local (plugin, icon, error);

	/* a REMOTE that's really LOCAL */
	if (g_str_has_prefix (as_icon_get_url (icon), "file://")) {
		as_icon_set_filename (icon, as_icon_get_url (icon) + 7);
		as_icon_set_kind (icon, AS_ICON_KIND_LOCAL);
		return gs_plugin_icons_load_local (plugin, icon, error);
	}

	/* convert filename from jpg to png */
	fn = as_icon_get_filename (icon);
	found = g_strstr_len (fn, -1, ".jpg");
	if (found != NULL)
		memcpy (found, ".png", 4);

	/* create runtime dir and download */
	if (!gs_mkdir_parent (fn, error))
		return NULL;
	if (!gs_plugin_icons_download (plugin, as_icon_get_url (icon), fn, error))
		return NULL;
	as_icon_set_kind (icon, AS_ICON_KIND_LOCAL);
	return gs_plugin_icons_load_local (plugin, icon, error);
}

static void
gs_plugin_icons_add_theme_path (GsPlugin *plugin, const gchar *path)
{
	GsPluginData *priv = gs_plugin_get_data (plugin);
	if (path == NULL)
		return;
	if (!g_hash_table_contains (priv->icon_theme_paths, path)) {
		gtk_icon_theme_prepend_search_path (priv->icon_theme, path);
		g_hash_table_add (priv->icon_theme_paths, g_strdup (path));
	}
}

static GdkPixbuf *
gs_plugin_icons_load_stock (GsPlugin *plugin, AsIcon *icon, GError **error)
{
	GsPluginData *priv = gs_plugin_get_data (plugin);
	gint size;
	g_autoptr(GMutexLocker) locker = g_mutex_locker_new (&priv->icon_theme_lock);

	/* required */
	if (as_icon_get_name (icon) == NULL) {
		g_set_error_literal (error,
				     GS_PLUGIN_ERROR,
				     GS_PLUGIN_ERROR_NOT_SUPPORTED,
				     "icon has no name");
		return NULL;
	}
	gs_plugin_icons_add_theme_path (plugin, as_icon_get_prefix (icon));
	size = (gint) (64 * gs_plugin_get_scale (plugin));
	return gtk_icon_theme_load_icon (priv->icon_theme,
					 as_icon_get_name (icon),
					 size,
					 GTK_ICON_LOOKUP_USE_BUILTIN |
					 GTK_ICON_LOOKUP_FORCE_SIZE,
					 error);
}

static GdkPixbuf *
gs_plugin_icons_load_cached (GsPlugin *plugin, AsIcon *icon, GError **error)
{
	if (!as_icon_load (icon, AS_ICON_LOAD_FLAG_SEARCH_SIZE, error))
		return NULL;
	return g_object_ref (as_icon_get_pixbuf (icon));
}

gboolean
gs_plugin_refine_app (GsPlugin *plugin,
		      GsApp *app,
		      GsPluginRefineFlags flags,
		      GCancellable *cancellable,
		      GError **error)
{
	GPtrArray *icons;
	guint i;

	/* not required */
	if ((flags & GS_PLUGIN_REFINE_FLAGS_REQUIRE_ICON) == 0)
		return TRUE;

	/* invalid */
	if (gs_app_get_pixbuf (app) != NULL)
		return TRUE;

	/* process all icons */
	icons = gs_app_get_icons (app);
	for (i = 0; i < icons->len; i++) {
		AsIcon *icon = g_ptr_array_index (icons, i);
		g_autoptr(GdkPixbuf) pixbuf = NULL;
		g_autoptr(GError) error_local = NULL;

		/* handle different icon types */
		switch (as_icon_get_kind (icon)) {
		case AS_ICON_KIND_LOCAL:
			pixbuf = gs_plugin_icons_load_local (plugin, icon, &error_local);
			break;
		case AS_ICON_KIND_STOCK:
			pixbuf = gs_plugin_icons_load_stock (plugin, icon, &error_local);
			break;
		case AS_ICON_KIND_REMOTE:
			pixbuf = gs_plugin_icons_load_remote (plugin, icon, &error_local);
			break;
		case AS_ICON_KIND_CACHED:
			pixbuf = gs_plugin_icons_load_cached (plugin, icon, &error_local);
			break;
		default:
			g_set_error (&error_local,
				     GS_PLUGIN_ERROR,
				     GS_PLUGIN_ERROR_NOT_SUPPORTED,
				     "icon kind '%s' unknown",
				     as_icon_kind_to_string (as_icon_get_kind (icon)));
			break;
		}
		if (pixbuf != NULL) {
			gs_app_set_pixbuf (app, pixbuf);
			break;
		}

		/* we failed, but keep going */
		g_debug ("failed to load icon for %s: %s",
			 gs_app_get_id (app),
			 error_local->message);
	}

	return TRUE;
}
