/*
 * Web view members and methods for "view-source" scheme
 *
 * Copyright (C) 2017  Patrick McDermott
 *
 * This file is part of Marquee.
 *
 * Marquee 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 3 of the License, or
 * (at your option) any later version.
 *
 * Marquee 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 Marquee.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "schemes.h"

#include <inttypes.h>
#include <string.h>

#include <glib.h>
#include <webkit2/webkit2.h>

#include "../application.h"
#include "../config.h"
#include "../string-utils.h"
#include "../tab-page.h"
#include "../web-view.h"

static gboolean
match_uri(const gchar *uri)
{
	return uri && g_str_has_prefix(uri, "view-source:");
}

static void
initialize(MqWebView *web_view, MqWebViewScheme *scheme, const gchar *uri)
{
	MqTabPage *origin_tab;

	/* TODO: Handle "view-source:URI" URIs. */
	g_assert(g_str_has_prefix(uri, "view-source:origin-tab="));

	/* Parse origin tab ID out of URI. */
	uri += strlen("view-source:origin-tab=");
	scheme->view_source.origin_tab_id = atoi64(uri);

	/* Look up origin tab. */
	origin_tab = mq_application_get_tab(mq_tab_page_get_application(
			mq_web_view_get_tab_page(web_view)),
			scheme->view_source.origin_tab_id);

	/* Get origin tab's URI. */
	scheme->view_source.uri = mq_web_view_get_uri(
		mq_tab_page_get_web_view(origin_tab));
}

static void
finalize(MqWebViewScheme *scheme)
{
	memset(&scheme->view_source, 0, sizeof(scheme->view_source));
}

static gchar *
rewrite_uri(MqWebView G_GNUC_UNUSED *web_view, MqWebViewScheme *scheme,
	const gchar G_GNUC_UNUSED *uri)
{
	/* TODO: Handle reloads and missing origin tab IDs (i.e. user loaded
	 * "view-source:URI"). */
	return g_strdup_printf("view-source:origin-tab=%" PRId64,
		scheme->view_source.origin_tab_id);
}

static gchar *
display_uri(MqWebView G_GNUC_UNUSED *web_view, MqWebViewScheme *scheme,
	const gchar G_GNUC_UNUSED *uri)
{
	return g_strdup_printf("view-source:%s", scheme->view_source.uri);
}

#define WKCMA(ACTION) \
	WEBKIT_CONTEXT_MENU_ACTION_##ACTION

#define ITEM_DECLS \
	GtkAction             *action; \
	WebKitContextMenuItem *menu_item;
#define ITEM_DECLS_NO_CUSTOM \
	WebKitContextMenuItem *menu_item;
#define NEW_CUSTOM_ITEM(NAME, LABEL) \
	G_STMT_START { \
		/* Don't blame me; blame WebKitGTK+ for using GtkAction. */ \
		G_GNUC_BEGIN_IGNORE_DEPRECATIONS \
		action = gtk_action_new(#NAME, (LABEL), NULL, NULL); \
		G_GNUC_END_IGNORE_DEPRECATIONS \
		g_signal_connect(action, "activate", \
			G_CALLBACK(menu_##NAME##_activate_cb), web_view); \
		menu_item = webkit_context_menu_item_new(action); \
		webkit_context_menu_append(context_menu, menu_item); \
	} G_STMT_END
#define NEW_STOCK_ITEM(STOCK) \
	G_STMT_START { \
		menu_item = webkit_context_menu_item_new_from_stock_action( \
			WEBKIT_CONTEXT_MENU_ACTION_##STOCK); \
		webkit_context_menu_append(context_menu, menu_item); \
	} G_STMT_END
#define NEW_SEPARATOR_ITEM() \
	G_STMT_START { \
		webkit_context_menu_append(context_menu, \
			webkit_context_menu_item_new_separator()); \
	} G_STMT_END
#define RESTORE_ITEMS(ITEMS) \
	G_STMT_START { \
		for (; ITEMS; ITEMS = ITEMS->next) { \
			webkit_context_menu_append(context_menu, ITEMS->data); \
			g_object_unref(ITEMS->data); \
		} \
	} G_STMT_END

static void
context_menu_document_cb(WebKitContextMenu *context_menu, GList *nav_items,
	MqWebView G_GNUC_UNUSED *web_view)
{
	ITEM_DECLS_NO_CUSTOM

	RESTORE_ITEMS(nav_items);    /* _Back, _Forward, _Stop, _Reload */
	NEW_SEPARATOR_ITEM();        /* --- */
	NEW_STOCK_ITEM(SELECT_ALL);  /* Select _All */
	NEW_SEPARATOR_ITEM();        /* --- */
}

#define PRESERVE_ITEM(ITEMS) \
	G_STMT_START { \
		g_object_ref(items->data); \
		ITEMS = g_list_prepend(ITEMS, items->data); \
	} G_STMT_END

static gboolean
context_menu(MqWebView *web_view, MqWebViewScheme G_GNUC_UNUSED *scheme,
	WebKitContextMenu *context_menu, GdkEvent G_GNUC_UNUSED *event,
	WebKitHitTestResult *hit_test_result)
{
	GList                      *items;
	GList                      *nav_items;
	GList                      *edit_items;
	gboolean                    is_selection;
	WebKitContextMenuAction     stock_action;
	WebKitHitTestResultContext  context;
	gboolean                    context_handled;
	WebKitContextMenuItem      *menu_item;

	/* Get more hints about the context, since WebKit doesn't describe
	 * context very well in hit test results.  Also, preserve menu items
	 * that aren't easy to reproduce (e.g. the Unicode menu and spelling
	 * guesses). */
	items = webkit_context_menu_get_items(context_menu);
	nav_items          = NULL;
	edit_items         = NULL;
	is_selection = FALSE;
	for (; items; items = items->next) {
		stock_action = webkit_context_menu_item_get_stock_action(
			items->data);
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wswitch"
		switch (stock_action) {
			case WKCMA(GO_BACK):
			case WKCMA(GO_FORWARD):
			case WKCMA(STOP):
			case WKCMA(RELOAD):
				PRESERVE_ITEM(nav_items);
				break;
			case WKCMA(COPY):
				PRESERVE_ITEM(edit_items);
				is_selection = TRUE;
				break;
		}
#pragma GCC diagnostic pop
	}
	nav_items  = g_list_reverse(nav_items);
	edit_items = g_list_reverse(edit_items);

	/* Clear the menu. */
	webkit_context_menu_remove_all(context_menu);

	/* Get the reported context (which isn't very descriptive) and save the
	 * hit test result for use by action callbacks. */
	context = webkit_hit_test_result_get_context(hit_test_result);
	if (scheme->normal.hit_test_result) {
		g_object_unref(scheme->normal.hit_test_result);
	}
	scheme->normal.hit_test_result = hit_test_result;
	g_object_ref(scheme->normal.hit_test_result);
	context_handled = FALSE;

	/* Build the context menu. */
	if (context & WEBKIT_HIT_TEST_RESULT_CONTEXT_DOCUMENT) {
		if (is_selection) {
			RESTORE_ITEMS(edit_items);  /* _Copy */
			context_handled = TRUE;
		} else {
			context_menu_document_cb(context_menu, nav_items,
				web_view);
			context_handled = TRUE;
		}
		if (context_handled) {
			NEW_SEPARATOR_ITEM();
		}
		NEW_STOCK_ITEM(INSPECT_ELEMENT);  /* Inspect Element */
	}

	/* Propagate the event further and show the context menu. */
	return FALSE;
}

static void
save_file(MqWebView *web_view, MqWebViewScheme *scheme)
{
	/* TODO: Stub */
	mq_web_view_get_scheme(web_view);
	*scheme = *scheme;
}

MqWebViewSchemeMethods mq_web_view_view_source_scheme_methods = {
	.match_uri    = match_uri,
	.initialize   = initialize,
	.finalize     = finalize,
	.rewrite_uri  = rewrite_uri,
	.display_uri  = display_uri,
	.context_menu = context_menu,
	.save_file    = save_file,
};