/*
 Copyright (C) 2008 Christian Dywan <christian@twotoasts.de>
 Copyright (C) 2008-2010 Arno Renevier <arno@renevier.net>

 This library 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.

 See the file COPYING for the full license text.
*/

/* This extensions add support for user addons: userscripts and userstyles */

#include <midori/midori.h>
#include <midori/sokoke.h>
#include <glib.h>
#include <glib/gstdio.h>

#include "config.h"

#if HAVE_UNISTD_H
    #include <unistd.h>
#endif

#ifndef X_OK
    #define X_OK 1
#endif

typedef enum
{
    ADDON_NONE,
    ADDONS_USER_SCRIPTS,
    ADDONS_USER_STYLES
} AddonsKind;

#define ADDONS_TYPE \
    (addons_get_type ())
#define ADDONS(obj) \
    (G_TYPE_CHECK_INSTANCE_CAST ((obj), ADDONS_TYPE, Addons))
#define ADDONS_CLASS(klass) \
    (G_TYPE_CHECK_CLASS_CAST ((klass), ADDONS_TYPE, AddonsClass))
#define IS_ADDONS(obj) \
    (G_TYPE_CHECK_INSTANCE_TYPE ((obj), ADDONS_TYPE))
#define IS_ADDONS_CLASS(klass) \
    (G_TYPE_CHECK_CLASS_TYPE ((klass), ADDONS_TYPE))
#define ADDONS_GET_CLASS(obj) \
    (G_TYPE_INSTANCE_GET_CLASS ((obj), ADDONS_TYPE, AddonsClass))

typedef struct _Addons                Addons;
typedef struct _AddonsClass           AddonsClass;

struct _AddonsClass
{
    GtkVBoxClass parent_class;
};

struct _Addons
{
    GtkVBox parent_instance;

    GtkWidget* toolbar;
    GtkWidget* treeview;

    AddonsKind kind;
};

static void
addons_iface_init (MidoriViewableIface* iface);

G_DEFINE_TYPE_WITH_CODE (Addons, addons, GTK_TYPE_VBOX,
                         G_IMPLEMENT_INTERFACE (MIDORI_TYPE_VIEWABLE,
                             addons_iface_init));

struct AddonElement
{
    gchar* fullpath;
    gchar* displayname;
    gchar* description;
    gchar* script_content;

    gboolean enabled;
    gboolean broken;

    GSList* includes;
    GSList* excludes;
};

struct AddonsList
{
    GtkListStore* liststore;
    GSList* elements;
};

static void
midori_addons_button_add_clicked_cb (GtkToolItem* toolitem,
                                     Addons*      addons)
{
    gchar* addons_type;
    gchar* path;
    GtkWidget* dialog;

    if (addons->kind == ADDONS_USER_SCRIPTS)
    {
        addons_type = g_strdup ("userscripts");
        path = g_build_path (G_DIR_SEPARATOR_S, g_get_user_data_dir (),
                             PACKAGE_NAME, "scripts", NULL);
    }
    else if (addons->kind == ADDONS_USER_STYLES)
    {
        addons_type = g_strdup ("userstyles");
        path = g_build_path (G_DIR_SEPARATOR_S, g_get_user_data_dir (),
                             PACKAGE_NAME, "styles", NULL);
    }
    else
        g_assert_not_reached ();

    dialog = gtk_message_dialog_new (
        GTK_WINDOW (gtk_widget_get_toplevel (GTK_WIDGET (addons))),
        GTK_DIALOG_DESTROY_WITH_PARENT,
        GTK_MESSAGE_INFO, GTK_BUTTONS_CLOSE,
        _("Copy %s to the folder %s."), addons_type, path);
    g_free (addons_type);
    g_free (path);
    gtk_dialog_run (GTK_DIALOG (dialog));
    gtk_widget_destroy (dialog);
}

GtkWidget*
addons_get_toolbar (MidoriViewable* viewable)
{
    GtkWidget* toolbar;
    GtkToolItem* toolitem;

    g_return_val_if_fail (IS_ADDONS (viewable), NULL);

    if (!ADDONS (viewable)->toolbar)
    {
        toolbar = gtk_toolbar_new ();
        gtk_toolbar_set_style (GTK_TOOLBAR (toolbar), GTK_TOOLBAR_BOTH_HORIZ);
        gtk_toolbar_set_icon_size (GTK_TOOLBAR (toolbar), GTK_ICON_SIZE_BUTTON);
        toolitem = gtk_tool_item_new ();
        gtk_toolbar_insert (GTK_TOOLBAR (toolbar), toolitem, -1);
        gtk_widget_show (GTK_WIDGET (toolitem));

        /* separator */
        toolitem = gtk_separator_tool_item_new ();
        gtk_separator_tool_item_set_draw (GTK_SEPARATOR_TOOL_ITEM (toolitem),
                                          FALSE);
        gtk_tool_item_set_expand (toolitem, TRUE);
        gtk_toolbar_insert (GTK_TOOLBAR (toolbar), toolitem, -1);
        gtk_widget_show (GTK_WIDGET (toolitem));

        /* add button */
        toolitem = gtk_tool_button_new_from_stock (GTK_STOCK_ADD);
        gtk_tool_item_set_is_important (toolitem, TRUE);
        g_signal_connect (toolitem, "clicked",
            G_CALLBACK (midori_addons_button_add_clicked_cb), viewable);
        gtk_toolbar_insert (GTK_TOOLBAR (toolbar), toolitem, -1);

        gtk_widget_show (GTK_WIDGET (toolitem));
        ADDONS (viewable)->toolbar = toolbar;

        g_signal_connect (toolbar, "destroy",
                          G_CALLBACK (gtk_widget_destroyed),
                          &ADDONS (viewable)->toolbar);
    }

    return ADDONS (viewable)->toolbar;
}

static const gchar*
addons_get_label (MidoriViewable* viewable)
{
    Addons* addons = ADDONS (viewable);
    if (addons->kind == ADDONS_USER_SCRIPTS)
        return _("Userscripts");
    else if (addons->kind == ADDONS_USER_STYLES)
        return _("Userstyles");
    return NULL;
}

static const gchar*
addons_get_stock_id (MidoriViewable* viewable)
{
    Addons* addons = ADDONS (viewable);
    if (addons->kind == ADDONS_USER_SCRIPTS)
        return STOCK_SCRIPT;
    else if (addons->kind == ADDONS_USER_STYLES)
        return STOCK_STYLE;
    return NULL;
}

static void
addons_iface_init (MidoriViewableIface* iface)
{
    iface->get_stock_id = addons_get_stock_id;
    iface->get_label = addons_get_label;
    iface->get_toolbar = addons_get_toolbar;
}

static void
addons_free_elements (GSList* elements)
{
    struct AddonElement* element;
    GSList* start = elements;

    while (elements)
    {
        element = elements->data;
        g_free (element->fullpath);
        g_free (element->displayname);
        g_free (element->description);
        g_free (element->script_content);
        g_slist_free (element->includes);
        g_slist_free (element->excludes);

        elements = g_slist_next (elements);
    }

    g_slist_free (start);
}

static void
addons_class_init (AddonsClass* class)
{
}

static void
addons_treeview_render_tick_cb (GtkTreeViewColumn* column,
                                GtkCellRenderer*   renderer,
                                GtkTreeModel*      model,
                                GtkTreeIter*       iter,
                                GtkWidget*         treeview)
{
    struct AddonElement *element;

    gtk_tree_model_get (model, iter, 0, &element, -1);

    g_object_set (renderer,
                  "active", element->enabled,
                  "sensitive", !element->broken,
                  NULL);
}

static void
addons_cell_renderer_toggled_cb (GtkCellRendererToggle* renderer,
                                 const gchar*           path,
                                 Addons*                addons)
{
    GtkTreeModel* model;
    GtkTreeIter iter;

    model = gtk_tree_view_get_model (GTK_TREE_VIEW (addons->treeview));
    if (gtk_tree_model_get_iter_from_string (model, &iter, path))
    {
        struct AddonElement *element;
        GtkTreePath* tree_path;

        gtk_tree_model_get (model, &iter, 0, &element, -1);

        element->enabled = !element->enabled;

        /* After enabling or disabling an element, the tree view
           is not updated automatically; we need to notify tree model
           in order to take the modification into account */
        tree_path = gtk_tree_path_new_from_string (path);
        gtk_tree_model_row_changed (model, tree_path, &iter);
        gtk_tree_path_free (tree_path);
    }
}

static void
addons_treeview_render_text_cb (GtkTreeViewColumn* column,
                                GtkCellRenderer*   renderer,
                                GtkTreeModel*      model,
                                GtkTreeIter*       iter,
                                GtkWidget*         treeview)
{
    struct AddonElement *element;

    gtk_tree_model_get (model, iter, 0, &element, -1);

    g_object_set (renderer, "text", element->displayname, NULL);
    if (!element->enabled)
        g_object_set (renderer, "sensitive", false, NULL);
    else
        g_object_set (renderer, "sensitive", true, NULL);
}

static void
addons_treeview_row_activated_cb (GtkTreeView*       treeview,
                                  GtkTreePath*       path,
                                  GtkTreeViewColumn* column,
                                  Addons*            addons)
{
    GtkTreeModel* model = gtk_tree_view_get_model (treeview);
    GtkTreeIter iter;
    if (gtk_tree_model_get_iter (model, &iter, path))
    {
        struct AddonElement *element;

        gtk_tree_model_get (model, &iter, 0, &element, -1);

        element->enabled = !element->enabled;

        /* After enabling or disabling an element, the tree view
           is not updated automatically; we need to notify tree model
           in order to take the modification into account */
        gtk_tree_model_row_changed (model, path, &iter);
    }
}

static GSList*
addons_get_directories (AddonsKind kind)
{
    gchar* folder_name;
    GSList* directories;
    const char* const* datadirs;
    gchar* path;

    g_assert (kind == ADDONS_USER_SCRIPTS || kind == ADDONS_USER_STYLES);

    directories = NULL;
    if (kind == ADDONS_USER_SCRIPTS)
        folder_name = g_strdup ("scripts");
    else if (kind == ADDONS_USER_STYLES)
        folder_name = g_strdup ("styles");
    else
        g_assert_not_reached ();

    path = g_build_path (G_DIR_SEPARATOR_S, g_get_user_data_dir (),
                         PACKAGE_NAME, folder_name, NULL);
    if (g_access (path, X_OK) == 0)
        directories = g_slist_prepend (directories, path);
    else
        g_free (path);

    datadirs = g_get_system_data_dirs ();
    while (*datadirs)
    {
        path = g_build_path (G_DIR_SEPARATOR_S, *datadirs,
                             PACKAGE_NAME, folder_name, NULL);
        if (g_access (path, X_OK) == 0)
            directories = g_slist_prepend (directories, path);
        else
            g_free (path);
        datadirs++;
    }

    g_free (folder_name);

    return directories;
}

static GSList*
addons_get_files (AddonsKind kind)
{
    GSList* files;
    GDir* addon_dir;
    GSList* list;
    GSList* directories;
    const gchar* filename;
    gchar* dirname;
    gchar* fullname;
    gchar* file_extension;

    g_assert (kind == ADDONS_USER_SCRIPTS || kind == ADDONS_USER_STYLES);

    if (kind == ADDONS_USER_SCRIPTS)
        file_extension = g_strdup (".js");
    else if (kind == ADDONS_USER_STYLES)
        file_extension = g_strdup (".css");

    files = NULL;

    directories = addons_get_directories (kind);
    list = directories;
    while (directories)
    {
        dirname = directories->data;
        if ((addon_dir = g_dir_open (dirname, 0, NULL)))
        {
            while ((filename = g_dir_read_name (addon_dir)))
            {
                if (g_str_has_suffix (filename, file_extension))
                {
                    fullname = g_build_filename (dirname, filename, NULL);
                    files = g_slist_prepend (files, fullname);
                }
            }
            g_dir_close (addon_dir);
        }
        g_free (dirname);
        directories = g_slist_next (directories);
    }

    g_slist_free (list);
    g_free (file_extension);

    return files;
}

static gboolean
js_metadata_from_file (const gchar* filename,
                       GSList**     includes,
                       GSList**     excludes,
                       gchar**      name,
                       gchar**      description)
{
    GIOChannel* channel;
    gboolean found_meta;
    gchar* line;
    gchar* rest_of_line;

    if (!g_file_test (filename, G_FILE_TEST_IS_REGULAR | G_FILE_TEST_IS_SYMLINK))
        return FALSE;

    channel = g_io_channel_new_file (filename, "r", 0);
    if (!channel)
        return FALSE;

    found_meta = FALSE;

    while (g_io_channel_read_line (channel, &line, NULL, NULL, NULL)
           == G_IO_STATUS_NORMAL)
    {
        if (g_str_has_prefix (line, "// ==UserScript=="))
            found_meta = TRUE;
        else if (found_meta)
        {
            if (g_str_has_prefix (line, "// ==/UserScript=="))
                found_meta = FALSE;
            else if (g_str_has_prefix (line, "// @require ") ||
                g_str_has_prefix (line, "// @resource "))
            {
                /* We don't support these, so abort here */
                g_free (line);
                g_io_channel_shutdown (channel, false, 0);
                g_slist_free (*includes);
                g_slist_free (*excludes);
                *includes = NULL;
                *excludes = NULL;
                return FALSE;
            }
             else if (includes && g_str_has_prefix (line, "// @include "))
            {
                 rest_of_line = g_strdup (line + strlen ("// @include "));
                 rest_of_line =  g_strstrip (rest_of_line);
                 *includes = g_slist_prepend (*includes, rest_of_line);
            }
             else if (excludes && g_str_has_prefix (line, "// @exclude "))
            {
                 rest_of_line = g_strdup (line + strlen ("// @exclude "));
                 rest_of_line =  g_strstrip (rest_of_line);
                 *excludes = g_slist_prepend (*excludes, rest_of_line);
            }
             else if (name && g_str_has_prefix (line, "// @name "))
            {
                 rest_of_line = g_strdup (line + strlen ("// @name "));
                 rest_of_line =  g_strstrip (rest_of_line);
                 *name = rest_of_line;
            }
             else if (description && g_str_has_prefix (line, "// @description "))
            {
                 rest_of_line = g_strdup (line + strlen ("// @description "));
                 rest_of_line =  g_strstrip (rest_of_line);
                 *description = rest_of_line;
            }
        }
        g_free (line);
    }
    g_io_channel_shutdown (channel, false, 0);
    g_io_channel_unref (channel);

    return TRUE;
}

static gboolean
css_metadata_from_file (const gchar* filename,
                        GSList**     includes,
                        GSList**     excludes)
{
    GIOChannel* channel;
    gchar* line;
    gchar* rest_of_line;

    if (!g_file_test (filename, G_FILE_TEST_IS_REGULAR | G_FILE_TEST_IS_SYMLINK))
        return FALSE;

    channel = g_io_channel_new_file (filename, "r", 0);
    if (!channel)
        return FALSE;

    while (g_io_channel_read_line (channel, &line, NULL, NULL, NULL)
           == G_IO_STATUS_NORMAL)
    {
        if (g_str_has_prefix (line, "@-moz-document"))
        { /* FIXME: We merely look for includes. We should honor blocks. */
             if (includes)
             {
                 gchar** parts;
                 guint i;

                 rest_of_line = g_strdup (line + strlen ("@-moz-document"));
                 rest_of_line = g_strstrip (rest_of_line);
                 parts = g_strsplit (rest_of_line, " ", 0);
                 i = 0;
                 while (parts[i])
                 {
                     gchar* value = NULL;
                     if (g_str_has_prefix (parts[i], "url-prefix("))
                         value = g_strdup (parts[i] + strlen ("url-prefix("));
                     else if (g_str_has_prefix (parts[i], "url("))
                         value = g_strdup (parts[i] + strlen ("url("));
                    if (value)
                    {
                         guint j;

                         if (value[0] != '\'' && value[0] != '"')
                         {
                             /* Wrong syntax, abort */
                             g_free (value);
                             g_strfreev (parts);
                             g_free (line);
                             g_io_channel_shutdown (channel, false, 0);
                             g_slist_free (*includes);
                             g_slist_free (*excludes);
                             *includes = NULL;
                             *excludes = NULL;
                             return FALSE;
                         }
                         j = 1;
                         while (value[j] != '\0')
                         {
                             if (value[j] == value[0])
                                 break;
                             j++;
                         }
                         *includes = g_slist_prepend (*includes, g_strndup (value + 1, j - 1));
                         g_free (value);
                    }

                    /* FIXME: Recognize "domain" */
                    i++;
                 }
                 g_strfreev (parts);
             }
        }
        g_free (line);
    }
    g_io_channel_shutdown (channel, false, 0);
    g_io_channel_unref (channel);

    return TRUE;
}

static gboolean
addons_get_element_content (gchar*     file_path,
                            AddonsKind kind,
                            gchar**    content)
{
    gchar* file_content;
    guint meta;
    guint i, n;

    g_assert (kind == ADDONS_USER_SCRIPTS || kind == ADDONS_USER_STYLES);

    if (g_file_get_contents (file_path, &file_content, NULL, NULL))
    {
        if (kind == ADDONS_USER_SCRIPTS)
        {
            *content = g_strdup_printf (
                "window.addEventListener ('DOMContentLoaded',"
                "function () { %s }, true);", file_content);
        }
        else if (kind == ADDONS_USER_STYLES)
        {
            meta = 0;
            n = strlen (file_content);
            for (i = 0; i < n; i++)
            {
                /* Replace line breaks with spaces */
                if (file_content[i] == '\n' || file_content[i] == '\r')
                    file_content[i] = ' ';
                /* Change all single quotes to double quotes */
                if (file_content[i] == '\'')
                    file_content[i] = '\"';
                /* Turn metadata we inspected earlier into comments */
                if (!meta && file_content[i] == '@')
                {
                    file_content[i] = '/';
                    meta++;
                }
                else if (meta == 1
                    && (file_content[i] == '-' || file_content[i] == 'n'))
                {
                    file_content[i] = '*';
                    meta++;
                }
                else if (meta == 2 && file_content[i] == '{')
                {
                    file_content[i - 1] = '*';
                    file_content[i] = '/';
                    meta++;
                }
                else if (meta == 3 && file_content[i] == '{')
                    meta++;
                else if (meta == 4 && file_content[i] == '}')
                    meta--;
                else if (meta == 3 && file_content[i] == '}')
                {
                    file_content[i] = ' ';
                    meta = 0;
                }
            }

            *content = g_strdup_printf (
                "window.addEventListener ('DOMContentLoaded',"
                "function () {"
                "var mystyle = document.createElement(\"style\");"
                "mystyle.setAttribute(\"type\", \"text/css\");"
                "mystyle.appendChild(document.createTextNode('%s'));"
                "var head = document.getElementsByTagName(\"head\")[0];"
                "if (head) head.appendChild(mystyle);"
                "else document.documentElement.insertBefore"
                "(mystyle, document.documentElement.firstChild);"
                "}, true);",
                file_content);

        }
        g_free (file_content);
        if (*content)
            return TRUE;
    }
    return FALSE;
}

static void
addons_update_elements (MidoriExtension* extension,
                        AddonsKind       kind)
{
    GSList* addon_files;
    GSList* files_list;
    gchar* name;
    gchar* fullpath;
    struct AddonElement* element;
    struct AddonsList* addons_list;
    GSList* elements = NULL;
    GtkListStore* liststore = NULL;
    GtkTreeIter iter;
    gchar* config_file;
    GKeyFile* keyfile;

    if (kind == ADDONS_USER_SCRIPTS)
        addons_list = g_object_get_data (G_OBJECT (extension), "scripts-list");
    else if (kind == ADDONS_USER_STYLES)
        addons_list = g_object_get_data (G_OBJECT (extension), "styles-list");
    else
        g_assert_not_reached ();

    if (addons_list)
    {
        liststore = addons_list->liststore;
        elements = addons_list->elements;
    }

    if (elements)
        addons_free_elements (elements);

    if (liststore)
        gtk_list_store_clear (liststore);
    else
        liststore = gtk_list_store_new (3, G_TYPE_POINTER,
                                        G_TYPE_INT,
                                        G_TYPE_STRING);

    keyfile = g_key_file_new ();
    config_file = g_build_filename (midori_extension_get_config_dir (extension),
                                    "addons", NULL);
    g_key_file_load_from_file (keyfile, config_file, G_KEY_FILE_NONE, NULL);

    addon_files = addons_get_files (kind);
    files_list = addon_files;

    elements = NULL;
    while (addon_files)
    {
        fullpath = addon_files->data;
        element = g_new (struct AddonElement, 1);
        element->displayname = g_filename_display_basename (fullpath);
        element->fullpath = fullpath;
        element->enabled = TRUE;
        element->broken = FALSE;
        element->includes = NULL;
        element->excludes = NULL;
        element->description = NULL;
        element->script_content = NULL;

        if (kind == ADDONS_USER_SCRIPTS)
        {
            name = NULL;
            if (!js_metadata_from_file (fullpath,
                                        &element->includes, &element->excludes,
                                        &name, &element->description))
                element->broken = TRUE;

            if (name)
                katze_assign (element->displayname, name);

            if (!element->broken)
                if (!addons_get_element_content (fullpath, kind,
                                                 &(element->script_content)))
                    element->broken = TRUE;

            if (g_key_file_get_integer (keyfile, "scripts", fullpath, NULL) & 1)
                element->enabled = FALSE;
        }
        else if (kind == ADDONS_USER_STYLES)
        {
            if (!css_metadata_from_file (fullpath,
                                         &element->includes,
                                         &element->excludes))
                element->broken = TRUE;

            if (!element->broken)
                if (!addons_get_element_content (fullpath, kind,
                                                 &(element->script_content)))
                    element->broken = TRUE;

            if (g_key_file_get_integer (keyfile, "styles", fullpath, NULL) & 1)
                element->enabled = FALSE;
        }

        gtk_list_store_append (liststore, &iter);
        gtk_list_store_set (liststore, &iter,
                0, element, 1, 0, 2, "", -1);

        addon_files = g_slist_next (addon_files);
        elements = g_slist_prepend (elements, element);
    }
    g_slist_free (files_list);
    g_free (config_file);
    g_key_file_free (keyfile);

    if (addons_list)
        g_free (addons_list);
    addons_list = g_new (struct AddonsList, 1);
    addons_list->elements = elements;
    addons_list->liststore = liststore;

    if (kind == ADDONS_USER_SCRIPTS)
        g_object_set_data (G_OBJECT (extension), "scripts-list", addons_list);
    else if (kind == ADDONS_USER_STYLES)
        g_object_set_data (G_OBJECT (extension), "styles-list", addons_list);
}

static void
addons_init (Addons* addons)
{
    GtkTreeViewColumn* column;
    GtkCellRenderer* renderer_text;
    GtkCellRenderer* renderer_toggle;

    addons->treeview = gtk_tree_view_new ();
    gtk_tree_view_set_headers_visible (GTK_TREE_VIEW (addons->treeview), FALSE);
    column = gtk_tree_view_column_new ();
    renderer_toggle = gtk_cell_renderer_toggle_new ();
    gtk_tree_view_column_pack_start (column, renderer_toggle, FALSE);
    gtk_tree_view_column_set_cell_data_func (column, renderer_toggle,
        (GtkTreeCellDataFunc)addons_treeview_render_tick_cb,
        addons->treeview, NULL);
    g_signal_connect (renderer_toggle, "toggled",
        G_CALLBACK (addons_cell_renderer_toggled_cb), addons);
    gtk_tree_view_append_column (GTK_TREE_VIEW (addons->treeview), column);
    column = gtk_tree_view_column_new ();
    renderer_text = gtk_cell_renderer_text_new ();
    gtk_tree_view_column_pack_start (column, renderer_text, FALSE);
    gtk_tree_view_column_set_cell_data_func (column, renderer_text,
        (GtkTreeCellDataFunc)addons_treeview_render_text_cb,
        addons->treeview, NULL);
    gtk_tree_view_append_column (GTK_TREE_VIEW (addons->treeview), column);
    g_signal_connect (addons->treeview, "row-activated",
                      G_CALLBACK (addons_treeview_row_activated_cb),
                      addons);
    gtk_widget_show (addons->treeview);
    gtk_box_pack_start (GTK_BOX (addons), addons->treeview, TRUE, TRUE, 0);
}

static gchar*
addons_convert_to_simple_regexp (const gchar* pattern)
{
    guint len;
    gchar* dest;
    guint pos;
    guint i;
    gchar c;

    len = strlen (pattern);
    dest = g_malloc0 (len * 2 + 1);
    dest[0] = '^';
    pos = 1;

    for (i = 0; i < len; i++)
    {
        c = pattern[i];
        switch (c)
        {
            case '*':
                dest[pos] = '.';
                dest[pos + 1] = c;
                pos++;
                pos++;
                break;
            case '.' :
            case '?' :
            case '^' :
            case '$' :
            case '+' :
            case '{' :
            case '[' :
            case '|' :
            case '(' :
            case ')' :
            case ']' :
            case '\\' :
                dest[pos] = '\\';
                dest[pos + 1] = c;
                pos++;
                pos++;
                break;
            case ' ' :
                break;
            default:
                dest[pos] = pattern[i];
                pos ++;
        }
    }
    return dest;
}

static gboolean
addons_may_run (const gchar* uri,
                GSList**     includes,
                GSList**     excludes)
{
    gboolean match;
    GSList* list;

    if (*includes)
        match = FALSE;
    else
        match = TRUE;

    list = *includes;
    while (list)
    {
        gchar* re = addons_convert_to_simple_regexp (list->data);
        gboolean matched = g_regex_match_simple (re, uri, 0, 0);
        g_free (re);
        if (matched)
        {
            match = TRUE;
            break;
        }
        list = g_slist_next (list);
    }
    if (!match)
        return FALSE;

    list = *excludes;
    while (list)
    {
        gchar* re = addons_convert_to_simple_regexp (list->data);
        gboolean matched = g_regex_match_simple (re, uri, 0, 0);
        g_free (re);
        if (matched)
        {
            match = FALSE;
            break;
        }
        list = g_slist_next (list);
    }
    return match;
}

static gboolean
addons_skip_element (struct AddonElement* element,
                     gchar* uri)
{
    if (!element->enabled || element->broken)
        return TRUE;
    if (element->includes || element->excludes)
        if (!addons_may_run (uri, &element->includes, &element->excludes))
            return TRUE;
    return FALSE;
}

static void
addons_context_ready_cb (WebKitWebView*   web_view,
                         WebKitWebFrame*  web_frame,
                         JSContextRef     js_context,
                         JSObjectRef      js_window,
                         MidoriExtension* extension)
{
    gchar* uri;
    GSList* scripts, *styles;
    struct AddonElement* script, *style;
    struct AddonsList* scripts_list, *styles_list;
    uri = katze_object_get_string (web_view, "uri");
    /* Don't run scripts or styles on blank or special pages */
    if (!(uri && *uri && strncmp (uri, "about:", 6)))
    {
        g_free (uri);
        return;
    }

    scripts_list = g_object_get_data (G_OBJECT (extension), "scripts-list");
    scripts = scripts_list->elements;
    while (scripts)
    {
        script = scripts->data;
        if (addons_skip_element (script, uri))
        {
            scripts = g_slist_next (scripts);
            continue;
        }
        if (script->script_content)
            webkit_web_view_execute_script (web_view, script->script_content);
        scripts = g_slist_next (scripts);
    }

    styles_list = g_object_get_data (G_OBJECT (extension), "styles-list");
    styles = styles_list->elements;
    while (styles)
    {
        style = styles->data;
        if (addons_skip_element (style, uri))
        {
            styles = g_slist_next (styles);
            continue;
        }
        if (style->script_content)
            webkit_web_view_execute_script (web_view, style->script_content);
        styles = g_slist_next (styles);
    }
}

static void
addons_add_tab_cb (MidoriBrowser* browser,
                   MidoriView*  view,
                   MidoriExtension* extension)
{
    GtkWidget* web_view = midori_view_get_web_view (view);
    g_signal_connect (web_view, "window-object-cleared",
        G_CALLBACK (addons_context_ready_cb), extension);
}

static void
addons_add_tab_foreach_cb (MidoriView*      view,
                           MidoriBrowser*   browser,
                           MidoriExtension* extension)
{
    addons_add_tab_cb (browser, view, extension);
}

static void
addons_deactivate_tabs (MidoriView*      view,
                        MidoriExtension* extension)
{
    GtkWidget* web_view = midori_view_get_web_view (view);
    g_signal_handlers_disconnect_by_func (
        web_view, addons_context_ready_cb, extension);
}

static void
addons_browser_destroy (MidoriBrowser*   browser,
                        MidoriExtension* extension)
{
    GtkWidget* scripts, *styles;

    midori_browser_foreach (browser, (GtkCallback)addons_deactivate_tabs, extension);
    g_signal_handlers_disconnect_by_func (browser, addons_add_tab_cb, extension);

    scripts = (GtkWidget*)g_object_get_data (G_OBJECT (browser), "scripts-addons");
    gtk_widget_destroy (scripts);
    styles = (GtkWidget*)g_object_get_data (G_OBJECT (browser), "styles-addons");
    gtk_widget_destroy (styles);
}

GtkWidget*
addons_new (AddonsKind kind, MidoriExtension* extension)
{
    GtkWidget* addons;
    GtkListStore* liststore;
    struct AddonsList* list;

    addons = g_object_new (ADDONS_TYPE, NULL);
    ADDONS (addons)->kind = kind;

    if (kind == ADDONS_USER_SCRIPTS)
        list = g_object_get_data (G_OBJECT (extension), "scripts-list");
    else if (kind == ADDONS_USER_STYLES)
        list = g_object_get_data (G_OBJECT (extension), "styles-list");
    else
        g_assert_not_reached ();

    liststore = list->liststore;
    gtk_tree_view_set_model (GTK_TREE_VIEW (ADDONS(addons)->treeview),
                             GTK_TREE_MODEL (liststore));
    gtk_widget_queue_draw (GTK_WIDGET (ADDONS(addons)->treeview));

    return addons;
}

static void
addons_app_add_browser_cb (MidoriApp*       app,
                           MidoriBrowser*   browser,
                           MidoriExtension* extension)
{
    GtkWidget* panel;
    GtkWidget* scripts, *styles;

    midori_browser_foreach (browser,
          (GtkCallback)addons_add_tab_foreach_cb, extension);
    g_signal_connect (browser, "add-tab",
        G_CALLBACK (addons_add_tab_cb), extension);
    panel = katze_object_get_object (browser, "panel");

    scripts = addons_new (ADDONS_USER_SCRIPTS, extension);
    gtk_widget_show (scripts);
    midori_panel_append_page (MIDORI_PANEL (panel), MIDORI_VIEWABLE (scripts));
    g_object_set_data (G_OBJECT (browser), "scripts-addons", scripts);

    styles = addons_new (ADDONS_USER_STYLES, extension);
    gtk_widget_show (styles);
    midori_panel_append_page (MIDORI_PANEL (panel), MIDORI_VIEWABLE (styles));
    g_object_set_data (G_OBJECT (browser), "styles-addons", styles);

    g_object_unref (panel);
}

static void
addons_save_settings (MidoriApp*       app,
                      MidoriExtension* extension)
{
    struct AddonsList* scripts_list, *styles_list;
    struct AddonElement* script, *style;
    GSList* scripts, *styles;
    GKeyFile* keyfile;
    const gchar* config_dir;
    gchar* config_file;
    GError* error = NULL;

    keyfile = g_key_file_new ();

    /* scripts */
    scripts_list = g_object_get_data (G_OBJECT (extension), "scripts-list");
    scripts = scripts_list->elements;
    while (scripts)
    {
        script = scripts->data;
        if (!script->enabled)
            g_key_file_set_integer (keyfile, "scripts", script->fullpath, 1);
        scripts = g_slist_next (scripts);
    }

    /* styles */
    styles_list = g_object_get_data (G_OBJECT (extension), "styles-list");
    styles = styles_list->elements;
    while (styles)
    {
        style = styles->data;
        if (!style->enabled)
            g_key_file_set_integer (keyfile, "styles", style->fullpath, 1);
        styles = g_slist_next (styles);
    }

    config_dir = midori_extension_get_config_dir (extension);
    config_file = g_build_filename (config_dir, "addons", NULL);
    katze_mkdir_with_parents (config_dir, 0700);
    sokoke_key_file_save_to_file (keyfile, config_file, &error);
    if (error)
    {
        g_warning (_("The configuration of the extension '%s' couldn't be saved: %s\n"),
                    _("User addons"), error->message);
        g_error_free (error);
    }

    g_free (config_file);
    g_key_file_free (keyfile);
}

static void
addons_disable_monitors (MidoriExtension* extension)
{
    GSList* monitors;

    monitors = g_object_get_data (G_OBJECT (extension), "monitors");
    if (!monitors)
        return;

    g_slist_foreach (monitors, (GFunc)g_file_monitor_cancel, NULL);
    g_slist_free (monitors);
    g_object_set_data (G_OBJECT (extension), "monitors", NULL);
}

static void
addons_deactivate_cb (MidoriExtension* extension,
                      MidoriApp*   app)
{
    KatzeArray* browsers;
    MidoriBrowser* browser;
    GSource* source;
    guint i = 0;

    addons_disable_monitors (extension);
    addons_save_settings (NULL, extension);

    browsers = katze_object_get_object (app, "browsers");
    while ((browser = katze_array_get_nth_item (browsers, i++)))
        addons_browser_destroy (browser, extension);

    source = g_object_get_data (G_OBJECT (extension), "monitor-timer");
    if (source && !g_source_is_destroyed (source))
        g_source_destroy (source);

    g_signal_handlers_disconnect_by_func (
          app, addons_app_add_browser_cb, extension);
    g_signal_handlers_disconnect_by_func (
          app, addons_save_settings, extension);
    g_signal_handlers_disconnect_by_func (
          extension, addons_deactivate_cb, app);

    g_object_unref (browsers);
}

static gboolean
addons_reset_all_elements_cb (MidoriExtension* extension)
{
    addons_save_settings (NULL, extension);
    addons_update_elements (extension, ADDONS_USER_STYLES);
    addons_update_elements (extension, ADDONS_USER_SCRIPTS);
    g_object_set_data (G_OBJECT (extension), "monitor-timer", NULL);
    return FALSE;
}

static void
addons_directory_monitor_changed (GFileMonitor*     monitor,
                                  GFile*            child,
                                  GFile*            other_file,
                                  GFileMonitorEvent flags,
                                  MidoriExtension*  extension)
{
    char* basename;
    GSource* source;

    basename = g_file_get_basename (child);
    if (g_str_has_prefix (basename, ".") ||
        g_str_has_suffix (basename, "~")) /* Hidden or temporary files */
        return;

    /* We receive a lot of change events, so we use a timeout to trigger
       elements update only once */
    source = g_object_get_data (G_OBJECT (extension), "monitor-timer");
    if (source && !g_source_is_destroyed (source))
        g_source_destroy (source);

    source = g_timeout_source_new_seconds (1);
    g_source_set_callback (source, (GSourceFunc)addons_reset_all_elements_cb,
                           extension, NULL);
    g_source_attach (source, NULL);
    g_object_set_data (G_OBJECT (extension), "monitor-timer", source);
    g_source_unref (source);
}

static void
addons_monitor_directories (MidoriExtension* extension,
                            AddonsKind kind)
{
    GSList* directories;
    GSList* list;
    GError* error;
    GSList* monitors;
    GFileMonitor* monitor;
    GFile* directory;

    g_assert (kind == ADDONS_USER_SCRIPTS || kind == ADDONS_USER_STYLES);

    monitors = g_object_get_data (G_OBJECT (extension), "monitors");

    directories = addons_get_directories (kind);
    list = directories;
    while (directories)
    {
        directory = g_file_new_for_path (directories->data);
        directories = g_slist_next (directories);
        error = NULL;
        monitor = g_file_monitor_directory (directory,
                                            G_FILE_MONITOR_NONE,
                                            NULL, &error);
        if (monitor)
        {
            g_signal_connect (monitor, "changed",
                G_CALLBACK (addons_directory_monitor_changed), extension);
            monitors = g_slist_prepend (monitors, monitor);
        }
        else
        {
            g_warning (_("Can't monitor folder '%s': %s"),
                       g_file_get_parse_name (directory), error->message);
            g_error_free (error);
        }
        g_object_unref (directory);
    }
    g_object_set_data (G_OBJECT (extension), "monitors", monitors);
    g_slist_free (directories);
}

static void
addons_activate_cb (MidoriExtension* extension,
                    MidoriApp*       app)
{
    KatzeArray* browsers;
    MidoriBrowser* browser;
    guint i;

    browsers = katze_object_get_object (app, "browsers");
    addons_update_elements (extension, ADDONS_USER_STYLES);
    addons_monitor_directories (extension, ADDONS_USER_STYLES);
    addons_update_elements (extension, ADDONS_USER_SCRIPTS);
    addons_monitor_directories (extension, ADDONS_USER_STYLES);

    i = 0;
    while ((browser = katze_array_get_nth_item (browsers, i++)))
        addons_app_add_browser_cb (app, browser, extension);
    g_object_unref (browsers);

    g_signal_connect (app, "add-browser",
        G_CALLBACK (addons_app_add_browser_cb), extension);

    g_signal_connect (app, "quit",
        G_CALLBACK (addons_save_settings), extension);

    g_signal_connect (extension, "deactivate",
        G_CALLBACK (addons_deactivate_cb), app);
}

MidoriExtension*
extension_init (void)
{
    MidoriExtension* extension = g_object_new (MIDORI_TYPE_EXTENSION,
        "name", _("User addons"),
        "description", _("Support for userscripts and userstyles"),
        "version", "0.1",
        "authors", "Arno Renevier <arno@renevier.net>",
        NULL);
    g_signal_connect (extension, "activate",
        G_CALLBACK (addons_activate_cb), NULL);

    return extension;
}
