//
//  Copyright (C) 2014 Tom Beckmann
//
//  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 3 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, see <http://www.gnu.org/licenses/>.
//

using Clutter;
using Meta;

namespace Gala.Plugins.Notify {
    /**
     * Wrapper class only containing the summary and body label. Allows us to
     * instantiate the content very easily for when we need to slide the old
     * and new content down.
     */
    class NormalNotificationContent : Actor {
        static Regex entity_regex;
        static Regex tag_regex;

        static construct {
            try {
                entity_regex = new Regex ("&(?!amp;|quot;|apos;|lt;|gt;)");
                tag_regex = new Regex ("<(?!\\/?[biu]>)");
            } catch (Error e) {}
        }

        const int LABEL_SPACING = 2;

        Text summary_label;
        Text body_label;

        construct {
            summary_label = new Text.with_text (null, "");
            summary_label.line_wrap = true;
            summary_label.use_markup = true;
            summary_label.line_wrap_mode = Pango.WrapMode.WORD_CHAR;

            body_label = new Text.with_text (null, "");
            body_label.line_wrap = true;
            body_label.use_markup = true;
            body_label.line_wrap_mode = Pango.WrapMode.WORD_CHAR;

            var style_path = new Gtk.WidgetPath ();
            style_path.append_type (typeof (Gtk.Window));
            style_path.append_type (typeof (Gtk.EventBox));
            style_path.iter_add_class (1, "gala-notification");
            style_path.append_type (typeof (Gtk.Label));

            var label_style_context = new Gtk.StyleContext ();
            label_style_context.add_provider (Gala.Utils.get_gala_css (), Gtk.STYLE_PROVIDER_PRIORITY_FALLBACK);
            label_style_context.set_path (style_path);

            Gdk.RGBA color;

            label_style_context.save ();
            label_style_context.add_class ("title");
            color = label_style_context.get_color (Gtk.StateFlags.NORMAL);
            summary_label.color = {
                (uint8) (color.red * 255),
                (uint8) (color.green * 255),
                (uint8) (color.blue * 255),
                (uint8) (color.alpha * 255)
            };
            label_style_context.restore ();

            label_style_context.save ();
            label_style_context.add_class ("label");
            color = label_style_context.get_color (Gtk.StateFlags.NORMAL);
            body_label.color = {
                (uint8) (color.red * 255),
                (uint8) (color.green * 255),
                (uint8) (color.blue * 255),
                (uint8) (color.alpha * 255)
            };
            label_style_context.restore ();

            add_child (summary_label);
            add_child (body_label);
        }

        public void set_values (string summary, string body) {
            summary_label.set_markup ("<b>%s</b>".printf (fix_markup (summary)));
            body_label.set_markup (fix_markup (body));
        }

        public override void get_preferred_height (float for_width, out float min_height, out float nat_height) {
            var scale = Utils.get_ui_scaling_factor ();
            float label_height;
            get_allocation_values (null, null, null, null, out label_height, null, scale);

            min_height = nat_height = label_height;
        }

        public override void allocate (ActorBox box, AllocationFlags flags) {
            var scale = Utils.get_ui_scaling_factor ();
            float label_x, label_width, summary_height, body_height, label_height, label_y;
            get_allocation_values (out label_x, out label_width, out summary_height,
                out body_height, out label_height, out label_y, scale);

            var summary_alloc = ActorBox ();
            summary_alloc.set_origin (label_x, label_y);
            summary_alloc.set_size (label_width, summary_height);
            summary_label.allocate (summary_alloc, flags);

            var body_alloc = ActorBox ();
            body_alloc.set_origin (label_x, label_y + summary_height + LABEL_SPACING * scale);
            body_alloc.set_size (label_width, body_height);
            body_label.allocate (body_alloc, flags);

            base.allocate (box, flags);
        }

        void get_allocation_values (out float label_x, out float label_width, out float summary_height,
            out float body_height, out float label_height, out float label_y, int scale) {
            var height = Notification.ICON_SIZE * scale;
            var margin = Notification.MARGIN * scale;
            var padding = Notification.PADDING * scale;
            var spacing = Notification.SPACING * scale;

            label_x = margin + padding + height + spacing;
            label_width = Notification.WIDTH * scale - label_x - margin - spacing;

            summary_label.get_preferred_height (label_width, null, out summary_height);
            body_label.get_preferred_height (label_width, null, out body_height);

            label_height = summary_height + LABEL_SPACING * scale + body_height;
            label_y = margin + padding;
            // center
            if (label_height < height) {
                label_y += (height - (int) label_height) / 2;
                label_height = height;
            }
        }

        /**
         * Copied from gnome-shell, fixes the mess of markup that is sent to us
         */
        string fix_markup (string markup) {
            var text = markup;

            try {
                text = entity_regex.replace (markup, markup.length, 0, "&amp;");
                text = tag_regex.replace (text, text.length, 0, "&lt;");
            } catch (Error e) {}

            return text;
        }
    }

    public class NormalNotification : Notification {
        public string summary { get; construct set; }
        public string body { get; construct set; }
        public uint32 sender_pid { get; construct; }
        public string[] notification_actions { get; construct set; }
#if HAS_MUTTER330
        public Meta.Display display { get; construct; }
#else
        public Screen screen { get; construct; }
#endif

        Actor content_container;
        NormalNotificationContent notification_content;
        NormalNotificationContent? old_notification_content = null;

#if HAS_MUTTER330
        public NormalNotification (Meta.Display display, uint32 id, string summary, string body, Gdk.Pixbuf? icon,
            NotificationUrgency urgency, int32 expire_timeout, uint32 pid, string[] actions) {
            Object (
                id: id,
                icon: icon,
                urgency: urgency,
                expire_timeout: expire_timeout,
                display: display,
                summary: summary,
                body: body,
                sender_pid: pid,
                notification_actions: actions
            );
        }
#else
        public NormalNotification (Screen screen, uint32 id, string summary, string body, Gdk.Pixbuf? icon,
            NotificationUrgency urgency, int32 expire_timeout, uint32 pid, string[] actions) {
            Object (
                id: id,
                icon: icon,
                urgency: urgency,
                expire_timeout: expire_timeout,
                screen: screen,
                summary: summary,
                body: body,
                sender_pid: pid,
                notification_actions: actions
            );
        }
#endif

        construct {
            content_container = new Actor ();

            notification_content = new NormalNotificationContent ();
            notification_content.set_values (summary, body);

            content_container.add_child (notification_content);
            insert_child_below (content_container, null);
        }

        public void update (string summary, string body, Gdk.Pixbuf? icon, int32 expire_timeout,
            string[] actions) {
            var visible_change = this.summary != summary || this.body != body;

            if (visible_change) {
                if (old_notification_content != null)
                    old_notification_content.destroy ();

                old_notification_content = new NormalNotificationContent ();
                old_notification_content.set_values (this.summary, this.body);

                content_container.add_child (old_notification_content);

                this.summary = summary;
                this.body = body;
                notification_content.set_values (summary, body);

                float content_height, old_content_height;
                notification_content.get_preferred_height (0, null, out content_height);
                old_notification_content.get_preferred_height (0, null, out old_content_height);

                content_height = float.max (content_height, old_content_height);

                play_update_transition (content_height + PADDING * 2 * style_context.get_scale ());

                get_transition ("switch").completed.connect (() => {
                    if (old_notification_content != null)
                        old_notification_content.destroy ();
                    old_notification_content = null;
                });
            }

            notification_actions = actions;
            update_base (icon, expire_timeout);
        }

        protected override void update_slide_animation () {
            if (old_notification_content != null)
                old_notification_content.y = animation_slide_y_offset;

            notification_content.y = animation_slide_y_offset - animation_slide_height;
        }

        public override void update_allocation (out float content_height, AllocationFlags flags) {
            var box = ActorBox ();
            box.set_origin (0, 0);
            box.set_size (width, height);

            content_container.allocate (box, flags);

            // the for_width is not needed in our implementation of get_preferred_height as we
            // assume a constant width
            notification_content.get_preferred_height (0, null, out content_height);

            var scale = style_context.get_scale ();
            var scaled_margin = MARGIN * scale;

            content_container.set_clip (scaled_margin, scaled_margin, scaled_margin * 2 + WIDTH * scale, content_height + PADDING * 2 * scale);
        }

        public override void get_preferred_height (float for_width, out float min_height, out float nat_height) {
            float content_height;
            notification_content.get_preferred_height (for_width, null, out content_height);

            min_height = nat_height = content_height + (MARGIN + PADDING) * 2 * style_context.get_scale ();
        }

        public override void activate () {
            // we currently only support the default action, which can be triggered by clicking
            // on the notification according to spec
            for (var i = 0; i < notification_actions.length; i += 2) {
                if (notification_actions[i] == "default") {
                    action_invoked (id, "default");
                    dismiss ();

                    return;
                }
            }

            // if no default action has been set, we fallback to trying to find a window for the
            // notification's sender process
            unowned Meta.Window? window = get_window ();
            if (window != null) {
                unowned Meta.Workspace workspace = window.get_workspace ();
#if HAS_MUTTER330
                var time = display.get_current_time ();

                if (workspace != display.get_workspace_manager ().get_active_workspace ())
                    workspace.activate_with_focus (window, time);
                else
                    window.activate (time);
#else
                var time = screen.get_display ().get_current_time ();

                if (workspace != screen.get_active_workspace ())
                    workspace.activate_with_focus (window, time);
                else
                    window.activate (time);
#endif

                dismiss ();
            }
        }

        unowned Meta.Window? get_window () {
            if (sender_pid == 0)
                return null;

#if HAS_MUTTER330
            unowned GLib.List<Meta.WindowActor> actors = display.get_window_actors ();
#else
            unowned GLib.List<Meta.WindowActor> actors = screen.get_window_actors ();
#endif
            foreach (unowned Meta.WindowActor actor in actors) {
                if (actor.is_destroyed ())
                    continue;

                unowned Meta.Window window = actor.get_meta_window ();

                // the windows are sorted by stacking order when returned
                // from meta_get_window_actors, so we can just pick the first
                // one we find and have a pretty good match
                if (window.get_pid () == sender_pid)
                    return window;
            }

            return null;
        }

        void dismiss () {
            closed (id, NotificationClosedReason.DISMISSED);
            close ();
        }
    }
}