/**
  Some of Gnome Shell's default behavior is really sub-optimal when using
  paperWM. This is a collection of monkey patches and preferences which works
  around these problems.
 */

var Extension = imports.misc.extensionUtils.extensions['paperwm@hedning:matrix.org'];

var Meta = imports.gi.Meta;
var Main = imports.ui.main;
var Workspace = imports.ui.workspace;
var utils = Extension.imports.utils;

var Convenience = Extension.imports.convenience;
var Scratch = Extension.imports.scratch;
var settings = Convenience.getSettings();
var Clutter = imports.gi.Clutter;

function overrideHotCorners() {
    for (let corner of Main.layoutManager.hotCorners) {
        if (!corner)
            continue;

        corner._toggleOverview = function() {};

        corner._pressureBarrier._trigger = function() {};
    }
}

function disableHotcorners() {
    let override = settings.get_boolean("override-hot-corner");
    if (override) {
        overrideHotCorners();
        signals.connect(Main.layoutManager,
                        'hot-corners-changed',
                        overrideHotCorners);
    } else {
        signals.disconnect(Main.layoutManager);
        Main.layoutManager._updateHotCorners();
    }
}

var savedMethods;
function saveMethod(obj, name) {
    let method = obj[name];
    let methods = savedMethods.get(obj);
    if (!methods) {
        methods = {};
        savedMethods.set(obj, methods);
    }
    methods[name] = method;
}

function getMethod(obj, name) {
    let methods = savedMethods.get(obj);
    return methods[name];
}


function overrideMethod(obj, name, method) {
    if (!getMethod(obj, name))
        saveMethod(obj, name);
    obj[name] = method;
}

function restoreMethod(obj, name) {
    let method = getMethod(obj, name);
    if (method)
        obj[name] = method;
}

var signals;
function init() {
    savedMethods = new Map();
    saveMethod(imports.ui.messageTray.MessageTray.prototype, '_updateState');
    saveMethod(imports.ui.windowManager.WindowManager.prototype, '_prepareWorkspaceSwitch');
    saveMethod(Workspace.Workspace.prototype, '_isOverviewWindow');

    signals = new utils.Signals();
}

function enable() {

    signals.connect(settings, 'changed::override-hot-corner',
                    disableHotcorners);
    disableHotcorners();


    function onlyScratchInOverview() {
        let obj = Workspace.Workspace.prototype;
        let name = '_isOverviewWindow';
        if (settings.get_boolean('only-scratch-in-overview')) {
            overrideMethod(obj, name, (win) => {
                let metaWindow = win.meta_window;
                return Scratch.isScratchWindow(metaWindow) && !metaWindow.skip_taskbar;
            });
        } else {
            restoreMethod(obj, name);
        }
    }
    signals.connect(settings, 'changed::only-scratch-in-overview',
                    onlyScratchInOverview);
    onlyScratchInOverview();

    /* The «native» workspace animation can be now (3.30) be disabled as it
       calls out of the function bound to the `switch-workspace` signal.
     */
    imports.ui.windowManager.WindowManager.prototype._prepareWorkspaceSwitch =
        function (from, to, direction) {
            if (this._switchData)
                return;

            let wgroup = global.window_group;
            let windows = global.get_window_actors();
            let switchData = {};

            this._switchData = switchData;
            switchData.movingWindowBin = new Clutter.Actor();
            switchData.windows = [];
            switchData.surroundings = {};
            switchData.gestureActivated = false;
            switchData.inProgress = false;

            switchData.container = new Clutter.Actor();

        };

    // Don't hide notifications when there's fullscreen windows in the workspace.
    // Fullscreen windows aren't special in paperWM and might not even be
    // visible, so hiding notifications makes no sense.
    with (imports.ui.messageTray) {
        MessageTray.prototype._updateState
            = function () {
                let hasMonitor = Main.layoutManager.primaryMonitor != null;
                this.actor.visible = !this._bannerBlocked && hasMonitor && this._banner != null;
                if (this._bannerBlocked || !hasMonitor)
                    return;

                // If our state changes caused _updateState to be called,
                // just exit now to prevent reentrancy issues.
                if (this._updatingState)
                    return;

                this._updatingState = true;

                // Filter out acknowledged notifications.
                let changed = false;
                this._notificationQueue = this._notificationQueue.filter(function(n) {
                    changed = changed || n.acknowledged;
                    return !n.acknowledged;
                });

                if (changed)
                    this.emit('queue-changed');

                let hasNotifications = Main.sessionMode.hasNotifications;

                if (this._notificationState == State.HIDDEN) {
                    let nextNotification = this._notificationQueue[0] || null;
                    if (hasNotifications && nextNotification) {
                        // Monkeypatch here
                        let limited = this._busy;
                        let showNextNotification = (!limited || nextNotification.forFeedback || nextNotification.urgency == Urgency.CRITICAL);
                        if (showNextNotification)
                            this._showNotification();
                    }
                } else if (this._notificationState == State.SHOWN) {
                    let expired = (this._userActiveWhileNotificationShown &&
                                   this._notificationTimeoutId == 0 &&
                                   this._notification.urgency != Urgency.CRITICAL &&
                                   !this._banner.focused &&
                                   !this._pointerInNotification) || this._notificationExpired;
                    let mustClose = (this._notificationRemoved || !hasNotifications || expired);

                    if (mustClose) {
                        let animate = hasNotifications && !this._notificationRemoved;
                        this._hideNotification(animate);
                    } else if (this._pointerInNotification && !this._banner.expanded) {
                        this._expandBanner(false);
                    } else if (this._pointerInNotification) {
                        this._ensureBannerFocused();
                    }
                }

                this._updatingState = false;

                // Clean transient variables that are used to communicate actions
                // to updateState()
                this._notificationExpired = false;
            };
    }
}

function disable() {
    for (let [obj, methods] of savedMethods) {
        for (let name in methods) {
            restoreMethod(obj, name);
        }
    }

    signals.destroy();
    Main.layoutManager._updateHotCorners();
}