const { Clutter, Cogl, GObject, Meta, Shell, St } = imports.gi;

var WindowFrameManager = class WindowFrameManager {
    constructor() {
        this._realms = Shell.Realms.get_default();
        let frames = this._realms.window_frames();
        this._frame_effects = [];

        global.window_manager.connect('map', this._handleWindowMap.bind(this));
        global.workspace_manager.connect('context-window-moved', this._onContextWindowMoved.bind(this));
        global.workspace_manager.connect('context-removed', this._onContextRemoved.bind(this));
        frames.connect('realm-frame-colors-changed', this._onFrameColorsChanged.bind(this));

        this.trackWindows();
    }

    _onContextWindowMoved(workspaceManager, window) {
        let actor = window.get_compositor_private();
        if (actor) {
            this.handleWindow(actor);
        }
        return Clutter.EVENT_PROPAGATE;
    }

    _handleWindowMap(shellwm, actor) {
        this.handleWindow(actor);
        return Clutter.EVENT_PROPAGATE;
    }

    _onContextRemoved(workspaceManager, id) {
        this.trackWindows();
    }

    _onFrameColorsChanged(realms) {
        this.trackWindows();
    }

    trackWindows() {
        var actors = global.get_window_actors();
        actors.forEach(a => this.handleWindow(a));
    }

    handleWindow(actor) {
        let win = actor.metaWindow;
        let win_id = win.get_stable_sequence();
        let effect = this._frame_effects[win_id];

        let frames = this._realms.window_frames();

        if (frames.has_frame(win) && frames.is_frame_enabled(win)) {
            let color = frames.color_for_window(win);

            if (effect) {
                effect.setColor(color);
            } else {
                let label = frames.label_for_window(win);
                effect = new RealmFrameEffect(actor, color, label);
                this._frame_effects[win_id] = effect;
            }
        } else if (effect) {
            effect.removeEffect(actor);
            this._frame_effects[win_id] = null;
        }
    }
}

var RealmFrameEffect = GObject.registerClass(
class RealmFrameEffect extends Clutter.Effect {
    _init(actor, color, label_text) {
        super._init();
        this._frame_width = 2;
        this._pipeline = null;
        this._color = color;
        this._label_on_top = true;
        this._label = null;
        this._label_text = label_text;

        if (label_text) {
            this._updateLabel(actor.metaWindow);
        }

        this._sizeChangedId = actor.metaWindow.connect('size-changed', window => {
            this._updateLabel(window);
        });

        actor.add_effect(this);
    }

    removeEffect(actor) {
        if (this._label) {
            actor.remove_child(this._label);
            this._label = null;
        }
        if (this._sizeChangedId) {
            let win = actor.metaWindow;
            win.disconnect(this._sizeChangedId);
            this._sizeChangedId = 0;
        }
        actor.remove_effect(this);
    }

    _createLabel(actor, label_text) {
        let label = new St.Label({
            style_class: 'realm-frame-label',
            z_position: 1.0,

        });
        label.set_text('  '+label_text+'  ');
        actor.add_child(label);
        return label;
    }

    _updateLabel(window) {
        if (!this._label_text) {
            return;
        }

        if (window.is_fullscreen()) {
            if (this._label) {
                let actor = window.get_compositor_private();
                actor.remove_child(this._label);
                this._label = null;
            }
        } else if (!this._label) {
            let actor = window.get_compositor_private();
            this._label = this._createLabel(actor, this._label_text);
        }

        if (this._label) {
            this._updateLabelPosition(window);
            this._updateLabelColor();
        }
    }

    _updateLabelPosition(window) {

        if (!this._label_height) {
            // If we scale the text, the reported size of the label will not be the value we need so
            // save the initial value.
            this._label_height = this._label.get_height();
        }


        let maximized = window.is_fullscreen() === true || // Fullscreen
            [Meta.MaximizeFlags.BOTH, Meta.MaximizeFlags.VERTICAL].includes(window.get_maximized());  // Maximized

        this._label_on_top = !maximized;

        let frame_rect = window.get_frame_rect();
        let buffer_rect = window.get_buffer_rect();

        let offsetX = frame_rect.x - buffer_rect.x;
        let offsetY = frame_rect.y - buffer_rect.y;


        if (window.get_client_type() === Meta.WindowClientType.WAYLAND) {
            let scaleFactor = St.ThemeContext.get_for_stage(global.stage).scale_factor;
            if (scaleFactor !== 1) {
                offsetX = offsetX / scaleFactor;
                this._label.set_style(`font-size: ${12 / scaleFactor}pt;`);
            }
            offsetX -= 1;
            offsetY -= 4;
        }

        // If label is on top and there is enough space above title bar move position up by label height
        if (this._label_on_top && this._label_height <= offsetY) {
            offsetY -= this._label_height;
        } else if (maximized) {
            offsetX = 0;
            offsetY = 0;
        }
        this._label.set_position(offsetX, offsetY);
    }

    _updateLabelColor() {
        let fg = new Clutter.Color({
            red: 0,
            green: 0,
            blue: 0,
            alpha: 96,
        });

        let bg = this._color.copy();

        if (this._label_on_top) {
            bg.alpha = 100;
        } else {
            bg.alpha = 200;
        }

        let clutter_text = this._label.get_clutter_text();
        clutter_text.set_color(fg);
        clutter_text.set_background_color(bg);
    }


    setColor(color) {
        if (this._color && this._color.equal(color)) {
            return;
        }
        this._color = color;
        this.setPipelineColor();
        if (this._label) {
            this._updateLabelColor();
        }
    }

    setPipelineColor() {
        if (!this._color || !this._pipeline) {
            return;
        }
        let s = this._color.to_string();

        let cogl_color = new Cogl.Color();
        cogl_color.init_from_4ub(this._color.red, this._color.green, this._color.blue, 0xc4);
        this._pipeline.set_color(cogl_color);
    }

    _calculate_frame_box(window, allocation) {
        let frame_rect = window.get_frame_rect();
        let buffer_rect = window.get_buffer_rect();

        let offsetX = frame_rect.x - buffer_rect.x;
        let offsetY = frame_rect.y - buffer_rect.y;

        let top = offsetY - 3;
        let bottom = offsetY - 1;
        let left = offsetX - 3;
        let right = offsetX - 1;

        let wayland = window.get_client_type() == Meta.WindowClientType.WAYLAND;

        if (wayland) {
            bottom += 4;
        }

        let fw = this._frame_width;


        switch (window.get_maximized()) {
            case Meta.MaximizeFlags.BOTH:
                top += fw;
                right += fw;
                bottom += fw - (wayland ? 5 : 0);
                left += fw;
                break;
            case Meta.MaximizeFlags.HORIZONTAL:
                right += fw;
                left += fw;
                break;
            case Meta.MaximizeFlags.VERTICAL:
                top += fw;
                bottom += fw;
                break;
        }

        if (window.is_fullscreen()) {
            top += 3;
            right += 2;
            bottom -= (wayland ? 3 : 0);
            left += 3;
        }

        if (!wayland && !window.decorated && !window.is_fullscreen() && (window.get_maximized() !== Meta.MaximizeFlags.BOTH)) {
            bottom += 4;
        }

        let x = left;
        let y = top + fw;
        let w = allocation.get_width() - (right + left);
        let h = allocation.get_height() - (bottom + top + fw);

        return [x, y, w, h];
    }

    draw_rect(node, x, y, width, height) {
        const box = new Clutter.ActorBox();
        box.set_origin(x, y);
        box.set_size(width, height);
        node.add_rectangle(box);
    }

    draw_hline(node, x, y, width, width_factor = 1) {
        this.draw_rect(node, x, y, width, this._frame_width * width_factor);
    }

    draw_vline(node, x, y, height, width_factor = 1) {
        this.draw_rect(node, x, y, this._frame_width * width_factor, height);
    }

    vfunc_paint_node(node, ctx) {
        let actor = this.get_actor();

        const actorNode = new Clutter.ActorNode(actor, -1);
        node.add_child(actorNode);

        if (!this._pipeline) {
            let framebuffer = ctx.get_framebuffer();
            let coglContext = framebuffer.get_context();
            this._pipeline = new Cogl.Pipeline(coglContext);
            this.setPipelineColor();
        }

        const pipelineNode = new Clutter.PipelineNode(this._pipeline);
        pipelineNode.set_name('Realm Frame');
        node.add_child(pipelineNode);

        let [x, y, width, height] = this._calculate_frame_box(actor.metaWindow, actor.get_allocation_box());

        // Top
        this.draw_hline(pipelineNode, x, y, width, 2);

        // Right
        this.draw_vline(pipelineNode, x + width, y, height);

        // Bottom
        this.draw_hline(pipelineNode, x, y + height, width);

        // Left
        this.draw_vline(pipelineNode, x, y, height);
    }
});