import GObject from 'gi://GObject';
import St from 'gi://St';
import Gio from 'gi://Gio';
import GLib from 'gi://GLib';
import Clutter from 'gi://Clutter';

import * as Main from 'resource:///org/gnome/shell/ui/main.js';
import * as PanelMenu from 'resource:///org/gnome/shell/ui/panelMenu.js';

const DESKMETER_API_URL = 'http://localhost:10000/api/current_task';
const DEBOUNCE_DELAY = 2200; // Wait 2.2s after workspace switch (dmcore polls every 2s)

const TaskIndicator = GObject.registerClass(
class TaskIndicator extends PanelMenu.Button {
    _init() {
        super._init(0.0, 'Deskmeter Task Indicator', false);

        // Create label for task display
        this._label = new St.Label({
            text: 'loading...',
            y_align: Clutter.ActorAlign.CENTER,
            style_class: 'deskmeter-task-label'
        });

        this.add_child(this._label);

        this._debounceTimeout = null;
        this._workspaceManager = global.workspace_manager;

        // Connect to workspace switch signal
        this._workspaceSwitchedId = this._workspaceManager.connect(
            'workspace-switched',
            this._onWorkspaceSwitched.bind(this)
        );

        // Initial update
        this._scheduleUpdate();
    }

    _onWorkspaceSwitched() {
        // Debounce updates - dmcore takes ~2 seconds to detect and update
        // We wait a bit to ensure the task has been updated in MongoDB
        this._scheduleUpdate();
    }

    _scheduleUpdate() {
        // Clear any pending update
        if (this._debounceTimeout) {
            GLib.source_remove(this._debounceTimeout);
        }

        // Schedule new update
        this._debounceTimeout = GLib.timeout_add(GLib.PRIORITY_DEFAULT, DEBOUNCE_DELAY, () => {
            this._updateTask();
            this._debounceTimeout = null;
            return GLib.SOURCE_REMOVE;
        });
    }

    _updateTask() {
        try {
            // Create HTTP request
            let file = Gio.File.new_for_uri(DESKMETER_API_URL);
            file.load_contents_async(null, (source, result) => {
                try {
                    let [success, contents] = source.load_contents_finish(result);
                    if (success) {
                        let decoder = new TextDecoder('utf-8');
                        let data = JSON.parse(decoder.decode(contents));

                        // Update label with task path
                        let displayText = data.task_path || 'no task';

                        // Optionally truncate long paths
                        if (displayText.length > 40) {
                            let parts = displayText.split('/');
                            if (parts.length > 2) {
                                displayText = '.../' + parts.slice(-2).join('/');
                            } else {
                                displayText = displayText.substring(0, 37) + '...';
                            }
                        }

                        this._label.set_text(displayText);
                    }
                } catch (e) {
                    this._label.set_text('error');
                    logError(e, 'Failed to parse deskmeter response');
                }
            });
        } catch (e) {
            this._label.set_text('offline');
            logError(e, 'Failed to fetch deskmeter task');
        }
    }

    destroy() {
        if (this._debounceTimeout) {
            GLib.source_remove(this._debounceTimeout);
            this._debounceTimeout = null;
        }

        if (this._workspaceSwitchedId) {
            this._workspaceManager.disconnect(this._workspaceSwitchedId);
            this._workspaceSwitchedId = null;
        }

        super.destroy();
    }
});

export default class Extension {
    constructor() {
        this._indicator = null;
    }

    enable() {
        this._indicator = new TaskIndicator();

        // Add to panel - position after workspace indicator
        // Panel boxes: left, center, right
        // We'll add it to the left panel, after other items
        Main.panel.addToStatusArea('deskmeter-task-indicator', this._indicator, 1, 'left');
    }

    disable() {
        if (this._indicator) {
            this._indicator.destroy();
            this._indicator = null;
        }
    }
}