/**
 * TaskListWidget - Unified Task Management
 * Integrates Todoist, Asana, TickTick, Notion tasks
 * 
 * Features:
 * - Auto-discovery of task sources
 * - Priority sorting
 * - Quick add
 * - Broadcasting task events
 */

import React, { useState, useEffect } from 'react';
import { CheckSquare, Square, Plus, Flag, Calendar as CalIcon, Trash2 } from 'lucide-react';
import { useLiveData } from '@/hooks/useLiveData';
import { useWidgetCommunication } from '@/contexts/WidgetContext';
import { cn } from '@/lib/utils';

interface Task {
    id: string;
    title: string;
    completed: boolean;
    priority: 1 | 2 | 3 | 4;
    dueDate?: string;
    project?: string;
    source: string;
}

interface TaskListWidgetProps {
    widgetId: string;
}

export default function TaskListWidget({ widgetId }: TaskListWidgetProps) {
    const [filter, setFilter] = useState<'all' | 'today' | 'high-priority'>('today');
    const [newTaskTitle, setNewTaskTitle] = useState('');

    // AUTO-DISCOVERY
    const {
        data: taskData,
        connected,
        recommendedSources,
        refetch,
    } = useLiveData({
        widgetId,
        widgetType: 'tasks',
        requiredSources: ['todoist', 'asana'],
        optionalSources: ['ticktick', 'notion-tasks'],
        autoConnect: true,
        pollInterval: 30000,
    });

    // INTER-WIDGET COMMUNICATION
    const { broadcastEvent, subscribeToEvent } = useWidgetCommunication(widgetId);

    // Broadcast task completion
    const handleToggleTask = async (task: Task) => {
        // TODO: API call to toggle task

        broadcastEvent({
            type: task.completed ? 'task.uncompleted' : 'task.completed',
            data: {
                taskId: task.id,
                title: task.title,
                source: task.source,
            },
        });

        refetch();
    };

    // Listen for calendar events to create tasks
    useEffect(() => {
        const unsub = subscribeToEvent('calendar.meeting.upcoming', (event) => {
            // Auto-create prep task for upcoming meetings
            const meetingTitle = event.data.title;
            // TODO: Create task "Prepare for: {meetingTitle}"
        });

        return () => unsub();
    }, []);

    const handleAddTask = async () => {
        if (!newTaskTitle.trim()) return;

        // TODO: API call to create task
        broadcastEvent({
            type: 'task.created',
            data: {
                title: newTaskTitle,
            },
        });

        setNewTaskTitle('');
        refetch();
    };

    const tasks: Task[] = taskData?.tasks || [];

    const filteredTasks = tasks.filter(task => {
        if (filter === 'today') {
            if (!task.dueDate) return false;
            return new Date(task.dueDate).toDateString() === new Date().toDateString();
        }
        if (filter === 'high-priority') {
            return task.priority === 1 || task.priority === 2;
        }
        return true;
    });

    const getPriorityColor = (priority: number) => {
        switch (priority) {
            case 1: return 'text-red-400';
            case 2: return 'text-orange-400';
            case 3: return 'text-yellow-400';
            default: return 'text-gray-400';
        }
    };

    return (
        <div className="h-full flex flex-col bg-gradient-to-br from-emerald-500/10 to-teal-500/10 backdrop-blur-sm border border-emerald-500/30 rounded-lg overflow-hidden">
            {/* Header */}
            <div className="p-4 border-b border-emerald-500/20">
                <div className="flex items-center gap-2 mb-3">
                    <CheckSquare className="w-5 h-5 text-emerald-400" />
                    <span className="font-display text-sm uppercase tracking-wider text-emerald-400">
                        Tasks
                    </span>
                    <div className="ml-auto px-2 py-1 bg-emerald-500/20 text-emerald-400 rounded text-xs">
                        {filteredTasks.filter(t => !t.completed).length} active
                    </div>
                </div>

                {/* Filters */}
                <div className="flex gap-2">
                    {(['all', 'today', 'high-priority'] as const).map((f) => (
                        <button
                            key={f}
                            onClick={() => setFilter(f)}
                            className={cn(
                                "px-3 py-1 rounded text-xs transition-all",
                                filter === f
                                    ? "bg-emerald-500 text-white"
                                    : "text-emerald-300 hover:bg-emerald-500/20"
                            )}
                        >
                            {f.replace('-', ' ')}
                        </button>
                    ))}
                </div>
            </div>

            {/* Quick Add */}
            <div className="p-3 border-b border-emerald-500/20 bg-black/20">
                <div className="flex gap-2">
                    <input
                        type="text"
                        value={newTaskTitle}
                        onChange={(e) => setNewTaskTitle(e.target.value)}
                        onKeyDown={(e) => e.key === 'Enter' && handleAddTask()}
                        placeholder="Add a task..."
                        className="flex-1 px-3 py-2 bg-white/5 border border-emerald-500/30 rounded text-sm text-white placeholder-emerald-300/50 focus:outline-none focus:border-emerald-500"
                    />
                    <button
                        onClick={handleAddTask}
                        className="p-2 bg-emerald-500 hover:bg-emerald-600 rounded transition-colors"
                    >
                        <Plus className="w-4 h-4 text-white" />
                    </button>
                </div>
            </div>

            {/* Task List */}
            <div className="flex-1 overflow-y-auto p-3 space-y-2">
                {filteredTasks.length === 0 && (
                    <div className="text-center py-8">
                        <CheckSquare className="w-8 h-8 text-emerald-400/30 mx-auto mb-2" />
                        <p className="text-sm text-emerald-300/50">No tasks for this filter</p>
                    </div>
                )}

                {filteredTasks.map((task) => (
                    <div
                        key={task.id}
                        className={cn(
                            "group flex items-start gap-3 p-3 rounded-lg border transition-all",
                            task.completed
                                ? "bg-gray-500/10 border-gray-500/20 opacity-50"
                                : "bg-emerald-500/10 border-emerald-500/30 hover:bg-emerald-500/20"
                        )}
                    >
                        {/* Checkbox */}
                        <button
                            onClick={() => handleToggleTask(task)}
                            className="mt-0.5"
                        >
                            {task.completed ? (
                                <CheckSquare className="w-5 h-5 text-emerald-400" />
                            ) : (
                                <Square className="w-5 h-5 text-emerald-300 hover:text-emerald-400" />
                            )}
                        </button>

                        {/* Task Content */}
                        <div className="flex-1">
                            <div className={cn(
                                "text-sm font-medium mb-1",
                                task.completed ? "line-through text-gray-400" : "text-white"
                            )}>
                                {task.title}
                            </div>

                            <div className="flex items-center gap-3 text-xs">
                                {/* Priority */}
                                <div className="flex items-center gap-1">
                                    <Flag className={cn("w-3 h-3", getPriorityColor(task.priority))} />
                                    <span className={getPriorityColor(task.priority)}>P{task.priority}</span>
                                </div>

                                {/* Due Date */}
                                {task.dueDate && (
                                    <div className="flex items-center gap-1 text-emerald-300">
                                        <CalIcon className="w-3 h-3" />
                                        {new Date(task.dueDate).toLocaleDateString('en-US', {
                                            month: 'short',
                                            day: 'numeric'
                                        })}
                                    </div>
                                )}

                                {/* Project */}
                                {task.project && (
                                    <span className="text-emerald-300/70">
                                        @ {task.project}
                                    </span>
                                )}

                                {/* Source */}
                                <span className="text-emerald-300/50 text-xs ml-auto">
                                    {task.source}
                                </span>
                            </div>
                        </div>

                        {/* Delete (on hover) */}
                        <button
                            className="opacity-0 group-hover:opacity-100 transition-opacity p-1 hover:bg-red-500/20 rounded"
                        >
                            <Trash2 className="w-4 h-4 text-red-400" />
                        </button>
                    </div>
                ))}
            </div>

            {/* Source Recommendations */}
            {recommendedSources.length > 0 && (
                <div className="p-3 border-t border-emerald-500/20 bg-orange-500/10">
                    <div className="text-xs text-orange-400 mb-2">
                        Missing Task Sources:
                    </div>
                    {recommendedSources.map((source) => (
                        <div key={source.id} className="flex items-center justify-between mb-1">
                            <span className="text-xs text-orange-300">{source.name}</span>
                            <button
                                onClick={() => refetch()}
                                className="px-2 py-1 bg-orange-500 text-white rounded text-xs"
                            >
                                Enable
                            </button>
                        </div>
                    ))}
                </div>
            )}

            {/* Stats Footer */}
            <div className="p-3 border-t border-emerald-500/20 bg-black/20">
                <div className="flex justify-around text-xs">
                    <div className="text-center">
                        <div className="text-emerald-400 font-semibold">
                            {tasks.filter(t => !t.completed).length}
                        </div>
                        <div className="text-emerald-300/50">Active</div>
                    </div>
                    <div className="text-center">
                        <div className="text-emerald-400 font-semibold">
                            {tasks.filter(t => t.completed).length}
                        </div>
                        <div className="text-emerald-300/50">Done</div>
                    </div>
                    <div className="text-center">
                        <div className="text-red-400 font-semibold">
                            {tasks.filter(t => !t.completed && t.priority <= 2).length}
                        </div>
                        <div className="text-emerald-300/50">High Pri</div>
                    </div>
                </div>
            </div>
        </div>
    );
}