<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\MobileTask;
use App\Models\MobileSubtask;
use App\Models\MobileTaskPin;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;

class TaskApiController extends Controller
{
    public function index(Request $request)
    {
        $user = $request->user();

        $query = MobileTask::with(['assignee', 'creator', 'subtasks', 'pins']);

        if ($request->has('status') && $request->status !== 'all') {
            $query->where('status', $request->status);
        }

        if ($request->has('project_id')) {
            $query->where('project_id', $request->project_id);
        }

        if ($request->has('assigned_to_me') && $request->assigned_to_me === 'true') {
            $query->where('assignee_id', $user->id);
        }

        $tasks = $query->latest()->get()->map(function ($task) use ($user) {
            $isPinned = $task->pins->contains('user_id', $user->id);
            return [
                'id' => $task->id,
                'title' => $task->title,
                'description' => $task->description,
                'status' => $task->status,
                'priority' => $task->priority,
                'due_date' => $task->due_date ? $task->due_date->format('Y-m-d') : null,
                'assignee_id' => $task->assignee_id,
                'assignee_name' => $task->assignee ? $task->assignee->name : 'Unassigned',
                'project_id' => $task->project_id,
                'is_pinned' => $isPinned,
                'subtasks_count' => $task->subtasks->count(),
                'completed_subtasks_count' => $task->subtasks->where('is_completed', true)->count(),
                'subtasks' => $task->subtasks->map(fn($s) => [
                    'id' => $s->id,
                    'title' => $s->title,
                    'is_completed' => (bool)$s->is_completed,
                ]),
                'created_at' => $task->created_at->toIso8601String(),
            ];
        });

        return response()->json([
            'success' => true,
            'data' => $tasks,
            'message' => null,
            'errors' => null,
        ]);
    }

    public function store(Request $request)
    {
        $request->validate([
            'title' => 'required|string|max:255',
            'description' => 'nullable|string',
            'priority' => 'nullable|string|in:low,medium,high,urgent',
            'due_date' => 'nullable|date',
            'assignee_id' => 'nullable|exists:users,id',
            'project_id' => 'nullable|exists:projects,id',
        ]);

        $user = $request->user();

        $task = MobileTask::create([
            'title' => $request->title,
            'description' => $request->description,
            'priority' => $request->priority ?? 'medium',
            'due_date' => $request->due_date,
            'assignee_id' => $request->assignee_id ?? $user->id,
            'project_id' => $request->project_id,
            'created_by' => $user->id,
        ]);

        return response()->json([
            'success' => true,
            'data' => $task->load(['assignee', 'subtasks']),
            'message' => 'Task created successfully',
            'errors' => null,
        ], 201);
    }

    public function show(Request $request, $id)
    {
        $user = $request->user();
        $task = MobileTask::with(['assignee', 'creator', 'subtasks', 'pins'])->find($id);

        if (!$task) {
            return response()->json([
                'success' => false,
                'data' => null,
                'message' => 'Task not found',
                'errors' => null,
            ], 404);
        }

        return response()->json([
            'success' => true,
            'data' => [
                'id' => $task->id,
                'title' => $task->title,
                'description' => $task->description,
                'status' => $task->status,
                'priority' => $task->priority,
                'due_date' => $task->due_date ? $task->due_date->format('Y-m-d') : null,
                'assignee_id' => $task->assignee_id,
                'assignee_name' => $task->assignee ? $task->assignee->name : 'Unassigned',
                'project_id' => $task->project_id,
                'is_pinned' => $task->pins->contains('user_id', $user->id),
                'subtasks' => $task->subtasks->map(fn($s) => [
                    'id' => $s->id,
                    'title' => $s->title,
                    'is_completed' => (bool)$s->is_completed,
                ]),
            ],
            'message' => null,
            'errors' => null,
        ]);
    }

    public function update(Request $request, $id)
    {
        $task = MobileTask::find($id);
        if (!$task) {
            return response()->json([
                'success' => false,
                'data' => null,
                'message' => 'Task not found',
                'errors' => null,
            ], 404);
        }

        $task->update($request->only([
            'title',
            'description',
            'status',
            'priority',
            'due_date',
            'assignee_id',
            'project_id',
        ]));

        return response()->json([
            'success' => true,
            'data' => $task->fresh(['assignee', 'subtasks']),
            'message' => 'Task updated successfully',
            'errors' => null,
        ]);
    }

    public function destroy(Request $request, $id)
    {
        $task = MobileTask::find($id);
        if (!$task) {
            return response()->json([
                'success' => false,
                'data' => null,
                'message' => 'Task not found',
                'errors' => null,
            ], 404);
        }

        $task->delete();

        return response()->json([
            'success' => true,
            'data' => null,
            'message' => 'Task deleted successfully',
            'errors' => null,
        ]);
    }

    public function claim(Request $request, $id)
    {
        $user = $request->user();
        $task = MobileTask::find($id);

        if (!$task) {
            return response()->json([
                'success' => false,
                'data' => null,
                'message' => 'Task not found',
                'errors' => null,
            ], 404);
        }

        $task->update(['assignee_id' => $user->id]);

        return response()->json([
            'success' => true,
            'data' => $task->fresh(['assignee']),
            'message' => 'Task claimed successfully',
            'errors' => null,
        ]);
    }

    public function pin(Request $request, $id)
    {
        $user = $request->user();
        $task = MobileTask::find($id);

        if (!$task) {
            return response()->json([
                'success' => false,
                'data' => null,
                'message' => 'Task not found',
                'errors' => null,
            ], 404);
        }

        $existing = MobileTaskPin::where('user_id', $user->id)->where('task_id', $id)->first();
        if ($existing) {
            $existing->delete();
            $isPinned = false;
        } else {
            MobileTaskPin::create(['user_id' => $user->id, 'task_id' => $id]);
            $isPinned = true;
        }

        return response()->json([
            'success' => true,
            'data' => ['is_pinned' => $isPinned],
            'message' => $isPinned ? 'Task pinned' : 'Task unpinned',
            'errors' => null,
        ]);
    }

    public function status(Request $request, $id)
    {
        $request->validate([
            'status' => 'required|string|in:todo,in_progress,done,archived',
        ]);

        $task = MobileTask::find($id);
        if (!$task) {
            return response()->json([
                'success' => false,
                'data' => null,
                'message' => 'Task not found',
                'errors' => null,
            ], 404);
        }

        $task->update(['status' => $request->status]);

        return response()->json([
            'success' => true,
            'data' => $task,
            'message' => 'Task status updated',
            'errors' => null,
        ]);
    }

    public function addSubtask(Request $request, $id)
    {
        $request->validate([
            'title' => 'required|string|max:255',
        ]);

        $task = MobileTask::find($id);
        if (!$task) {
            return response()->json([
                'success' => false,
                'data' => null,
                'message' => 'Task not found',
                'errors' => null,
            ], 404);
        }

        $subtask = MobileSubtask::create([
            'task_id' => $task->id,
            'title' => $request->title,
            'is_completed' => false,
        ]);

        return response()->json([
            'success' => true,
            'data' => $subtask,
            'message' => 'Subtask added successfully',
            'errors' => null,
        ], 201);
    }

    public function toggleSubtask(Request $request, $taskId, $subtaskId)
    {
        $subtask = MobileSubtask::where('task_id', $taskId)->where('id', $subtaskId)->first();
        if (!$subtask) {
            return response()->json([
                'success' => false,
                'data' => null,
                'message' => 'Subtask not found',
                'errors' => null,
            ], 404);
        }

        $subtask->update(['is_completed' => !$subtask->is_completed]);

        return response()->json([
            'success' => true,
            'data' => $subtask,
            'message' => 'Subtask toggled successfully',
            'errors' => null,
        ]);
    }
}