<?php

namespace App\Http\Controllers;

use App\Notifications\TaskDateUpdated;
use App\Notifications\TaskDeleted;
use App\Notifications\VolunteerAssignedToTask;
use App\Notifications\VolunteerUnassignedFromTask;
use App\Models\Event;
use App\Models\Notification;
use App\Models\Task;
use App\Models\User;
use Carbon\Carbon;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Gate;
use Illuminate\Support\Facades\Log;
use App\Services\FormatDate;

class TasksController extends Controller
{
    public function create(Request $request): JsonResponse {

        if(Gate::denies('create', Task::class)) {
            return response()->json(["message" => "Can't create task"], 403);
        }

        try {

            $event = Event::find($request["event_id"]);

            $event->tasks()->create([
                "name" => $request["name"],
                "description" => $request["description"],
                "start" => $request["start"],
                "end" => $request["end"],
                "location" => $request["location"],
                "max_participants" => $request["max_participants"],
            ]);

            return response()->json(['message' => "Task created"], 200);

        } catch(\Exception $e) {
            Log::info($e->getMessage());
            return response()->json(['message' => "Server error"], 500);
        }
    }

    public function assignSelf(Request $request): JsonResponse
    {
        try {
            $task = Task::findOrFail($request["task_id"]);

            if ($task->users()->count() >= $task->max_participants) {
                return response()->json(["message" => "Max participants reached"], 403);
            }

            if ($task->users()->where('users.id', $request->user()->id)->exists()) {
                return response()->json(["message" => "Already registered"], 409);
            }

            $task->users()->attach($request->user()->id);

            return response()->json(['message' => "Task assigned"], 200);

        } catch (\Throwable $e) {
            Log::error($e->getMessage());
            return response()->json(['message' => "Server error"], 500);
        }
    }

    public function assignUser(Request $request, int $id): JsonResponse
    {
        if (Gate::denies('assignOther', Task::class)) {
            return response()->json(['message' => "Can't create task"], 403);
        }

        try {
            $task = Task::findOrFail($request['task_id']);
            $event = Event::findOrFail($task->events_id);
            $user = User::findOrFail($id);

            if ($task->users()->where('user_id', $id)->exists()) {
                return response()->json(['message' => 'User already assigned to this task'], 400);
            }

            if ($task->max_participants === $task->users()->count()) {
                return response()->json(['message' => 'Max participants reached'], 403);
            }

            $task->users()->attach($id);

            if (Carbon::now()->lessThanOrEqualTo($task->end)) {
                $user->notify(new VolunteerAssignedToTask($task, $event));
            }

            return response()->json(['message' => 'Task assigned'], 200);

        } catch (\Exception $e) {
            Log::error($e->getMessage());
            return response()->json(['message' => 'Server error'], 500);
        }
    }

    public function getEventTasks(Request $request, int $id): JsonResponse {

        try {

            $event = Event::find($id);

            return response()->json(['data' => $event->tasks()->get()]);

        } catch(\Exception $e) {
            Log::info($e->getMessage());
            return response()->json(['message' => "Server error"], 500);
        }
    }

    public function deleteTask(Request $request, int $id): JsonResponse
    {
        if (Gate::denies('delete', Task::class)) {
            return response()->json(['message' => "Can't delete task"], 403);
        }

        try {
            $task = Task::with('users')->findOrFail($id);
            $event = Event::findOrFail($task->events_id);

            if (Carbon::now()->lessThanOrEqualTo($task->end) && $task->users->isNotEmpty()) {
                Notification::send($task->users, new TaskDeleted($task, $event));
            }

            $task->delete();

            return response()->json(['message' => 'Task deleted and participants notified'], 200);

        } catch (\Exception $e) {
            Log::error($e->getMessage());
            return response()->json(['message' => 'Server error'], 500);
        }
    }

    public function update(Request $request, int $id): JsonResponse
    {
        if (Gate::denies('update', Task::class)) {
            return response()->json(['message' => 'Forbidden'], 403);
        }

        try {
            $task = Task::with('users')->findOrFail($id);

            $datesChanged = $task->start !== $request['start'] || $task->end !== $request['end'];

            if ($datesChanged && Carbon::now()->lessThanOrEqualTo($task->end)) {
                $event = Event::findOrFail($task->events_id);

                Notification::send($task->users, new TaskDateUpdated(
                    task: $task,
                    event: $event,
                    oldStart: FormatDate::formatDate($task->start),
                    oldEnd: FormatDate::formatDate($task->end),
                    newStart: FormatDate::formatDate($request['start']),
                    newEnd: FormatDate::formatDate($request['end']),
                ));
            }

            $task->update([
                'name' => $request['name'],
                'description' => $request['description'],
                'start' => $request['start'],
                'end' => $request['end'],
                'location' => $request['location'],
                'max_participants' => $request['max_participants'],
            ]);

            return response()->json(['message' => 'Task updated'], 200);

        } catch (\Exception $e) {
            Log::error($e->getMessage());
            return response()->json(['message' => 'Server error'], 500);
        }
    }

    public function unassignSelf(Request $request): JsonResponse {
        try {
            $task = Task::find($request["task_id"]);
            $userId = $request->user()->id;

            if (!$task) {
                return response()->json(["message" => "Task not found"], 404);
            }

            $task->users()->detach($userId);

            return response()->json(['message' => "Successfully unassigned from task"], 200);

        } catch (\Exception $e) {
            Log::error("UnassignSelf error: " . $e->getMessage());
            return response()->json(['message' => "Server error"], 500);
        }
    }

    public function unassignUser(Request $request, int $id): JsonResponse
    {
        if (Gate::denies('unassignOther', Task::class)) {
            return response()->json(['message' => 'Unauthorized'], 403);
        }

        try {
            $task = Task::findOrFail($request['task_id']);
            $user = User::findOrFail($id);

            if (!$task->users()->where('user_id', $id)->exists()) {
                return response()->json(['message' => 'User is not assigned to this task'], 400);
            }

            $task->users()->detach($id);

            if (Carbon::now()->lessThanOrEqualTo($task->end)) {
                $event = Event::findOrFail($task->events_id);
                $user->notify(new VolunteerUnassignedFromTask($task, $event));
            }

            return response()->json(['message' => 'User unassigned successfully'], 200);

        } catch (\Exception $e) {
            Log::error("UnassignUser error: " . $e->getMessage());
            return response()->json(['message' => 'Server error'], 500);
        }
    }
}