<?php
namespace App\Controllers;

use App\Helpers\Response;
use App\Helpers\Validator;
use App\Middleware\JwtAuthMiddleware;
use App\Middleware\RateLimitMiddleware;
use App\Models\Queue;
use App\Services\AuditLogger;
use App\Services\NotificationService;
use App\Services\SmartQueueEngine;

/**
 * Class QueueController
 * Smart Queue & Realtime Board REST API Controller
 *
 * @package App\Controllers
 */
class QueueController
{
    private Queue $queueModel;
    private SmartQueueEngine $aiEngine;

    public function __construct()
    {
        $this->queueModel = new Queue();
        $this->aiEngine = new SmartQueueEngine();
    }

    /**
     * GET /api/v1/queues - Realtime Queue Board
     */
    public function index(): void
    {
        RateLimitMiddleware::handle(60, 60);
        
        $branchId = isset($_GET['branch_id']) ? (int)$_GET['branch_id'] : null;
        $board = $this->queueModel->getRealtimeBoard($branchId);

        Response::success('Realtime Queue Board Data', [
            'total_active' => count($board),
            'branch_id' => $branchId ?: 'All',
            'queues' => $board,
        ]);
    }

    /**
     * POST /api/v1/queues/walkin - Create Walk-in Queue & Execute AI Assign
     */
    public function walkin(): void
    {
        RateLimitMiddleware::handle(30, 60);
        $user = JwtAuthMiddleware::handle(); // ต้องเป็นเจ้าหน้าที่ Reception/Admin ที่ล็อกอิน

        $input = json_decode(file_get_contents('php://input'), true) ?? $_POST;
        $validator = Validator::make($input, [
            'patient_id' => 'required|numeric',
            'service_id' => 'required|numeric',
            'priority'   => 'in:Normal,VIP,Emergency',
        ]);

        if ($validator->fails()) {
            Response::error('ข้อมูลไม่ครบถ้วนหรือไม่ถูกต้อง', 422, $validator->getErrors());
        }

        $input['branch_id'] = $input['branch_id'] ?? $user['branch'];
        $input['created_by'] = $user['id'];
        $input['booking_type'] = 'Walk_in';

        // Execute Smart Queue AI Engine
        $res = $this->aiEngine->allocateQueue($input);

        Response::success('ออกคิวนวดสำเร็จ พร้อมประเมินเวลาโดย Smart AI', $res, 201);
    }

    /**
     * POST /api/v1/queues/smart-assign - Manual Trigger AI Allocation for a waiting queue
     */
    public function smartAssign(): void
    {
        JwtAuthMiddleware::handle();
        $input = json_decode(file_get_contents('php://input'), true) ?? $_POST;
        
        if (empty($input['queue_id'])) {
            Response::error('กรุณาระบุหมายเลขคิวที่ต้องการจัดสรร', 400);
        }

        $db = \App\Models\Model::getDB();
        $stmt = $db->prepare("CALL sp_assign_smart_queue(:qid, @t_id, @r_id, @e_start, @e_end, @msg)");
        $stmt->execute(['qid' => (int)$input['queue_id']]);
        $stmt->closeCursor();

        $res = $db->query("SELECT @t_id AS t_id, @r_id AS r_id, @e_start AS e_start, @e_end AS e_end, @msg AS msg")->fetch();

        Response::success('Smart AI Allocation Executed', $res);
    }

    /**
     * PUT /api/v1/queues/{id}/status - Update Queue Status (Calling / In_Progress / Completed / Cancelled)
     */
    public function updateStatus(int $queueId): void
    {
        $user = JwtAuthMiddleware::handle();
        $input = json_decode(file_get_contents('php://input'), true) ?? $_POST;

        $newStatus = $input['status'] ?? null;
        $allowed = ['Waiting', 'Assigned', 'In_Progress', 'Completed', 'Cancelled', 'No_Show'];
        if (!in_array($newStatus, $allowed, true)) {
            Response::error('สถานะคิวไม่ถูกต้อง', 400);
        }

        $existing = $this->queueModel->find($queueId);
        if (!$existing) {
            Response::error('ไม่พบข้อมูลคิวนี้', 404);
        }

        $updateData = [
            'status' => $newStatus,
            'updated_at' => date('Y-m-d H:i:s'),
        ];

        if ($newStatus === 'In_Progress') {
            $updateData['actual_start_time'] = date('Y-m-d H:i:s');
            // แจ้งเรียกคิวออกทีวีและ LINE Notify
            if (!empty($existing['room_id'])) {
                $room = (new \App\Models\Room())->find((int)$existing['room_id']);
                (new NotificationService())->notifyQueueCalled($existing['queue_no'], $room['room_no'] ?? '-', 'ผู้รับบริการ');
            }
        } elseif ($newStatus === 'Completed') {
            $updateData['actual_end_time'] = date('Y-m-d H:i:s');
            if (!empty($existing['actual_start_time'])) {
                $mins = round((time() - strtotime($existing['actual_start_time'])) / 60);
                $updateData['service_time_mins'] = $mins > 0 ? $mins : 60;
            }
        }

        $this->queueModel->update($queueId, $updateData);
        AuditLogger::logQueueUpdate($queueId, $existing['queue_no'], $existing['status'], $newStatus);

        // คำนวณ Workload ใหม่ให้หมอนวดหากคิวจบหรือยกเลิก
        if (!empty($existing['therapist_id'])) {
            (new \App\Services\WorkloadBalancer())->updateScore((int)$existing['therapist_id']);
        }

        Response::success("อัปเดตสถานะคิวเป็น {$newStatus} เรียบร้อยแล้ว", ['queue_id' => $queueId, 'status' => $newStatus]);
    }
}