<?php
// models/DispatchEngine.php
require_once dirname(__DIR__) . '/config/database.php';
require_once __DIR__ . '/User.php';
require_once __DIR__ . '/Job.php';
require_once __DIR__ . '/Setting.php';
require_once __DIR__ . '/Notification.php';

class DispatchEngine {
    private $conn;
    private $settingModel;
    private $userModel;
    private $jobModel;
    
    public function __construct() {
        $this->conn = Database::getInstance();
        $this->settingModel = new Setting();
        $this->userModel = new User();
        $this->jobModel = new Job();
    }

    /**
     * Run auto-dispatch for a newly created job
     * @param int $job_id
     * @return bool True if successfully assigned, false if no one available
     */
    public function runAutoDispatch($job_id) {
        // 1. Check if auto dispatch is enabled
        $dispatchSettings = $this->settingModel->getAllFlat();
        if (!isset($dispatchSettings['auto_dispatch_enabled']) || $dispatchSettings['auto_dispatch_enabled'] != '1') {
            return false;
        }

        // 2. Find available staff
        $staff = $this->userModel->getAvailableStaff();
        if (!$staff) {
            // No one is available, leave job as pending
            return false;
        }
        
        $staff_id = $staff['id'];
        $staff_name = $staff['full_name'];

        // 3. Assign the job
        $query = "UPDATE jobs SET status = 'assigned', assigned_to = :staff_id WHERE id = :job_id";
        $stmt = $this->conn->prepare($query);
        $stmt->bindParam(':staff_id', $staff_id);
        $stmt->bindParam(':job_id', $job_id);
        
        if ($stmt->execute()) {
            // Log timeline
            $this->jobModel->logTimeline($job_id, 'assigned', "ระบบจ่ายงานอัตโนมัติไปยัง: " . $staff_name, null);
            
            // Note: Notification will be sent later in the job lifecycle if needed, 
            // but we can also trigger a specific "Auto Assigned" notification here.
            try {
                $job = $this->jobModel->getById($job_id);
                if ($job) {
                    $notification = new Notification();
                    $msg = "🤖 [Auto Dispatch]\nระบบมอบหมายงาน " . $job['job_number'] . "\nให้กับ: " . $staff_name;
                    $notification->sendToAll($msg);
                }
            } catch (Exception $e) {
                // Ignore
            }
            
            return true;
        }
        
        return false;
    }
}