<?php
/**
 * Export Tickets API
 *
 * Exports tickets to CSV format with optional filtering
 */

// Disable error display in the output
ini_set('display_errors', 0);
error_reporting(E_ALL);

// Apply rate limiting
require_once dirname(__DIR__) . '/middleware/RateLimitMiddleware.php';
RateLimitMiddleware::apply('api');

try {
    // Include required files
    require_once dirname(__DIR__) . '/config/config.php';
    require_once dirname(__DIR__) . '/models/TicketModel.php';

    // Check authentication via session
    session_start();
    if (!isset($_SESSION['user']) || !isset($_SESSION['user']['user_id'])) {
        header('Content-Type: application/json');
        http_response_code(401);
        echo json_encode(['success' => false, 'error' => 'Authentication required']);
        exit;
    }

    $currentUser = $_SESSION['user'];

    // Create database connection
    $conn = new mysqli(
        $GLOBALS['config']['DB_HOST'],
        $GLOBALS['config']['DB_USER'],
        $GLOBALS['config']['DB_PASS'],
        $GLOBALS['config']['DB_NAME']
    );

    if ($conn->connect_error) {
        throw new Exception("Database connection failed");
    }

    // Get filter parameters
    $status = isset($_GET['status']) ? $_GET['status'] : null;
    $category = isset($_GET['category']) ? $_GET['category'] : null;
    $type = isset($_GET['type']) ? $_GET['type'] : null;
    $search = isset($_GET['search']) ? trim($_GET['search']) : null;
    $format = isset($_GET['format']) ? $_GET['format'] : 'csv';

    // Initialize model
    $ticketModel = new TicketModel($conn);

    // Get all tickets (no pagination for export)
    $result = $ticketModel->getAllTickets(1, 10000, $status, 'created_at', 'desc', $category, $type, $search);
    $tickets = $result['tickets'];

    if ($format === 'csv') {
        // CSV Export
        header('Content-Type: text/csv; charset=utf-8');
        header('Content-Disposition: attachment; filename="tickets_export_' . date('Y-m-d_His') . '.csv"');
        header('Cache-Control: no-cache, must-revalidate');
        header('Pragma: no-cache');

        // Create output stream
        $output = fopen('php://output', 'w');

        // Add BOM for Excel UTF-8 compatibility
        fprintf($output, chr(0xEF) . chr(0xBB) . chr(0xBF));

        // CSV Headers
        $headers = [
            'Ticket ID',
            'Title',
            'Status',
            'Priority',
            'Category',
            'Type',
            'Created By',
            'Assigned To',
            'Created At',
            'Updated At',
            'Description'
        ];
        fputcsv($output, $headers);

        // CSV Data
        foreach ($tickets as $ticket) {
            $row = [
                $ticket['ticket_id'],
                $ticket['title'],
                $ticket['status'],
                'P' . $ticket['priority'],
                $ticket['category'],
                $ticket['type'],
                $ticket['creator_display_name'] ?? $ticket['creator_username'] ?? 'System',
                $ticket['assigned_display_name'] ?? $ticket['assigned_username'] ?? 'Unassigned',
                $ticket['created_at'],
                $ticket['updated_at'],
                $ticket['description']
            ];
            fputcsv($output, $row);
        }

        fclose($output);
        exit;

    } elseif ($format === 'json') {
        // JSON Export
        header('Content-Type: application/json');
        header('Content-Disposition: attachment; filename="tickets_export_' . date('Y-m-d_His') . '.json"');

        echo json_encode([
            'exported_at' => date('c'),
            'total_tickets' => count($tickets),
            'tickets' => array_map(function($t) {
                return [
                    'ticket_id' => $t['ticket_id'],
                    'title' => $t['title'],
                    'status' => $t['status'],
                    'priority' => $t['priority'],
                    'category' => $t['category'],
                    'type' => $t['type'],
                    'description' => $t['description'],
                    'created_by' => $t['creator_display_name'] ?? $t['creator_username'],
                    'assigned_to' => $t['assigned_display_name'] ?? $t['assigned_username'],
                    'created_at' => $t['created_at'],
                    'updated_at' => $t['updated_at']
                ];
            }, $tickets)
        ], JSON_PRETTY_PRINT);
        exit;

    } else {
        header('Content-Type: application/json');
        http_response_code(400);
        echo json_encode(['success' => false, 'error' => 'Invalid format. Use csv or json.']);
        exit;
    }

} catch (Exception $e) {
    header('Content-Type: application/json');
    http_response_code(500);
    echo json_encode([
        'success' => false,
        'error' => $e->getMessage()
    ]);
}