<?php

/**
 * Custom Fields Management API
 * CRUD operations for custom field definitions
 */

ini_set('display_errors', 0);
error_reporting(E_ALL);

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

try {
    require_once dirname(__DIR__) . '/config/config.php';
    require_once dirname(__DIR__) . '/helpers/Database.php';
    require_once dirname(__DIR__) . '/models/CustomFieldModel.php';
    require_once dirname(__DIR__) . '/models/AuditLogModel.php';

    // Check authentication
    if (session_status() === PHP_SESSION_NONE) {
        session_start();
    }
    if (!isset($_SESSION['user']) || !isset($_SESSION['user']['user_id'])) {
        http_response_code(401);
        echo json_encode(['success' => false, 'error' => 'Authentication required']);
        exit;
    }

    // Check admin privileges for write operations
    if ($_SERVER['REQUEST_METHOD'] !== 'GET' && !$_SESSION['user']['is_admin']) {
        http_response_code(403);
        echo json_encode(['success' => false, 'error' => 'Admin privileges required']);
        exit;
    }

    // CSRF Protection for write operations
    if ($_SERVER['REQUEST_METHOD'] !== 'GET') {
        require_once dirname(__DIR__) . '/middleware/CsrfMiddleware.php';
        $csrfToken = $_SERVER['HTTP_X_CSRF_TOKEN'] ?? '';
        if (!CsrfMiddleware::validateToken($csrfToken)) {
            http_response_code(403);
            echo json_encode(['success' => false, 'error' => 'Invalid CSRF token']);
            exit;
        }
    }

    // Use centralized database connection
    $conn = Database::getConnection();

    header('Content-Type: application/json');

    $model = new CustomFieldModel($conn);
    $auditLog = new AuditLogModel($conn);
    $currentUserId = $_SESSION['user']['user_id'];
    $method = $_SERVER['REQUEST_METHOD'];
    $id = isset($_GET['id']) ? (int)$_GET['id'] : null;
    $category = isset($_GET['category']) ? $_GET['category'] : null;

    switch ($method) {
        case 'GET':
            if ($id) {
                $field = $model->getDefinition($id);
                echo json_encode(['success' => (bool)$field, 'field' => $field]);
            } else {
                // Get all definitions, optionally filtered by category
                $activeOnly = !isset($_GET['include_inactive']);
                $fields = $model->getAllDefinitions($category, $activeOnly);
                echo json_encode(['success' => true, 'fields' => $fields]);
            }
            break;

        case 'POST':
            $data = json_decode(file_get_contents('php://input'), true);
            if (!is_array($data)) {
                http_response_code(400);
                echo json_encode(['success' => false, 'error' => 'Invalid JSON']);
                exit;
            }
            $result = $model->createDefinition($data);
            if (!empty($result['success'])) {
                $auditLog->log($currentUserId, 'create', 'custom_field', (string)($result['field_id'] ?? ''), [
                    'field_name' => $data['field_name'] ?? null,
                    'field_label' => $data['field_label'] ?? null,
                    'field_type' => $data['field_type'] ?? null
                ]);
            }
            echo json_encode($result);
            break;

        case 'PUT':
            if (!$id) {
                http_response_code(400);
                echo json_encode(['success' => false, 'error' => 'ID required']);
                exit;
            }

            $data = json_decode(file_get_contents('php://input'), true);
            if (!is_array($data)) {
                http_response_code(400);
                echo json_encode(['success' => false, 'error' => 'Invalid JSON']);
                exit;
            }
            $result = $model->updateDefinition($id, $data);
            if (!empty($result['success'])) {
                $auditLog->log($currentUserId, 'update', 'custom_field', (string)$id, [
                    'entity' => 'custom_field',
                    'field_name' => $data['field_name'] ?? null,
                    'field_label' => $data['field_label'] ?? null,
                    'field_type' => $data['field_type'] ?? null
                ]);
            }
            echo json_encode($result);
            break;

        case 'DELETE':
            if (!$id) {
                http_response_code(400);
                echo json_encode(['success' => false, 'error' => 'ID required']);
                exit;
            }

            $toDelete = $model->getDefinition($id);
            $result = $model->deleteDefinition($id);
            if (!empty($result['success'])) {
                $auditLog->log($currentUserId, 'delete', 'custom_field', (string)$id, [
                    'entity' => 'custom_field',
                    'field_name' => $toDelete['field_name'] ?? 'unknown'
                ]);
            }
            echo json_encode($result);
            break;

        default:
            http_response_code(405);
            echo json_encode(['success' => false, 'error' => 'Method not allowed']);
    }
} catch (Exception $e) {
    error_log("Custom fields API error: " . $e->getMessage());
    http_response_code(500);
    echo json_encode(['success' => false, 'error' => 'An internal error occurred']);
}