<?php
/**
 * ResponseHelper - Standardized JSON response formatting
 *
 * Provides consistent API response structure across all endpoints.
 */
class ResponseHelper {
    /**
     * Send a success response
     *
     * @param array $data Additional data to include
     * @param string $message Success message
     * @param int $code HTTP status code
     */
    public static function success($data = [], $message = 'Success', $code = 200) {
        http_response_code($code);
        header('Content-Type: application/json');
        echo json_encode(array_merge([
            'success' => true,
            'message' => $message
        ], $data));
        exit;
    }

    /**
     * Send an error response
     *
     * @param string $message Error message
     * @param int $code HTTP status code
     * @param array $data Additional data to include
     */
    public static function error($message, $code = 400, $data = []) {
        http_response_code($code);
        header('Content-Type: application/json');
        echo json_encode(array_merge([
            'success' => false,
            'error' => $message
        ], $data));
        exit;
    }

    /**
     * Send an unauthorized response (401)
     *
     * @param string $message Error message
     */
    public static function unauthorized($message = 'Authentication required') {
        self::error($message, 401);
    }

    /**
     * Send a forbidden response (403)
     *
     * @param string $message Error message
     */
    public static function forbidden($message = 'Access denied') {
        self::error($message, 403);
    }

    /**
     * Send a not found response (404)
     *
     * @param string $message Error message
     */
    public static function notFound($message = 'Resource not found') {
        self::error($message, 404);
    }

    /**
     * Send a validation error response (422)
     *
     * @param array $errors Validation errors
     * @param string $message Error message
     */
    public static function validationError($errors, $message = 'Validation failed') {
        self::error($message, 422, ['validation_errors' => $errors]);
    }

    /**
     * Send a server error response (500)
     *
     * @param string $message Error message
     */
    public static function serverError($message = 'Internal server error') {
        self::error($message, 500);
    }

    /**
     * Send a rate limit exceeded response (429)
     *
     * @param int $retryAfter Seconds until retry is allowed
     * @param string $message Error message
     */
    public static function rateLimitExceeded($retryAfter = 60, $message = 'Rate limit exceeded') {
        header('Retry-After: ' . $retryAfter);
        self::error($message, 429, ['retry_after' => $retryAfter]);
    }

    /**
     * Send a created response (201)
     *
     * @param array $data Resource data
     * @param string $message Success message
     */
    public static function created($data = [], $message = 'Resource created') {
        self::success($data, $message, 201);
    }

    /**
     * Send a no content response (204)
     */
    public static function noContent() {
        http_response_code(204);
        exit;
    }
}