import { NextResponse } from 'next/server';

export type ErrorCode = 
  | 'UNAUTHORIZED'
  | 'FORBIDDEN'
  | 'NOT_FOUND'
  | 'VALIDATION_ERROR'
  | 'INTERNAL_ERROR'
  | 'BAD_REQUEST';

export interface ApiError {
  error: string;
  code: ErrorCode;
  details?: Record<string, unknown>;
}

const ERROR_MESSAGES: Record<ErrorCode, string> = {
  UNAUTHORIZED: '未授权，请先登录',
  FORBIDDEN: '无权限执行此操作',
  NOT_FOUND: '请求的资源不存在',
  VALIDATION_ERROR: '数据验证失败',
  INTERNAL_ERROR: '服务器内部错误',
  BAD_REQUEST: '请求参数错误',
};

export function unauthorized(message?: string): NextResponse<ApiError> {
  return NextResponse.json(
    { error: message || ERROR_MESSAGES.UNAUTHORIZED, code: 'UNAUTHORIZED' },
    { status: 401 }
  );
}

export function forbidden(message?: string): NextResponse<ApiError> {
  return NextResponse.json(
    { error: message || ERROR_MESSAGES.FORBIDDEN, code: 'FORBIDDEN' },
    { status: 403 }
  );
}

export function notFound(message?: string): NextResponse<ApiError> {
  return NextResponse.json(
    { error: message || ERROR_MESSAGES.NOT_FOUND, code: 'NOT_FOUND' },
    { status: 404 }
  );
}

export function validationError(message: string, details?: Record<string, unknown>): NextResponse<ApiError> {
  return NextResponse.json(
    { error: message, code: 'VALIDATION_ERROR', details },
    { status: 400 }
  );
}

export function badRequest(message: string): NextResponse<ApiError> {
  return NextResponse.json(
    { error: message, code: 'BAD_REQUEST' },
    { status: 400 }
  );
}

export function internalError(message = '服务器错误'): NextResponse<ApiError> {
  console.error(message);
  return NextResponse.json(
    { error: ERROR_MESSAGES.INTERNAL_ERROR, code: 'INTERNAL_ERROR' },
    { status: 500 }
  );
}

export function success<T>(data: T, status = 200): NextResponse<T> {
  return NextResponse.json(data, { status });
}

export function handleApiError(error: unknown): NextResponse<ApiError> {
  console.error('API Error:', error);
  
  if (error instanceof Error) {
    if (error.message.includes('未授权')) {
      return unauthorized(error.message);
    }
    if (error.message.includes('无权限')) {
      return forbidden(error.message);
    }
    if (error.message.includes('不存在')) {
      return notFound(error.message);
    }
  }
  
  return internalError();
}