import { ZodError } from 'zod';

type HttpErrorOptions = {
  code?: string;
  details?: unknown;
  expose?: boolean;
};

type JsonBodyParseError = SyntaxError & {
  status?: number;
  type?: string;
};

export function resolveHttpErrorCode(statusCode: number) {
  switch (statusCode) {
    case 400:
      return 'BAD_REQUEST';
    case 401:
      return 'UNAUTHORIZED';
    case 429:
      return 'TOO_MANY_REQUESTS';
    case 403:
      return 'FORBIDDEN';
    case 404:
      return 'NOT_FOUND';
    case 409:
      return 'CONFLICT';
    case 502:
      return 'UPSTREAM_ERROR';
    default:
      return 'INTERNAL_SERVER_ERROR';
  }
}

export function resolveHttpErrorMessage(statusCode: number) {
  switch (statusCode) {
    case 400:
      return '请求参数不合法';
    case 401:
      return '未授权访问';
    case 429:
      return '请求过于频繁';
    case 403:
      return '禁止访问';
    case 404:
      return '资源不存在';
    case 409:
      return '请求冲突';
    case 502:
      return '上游服务请求失败';
    default:
      return '服务器内部错误';
  }
}

function isJsonBodyParseError(error: unknown): error is JsonBodyParseError {
  return (
    error instanceof SyntaxError &&
    typeof error === 'object' &&
    'status' in error &&
    'type' in error &&
    (error.status === 400 || error.type === 'entity.parse.failed')
  );
}

function serializeZodIssues(error: ZodError) {
  return error.issues.map((issue) => ({
    path: issue.path.join('.'),
    message: issue.message,
    code: issue.code,
  }));
}

export class HttpError extends Error {
  statusCode: number;
  expose: boolean;
  code: string;
  details?: unknown;

  constructor(
    statusCode: number,
    message: string,
    options: HttpErrorOptions = {},
  ) {
    super(message);
    this.name = 'HttpError';
    this.statusCode = statusCode;
    this.expose = options.expose ?? statusCode < 500;
    this.code = options.code ?? resolveHttpErrorCode(statusCode);
    this.details = options.details;
  }
}

export function badRequest(message: string, details?: unknown) {
  return new HttpError(400, message, {
    code: 'BAD_REQUEST',
    details,
  });
}

export function invalidRequest(message = '请求参数不合法', details?: unknown) {
  return new HttpError(400, message, {
    code: 'INVALID_REQUEST',
    details,
  });
}

export function unauthorized(message = '未授权访问') {
  return new HttpError(401, message, {
    code: 'UNAUTHORIZED',
  });
}

export function forbidden(message = '禁止访问') {
  return new HttpError(403, message, {
    code: 'FORBIDDEN',
  });
}

export function tooManyRequests(message = '请求过于频繁', details?: unknown) {
  return new HttpError(429, message, {
    code: 'TOO_MANY_REQUESTS',
    details,
  });
}

export function captchaRequired(message = '需要完成人机校验', details?: unknown) {
  return new HttpError(403, message, {
    code: 'CAPTCHA_REQUIRED',
    details,
  });
}

export function notFound(message = '资源不存在') {
  return new HttpError(404, message, {
    code: 'NOT_FOUND',
  });
}

export function conflict(message: string, details?: unknown) {
  return new HttpError(409, message, {
    code: 'CONFLICT',
    details,
  });
}

export function upstreamError(message: string, details?: unknown) {
  return new HttpError(502, message, {
    code: 'UPSTREAM_ERROR',
    details,
  });
}

export function toHttpError(error: unknown) {
  if (error instanceof HttpError) {
    return error;
  }

  if (error instanceof ZodError) {
    return invalidRequest('请求参数不合法', {
      issues: serializeZodIssues(error),
    });
  }

  if (isJsonBodyParseError(error)) {
    return badRequest('JSON 请求体格式错误');
  }

  return new HttpError(500, '服务器内部错误', {
    code: 'INTERNAL_SERVER_ERROR',
    expose: false,
  });
}