/**
 * Authentication error messages and handling utilities
 */

interface AuthErrorMapping {
  [key: string]: {
    title: string;
    description?: string;
  };
}

const AUTH_ERROR_MESSAGES: AuthErrorMapping = {
  // Common HTTP errors
  "401": {
    title: "Invalid credentials",
    description: "Please check your email and password"
  },
  "403": {
    title: "Access denied",
    description: "Your account may be suspended or restricted"
  },
  "404": {
    title: "Account not found",
    description: "No account exists with this email address"
  },
  "409": {
    title: "Account conflict",
    description: "An account with this email already exists"
  },
  "429": {
    title: "Too many attempts",
    description: "Please wait before trying again"
  },
  "500": {
    title: "Server error",
    description: "Something went wrong on our end. Please try again"
  },
  "503": {
    title: "Service unavailable",
    description: "Login service is temporarily down"
  },

  // FastAPI specific errors
  "LOGIN_BAD_CREDENTIALS": {
    title: "Invalid credentials",
    description: "The email or password you entered is incorrect"
  },
  "LOGIN_USER_NOT_VERIFIED": {
    title: "Account not verified",
    description: "Please verify your email address before signing in"
  },
  "USER_INACTIVE": {
    title: "Account inactive",
    description: "Your account has been deactivated. Contact support for assistance"
  },
  "REGISTER_USER_ALREADY_EXISTS": {
    title: "Account already exists",
    description: "An account with this email address already exists"
  },
  "REGISTER_INVALID_PASSWORD": {
    title: "Invalid password",
    description: "Password must meet security requirements"
  },

  // OAuth errors
  "access_denied": {
    title: "Access denied",
    description: "You denied access or cancelled the login process"
  },
  "invalid_request": {
    title: "Invalid request",
    description: "The login request was malformed"
  },
  "unauthorized_client": {
    title: "Authentication failed",
    description: "The application is not authorized to perform this action"
  },
  "unsupported_response_type": {
    title: "Login method not supported",
    description: "This login method is not currently available"
  },
  "invalid_scope": {
    title: "Invalid permissions",
    description: "The requested permissions are not valid"
  },
  "server_error": {
    title: "Server error",
    description: "An error occurred on the authentication server"
  },
  "temporarily_unavailable": {
    title: "Service unavailable",
    description: "Login is temporarily unavailable. Please try again later"
  },

  // Network errors
  "NETWORK_ERROR": {
    title: "Connection failed",
    description: "Please check your internet connection and try again"
  },
  "TIMEOUT": {
    title: "Request timeout",
    description: "The login request took too long. Please try again"
  },

  // Generic fallbacks
  "UNKNOWN_ERROR": {
    title: "Login failed",
    description: "An unexpected error occurred. Please try again"
  }
};

/**
 * Get a user-friendly error message for authentication errors
 * @param errorCode - The error code or message from the API
 * @param returnTitle - Whether to return just the title or full description
 * @returns Formatted error message
 */
export function getAuthErrorMessage(errorCode: string, returnTitle: boolean = false): string {
  if (!errorCode) {
    const fallback = AUTH_ERROR_MESSAGES.UNKNOWN_ERROR;
    return returnTitle ? fallback.title : fallback.description || fallback.title;
  }

  // Clean up the error code
  const cleanErrorCode = errorCode.trim().toUpperCase();
  
  // Try exact match first
  let errorInfo = AUTH_ERROR_MESSAGES[cleanErrorCode] || AUTH_ERROR_MESSAGES[errorCode];
  
  // Try partial matches for HTTP status codes
  if (!errorInfo) {
    const statusCodeMatch = errorCode.match(/(\d{3})/);
    if (statusCodeMatch) {
      errorInfo = AUTH_ERROR_MESSAGES[statusCodeMatch[1]];
    }
  }
  
  // Try partial matches for common error patterns
  if (!errorInfo) {
    const patterns = [
      { pattern: /credential|password|email/i, code: "LOGIN_BAD_CREDENTIALS" },
      { pattern: /verify|verification/i, code: "LOGIN_USER_NOT_VERIFIED" },
      { pattern: /inactive|disabled|suspended/i, code: "USER_INACTIVE" },
      { pattern: /exists|duplicate/i, code: "REGISTER_USER_ALREADY_EXISTS" },
      { pattern: /network|connection/i, code: "NETWORK_ERROR" },
      { pattern: /timeout/i, code: "TIMEOUT" },
      { pattern: /rate|limit|many/i, code: "429" },
    ];

    for (const { pattern, code } of patterns) {
      if (pattern.test(errorCode)) {
        errorInfo = AUTH_ERROR_MESSAGES[code];
        break;
      }
    }
  }
  
  // Fallback to unknown error
  if (!errorInfo) {
    errorInfo = AUTH_ERROR_MESSAGES.UNKNOWN_ERROR;
  }
  
  return returnTitle ? errorInfo.title : errorInfo.description || errorInfo.title;
}

/**
 * Get both title and description for an error
 * @param errorCode - The error code or message from the API
 * @returns Object with title and description
 */
export function getAuthErrorDetails(errorCode: string): { title: string; description: string } {
  const title = getAuthErrorMessage(errorCode, true);
  const description = getAuthErrorMessage(errorCode, false);
  
  return { title, description };
}

/**
 * Check if an error is a network-related error
 * @param error - The error object or message
 * @returns True if it's a network error
 */
export function isNetworkError(error: unknown): boolean {
  if (error instanceof TypeError && error.message.includes('fetch')) {
    return true;
  }
  
  if (typeof error === 'string') {
    return /network|connection|fetch|cors/i.test(error);
  }
  
  return false;
}

/**
 * Check if an error should trigger a retry action
 * @param errorCode - The error code or message
 * @returns True if retry is recommended
 */
export function shouldRetry(errorCode: string): boolean {
  const retryableCodes = ['500', '503', '429', 'NETWORK_ERROR', 'TIMEOUT', 'server_error', 'temporarily_unavailable'];
  
  return retryableCodes.some(code => 
    errorCode.includes(code) || 
    errorCode.toUpperCase().includes(code)
  );
}