/**
 * Custom error class for chat model authentication errors
 */
export class ChatModelAuthError extends Error {
  /**
   * Creates a new ChatModelAuthError
   *
   * @param message - The error message
   * @param cause - The original error that caused this error
   */
  constructor(
    message: string,
    public readonly cause?: unknown,
  ) {
    super(message);
    this.name = 'ChatModelAuthError';

    // Maintains proper stack trace for where our error was thrown
    if (Error.captureStackTrace) {
      Error.captureStackTrace(this, ChatModelAuthError);
    }
  }

  /**
   * Returns a string representation of the error
   */
  toString(): string {
    return `${this.name}: ${this.message}${this.cause ? ` (Caused by: ${this.cause})` : ''}`;
  }
}

export class ChatModelForbiddenError extends Error {
  constructor(
    message: string,
    public readonly cause?: unknown,
  ) {
    super(message);
    this.name = 'ChatModelForbiddenError';

    if (Error.captureStackTrace) {
      Error.captureStackTrace(this, ChatModelForbiddenError);
    }
  }

  /**
   * Returns a string representation of the error
   */
  toString(): string {
    return `${this.name}: ${this.message}${this.cause ? ` (Caused by: ${this.cause})` : ''}`;
  }
}

export const LLM_FORBIDDEN_ERROR_MESSAGE =
  '访问被拒绝（403禁止）。请检查: n  n1。您的API密钥具有所需权限\n\n2。设置OLLAMA_ORIGINS=chrome-extension://* \nsee https://github.com/ollama/ollama/blob/main/docs/faq.md';

/**
 * Checks if an error is related to API authentication
 *
 * @param error - The error to check
 * @returns boolean indicating if it's an authentication error
 */
export function isAuthenticationError(error: unknown): boolean {
  if (!(error instanceof Error)) return false;

  // Get the error message
  const errorMessage = error.message || '';

  // Get error name - sometimes error.name just returns "Error" for custom errors
  let errorName = error.name || '';

  // Try to extract the constructor name, which often contains the actual error type
  // This works better than error.name for many custom errors
  const constructorName = error.constructor?.name;
  if (constructorName && constructorName !== 'Error') {
    errorName = constructorName;
  }

  // Check if the error name indicates an authentication error
  if (errorName === 'AuthenticationError') {
    return true;
  }

  // Fallback: check the message for authentication-related indicators
  return (
    errorMessage.toLowerCase().includes('authentication') ||
    errorMessage.includes(' 401') ||
    errorMessage.toLowerCase().includes('api key')
  );
}

/**
 * Checks if an error is related 403 Forbidden
 *
 * @param error - The error to check
 * @returns boolean indicating if it's an 403 Forbidden error
 */
export function isForbiddenError(error: unknown): boolean {
  if (!(error instanceof Error)) return false;
  return error.message.includes(' 403') && error.message.includes('Forbidden');
}