import { google, gmail_v1 } from 'googleapis';
import { getAuthenticatedClient } from './auth.js';
let gmailClient: gmail_v1.Gmail | null = null;
export async function getGmailClient(): Promise<gmail_v1.Gmail> {
if (!gmailClient) {
const auth = await getAuthenticatedClient();
gmailClient = google.gmail({ version: 'v1', auth });
}
return gmailClient;
}
export function resetGmailClient(): void {
gmailClient = null;
}
export class GmailApiError extends Error {
code: number;
details?: unknown;
constructor(message: string, code: number, details?: unknown) {
super(message);
this.name = 'GmailApiError';
this.code = code;
this.details = details;
}
static fromGoogleError(error: unknown): GmailApiError {
if (error && typeof error === 'object' && 'code' in error) {
const googleError = error as { code: number; message?: string; errors?: unknown };
return new GmailApiError(
googleError.message || 'Unknown Gmail API error',
googleError.code,
googleError.errors
);
}
if (error instanceof Error) {
return new GmailApiError(error.message, 500);
}
return new GmailApiError('Unknown error', 500);
}
}
export async function withErrorHandling<T>(
operation: () => Promise<T>,
context: string
): Promise<T> {
try {
return await operation();
} catch (error) {
const gmailError = GmailApiError.fromGoogleError(error);
// Add context to the error message
gmailError.message = `${context}: ${gmailError.message}`;
// Map common error codes to user-friendly messages
switch (gmailError.code) {
case 401:
gmailError.message = 'Authentication expired. Please run "gmail-mcp auth" to re-authenticate.';
break;
case 403:
gmailError.message = `Permission denied: ${gmailError.message}. Check that the required Gmail API scopes are enabled.`;
break;
case 404:
gmailError.message = `Not found: ${gmailError.message}`;
break;
case 429:
gmailError.message = 'Rate limit exceeded. Please wait a moment and try again.';
break;
}
throw gmailError;
}
}
