import { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
import { OAuth2Client } from "google-auth-library";
import { google, gmail_v1 } from "googleapis";
import { BaseToolHandler } from "../BaseToolHandler.js";
interface CreateDraftArgs {
to: string | string[];
subject: string;
body: string;
cc?: string | string[];
bcc?: string | string[];
isHtml?: boolean;
replyToMessageId?: string;
threadId?: string;
}
export class CreateDraftHandler extends BaseToolHandler {
async runTool(args: CreateDraftArgs, oauth2Client: OAuth2Client): Promise<CallToolResult> {
try {
const gmail = google.gmail({ version: 'v1', auth: oauth2Client });
// Get user's email address
const profile = await gmail.users.getProfile({ userId: 'me' });
const userEmail = profile.data.emailAddress;
// Create the email message
const message = this.createMessage(
userEmail!,
args.to,
args.subject,
args.body,
args.cc,
args.bcc,
args.isHtml || false,
args.replyToMessageId
);
// Create the draft
const requestBody: gmail_v1.Schema$Draft = {
message: {
raw: message,
threadId: args.threadId
}
};
const response = await gmail.users.drafts.create({
userId: 'me',
requestBody
});
return {
content: [
{
type: "text",
text: JSON.stringify({
success: true,
draftId: response.data.id,
messageId: response.data.message?.id,
threadId: response.data.message?.threadId
}, null, 2)
}
]
};
} catch (error) {
this.handleGoogleApiError(error);
throw error;
}
}
private createMessage(
from: string,
to: string | string[],
subject: string,
body: string,
cc?: string | string[],
bcc?: string | string[],
isHtml: boolean = false,
replyToMessageId?: string
): string {
const boundary = "boundary_" + Date.now();
const toAddresses = Array.isArray(to) ? to.join(', ') : to;
let messageParts = [
`From: ${from}`,
`To: ${toAddresses}`,
`Subject: ${subject}`,
'MIME-Version: 1.0'
];
// Add CC if provided
if (cc) {
const ccAddresses = Array.isArray(cc) ? cc.join(', ') : cc;
messageParts.push(`Cc: ${ccAddresses}`);
}
// Add BCC if provided
if (bcc) {
const bccAddresses = Array.isArray(bcc) ? bcc.join(', ') : bcc;
messageParts.push(`Bcc: ${bccAddresses}`);
}
// Add In-Reply-To header if replying
if (replyToMessageId) {
messageParts.push(`In-Reply-To: ${replyToMessageId}`);
messageParts.push(`References: ${replyToMessageId}`);
}
// Set content type
if (isHtml) {
messageParts.push(`Content-Type: multipart/alternative; boundary="${boundary}"`);
messageParts.push('');
messageParts.push(`--${boundary}`);
messageParts.push('Content-Type: text/plain; charset=UTF-8');
messageParts.push('');
messageParts.push(this.htmlToText(body));
messageParts.push('');
messageParts.push(`--${boundary}`);
messageParts.push('Content-Type: text/html; charset=UTF-8');
messageParts.push('');
messageParts.push(body);
messageParts.push('');
messageParts.push(`--${boundary}--`);
} else {
messageParts.push('Content-Type: text/plain; charset=UTF-8');
messageParts.push('');
messageParts.push(body);
}
const message = messageParts.join('\r\n');
// Encode in base64
const encodedMessage = Buffer.from(message)
.toString('base64')
.replace(/\+/g, '-')
.replace(/\//g, '_')
.replace(/=+$/, '');
return encodedMessage;
}
private htmlToText(html: string): string {
// Simple HTML to text conversion
return html
.replace(/<br\s*\/?>/gi, '\n')
.replace(/<\/p>/gi, '\n\n')
.replace(/<[^>]+>/g, '')
.replace(/ /g, ' ')
.replace(/&/g, '&')
.replace(/</g, '<')
.replace(/>/g, '>')
.replace(/"/g, '"')
.replace(/'/g, "'")
.trim();
}
}
