import { NextResponse } from 'next/server';
import Imap from 'imap';
import nodemailer from 'nodemailer';
import { parseEmailHeaders } from '@/lib/email-parser';
import { cookies } from 'next/headers';

interface StoredCredentials {
  email: string;
  password: string;
  host: string;
  port: number;
}

interface Email {
  id: string;
  from: string;
  subject: string;
  date: Date;
  read: boolean;
  starred: boolean;
  body: string;
}

interface ImapBox {
  messages: {
    total: number;
  };
}

interface ImapMessage {
  on: (event: string, callback: (data: any) => void) => void;
  once: (event: string, callback: (data: any) => void) => void;
  attributes: {
    uid: number;
    flags: string[];
    size: number;
  };
  body: {
    [key: string]: {
      on: (event: string, callback: (data: any) => void) => void;
    };
  };
}

interface ImapConfig {
  user: string;
  password: string;
  host: string;
  port: number;
  tls: boolean;
  authTimeout: number;
  connTimeout: number;
  debug?: (info: string) => void;
}

function getStoredCredentials(): StoredCredentials | null {
  const cookieStore = cookies();
  
  const email = cookieStore.get('imap_email')?.value;
  const password = cookieStore.get('imap_password')?.value;
  const host = cookieStore.get('imap_host')?.value;
  const port = cookieStore.get('imap_port')?.value;

  if (!email || !password || !host || !port) {
    console.log('Missing credentials in cookies');
    return null;
  }

  return {
    email,
    password,
    host,
    port: parseInt(port)
  };
}

export async function GET() {
  try {
    const credentials = getStoredCredentials();
    if (!credentials) {
      return NextResponse.json(
        { error: 'No stored credentials found' },
        { status: 401 }
      );
    }

    const imapConfig: ImapConfig = {
      user: credentials.email,
      password: credentials.password,
      host: credentials.host,
      port: credentials.port,
      tls: true,
      authTimeout: 10000,
      connTimeout: 10000,
      debug: (info: string) => console.log('IMAP Debug:', info)
    };

    console.log('IMAP Config:', {
      ...imapConfig,
      password: '***'
    });

    const imap = new Imap(imapConfig);

    const connectPromise = new Promise((resolve, reject) => {
      imap.once('ready', () => resolve(true));
      imap.once('error', (err: Error) => reject(err));
      imap.connect();
    });

    await connectPromise;

    const openBoxPromise = new Promise<ImapBox>((resolve, reject) => {
      imap.openBox('INBOX', false, (err: Error | null, box: ImapBox) => {
        if (err) reject(err);
        else resolve(box);
      });
    });

    const box = await openBoxPromise;

    const fetchPromise = (imap: Imap, seqno: number): Promise<ImapMessage> => {
      return new Promise((resolve, reject) => {
        const f = imap.fetch(seqno, { bodies: ['HEADER', 'TEXT'] });
        f.on('message', (msg: ImapMessage) => {
          resolve(msg);
        });
        f.once('error', reject);
      });
    };

    const processMessage = (msg: ImapMessage): Promise<any> => {
      return new Promise((resolve, reject) => {
        let body = '';
        msg.body['TEXT'].on('data', (chunk: Buffer) => {
          body += chunk.toString('utf8');
        });
        msg.body['TEXT'].on('end', () => {
          const headers = parseEmailHeaders(body);
          resolve({
            uid: msg.attributes.uid,
            flags: msg.attributes.flags,
            size: msg.attributes.size,
            ...headers
          });
        });
        msg.body['TEXT'].on('error', reject);
      });
    };

    const messages: any[] = [];
    for (let seqno = 1; seqno <= 10; seqno++) {
      const msg = await fetchPromise(imap, seqno);
      const processedMsg = await processMessage(msg);
      messages.push(processedMsg);
    }
    imap.end();

    const emails: Email[] = messages.map((msg) => {
      return {
        id: msg.uid.toString(),
        from: msg.from,
        subject: msg.subject,
        date: msg.date,
        read: !msg.flags?.includes('\\Unseen'),
        starred: msg.flags?.includes('\\Flagged') || false,
        body: msg.body
      };
    });

    return NextResponse.json(emails);
  } catch (error) {
    console.error('Error fetching emails:', error);
    const status = error instanceof Error && error.message.includes('Invalid login')
      ? 401
      : 500;
    return NextResponse.json(
      { error: error instanceof Error ? error.message : 'Failed to fetch emails' },
      { status }
    );
  }
}

export async function POST(request: Request) {
  try {
    const credentials = getStoredCredentials();
    if (!credentials) {
      return NextResponse.json(
        { error: 'No stored credentials found' },
        { status: 401 }
      );
    }

    let body;
    try {
      body = await request.json();
    } catch (error) {
      return NextResponse.json(
        { error: 'Invalid JSON in request body' },
        { status: 400 }
      );
    }

    const { to, subject, body: emailBody, attachments } = body;

    if (!to || !subject || !emailBody) {
      return NextResponse.json(
        { error: 'Missing required fields: to, subject, or body' },
        { status: 400 }
      );
    }

    const transporter = nodemailer.createTransport({
      host: credentials.host,
      port: credentials.port,
      secure: true,
      auth: {
        user: credentials.email,
        pass: credentials.password,
      },
    });

    const mailOptions = {
      from: credentials.email,
      to,
      subject,
      text: emailBody,
      attachments: attachments || [],
    };

    const info = await transporter.sendMail(mailOptions);
    console.log('Email sent:', info.messageId);

    return NextResponse.json({ 
      success: true, 
      messageId: info.messageId,
      message: 'Email sent successfully'
    });
  } catch (error) {
    console.error('Error sending email:', error);
    return NextResponse.json(
      { 
        error: error instanceof Error ? error.message : 'Failed to send email',
        details: error instanceof Error ? error.stack : undefined
      },
      { status: 500 }
    );
  }
}