import { NextRequest, NextResponse } from 'next/server';
import { db } from '@/app/db/drizzle';
import { emails } from '@/app/db/schema';
import { authenticate, getBody } from '@/app/lib/utils';
import { eq } from 'drizzle-orm';
import { CopyObjectCommand, GetObjectCommand, HeadObjectCommand } from '@aws-sdk/client-s3';
import { getS3Client } from '@/app/lib/utils';
import nodemailer from 'nodemailer';
import { Readable } from 'stream';

export async function GET(req: NextRequest) {
  if (!authenticate(req)) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });

  const { searchParams } = new URL(req.url);
  const bucket = searchParams.get('bucket');
  const key = searchParams.get('key');
  if (!bucket || !key) return NextResponse.json({ error: 'Missing params' }, { status: 400 });

  const [email] = await db.select().from(emails).where(eq(emails.s3Key, key));
  if (!email) return NextResponse.json({ error: 'Email not found' }, { status: 404 });

  return NextResponse.json({
    subject: email.subject,
    from: email.from,
    to: email.to?.join(', '),
    html: email.html,
    raw: email.raw,
    processed: email.processed ? 'true' : 'false',
  });
}

// PUT: Update processed in S3 and DB
export async function PUT(req: NextRequest) {
  if (!authenticate(req)) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });

  const { bucket, key, processed } = await req.json();
  if (!bucket || !key) return NextResponse.json({ error: 'Missing params' }, { status: 400 });

  const s3 = getS3Client();
  const head = await s3.send(new HeadObjectCommand({ Bucket: bucket, Key: key }));
  const newMeta = { ...head.Metadata, [process.env.PROCESSED_META_KEY!]: processed };
  await s3.send(new CopyObjectCommand({
    Bucket: bucket,
    Key: key,
    CopySource: `${bucket}/${key}`,
    Metadata: newMeta,
    MetadataDirective: 'REPLACE'
  }));

  await db.update(emails).set({ processed: processed === 'true' }).where(eq(emails.s3Key, key));

  return NextResponse.json({ success: true });
}

// POST: Resend, update in S3 and DB
export async function POST(req: NextRequest) {
  if (!authenticate(req)) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });

  const { bucket, key } = await req.json();
  if (!bucket || !key) return NextResponse.json({ error: 'Missing params' }, { status: 400 });

  const s3 = getS3Client();
  const { Body } = await s3.send(new GetObjectCommand({ Bucket: bucket, Key: key }));
  const raw = await getBody(Body as Readable);

  const transporter = nodemailer.createTransport({
    host: process.env.SMTP_HOST,
    port: Number(process.env.SMTP_PORT),
    secure: false,
    auth: { user: process.env.SMTP_USER, pass: process.env.SMTP_PASS },
    tls: { rejectUnauthorized: false }
  });

  try {
    await transporter.sendMail({ raw });
    // Update S3 Metadata
    const head = await s3.send(new HeadObjectCommand({ Bucket: bucket, Key: key }));
    const newMeta = { ...head.Metadata, [process.env.PROCESSED_META_KEY!]: process.env.PROCESSED_META_VALUE! };
    await s3.send(new CopyObjectCommand({
      Bucket: bucket,
      Key: key,
      CopySource: `${bucket}/${key}`,
      Metadata: newMeta,
      MetadataDirective: 'REPLACE'
    }));
    // Update DB
    await db.update(emails).set({ processed: true }).where(eq(emails.s3Key, key));
    return NextResponse.json({ message: 'Resent successfully' });
  } catch (error) {
    return NextResponse.json({ error: (error as Error).message }, { status: 500 });
  }
}