import { mkdir } from 'node:fs/promises';
import { join } from 'node:path';
import type { EmailMessage } from 'types';
import { createRouter } from '../../create-router';
import { DATA_PATH } from '@@/data-path';
import { openEmailDb, rowToSummary, getSyncMeta } from './email-db';
import { accountsRouter } from './accounts';

export const emailRouter = createRouter();

emailRouter.route('/accounts', accountsRouter);

emailRouter.get('/messages', async (ctx) => {
  const email = ctx.get('user').email;
  const page = Number(ctx.req.query('page') ?? '1');
  const limit = Number(ctx.req.query('limit') ?? '50');
  const folder = ctx.req.query('folder') ?? 'inbox';
  const offset = (page - 1) * limit;

  const folderWhere = folder === 'all' ? 'deleted = 0' : `deleted = 0 AND labels LIKE '%${folder}%'`;

  const db = openEmailDb(email);
  try {
    const rows = db
      .query(`SELECT * FROM emails WHERE ${folderWhere} ORDER BY date DESC LIMIT ? OFFSET ?`)
      .all(limit, offset) as Record<string, unknown>[];
    const countRow = db.query(`SELECT COUNT(*) as total FROM emails WHERE ${folderWhere}`).get() as { total: number };
    const messages = rows.map(rowToSummary);
    return ctx.json({ messages, total: countRow.total });
  } finally {
    db.close();
  }
});

emailRouter.get('/messages/:id', async (ctx) => {
  const email = ctx.get('user').email;
  const id = ctx.req.param('id');

  const db = openEmailDb(email);
  try {
    const row = db.query('SELECT * FROM emails WHERE id = ? AND deleted = 0').get(id) as Record<string, unknown> | null;
    if (!row) return ctx.text('Not found', 404);

    const attachmentRows = db.query('SELECT * FROM attachments WHERE email_id = ? ORDER BY idx').all(id) as Array<
      Record<string, unknown>
    >;

    const from = row.from_name ? `${row.from_name} <${row.from_address}>` : (row.from_address as string);

    const message: EmailMessage = {
      id: row.id as string,
      from,
      to: row.to_address as string,
      cc: (row.cc as string) ?? undefined,
      subject: row.subject as string,
      date: row.date as string,
      snippet: row.snippet as string,
      html: (row.html as string) ?? undefined,
      text: (row.text_body as string) ?? undefined,
      attachments: attachmentRows.map((a) => ({
        filename: a.filename as string,
        size: a.size as number,
        contentType: a.content_type as string,
      })),
      ...(row.attachment_count ? { attachmentCount: row.attachment_count as number } : {}),
      ...(row.read ? { read: true } : {}),
      ...(row.labels ? { labels: (row.labels as string).split(',') } : {}),
    };

    return ctx.json(message);
  } finally {
    db.close();
  }
});

emailRouter.post('/messages/:id/attachments/:index/extract', async (ctx) => {
  const email = ctx.get('user').email;
  const id = ctx.req.param('id');
  const index = Number(ctx.req.param('index'));

  const db = openEmailDb(email);
  try {
    const row = db.query('SELECT filename, content FROM attachments WHERE email_id = ? AND idx = ?').get(id, index) as {
      filename: string;
      content: string | null;
    } | null;
    if (!row || !row.content) return ctx.text('Attachment not found', 404);

    const fileName = row.filename ?? 'unknown';
    const attachDir = join(DATA_PATH, email, 'Gmail', 'emails', 'attachments');
    const destPath = join(attachDir, fileName);

    const destFile = Bun.file(destPath);
    if (!(await destFile.exists())) {
      await mkdir(attachDir, { recursive: true });
      const binary = Buffer.from(row.content, 'base64');
      await Bun.write(destPath, binary);
    }

    return ctx.json({ filePath: `Gmail/emails/attachments/${fileName}`, fileName, root: 'user-data' });
  } catch {
    return ctx.text('Failed to extract attachment', 500);
  } finally {
    db.close();
  }
});

emailRouter.patch('/messages/:id/read', async (ctx) => {
  const email = ctx.get('user').email;
  const id = ctx.req.param('id');

  const db = openEmailDb(email);
  try {
    db.run('UPDATE emails SET read = 1 WHERE id = ? AND read = 0', [id]);
    return ctx.json({ ok: true });
  } finally {
    db.close();
  }
});

emailRouter.delete('/messages/:id', async (ctx) => {
  const email = ctx.get('user').email;
  const id = ctx.req.param('id');

  const db = openEmailDb(email);
  try {
    const result = db.run('UPDATE emails SET deleted = 1 WHERE id = ? AND deleted = 0', [id]);
    if (result.changes === 0) return ctx.text('Not found', 404);
    return ctx.json({ ok: true });
  } finally {
    db.close();
  }
});

emailRouter.get('/sync-status', async (ctx) => {
  const email = ctx.get('user').email;

  const db = openEmailDb(email);
  try {
    const lastSyncAt = getSyncMeta(db, 'last_sync_at');
    return ctx.json({ lastSyncAt });
  } finally {
    db.close();
  }
});

emailRouter.get('/stats', async (ctx) => {
  const email = ctx.get('user').email;
  const folder = ctx.req.query('folder') ?? 'inbox';

  const folderWhere = folder === 'all' ? 'deleted = 0' : `deleted = 0 AND labels LIKE '%${folder}%'`;

  const db = openEmailDb(email);
  try {
    const total = (db.query(`SELECT COUNT(*) as count FROM emails WHERE ${folderWhere}`).get() as { count: number })
      .count;
    const byDomain = db
      .query(
        `SELECT from_domain, COUNT(*) as count FROM emails WHERE ${folderWhere} GROUP BY from_domain ORDER BY count DESC LIMIT 20`,
      )
      .all() as Array<{ from_domain: string; count: number }>;
    const bySender = db
      .query(
        `SELECT from_address, from_name, COUNT(*) as count FROM emails WHERE ${folderWhere} GROUP BY from_address ORDER BY count DESC LIMIT 20`,
      )
      .all() as Array<{ from_address: string; from_name: string; count: number }>;

    return ctx.json({ total, byDomain, bySender });
  } finally {
    db.close();
  }
});

emailRouter.get('/labels', async (ctx) => {
  const email = ctx.get('user').email;

  const db = openEmailDb(email);
  try {
    const rows = db.query('SELECT labels FROM emails WHERE deleted = 0 AND labels IS NOT NULL').all() as Array<{
      labels: string;
    }>;

    const counts = new Map<string, number>();
    for (const row of rows) {
      for (const label of row.labels.split(',')) {
        const trimmed = label.trim().toLowerCase();
        if (trimmed) counts.set(trimmed, (counts.get(trimmed) ?? 0) + 1);
      }
    }

    const labels = [...counts.entries()].map(([label, count]) => ({ label, count })).sort((a, b) => b.count - a.count);

    return ctx.json({ labels });
  } finally {
    db.close();
  }
});