import { Router } from 'express';
import { query } from '../config/db.js';
import { requireAuth } from '../middleware/auth.js';
import { getRole } from './guards.js';

const router = Router();
router.use(requireAuth);

async function attachReactions(messages) {
  if (!messages.length) return messages;
  const ids = messages.map((m) => m.id);
  const { rows } = await query(
    `SELECT target_id, emoji, COUNT(*)::int AS count, array_agg(user_id) AS users
     FROM reactions WHERE target_type = 'chat' AND target_id = ANY($1)
     GROUP BY target_id, emoji`,
    [ids],
  );
  const byMsg = {};
  for (const r of rows) {
    if (!byMsg[r.target_id]) byMsg[r.target_id] = [];
    byMsg[r.target_id].push({ emoji: r.emoji, count: r.count, users: r.users });
  }
  return messages.map((m) => ({ ...m, reactions: byMsg[m.id] || [] }));
}

// GET /api/chat/:workspaceId — last 100 messages
router.get('/:workspaceId', async (req, res) => {
  const role = await getRole(req.params.workspaceId, req.user.id);
  if (!role) return res.status(403).json({ error: 'Not a workspace member' });
  const { rows } = await query(
    `SELECT m.*, u.name AS author_name, u.avatar AS author_avatar
     FROM chat_messages m LEFT JOIN users u ON u.id = m.user_id
     WHERE m.workspace_id = $1 ORDER BY m.created_at DESC LIMIT 100`,
    [req.params.workspaceId],
  );
  const withReactions = await attachReactions(rows.reverse());
  return res.json({ messages: withReactions });
});

// POST /api/chat/:workspaceId { body } — post + realtime broadcast + notify others
router.post('/:workspaceId', async (req, res) => {
  const wsId = req.params.workspaceId;
  const role = await getRole(wsId, req.user.id);
  if (!role) return res.status(403).json({ error: 'Not a workspace member' });
  const { body = '', attachment = '' } = req.body ?? {};
  if (String(body).trim().length < 1 || String(body).length > 2000) {
    return res.status(400).json({ error: 'Body must be 1-2000 chars' });
  }
  const { rows } = await query(
    'INSERT INTO chat_messages (workspace_id, user_id, body, attachment) VALUES ($1,$2,$3,$4) RETURNING *',
    [wsId, req.user.id, String(body).trim(), String(attachment).slice(0, 2000)],
  );
  const { rows: author } = await query('SELECT name, avatar FROM users WHERE id = $1', [req.user.id]);
  const msg = { ...rows[0], author_name: author[0]?.name, author_avatar: author[0]?.avatar, reactions: [] };
  const io = req.app.get('io');
  io?.to(`chat:${wsId}`).emit('chat:message', { message: msg });
  // Notify all other members
  const { rows: members } = await query(
    'SELECT user_id FROM workspace_members WHERE workspace_id = $1 AND user_id <> $2',
    [wsId, req.user.id],
  );
  const { rows: wsRows } = await query('SELECT name FROM workspaces WHERE id = $1', [wsId]);
  for (const m of members) {
    await query(
      `INSERT INTO notifications (user_id, type, title, body, link)
       VALUES ($1,'chat',$2,$3,$4)`,
      [m.user_id, `💬 ${author[0]?.name || 'Someone'} in ${wsRows[0]?.name || ''}`,
        String(body).trim().slice(0, 140), '/chat'],
    );
    io?.to(`user:${m.user_id}`).emit('notification:new', { type: 'chat' });
  }
  return res.status(201).json({ message: msg });
});

// PATCH /api/chat/message/:id { body } (own)
router.patch('/message/:id', async (req, res) => {
  const { rows } = await query('SELECT * FROM chat_messages WHERE id = $1', [req.params.id]);
  const msg = rows[0];
  if (!msg) return res.status(404).json({ error: 'Not found' });
  if (msg.user_id !== req.user.id) return res.status(403).json({ error: 'Forbidden' });
  const { body = '' } = req.body ?? {};
  if (String(body).trim().length < 1 || String(body).length > 2000) {
    return res.status(400).json({ error: 'Body must be 1-2000 chars' });
  }
  const { rows: updated } = await query(
    'UPDATE chat_messages SET body = $1, edited_at = now() WHERE id = $2 RETURNING *',
    [String(body).trim(), msg.id],
  );
  req.app.get('io')?.to(`chat:${msg.workspace_id}`).emit('chat:edited', { message: updated[0] });
  return res.json({ message: updated[0] });
});

// GET /api/chat/:workspaceId/search?q=
router.get('/:workspaceId/search', async (req, res) => {
  const role = await getRole(req.params.workspaceId, req.user.id);
  if (!role) return res.status(403).json({ error: 'Not a workspace member' });
  const q = String(req.query.q || '').slice(0, 100);
  if (q.length < 2) return res.json({ messages: [] });
  const { rows } = await query(
    `SELECT m.*, u.name AS author_name FROM chat_messages m
     LEFT JOIN users u ON u.id = m.user_id
     WHERE m.workspace_id = $1 AND m.body ILIKE $2
     ORDER BY m.created_at DESC LIMIT 30`,
    [req.params.workspaceId, `%${q}%`],
  );
  return res.json({ messages: rows });
});
router.delete('/message/:id', async (req, res) => {
  const { rows } = await query('SELECT * FROM chat_messages WHERE id = $1', [req.params.id]);
  const msg = rows[0];
  if (!msg) return res.status(404).json({ error: 'Not found' });
  const role = await getRole(msg.workspace_id, req.user.id);
  const { rows: me } = await query('SELECT is_admin FROM users WHERE id = $1', [req.user.id]);
  if (msg.user_id !== req.user.id && !me[0]?.is_admin && role !== 'owner' && role !== 'admin') {
    return res.status(403).json({ error: 'Forbidden' });
  }
  await query('DELETE FROM chat_messages WHERE id = $1', [msg.id]);
  req.app.get('io')?.to(`chat:${msg.workspace_id}`).emit('chat:deleted', { id: msg.id });
  return res.status(204).end();
});

export default router;