/**
 * GET /api/messages/:instanceId/chats
 * Get all chats for an instance
 */
import { query } from '../../../utils/database'

interface ChatRow {
  id: string
  jid: string
  name: string | null
  is_group: boolean
  unread_count: number
  last_message_at: Date | null
}

export default defineEventHandler(async (event) => {
  const username = getHeader(event, 'x-authentik-username')
  if (!username) {
    throw createError({ statusCode: 401, message: 'Unauthorized' })
  }

  const instanceId = getRouterParam(event, 'instanceId')

  // Verify instance exists
  const instanceCheck = await query('SELECT id FROM instances WHERE id = $1', [instanceId])
  if (instanceCheck.rows.length === 0) {
    throw createError({ statusCode: 404, message: 'Instance not found' })
  }

  // Get chats with last message
  const result = await query<ChatRow>(
    `SELECT c.id, c.jid, c.name, c.is_group, c.unread_count, c.last_message_at
     FROM chats c
     WHERE c.instance_id = $1
     ORDER BY c.last_message_at DESC NULLS LAST`,
    [instanceId]
  )

  return result.rows.map(row => ({
    id: row.id,
    jid: row.jid,
    name: row.name || row.jid.split('@')[0],
    isGroup: row.is_group,
    unreadCount: row.unread_count,
    lastMessageAt: row.last_message_at
  }))
})