import { pool, rowToTicket } from './db';
import type { Ticket, TicketFilters, StatsResponse } from './types';

// List tickets with optional filters. Text search spans number + short desc +
// assignee. Ordered newest-activity-first so the operational board is useful.
export async function listTickets(f: TicketFilters): Promise<Ticket[]> {
  const where: string[] = [];
  const params: unknown[] = [];
  const add = (sql: string, val: unknown) => { params.push(val); where.push(sql.replace('$?', `$${params.length}`)); };

  if (f.status)   add('status = $?', f.status);
  if (f.state)    add('state = $?', f.state);
  if (f.group)    add('assignment_group = $?', f.group);
  if (f.assignee) add('assigned_to = $?', f.assignee);
  if (f.q) {
    params.push(`%${f.q.toLowerCase()}%`);
    const p = `$${params.length}`;
    where.push(`(lower(number) LIKE ${p} OR lower(short_desc) LIKE ${p} OR lower(coalesce(assigned_to,'')) LIKE ${p})`);
  }

  const sql = `
    SELECT * FROM tickets
    ${where.length ? 'WHERE ' + where.join(' AND ') : ''}
    ORDER BY last_activity_at DESC NULLS LAST, number DESC
    LIMIT 2000
  `;
  const { rows } = await pool.query(sql, params);
  return rows.map(rowToTicket);
}

export async function getTicket(number: string): Promise<Ticket | null> {
  const { rows } = await pool.query(`SELECT * FROM tickets WHERE number = $1`, [number]);
  return rows[0] ? rowToTicket(rows[0]) : null;
}

export async function getStats(): Promise<StatsResponse> {
  const [totals, byState, byGroup, byAssignee] = await Promise.all([
    pool.query<{ status: string; n: string }>(`SELECT status, count(*)::text AS n FROM tickets GROUP BY status`),
    pool.query<{ state: string; n: string }>(
      `SELECT state, count(*)::text AS n FROM tickets WHERE status='active' GROUP BY state ORDER BY count(*) DESC`),
    pool.query<{ g: string; n: string }>(
      `SELECT coalesce(assignment_group,'—') AS g, count(*)::text AS n FROM tickets WHERE status='active' GROUP BY g ORDER BY count(*) DESC`),
    pool.query<{ a: string; n: string }>(
      `SELECT coalesce(assigned_to,'—') AS a, count(*)::text AS n FROM tickets WHERE status='active' GROUP BY a ORDER BY count(*) DESC LIMIT 20`),
  ]);

  const active = Number(totals.rows.find(r => r.status === 'active')?.n ?? '0');
  const closed = Number(totals.rows.find(r => r.status === 'closed')?.n ?? '0');
  return {
    total: active + closed,
    active,
    closed,
    byState:    byState.rows.map(r => ({ state: r.state || '—', count: Number(r.n) })),
    byGroup:    byGroup.rows.map(r => ({ group: r.g, count: Number(r.n) })),
    byAssignee: byAssignee.rows.map(r => ({ assignee: r.a, count: Number(r.n) })),
  };
}