import { Router } from "express";
import { db } from "../db.ts";

export const bookingRouter = Router();

function publicBusiness(slug: string) {
  return db
    .prepare(
      `SELECT id, name, industry, currency, currency_symbol, phone, address, timezone,
              booking_enabled, cancel_window_hours, cancel_penalty_pct, require_deposit, deposit_pct
       FROM businesses WHERE slug = ? AND status = 'active'`
    )
    .get(slug) as any;
}

// Public business info + services + employees
bookingRouter.get("/:slug", (req, res) => {
  const biz = publicBusiness(req.params.slug);
  if (!biz) return res.status(404).json({ error: "Negocio no encontrado" });
  if (!biz.booking_enabled) return res.status(403).json({ error: "Las reservas online están desactivadas" });
  const services = db
    .prepare(`SELECT id, name, description, category, duration_min, price, color FROM services WHERE business_id = ? AND active = 1 ORDER BY category, name`)
    .all(biz.id);
  const employees = db
    .prepare(`SELECT id, name, role, color FROM employees WHERE business_id = ? AND active = 1 ORDER BY name`)
    .all(biz.id);
  res.json({ business: { ...biz, currency_symbol: biz.currency_symbol || "$" }, services, employees });
});

// Available slots for a service + employee on a given date
bookingRouter.get("/:slug/slots", (req, res) => {
  const biz = publicBusiness(req.params.slug);
  if (!biz || !biz.booking_enabled) return res.status(404).json({ error: "No disponible" });
  const serviceId = Number(req.query.service_id);
  const employeeId = req.query.employee_id ? Number(req.query.employee_id) : null;
  const date = req.query.date as string; // YYYY-MM-DD
  if (!serviceId || !date) return res.status(400).json({ error: "service_id y date son obligatorios" });
  const service = db.prepare(`SELECT * FROM services WHERE id = ? AND business_id = ? AND active = 1`).get(serviceId, biz.id) as any;
  if (!service) return res.status(400).json({ error: "Servicio no válido" });

  // candidate employees
  let candidates: number[];
  if (employeeId) {
    const ok = db.prepare(`SELECT 1 FROM employee_services WHERE service_id = ? AND employee_id = ?`).get(serviceId, employeeId);
    if (!ok) return res.status(400).json({ error: "El especialista no ofrece este servicio" });
    candidates = [employeeId];
  } else {
    candidates = db.prepare(`SELECT employee_id id FROM employee_services WHERE service_id = ?`).all(serviceId).map((r: any) => r.id);
    if (candidates.length === 0) {
      const any = db.prepare(`SELECT id FROM employees WHERE business_id = ? AND active = 1 LIMIT 1`).get(biz.id) as any;
      candidates = any ? [any.id] : [];
    }
  }
  if (candidates.length === 0) return res.json({ slots: [] });

  // business hours 09:00–20:00, 30-min grid; reject past times
  const dayStart = new Date(`${date}T09:00:00`);
  const dayEnd = new Date(`${date}T20:00:00`);
  const now = new Date();
  const slots: { time: string; iso: string; employee_id: number; employee_name: string }[] = [];
  const dur = service.duration_min;

  // gather existing appointments that day for these employees
  const startOfDayIso = `${date}T00:00:00`;
  const endOfDayIso = `${date}T23:59:59`;
  const existing = db
    .prepare(
      `SELECT employee_id, start_at, end_at FROM appointments
       WHERE business_id = ? AND employee_id IN (${candidates.map(() => "?").join(",")})
         AND status IN ('scheduled','completed') AND start_at >= ? AND start_at <= ?`
    )
    .all(biz.id, ...candidates, startOfDayIso, endOfDayIso) as any[];

  for (let t = dayStart.getTime(); t + dur * 60000 <= dayEnd.getTime(); t += 30 * 60000) {
    if (t < now.getTime() + 30 * 60000) continue; // skip past / too-soon
    const slotStart = t;
    const slotEnd = t + dur * 60000;
    // find an employee free in this window
    for (const empId of candidates) {
      const busy = existing.some(
        (b) => b.employee_id === empId && slotStart < new Date(b.end_at).getTime() && slotEnd > new Date(b.start_at).getTime()
      );
      if (!busy) {
        const emp = db.prepare(`SELECT name FROM employees WHERE id = ?`).get(empId) as any;
        slots.push({
          time: new Date(t).toLocaleTimeString("es-MX", { hour: "2-digit", minute: "2-digit", hour12: true }),
          iso: new Date(t).toISOString(),
          employee_id: empId,
          employee_name: emp?.name,
        });
        break; // one free employee per slot is enough
      }
    }
    if (slots.length >= 40) break;
  }
  res.json({ slots, service: { id: service.id, name: service.name, price: service.price, duration_min: service.duration_min } });
});

// Create a booking from the public site (no auth): creates/finds client + appointment
bookingRouter.post("/:slug/book", (req, res) => {
  const biz = publicBusiness(req.params.slug);
  if (!biz || !biz.booking_enabled) return res.status(404).json({ error: "No disponible" });
  const { service_id, employee_id, start_at, client } = req.body ?? {};
  if (!service_id || !start_at || !client?.name) return res.status(400).json({ error: "Faltan datos (servicio, hora o nombre)" });
  const service = db.prepare(`SELECT * FROM services WHERE id = ? AND business_id = ? AND active = 1`).get(Number(service_id), biz.id) as any;
  if (!service) return res.status(400).json({ error: "Servicio no válido" });
  const start = new Date(start_at);
  if (isNaN(start.getTime()) || start.getTime() < Date.now()) return res.status(400).json({ error: "Fecha inválida" });

  // resolve employee
  let empId = employee_id ? Number(employee_id) : null;
  if (!empId) {
    const cand = db.prepare(`SELECT employee_id id FROM employee_services WHERE service_id = ? LIMIT 1`).get(Number(service_id)) as any;
    empId = cand?.id ?? null;
  }
  if (!empId) return res.status(400).json({ error: "Sin especialista disponible" });

  // resolve client (by phone/email or create)
  let clientId: number | null = null;
  const match = client.phone
    ? (db.prepare(`SELECT id FROM clients WHERE business_id = ? AND phone = ?`).get(biz.id, client.phone) as any)
    : client.email
    ? (db.prepare(`SELECT id FROM clients WHERE business_id = ? AND email = ?`).get(biz.id, client.email) as any)
    : null;
  if (match) clientId = match.id;
  else {
    const created = db
      .prepare(`INSERT INTO clients (business_id, name, email, phone, tags) VALUES (?, ?, ?, ?, 'Online') RETURNING id`)
      .get(biz.id, client.name, client.email || null, client.phone || null) as any;
    clientId = created.id;
  }

  const endIso = new Date(start.getTime() + service.duration_min * 60000).toISOString().replace(/\.\d{3}Z$/, "Z");
  const startIso = start.toISOString().replace(/\.\d{3}Z$/, "Z");
  const appt = db
    .prepare(
      `INSERT INTO appointments (business_id, service_id, employee_id, client_id, start_at, end_at, status, price, notes)
       VALUES (?, ?, ?, ?, ?, ?, 'scheduled', ?, ?) RETURNING *`
    )
    .get(biz.id, Number(service_id), empId, clientId, startIso, endIso, service.price, client.notes || "Reserva online") as any;

  res.status(201).json({
    appointment: {
      id: appt.id,
      start_at: appt.start_at,
      end_at: appt.end_at,
      price: appt.price,
      service_name: service.name,
      employee_name: (db.prepare(`SELECT name FROM employees WHERE id = ?`).get(empId) as any)?.name,
    },
    business: { name: biz.name, currency_symbol: biz.currency_symbol },
    client_created: !match,
  });
});