import { Router } from "express";
import { db } from "../db.ts";
import type { AuthedRequest } from "../lib/auth.ts";
import { ownerOnly } from "../lib/auth.ts";
import {
  bizDateISO,
  bizDayBoundsSqlite,
  bizDayBoundsIso,
  toIsoUtc,
} from "../lib/time.ts";
import { cancelRate, noShowRate, completionRate } from "../lib/metrics.ts";

export const dashboardRouter = Router();

dashboardRouter.use(ownerOnly);

const DEFAULT_TZ = "America/Mexico_City";

/** Fetch the business timezone once per handler. */
function bizTz(bid: number | null): string {
  const row = db.prepare(`SELECT timezone t FROM businesses WHERE id = ?`).get(bid) as { t?: string } | undefined;
  return row?.t || DEFAULT_TZ;
}

/** Clamp the range query param into [7, 120], default 30. */
function clampRange(raw: unknown): number {
  const n = Number(raw);
  if (!Number.isFinite(n) || n <= 0) return 30;
  return Math.min(120, Math.max(7, Math.round(n)));
}

dashboardRouter.get("/overview", (req: AuthedRequest, res) => {
  const bid = req.user!.business_id;
  const range = clampRange(req.query.range);
  const tz = bizTz(bid);
  const scalar = (sql: string, ...args: any[]) => (db.prepare(sql).get(...args) as any)?.v ?? 0;

  // Business-local windows, expressed as canonical SQLite UTC strings.
  // created_at is stored in a MIXED format (ISO-Z from seed, space from app default),
  // so we wrap it with datetime() for correct chronological comparison. start_at is
  // consistently ISO-Z, so it compares directly against ISO-Z bounds.
  const todaySql = bizDayBoundsSqlite(tz, 0);
  const rangeStart = bizDayBoundsSqlite(tz, -range).start; // range days ago, biz-local midnight
  const prevStart = bizDayBoundsSqlite(tz, -range * 2).start; // preceding equal-length window
  const todayIso = bizDayBoundsIso(tz, 0);
  const weekStartIso = bizDayBoundsIso(tz, -7).start;
  const rangeStartIso = bizDayBoundsIso(tz, -range).start;
  const nowIso = toIsoUtc(new Date());

  const revenue_today = scalar(
    `SELECT COALESCE(SUM(amount+tip),0) v FROM tickets
     WHERE business_id = ? AND datetime(created_at) >= ? AND datetime(created_at) <= ?`,
    bid, todaySql.start, todaySql.end
  );
  const revenue_range = scalar(
    `SELECT COALESCE(SUM(amount+tip),0) v FROM tickets WHERE business_id = ? AND datetime(created_at) >= ?`,
    bid, rangeStart
  );
  const revenue_prev = scalar(
    `SELECT COALESCE(SUM(amount+tip),0) v FROM tickets
     WHERE business_id = ? AND datetime(created_at) >= ? AND datetime(created_at) < ?`,
    bid, prevStart, rangeStart
  );
  const revenue_change_pct =
    revenue_prev > 0 ? Math.round(((revenue_range - revenue_prev) / revenue_prev) * 1000) / 10 : 0;

  const appts_today = scalar(
    `SELECT COUNT(*) v FROM appointments WHERE business_id = ? AND start_at >= ? AND start_at <= ?`,
    bid, todayIso.start, todayIso.end
  );
  const appts_week = scalar(
    `SELECT COUNT(*) v FROM appointments WHERE business_id = ? AND start_at >= ?`,
    bid, weekStartIso
  );
  const appts_upcoming = scalar(
    `SELECT COUNT(*) v FROM appointments WHERE business_id = ? AND status = 'scheduled' AND start_at >= ?`,
    bid, nowIso
  );
  const active_clients = scalar(
    `SELECT COUNT(DISTINCT client_id) v FROM tickets WHERE business_id = ? AND datetime(created_at) >= ?`,
    bid, bizDayBoundsSqlite(tz, -30).start
  );
  const avg_ticket = scalar(
    `SELECT COALESCE(AVG(amount+tip),0) v FROM tickets WHERE business_id = ? AND datetime(created_at) >= ?`,
    bid, rangeStart
  );

  // Rates over appointments scheduled (start_at) in the window.
  const apptWindowTotal = scalar(
    `SELECT COUNT(*) v FROM appointments WHERE business_id = ? AND start_at >= ?`,
    bid, rangeStartIso
  );
  const cancelledCount = scalar(
    `SELECT COUNT(*) v FROM appointments WHERE business_id = ? AND status = 'cancelled' AND start_at >= ?`,
    bid, rangeStartIso
  );
  const noShowCount = scalar(
    `SELECT COUNT(*) v FROM appointments WHERE business_id = ? AND status = 'no_show' AND start_at >= ?`,
    bid, rangeStartIso
  );
  const completedCount = scalar(
    `SELECT COUNT(*) v FROM appointments WHERE business_id = ? AND status = 'completed' AND start_at >= ?`,
    bid, rangeStartIso
  );
  const cancel_rate = cancelRate(cancelledCount, apptWindowTotal);
  const no_show_rate = noShowRate(noShowCount, apptWindowTotal);
  const completion_pct = completionRate(completedCount, apptWindowTotal);

  res.json({
    revenue_today: Math.round(revenue_today * 100) / 100,
    revenue_range: Math.round(revenue_range * 100) / 100,
    revenue_prev: Math.round(revenue_prev * 100) / 100,
    revenue_change_pct,
    appts_today,
    appts_week,
    appts_upcoming,
    active_clients,
    avg_ticket: Math.round(avg_ticket * 100) / 100,
    cancel_rate,
    no_show_rate,
    completion_pct,
    range,
  });
});

dashboardRouter.get("/best-employees", (req: AuthedRequest, res) => {
  const bid = req.user!.business_id;
  const range = clampRange(req.query.range);
  const tz = bizTz(bid);
  const rangeStart = bizDayBoundsSqlite(tz, -range).start;
  const ratingSince = bizDayBoundsSqlite(tz, -90).start;
  const rows = db
    .prepare(
      `SELECT e.id, e.name, e.color, e.role,
              COUNT(t.id) appts,
              COALESCE(SUM(t.amount+t.tip),0) revenue,
              COALESCE((SELECT AVG(rating) FROM reviews WHERE employee_id = e.id AND datetime(created_at) >= ?), e.rating) avg_rating
       FROM employees e
       LEFT JOIN tickets t ON t.employee_id = e.id AND datetime(t.created_at) >= ?
       WHERE e.business_id = ?
       GROUP BY e.id
       ORDER BY revenue DESC`
    )
    .all(ratingSince, rangeStart, bid) as any[];
  const totalAppts = rows.reduce((a, r) => a + r.appts, 0);
  const out = rows.map((r) => ({
    employee: { id: r.id, name: r.name, color: r.color, role: r.role },
    appointments: r.appts,
    revenue: Math.round(r.revenue * 100) / 100,
    avg_rating: Math.round(r.avg_rating * 10) / 10,
    share_pct: totalAppts > 0 ? Math.round((r.appts / totalAppts) * 100) : 0,
  }));
  res.json({ employees: out });
});

dashboardRouter.get("/best-services", (req: AuthedRequest, res) => {
  const bid = req.user!.business_id;
  const range = clampRange(req.query.range);
  const tz = bizTz(bid);
  const rangeStart = bizDayBoundsSqlite(tz, -range).start;
  const rows = db
    .prepare(
      `SELECT s.id, s.name, s.category, s.color,
              COUNT(t.id) count,
              COALESCE(SUM(t.amount+t.tip),0) revenue
       FROM services s
       LEFT JOIN tickets t ON t.service_id = s.id AND datetime(t.created_at) >= ?
       WHERE s.business_id = ?
       GROUP BY s.id
       ORDER BY revenue DESC`
    )
    .all(rangeStart, bid) as any[];
  const out = rows.map((r) => ({
    service: { id: r.id, name: r.name, category: r.category, color: r.color },
    count: r.count,
    revenue: Math.round(r.revenue * 100) / 100,
  }));
  res.json({ services: out });
});

dashboardRouter.get("/top-tickets", (req: AuthedRequest, res) => {
  const bid = req.user!.business_id;
  const limit = Math.min(50, Number(req.query.limit) || 10);
  const range = clampRange(req.query.range);
  const tz = bizTz(bid);
  const rangeStart = bizDayBoundsSqlite(tz, -range).start;
  const rows = db
    .prepare(
      `SELECT t.*, s.name service_name, s.category service_category, s.color service_color,
              e.name employee_name, e.color employee_color,
              c.name client_name
       FROM tickets t
       JOIN services s ON s.id = t.service_id
       JOIN employees e ON e.id = t.employee_id
       JOIN clients c ON c.id = t.client_id
       WHERE t.business_id = ? AND datetime(t.created_at) >= ?
       ORDER BY (t.amount + t.tip) DESC
       LIMIT ?`
    )
    .all(bid, rangeStart, limit) as any[];
  const out = rows.map((t) => ({
    ticket: {
      id: t.id,
      business_id: t.business_id,
      appointment_id: t.appointment_id,
      client_id: t.client_id,
      employee_id: t.employee_id,
      service_id: t.service_id,
      amount: t.amount,
      tip: t.tip,
      payment_method: t.payment_method,
      created_at: t.created_at,
      service: { id: t.service_id, name: t.service_name, category: t.service_category, color: t.service_color },
      employee: { id: t.employee_id, name: t.employee_name, color: t.employee_color },
      client: { id: t.client_id, name: t.client_name },
    },
  }));
  res.json({ tickets: out });
});

dashboardRouter.get("/top-clients", (req: AuthedRequest, res) => {
  const bid = req.user!.business_id;
  const limit = Math.min(50, Number(req.query.limit) || 10);
  const range = clampRange(req.query.range);
  const tz = bizTz(bid);
  const rangeStart = bizDayBoundsSqlite(tz, -range).start;
  const rows = db
    .prepare(
      `SELECT c.id, c.name, c.tags, c.phone,
              COUNT(t.id) visits,
              COALESCE(SUM(t.amount+t.tip),0) total,
              MAX(t.created_at) last_visit
       FROM clients c
       LEFT JOIN tickets t ON t.client_id = c.id AND datetime(t.created_at) >= ?
       WHERE c.business_id = ?
       GROUP BY c.id
       HAVING visits > 0
       ORDER BY total DESC
       LIMIT ?`
    )
    .all(rangeStart, bid, limit) as any[];
  const out = rows.map((r) => ({
    client: { id: r.id, name: r.name, tags: r.tags, phone: r.phone },
    visits: r.visits,
    total_spent: Math.round(r.total * 100) / 100,
    last_visit: r.last_visit,
  }));
  res.json({ clients: out });
});

dashboardRouter.get("/frequent-clients", (req: AuthedRequest, res) => {
  const bid = req.user!.business_id;
  const limit = Math.min(50, Number(req.query.limit) || 10);
  const range = clampRange(req.query.range);
  const tz = bizTz(bid);
  const rangeStart = bizDayBoundsSqlite(tz, -range).start;
  const rows = db
    .prepare(
      `SELECT c.id, c.name, c.tags, c.phone,
              COUNT(t.id) visits,
              COALESCE(SUM(t.amount+t.tip),0) total,
              MAX(t.created_at) last_visit
       FROM clients c
       JOIN tickets t ON t.client_id = c.id AND datetime(t.created_at) >= ?
       WHERE c.business_id = ?
       GROUP BY c.id
       ORDER BY visits DESC, total DESC
       LIMIT ?`
    )
    .all(rangeStart, bid, limit) as any[];
  const out = rows.map((r) => ({
    client: { id: r.id, name: r.name, tags: r.tags, phone: r.phone },
    visits: r.visits,
    total_spent: Math.round(r.total * 100) / 100,
    last_visit: r.last_visit,
  }));
  res.json({ clients: out });
});

dashboardRouter.get("/revenue-trend", (req: AuthedRequest, res) => {
  const bid = req.user!.business_id;
  const days = Math.min(120, Math.max(1, Number(req.query.days) || 30));
  const tz = bizTz(bid);
  const rangeStart = bizDayBoundsSqlite(tz, -days).start;
  // Pull raw tickets and bucket by BUSINESS-LOCAL date in JS (SQLite date() would use UTC,
  // misattributing the evening rush to the next day).
  const rows = db
    .prepare(
      `SELECT created_at, amount, tip FROM tickets
       WHERE business_id = ? AND datetime(created_at) >= ?`
    )
    .all(bid, rangeStart) as { created_at: string; amount: number; tip: number }[];
  const map = new Map<string, { revenue: number; appts: number }>();
  for (const r of rows) {
    // Stored created_at may be "YYYY-MM-DD HH:MM:SS" (space) or "YYYY-MM-DDTHH:MM:SSZ";
    // normalize to an ISO UTC instant before converting to the biz date.
    const iso = typeof r.created_at === "string" && r.created_at.includes("T")
      ? r.created_at
      : String(r.created_at).replace(" ", "T") + "Z";
    const key = bizDateISO(new Date(iso), tz);
    const cur = map.get(key) ?? { revenue: 0, appts: 0 };
    cur.revenue += Number(r.amount) + Number(r.tip);
    cur.appts += 1;
    map.set(key, cur);
  }
  const out: { date: string; revenue: number; appts: number }[] = [];
  const now = new Date();
  for (let i = days - 1; i >= 0; i--) {
    const d = new Date(now.getTime() - i * 86400000);
    const key = bizDateISO(d, tz);
    const row = map.get(key);
    out.push({
      date: key,
      revenue: row ? Math.round(row.revenue * 100) / 100 : 0,
      appts: row ? row.appts : 0,
    });
  }
  res.json({ points: out });
});

dashboardRouter.get("/revenue-by-category", (req: AuthedRequest, res) => {
  const bid = req.user!.business_id;
  const range = clampRange(req.query.range);
  const tz = bizTz(bid);
  const rangeStart = bizDayBoundsSqlite(tz, -range).start;
  const rows = db
    .prepare(
      `SELECT s.category, COUNT(t.id) count, COALESCE(SUM(t.amount+t.tip),0) revenue
       FROM tickets t
       JOIN services s ON s.id = t.service_id
       WHERE t.business_id = ? AND datetime(t.created_at) >= ?
       GROUP BY s.category
       ORDER BY revenue DESC`
    )
    .all(bid, rangeStart) as any[];
  const out = rows.map((r) => ({
    category: r.category,
    count: r.count,
    revenue: Math.round(r.revenue * 100) / 100,
  }));
  res.json({ slices: out });
});

dashboardRouter.get("/tickets", (req: AuthedRequest, res) => {
  const bid = req.user!.business_id;
  const limit = Math.min(200, Number(req.query.limit) || 50);
  const rows = db
    .prepare(
      `SELECT t.*, s.name service_name, s.category service_category, s.color service_color,
              e.name employee_name, e.color employee_color,
              c.name client_name
       FROM tickets t
       JOIN services s ON s.id = t.service_id
       JOIN employees e ON e.id = t.employee_id
       JOIN clients c ON c.id = t.client_id
       WHERE t.business_id = ?
       ORDER BY t.created_at DESC
       LIMIT ?`
    )
    .all(bid, limit) as any[];
  const out = rows.map((t) => ({
    id: t.id,
    business_id: t.business_id,
    appointment_id: t.appointment_id,
    client_id: t.client_id,
    employee_id: t.employee_id,
    service_id: t.service_id,
    amount: t.amount,
    tip: t.tip,
    commission: t.commission,
    payment_method: t.payment_method,
    created_at: t.created_at,
    service: { id: t.service_id, name: t.service_name, category: t.service_category, color: t.service_color },
    employee: { id: t.employee_id, name: t.employee_name, color: t.employee_color },
    client: { id: t.client_id, name: t.client_name },
  }));
  res.json({ tickets: out });
});

dashboardRouter.get("/commissions", (req: AuthedRequest, res) => {
  const bid = req.user!.business_id;
  const range = clampRange(req.query.range);
  const tz = bizTz(bid);
  const rangeStart = bizDayBoundsSqlite(tz, -range).start;
  const rows = db
    .prepare(
      `SELECT e.id, e.name, e.color, e.role,
              COUNT(t.id) sales,
              COALESCE(SUM(t.amount + t.tip), 0) revenue,
              COALESCE(SUM(t.commission), 0) commission
       FROM employees e
       LEFT JOIN tickets t ON t.employee_id = e.id AND datetime(t.created_at) >= ?
       WHERE e.business_id = ?
       GROUP BY e.id
       ORDER BY commission DESC`
    )
    .all(rangeStart, bid) as any[];
  const out = rows.map((r) => ({
    employee: { id: r.id, name: r.name, color: r.color, role: r.role },
    sales: r.sales,
    revenue: Math.round(r.revenue * 100) / 100,
    commission: Math.round(r.commission * 100) / 100,
  }));
  const total = out.reduce((a, r) => a + r.commission, 0);
  res.json({ rows: out, total: Math.round(total * 100) / 100 });
});