import { PrismaClient } from '@prisma/client';

const prisma = new PrismaClient();

// ====== Config ======
const PREVIOUS_WEEKS = 5;
const INCLUDE_CURRENT = false;

function timeAt(hour: number, minute: number) {
  return new Date(Date.UTC(1970, 0, 1, hour, minute, 0));
}

function mondayOfThisWeekUTC(now = new Date()) {
  const d = new Date(Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate()));
  const day = d.getUTCDay();
  const diffToMonday = (day + 6) % 7;
  d.setUTCDate(d.getUTCDate() - diffToMonday);
  d.setUTCHours(0, 0, 0, 0);
  return d;
}

function weekDatesFromMonday(monday: Date) {
  return Array.from({ length: 5 }, (_, i) => {
    const d = new Date(monday);
    d.setUTCDate(monday.getUTCDate() + i);
    return d;
  });
}

function mondayNWeeksBefore(monday: Date, n: number) {
  const d = new Date(monday);
  d.setUTCDate(d.getUTCDate() - n * 7);
  return d;
}

function rndInt(min: number, max: number) {
  return Math.floor(Math.random() * (max - min + 1)) + min;
}

async function main() {
  // Bank codes utilisés
  const BANKS = ['G1', 'G56', 'G48', 'G700', 'G105', 'G305', 'G43'] as const;
  const bcRows = await prisma.bankCodes.findMany({
    where: { bank_code: { in: BANKS as unknown as string[] } },
    select: { id: true, bank_code: true },
  });
  const bcMap = new Map(bcRows.map(b => [b.bank_code, b.id]));
  for (const c of BANKS) {
    if (!bcMap.has(c)) throw new Error(`Bank code manquant: ${c}`);
  }

  const employees = await prisma.employees.findMany({ select: { id: true } });
  if (!employees.length) {
    console.log('Aucun employé — rien à insérer.');
    return;
  }

  const tsByEmp = new Map<number, { id: number }[]>();
  {
    const allTs = await prisma.timesheets.findMany({
      where: { employee_id: { in: employees.map(e => e.id) } },
      select: { id: true, employee_id: true },
      orderBy: { id: 'asc' },
    });
    for (const e of employees) {
      tsByEmp.set(e.id, allTs.filter(t => t.employee_id === e.id).map(t => ({ id: t.id })));
    }
  }

  const mondayThisWeek = mondayOfThisWeekUTC();
  const mondays: Date[] = [];

  if (INCLUDE_CURRENT) mondays.push(mondayThisWeek);
  for (let n = 1; n <= PREVIOUS_WEEKS; n++) {
    mondays.push(mondayNWeeksBefore(mondayThisWeek, n));
  }

  let created = 0;

  for (let wi = 0; wi < mondays.length; wi++) {
    const monday = mondays[wi];
    const weekDays = weekDatesFromMonday(monday);

    for (let ei = 0; ei < employees.length; ei++) {
      const e = employees[ei];
      const tss = tsByEmp.get(e.id) ?? [];
      if (!tss.length) continue;

      const baseStartHour = 6 + (ei % 5);
      const baseStartMinute = (ei * 15) % 60;

      for (let di = 0; di < weekDays.length; di++) {
        const date = weekDays[di];

        // Tirage aléatoire du bank_code
        const randomCode = BANKS[Math.floor(Math.random() * BANKS.length)];
        const bank_code_id = bcMap.get(randomCode)!;

        const duration = rndInt(4, 10);

        const dayWeekOffset = (di + wi + (ei % 3)) % 3;
        const startH = Math.min(12, baseStartHour + dayWeekOffset);
        const startM = baseStartMinute;
        const endH = startH + duration;
        const endM = startM;

        const ts = tss[(di + wi) % tss.length];

        await prisma.shifts.create({
          data: {
            timesheet_id: ts.id,
            bank_code_id,
            description: `Shift ${di + 1} (semaine du ${monday.toISOString().slice(0, 10)}) emp ${e.id} — ${randomCode}`,
            date,
            start_time: timeAt(startH, startM),
            end_time: timeAt(endH, endM),
            is_approved: Math.random() < 0.5,
          },
        });
        created++;
      }
    }
  }

  const total = await prisma.shifts.count();
  console.log(`✓ Shifts: ${created} nouvelles lignes, ${total} total rows (${INCLUDE_CURRENT ? 'courante +' : ''}${PREVIOUS_WEEKS} semaines précédentes, L→V)`);
}

main().finally(() => prisma.$disconnect());