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

const prisma = new PrismaClient();

// ====== Config ======
const PREVIOUS_WEEKS = 16;      // nombre de semaines à créer (passé)
const INCLUDE_CURRENT = false;  // true si tu veux aussi la semaine courante

// Lundi (UTC) de la semaine courante
function mondayOfThisWeekUTC(now = new Date()) {
  const d = new Date(Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate()));
  const day = d.getUTCDay();                 // 0=Dim, 1=Lun, ...
  const diffToMonday = (day + 6) % 7;        // 0 si lundi
  d.setUTCDate(d.getUTCDate() - diffToMonday);
  d.setUTCHours(0, 0, 0, 0);
  return d;
}
function mondayNWeeksBefore(monday: Date, n: number) {
  const d = new Date(monday);
  d.setUTCDate(d.getUTCDate() - n * 7);
  return d;
}

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

  // Construit la liste des lundis (1 par semaine)
  const mondays: Date[] = [];
  const mondayThisWeek = mondayOfThisWeekUTC();
  if (INCLUDE_CURRENT) mondays.push(mondayThisWeek);
  for (let n = 1; n <= PREVIOUS_WEEKS; n++) {
    mondays.push(mondayNWeeksBefore(mondayThisWeek, n));
  }

  // Prépare les lignes (1 timesheet / employé / semaine)
  const rows: Prisma.TimesheetsCreateManyInput[] = [];
  for (const e of employees) {
    for (const monday of mondays) {
      rows.push({
        employee_id: e.id,
        start_date: monday,
        is_approved: Math.random() < 0.3,
      } as Prisma.TimesheetsCreateManyInput);
    }
  }

  // Insert en bulk et ignore les doublons si déjà présents
  if (rows.length) {
    await prisma.timesheets.createMany({ data: rows, skipDuplicates: true });
  }

  const total = await prisma.timesheets.count();
  console.log(`✓ Timesheets: ${total} rows (ajout potentiel: ${rows.length}, ${INCLUDE_CURRENT ? 'courante +' : ''}${PREVIOUS_WEEKS} semaines)`);
}

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