// Seeds ~800 realistic Austrian/DACH employees + org structure + a handful of
// open positions, per spec §5.
//
// Run with:  node --env-file=.env.local supabase/seed.ts
// Uses the service-role key over the Supabase REST API (bypasses RLS) — no
// direct Postgres connection needed. All row ids are generated client-side
// so parent/child references never require a round-trip.

import { createClient } from "@supabase/supabase-js";
import { randomUUID } from "node:crypto";

const SUPABASE_URL = process.env.NEXT_PUBLIC_SUPABASE_URL;
const SERVICE_ROLE_KEY = process.env.SUPABASE_SERVICE_ROLE_KEY;
if (!SUPABASE_URL || !SERVICE_ROLE_KEY) {
  throw new Error("Missing NEXT_PUBLIC_SUPABASE_URL or SUPABASE_SERVICE_ROLE_KEY in the environment");
}

const ADMIN_EMAIL = "m.stubhan@loudspring.at";
const MANAGER_TEST_EMAIL = "manager-test@test.manner.at";

const supabase = createClient(SUPABASE_URL, SERVICE_ROLE_KEY, {
  auth: { autoRefreshToken: false, persistSession: false },
});

// ── RNG helpers ──────────────────────────────────────────────
function randInt(min: number, max: number): number {
  return Math.floor(Math.random() * (max - min + 1)) + min;
}
function pick<T>(arr: readonly T[]): T {
  return arr[randInt(0, arr.length - 1)];
}
function chance(probability: number): boolean {
  return Math.random() < probability;
}
function weightedPick<T>(entries: readonly (readonly [T, number])[]): T {
  const total = entries.reduce((sum, [, w]) => sum + w, 0);
  let r = Math.random() * total;
  for (const [value, w] of entries) {
    r -= w;
    if (r <= 0) return value;
  }
  return entries[entries.length - 1][0];
}
function addDays(d: Date, days: number): Date {
  const r = new Date(d);
  r.setDate(r.getDate() + days);
  return r;
}
function isoDate(d: Date): string {
  return d.toISOString().slice(0, 10);
}
function randomDateBetween(start: Date, end: Date): Date {
  const t = start.getTime() + Math.random() * (end.getTime() - start.getTime());
  return new Date(t);
}
function slugify(s: string): string {
  return s
    .toLowerCase()
    .replace(/ä/g, "ae")
    .replace(/ö/g, "oe")
    .replace(/ü/g, "ue")
    .replace(/ß/g, "ss")
    .replace(/[^a-z0-9]+/g, "");
}

const TODAY = new Date();

// ── Name pools ───────────────────────────────────────────────
const MALE_FIRST_NAMES = [
  "Michael", "Andreas", "Thomas", "Stefan", "Christian", "Martin", "Markus", "Daniel",
  "Christoph", "Alexander", "Wolfgang", "Peter", "Josef", "Franz", "Johann", "Georg",
  "Bernhard", "Florian", "Manuel", "Philipp", "Sebastian", "Patrick", "Dominik", "Simon",
  "Lukas", "David", "Matthias", "Robert", "Gerhard", "Helmut", "Karl", "Anton", "Rudolf",
  "Herbert", "Kurt", "Werner", "Erwin", "Hannes", "Fabian", "Julian",
];
const FEMALE_FIRST_NAMES = [
  "Maria", "Anna", "Sabine", "Andrea", "Claudia", "Petra", "Julia", "Sarah", "Lisa",
  "Nicole", "Christine", "Elisabeth", "Monika", "Barbara", "Karin", "Silvia", "Martina",
  "Susanne", "Katharina", "Eva", "Michaela", "Stephanie", "Verena", "Melanie", "Sandra",
  "Birgit", "Ingrid", "Renate", "Gabriele", "Brigitte", "Theresa", "Laura", "Hannah",
  "Johanna", "Magdalena", "Carina", "Vanessa", "Nadine", "Bettina", "Ursula",
];
const LAST_NAMES = [
  "Gruber", "Huber", "Bauer", "Wagner", "Müller", "Pichler", "Steiner", "Moser", "Mayer",
  "Hofer", "Leitner", "Berger", "Fuchs", "Eder", "Fischer", "Schmid", "Winkler", "Weber",
  "Schwarz", "Maier", "Schneider", "Reiter", "Mayr", "Wolf", "Aigner", "Lang",
  "Baumgartner", "Auer", "Brunner", "Wallner", "Wimmer", "Egger", "Binder", "Wieser",
  "Höller", "Schmidt", "Riegler", "Kaiser", "Lechner", "Kogler", "Peer", "Lehner",
  "Zimmermann", "Pöll", "Haas", "Novak", "Horvat", "Vukovic", "Yilmaz", "Demir", "Kovac",
  "Nemec", "Simic", "Kralj", "Toth", "Szabo",
];

const NATIONALITIES: readonly (readonly [string, number])[] = [
  ["Österreich", 75],
  ["Deutschland", 5],
  ["Tschechien", 3],
  ["Slowenien", 2],
  ["Türkei", 5],
  ["Serbien", 3],
  ["Kroatien", 3],
  ["Bosnien", 2],
  ["Ungarn", 2],
];
function addressCountryFor(nationality: string): string {
  return ["Österreich", "Deutschland", "Tschechien", "Slowenien"].includes(nationality) ? nationality : "Andere";
}

const STREETS = ["Hauptstraße", "Bahnhofstraße", "Schulgasse", "Kirchenplatz", "Gartenweg", "Industriestraße", "Ringstraße", "Feldweg"];
const EXIT_REASONS = [
  "Einvernehmliche Auflösung", "Kündigung AN", "Kündigung AG", "Befristungsablauf", "Pensionierung", "Entlassung",
];

// ── Locations ────────────────────────────────────────────────
const LOCATIONS = [
  { id: randomUUID(), name: "Wien-Hernals", country: "Österreich" },
  { id: randomUUID(), name: "Wolkersdorf", country: "Österreich" },
  { id: randomUUID(), name: "Köln", country: "Deutschland" },
  { id: randomUUID(), name: "Brünn", country: "Tschechien" },
  { id: randomUUID(), name: "Ljubljana", country: "Slowenien" },
] as const;
const LOCATION_WEIGHTS: readonly (readonly [(typeof LOCATIONS)[number], number])[] = [
  [LOCATIONS[0], 55],
  [LOCATIONS[1], 20],
  [LOCATIONS[2], 10],
  [LOCATIONS[3], 10],
  [LOCATIONS[4], 5],
];

// ── Org structure ────────────────────────────────────────────
type TeamDef = { name: string; leadTitle: string; icTitles: string[]; baseSize: number };
type DeptDef = { name: string; teams: TeamDef[] };
type DivisionDef = { name: string; headTitle: string; departments: DeptDef[] };

const SCALE = 1.44; // brings the ~556-person base roster up to ~800

const DIVISIONS: DivisionDef[] = [
  {
    name: "Produktion",
    headTitle: "Bereichsleitung Produktion",
    departments: [
      {
        name: "Fertigung",
        teams: [
          { name: "Montage", leadTitle: "Teamleitung Montage", icTitles: ["Maschinenbediener:in", "Montagemitarbeiter:in", "Anlagenführer:in"], baseSize: 45 },
          { name: "CNC-Fertigung", leadTitle: "Teamleitung CNC-Fertigung", icTitles: ["CNC-Fräser:in", "CNC-Dreher:in", "Zerspanungstechniker:in"], baseSize: 35 },
          { name: "Qualitätssicherung Fertigung", leadTitle: "Teamleitung Qualitätssicherung Fertigung", icTitles: ["Qualitätsprüfer:in", "Messtechniker:in"], baseSize: 22 },
        ],
      },
      {
        name: "Instandhaltung",
        teams: [
          { name: "Elektrotechnik", leadTitle: "Teamleitung Elektrotechnik", icTitles: ["Elektrotechniker:in", "Automatisierungstechniker:in"], baseSize: 24 },
          { name: "Mechanik", leadTitle: "Teamleitung Mechanik", icTitles: ["Industriemechaniker:in", "Schlosser:in"], baseSize: 22 },
        ],
      },
    ],
  },
  {
    name: "Logistik & Einkauf",
    headTitle: "Bereichsleitung Logistik & Einkauf",
    departments: [
      {
        name: "Logistik",
        teams: [
          { name: "Lager", leadTitle: "Teamleitung Lager", icTitles: ["Lagerlogistiker:in", "Staplerfahrer:in", "Kommissionierer:in"], baseSize: 30 },
          { name: "Versand", leadTitle: "Teamleitung Versand", icTitles: ["Versandmitarbeiter:in", "Speditionskaufmann/-frau"], baseSize: 20 },
          { name: "Fuhrpark", leadTitle: "Teamleitung Fuhrpark", icTitles: ["Berufskraftfahrer:in", "Fuhrparkdisponent:in"], baseSize: 16 },
        ],
      },
      {
        name: "Einkauf",
        teams: [
          { name: "Strategischer Einkauf", leadTitle: "Teamleitung Strategischer Einkauf", icTitles: ["Einkäufer:in", "Category Manager:in"], baseSize: 14 },
          { name: "Operativer Einkauf", leadTitle: "Teamleitung Operativer Einkauf", icTitles: ["Operative:r Einkäufer:in", "Bestelldisponent:in"], baseSize: 14 },
        ],
      },
    ],
  },
  {
    name: "Vertrieb & Marketing",
    headTitle: "Bereichsleitung Vertrieb & Marketing",
    departments: [
      {
        name: "Vertrieb",
        teams: [
          { name: "Key Account Management", leadTitle: "Teamleitung Key Account Management", icTitles: ["Key Account Manager:in", "Sales Manager:in"], baseSize: 16 },
          { name: "Außendienst", leadTitle: "Teamleitung Außendienst", icTitles: ["Außendienstmitarbeiter:in", "Gebietsverkaufsleiter:in"], baseSize: 22 },
          { name: "Vertriebsinnendienst", leadTitle: "Teamleitung Vertriebsinnendienst", icTitles: ["Vertriebsinnendienstmitarbeiter:in", "Auftragssachbearbeiter:in"], baseSize: 18 },
        ],
      },
      {
        name: "Marketing",
        teams: [
          { name: "Brand Marketing", leadTitle: "Teamleitung Brand Marketing", icTitles: ["Brand Manager:in", "Produktmanager:in"], baseSize: 12 },
          { name: "Digital Marketing", leadTitle: "Teamleitung Digital Marketing", icTitles: ["Digital Marketing Manager:in", "Social-Media-Manager:in"], baseSize: 12 },
        ],
      },
    ],
  },
  {
    name: "Forschung & Entwicklung",
    headTitle: "Bereichsleitung Forschung & Entwicklung",
    departments: [
      {
        name: "Produktentwicklung",
        teams: [
          { name: "Rezeptur & Sensorik", leadTitle: "Teamleitung Rezeptur & Sensorik", icTitles: ["Lebensmitteltechniker:in", "Sensoriker:in"], baseSize: 16 },
          { name: "Verpackungsentwicklung", leadTitle: "Teamleitung Verpackungsentwicklung", icTitles: ["Verpackungstechniker:in", "Packmittelentwickler:in"], baseSize: 12 },
        ],
      },
      {
        name: "Verfahrenstechnik",
        teams: [
          { name: "Prozessoptimierung", leadTitle: "Teamleitung Prozessoptimierung", icTitles: ["Verfahrenstechniker:in", "Prozessingenieur:in"], baseSize: 14 },
          { name: "Anlagentechnik", leadTitle: "Teamleitung Anlagentechnik", icTitles: ["Anlagentechniker:in", "Projektingenieur:in"], baseSize: 12 },
        ],
      },
    ],
  },
  {
    name: "Qualitätsmanagement",
    headTitle: "Bereichsleitung Qualitätsmanagement",
    departments: [
      {
        name: "Qualitätssicherung",
        teams: [
          { name: "Wareneingangsprüfung", leadTitle: "Teamleitung Wareneingangsprüfung", icTitles: ["Qualitätsprüfer:in", "Wareneingangskontrolleur:in"], baseSize: 14 },
          { name: "Prozessaudit", leadTitle: "Teamleitung Prozessaudit", icTitles: ["Qualitätsauditor:in", "QM-Beauftragte:r"], baseSize: 10 },
        ],
      },
      {
        name: "Lebensmittelsicherheit",
        teams: [
          { name: "Hygienemanagement", leadTitle: "Teamleitung Hygienemanagement", icTitles: ["Hygienebeauftragte:r", "Lebensmittelsicherheitsbeauftragte:r"], baseSize: 12 },
          { name: "Zertifizierung", leadTitle: "Teamleitung Zertifizierung", icTitles: ["Zertifizierungsmanager:in", "QM-Sachbearbeiter:in"], baseSize: 10 },
        ],
      },
    ],
  },
  {
    name: "IT",
    headTitle: "Bereichsleitung IT",
    departments: [
      {
        name: "Business Applications",
        teams: [
          { name: "SAP-Team", leadTitle: "Teamleitung SAP-Team", icTitles: ["SAP-Consultant", "SAP-Entwickler:in"], baseSize: 12 },
          { name: "Power Platform & Automatisierung", leadTitle: "Teamleitung Power Platform & Automatisierung", icTitles: ["Power Platform Developer:in", "Prozessautomatisierer:in"], baseSize: 10 },
        ],
      },
      {
        name: "Infrastruktur",
        teams: [
          { name: "Netzwerk & Security", leadTitle: "Teamleitung Netzwerk & Security", icTitles: ["Netzwerktechniker:in", "IT-Security-Spezialist:in"], baseSize: 12 },
          { name: "IT-Support", leadTitle: "Teamleitung IT-Support", icTitles: ["IT-Support-Mitarbeiter:in", "Systemadministrator:in"], baseSize: 14 },
        ],
      },
    ],
  },
  {
    name: "Finanzen & Controlling",
    headTitle: "Bereichsleitung Finanzen & Controlling",
    departments: [
      {
        name: "Finanzen",
        teams: [
          { name: "Buchhaltung", leadTitle: "Teamleitung Buchhaltung", icTitles: ["Buchhalter:in", "Bilanzbuchhalter:in"], baseSize: 16 },
          { name: "Treasury", leadTitle: "Teamleitung Treasury", icTitles: ["Treasury-Manager:in", "Finanzanalyst:in"], baseSize: 10 },
        ],
      },
      {
        name: "Controlling",
        teams: [
          { name: "Konzerncontrolling", leadTitle: "Teamleitung Konzerncontrolling", icTitles: ["Controller:in", "Financial Analyst:in"], baseSize: 12 },
          { name: "Werkscontrolling", leadTitle: "Teamleitung Werkscontrolling", icTitles: ["Werkscontroller:in", "Kostenrechner:in"], baseSize: 12 },
        ],
      },
    ],
  },
  {
    name: "Human Resources",
    headTitle: "Bereichsleitung Human Resources",
    departments: [
      {
        name: "HR Business Partner",
        teams: [
          { name: "Recruiting", leadTitle: "Teamleitung Recruiting", icTitles: ["Recruiter:in", "Talent Acquisition Manager:in"], baseSize: 10 },
          { name: "Personalentwicklung", leadTitle: "Teamleitung Personalentwicklung", icTitles: ["Personalentwickler:in", "Trainer:in"], baseSize: 8 },
        ],
      },
      {
        name: "Personaladministration",
        teams: [
          { name: "Gehaltsabrechnung", leadTitle: "Teamleitung Gehaltsabrechnung", icTitles: ["Payroll-Spezialist:in", "Personalverrechner:in"], baseSize: 10 },
          { name: "HR-Systeme", leadTitle: "Teamleitung HR-Systeme", icTitles: ["HR-IT-Spezialist:in", "HRIS Manager:in"], baseSize: 8 },
        ],
      },
    ],
  },
];

// ── Employee generation ──────────────────────────────────────
type EmployeeRow = {
  id: string;
  first_name: string;
  last_name: string;
  gender: "m" | "w";
  birth_date: string;
  sv_nummer: string;
  nationality: string;
  address: string;
  address_country: string;
  email: string;
  phone: string;
  team_id: string | null;
  division_id: string;
  job_title: string;
  location_id: string;
  manager_id: string | null;
  org_level: number;
  is_lead: boolean;
  employment_type: "Vollzeit" | "Teilzeit";
  weekly_hours: number;
  monthly_salary_gross: number;
  contract_type: "unbefristet" | "befristet";
  contract_end_date: string | null;
  paygrade: "A" | "B" | "C" | "D" | "E" | "F";
  source: "Intern" | "Extern";
  status: "Aktiv" | "Karenz" | "Geplant" | "Ausgetreten";
  entry_date: string;
  exit_date: string | null;
  exit_reason: string | null;
  karenz_return_date: string | null;
};

type HistoryRow = {
  employee_id: string;
  event_date: string;
  event_type: string;
  description: string;
};

const usedEmails = new Set<string>();

function makeEmail(firstName: string, lastName: string): string {
  const base = `${slugify(firstName)}.${slugify(lastName)}`;
  let email = `${base}@test.manner.at`;
  let n = 2;
  while (usedEmails.has(email)) {
    email = `${base}${n}@test.manner.at`;
    n += 1;
  }
  usedEmails.add(email);
  return email;
}

function makeSvNummer(birthDate: Date): string {
  const dd = String(birthDate.getDate()).padStart(2, "0");
  const mm = String(birthDate.getMonth() + 1).padStart(2, "0");
  const yy = String(birthDate.getFullYear()).slice(-2);
  const prefix = String(randInt(1000, 9999));
  return `${prefix} ${dd}${mm}${yy}`;
}

function birthDateForAge(age: number): Date {
  const year = TODAY.getFullYear() - age;
  return new Date(year, randInt(0, 11), randInt(1, 28));
}

function paygradeAndSalaryForIc(): { paygrade: EmployeeRow["paygrade"]; salary: number } {
  const grade = weightedPick<EmployeeRow["paygrade"]>([
    ["A", 15],
    ["B", 35],
    ["C", 30],
    ["D", 20],
  ]);
  const ranges: Record<string, [number, number]> = {
    A: [2200, 2700],
    B: [2600, 3300],
    C: [3200, 4100],
    D: [4000, 5200],
  };
  const [min, max] = ranges[grade];
  return { paygrade: grade, salary: randInt(min, max) };
}

function newHireBase(jobTitle: string, orgLevel: number, isLead: boolean, teamId: string | null, divisionId: string, managerId: string | null) {
  const gender: "m" | "w" = chance(0.48) ? "m" : "w";
  const firstName = pick(gender === "m" ? MALE_FIRST_NAMES : FEMALE_FIRST_NAMES);
  const lastName = pick(LAST_NAMES);
  const nationality = weightedPick(NATIONALITIES);
  const location = weightedPick(LOCATION_WEIGHTS);

  return {
    id: randomUUID(),
    first_name: firstName,
    last_name: lastName,
    gender,
    nationality,
    address: `${pick(STREETS)} ${randInt(1, 90)}, ${randInt(1010, 2500)} Wien`,
    address_country: addressCountryFor(nationality),
    email: makeEmail(firstName, lastName),
    phone: `+43 664 ${randInt(1000000, 9999999)}`,
    team_id: teamId,
    division_id: divisionId,
    job_title: jobTitle,
    location_id: location.id,
    manager_id: managerId,
    org_level: orgLevel,
    is_lead: isLead,
  };
}

const employees: EmployeeRow[] = [];
const history: HistoryRow[] = [];
const icPoolForStatusAssignment: EmployeeRow[] = [];

function finalizeEmployee(base: ReturnType<typeof newHireBase>, opts: { salary: number; paygrade: EmployeeRow["paygrade"] }): EmployeeRow {
  const age = randInt(22, 60);
  const birthDate = birthDateForAge(age);
  const maxTenureYears = Math.min(15, age - 20);
  const entryDate = randomDateBetween(addDays(TODAY, -maxTenureYears * 365), addDays(TODAY, -30));

  const employmentType: "Vollzeit" | "Teilzeit" = chance(0.8) ? "Vollzeit" : "Teilzeit";
  const weeklyHours = employmentType === "Vollzeit" ? 38.5 : pick([15, 18, 20, 25, 28, 30, 32, 35]);

  const isBefristet = chance(0.1) && entryDate > addDays(TODAY, -540);
  const contractEndDate = isBefristet ? addDays(TODAY, randInt(90, 540)) : null;

  const row: EmployeeRow = {
    ...base,
    birth_date: isoDate(birthDate),
    sv_nummer: makeSvNummer(birthDate),
    employment_type: employmentType,
    weekly_hours: weeklyHours,
    monthly_salary_gross: opts.salary,
    contract_type: isBefristet ? "befristet" : "unbefristet",
    contract_end_date: contractEndDate ? isoDate(contractEndDate) : null,
    paygrade: opts.paygrade,
    source: chance(0.15) ? "Intern" : "Extern",
    status: "Aktiv",
    entry_date: isoDate(entryDate),
    exit_date: null,
    exit_reason: null,
    karenz_return_date: null,
  };

  history.push({
    employee_id: row.id,
    event_date: row.entry_date,
    event_type: "Eintritt",
    description: `Eintritt als ${row.job_title}`,
  });

  if (row.status === "Aktiv" && entryDate < addDays(TODAY, -2 * 365) && chance(0.06)) {
    const promoDate = randomDateBetween(addDays(entryDate, 365), addDays(TODAY, -30));
    history.push({
      employee_id: row.id,
      event_date: isoDate(promoDate),
      event_type: "Beförderung",
      description: `Beförderung im Rahmen der Laufbahnentwicklung, neue Position: ${row.job_title}`,
    });
  }
  if (chance(0.08)) {
    const adjDate = randomDateBetween(addDays(entryDate, 180), TODAY);
    history.push({
      employee_id: row.id,
      event_date: isoDate(adjDate),
      event_type: "Gehaltsanpassung",
      description: "Jährliche Gehaltsanpassung im Rahmen der Kollektivvertragsrunde",
    });
  }

  return row;
}

type TeamRef = { id: string; org_number: string; name: string; department_id: string };
type DeptRef = { id: string; org_number: string; name: string; division_id: string };
type DivisionRef = { id: string; org_number: string; name: string };

const divisionRows: DivisionRef[] = [];
const departmentRows: DeptRef[] = [];
const teamRows: TeamRef[] = [];

// Geschäftsführung: small division, no departments/teams — CEO and their
// assistant sit directly under it (§5).
const gfDivisionId = randomUUID();
divisionRows.push({ id: gfDivisionId, org_number: "20900000", name: "Geschäftsführung" });

const ceo = finalizeEmployee(
  newHireBase("Geschäftsführer:in", 0, true, null, gfDivisionId, null),
  { salary: 15500, paygrade: "F" }
);
const gfAssistant = finalizeEmployee(
  newHireBase("Assistenz der Geschäftsführung", 3, false, null, gfDivisionId, ceo.id),
  { salary: 3900, paygrade: "C" }
);
employees.push(ceo, gfAssistant);

let divisionCounter = 0;
let deptCounter = 0;
let teamCounter = 0;

for (const div of DIVISIONS) {
  divisionCounter += 1;
  const divisionId = randomUUID();
  const divisionOrgNumber = `20${String(divisionCounter * 100000).padStart(6, "0")}`;
  divisionRows.push({ id: divisionId, org_number: divisionOrgNumber, name: div.name });

  const divisionHead = finalizeEmployee(
    newHireBase(div.headTitle, 1, true, null, divisionId, ceo.id),
    { salary: randInt(9000, 11500), paygrade: "F" }
  );
  employees.push(divisionHead);

  for (const dept of div.departments) {
    deptCounter += 1;
    const departmentId = randomUUID();
    const deptOrgNumber = `21${String(deptCounter * 10000).padStart(6, "0")}`;
    departmentRows.push({ id: departmentId, org_number: deptOrgNumber, name: dept.name, division_id: divisionId });

    for (const team of dept.teams) {
      teamCounter += 1;
      const teamId = randomUUID();
      const teamOrgNumber = `22${String(teamCounter * 1000).padStart(6, "0")}`;
      teamRows.push({ id: teamId, org_number: teamOrgNumber, name: team.name, department_id: departmentId });

      const size = Math.max(2, Math.round(team.baseSize * SCALE));

      const teamLead = finalizeEmployee(
        newHireBase(team.leadTitle, 2, true, teamId, divisionId, divisionHead.id),
        { salary: randInt(5000, 6800), paygrade: "E" }
      );
      employees.push(teamLead);

      for (let i = 0; i < size - 1; i++) {
        const jobTitle = pick(team.icTitles);
        const { paygrade, salary } = paygradeAndSalaryForIc();
        const ic = finalizeEmployee(
          newHireBase(jobTitle, 3, false, teamId, divisionId, teamLead.id),
          { salary, paygrade }
        );
        employees.push(ic);
        icPoolForStatusAssignment.push(ic);
      }
    }
  }
}

// ── Apply the target status distribution (§5) across the IC pool ────────
function shuffle<T>(arr: T[]): T[] {
  const a = [...arr];
  for (let i = a.length - 1; i > 0; i--) {
    const j = randInt(0, i);
    [a[i], a[j]] = [a[j], a[i]];
  }
  return a;
}
const shuffledIcs = shuffle(icPoolForStatusAssignment);
let cursor = 0;

// ~40 Ausgetreten
for (let i = 0; i < 40 && cursor < shuffledIcs.length; i++, cursor++) {
  const e = shuffledIcs[cursor];
  const entryDate = new Date(e.entry_date);
  const exitDate = randomDateBetween(addDays(entryDate, 90), TODAY);
  e.status = "Ausgetreten";
  e.exit_date = isoDate(exitDate);
  e.exit_reason = pick(EXIT_REASONS);
  history.push({ employee_id: e.id, event_date: e.exit_date, event_type: "Austritt", description: `Austritt (${e.exit_reason})` });
}

// ~12 Karenz
for (let i = 0; i < 12 && cursor < shuffledIcs.length; i++, cursor++) {
  const e = shuffledIcs[cursor];
  const entryDate = new Date(e.entry_date);
  const karenzStart = randomDateBetween(addDays(entryDate, 180), addDays(TODAY, -10));
  const returnDate = addDays(TODAY, randInt(10, 300));
  e.status = "Karenz";
  e.karenz_return_date = isoDate(returnDate);
  history.push({
    employee_id: e.id,
    event_date: isoDate(karenzStart),
    event_type: "Karenz",
    description: `Karenzantritt, geplante Rückkehr am ${isoDate(returnDate)}`,
  });
}

// ~3 Geplant (future entry — overwrite entry_date/history)
for (let i = 0; i < 3 && cursor < shuffledIcs.length; i++, cursor++) {
  const e = shuffledIcs[cursor];
  const futureEntry = addDays(TODAY, randInt(10, 90));
  e.status = "Geplant";
  e.entry_date = isoDate(futureEntry);
  const historyEntry = history.find((h) => h.employee_id === e.id && h.event_type === "Eintritt");
  if (historyEntry) historyEntry.event_date = e.entry_date;
}

// ~3 planned future exits (still Aktiv until the exit date arrives)
for (let i = 0; i < 3 && cursor < shuffledIcs.length; i++, cursor++) {
  const e = shuffledIcs[cursor];
  const futureExit = addDays(TODAY, randInt(10, 90));
  e.exit_date = isoDate(futureExit);
  e.exit_reason = pick(EXIT_REASONS);
}

// ── Open positions (§4.6 / §5) ───────────────────────────────
type PositionRow = {
  title: string;
  team_id: string;
  is_lead: boolean;
  reports_to_employee_id: string | null;
  status: "open";
  created_at: string;
};
const positions: PositionRow[] = [];
{
  const pool = shuffle([...teamRows]);
  for (let i = 0; i < 8; i++) {
    const team = pool[i % pool.length];
    const leadOfTeam = employees.find((e) => e.team_id === team.id && e.is_lead);
    const isLeadPosition = i < 2; // first two are leadership requisitions
    const reportsTo = isLeadPosition
      ? (employees.find((e) => e.division_id === leadOfTeam?.division_id && e.org_level === 1)?.id ?? null)
      : (leadOfTeam?.id ?? null);
    positions.push({
      title: isLeadPosition ? `Teamleitung ${team.name}` : "Neue Position",
      team_id: team.id,
      is_lead: isLeadPosition,
      reports_to_employee_id: reportsTo,
      status: "open",
      created_at: new Date(addDays(TODAY, -randInt(1, 45))).toISOString(),
    });
  }
}

// ── Insert helpers ───────────────────────────────────────────
async function insertInChunks(table: string, rows: Record<string, unknown>[], chunkSize = 200) {
  for (let i = 0; i < rows.length; i += chunkSize) {
    const chunk = rows.slice(i, i + chunkSize);
    const { error } = await supabase.from(table).insert(chunk);
    if (error) throw new Error(`Insert into ${table} failed: ${error.message}`);
  }
  console.log(`  inserted ${rows.length} row(s) into ${table}`);
}

async function main() {
  console.log("Seeding locations...");
  await insertInChunks("locations", LOCATIONS.map((l) => ({ ...l })));

  console.log("Seeding divisions...");
  await insertInChunks("divisions", divisionRows);

  console.log("Seeding departments...");
  await insertInChunks("departments", departmentRows);

  console.log("Seeding teams...");
  await insertInChunks("teams", teamRows);

  console.log(`Seeding ${employees.length} employees...`);
  await insertInChunks("employees", employees);

  console.log(`Seeding ${history.length} employee_history rows...`);
  await insertInChunks("employee_history", history);

  console.log(`Seeding ${positions.length} open positions...`);
  await insertInChunks("positions", positions);

  console.log("Creating hr_admin account...");
  const adminPassword = randomUUID().slice(0, 12) + "!Aa1";
  const { data: adminUser, error: adminErr } = await supabase.auth.admin.createUser({
    email: ADMIN_EMAIL,
    password: adminPassword,
    email_confirm: true,
  });
  if (adminErr) throw new Error(`Creating admin user failed: ${adminErr.message}`);
  await supabase.from("profiles").insert({
    id: adminUser.user.id,
    email: ADMIN_EMAIL,
    full_name: "Maximilian Stubhan",
    role: "hr_admin",
  });

  console.log("Creating manager test account...");
  const managerPassword = randomUUID().slice(0, 12) + "!Bb2";
  const { data: managerUser, error: managerErr } = await supabase.auth.admin.createUser({
    email: MANAGER_TEST_EMAIL,
    password: managerPassword,
    email_confirm: true,
  });
  if (managerErr) throw new Error(`Creating manager test user failed: ${managerErr.message}`);
  await supabase.from("profiles").insert({
    id: managerUser.user.id,
    email: MANAGER_TEST_EMAIL,
    full_name: "Test Manager",
    role: "manager",
  });

  console.log("\nDone.");
  console.log(`hr_admin login:  ${ADMIN_EMAIL} / ${adminPassword}`);
  console.log(`manager login:   ${MANAGER_TEST_EMAIL} / ${managerPassword}`);
  console.log("(Passwords are shown once here only — store them somewhere safe.)");
}

main().catch((err) => {
  console.error(err);
  process.exit(1);
});