/**
 * seed-vacations.ts
 * Populates 15 vacation days per resource per year (2025, 2026, 2027-partial).
 * Spread across 3 blocks:
 *   – Spring/Easter  (5 days, fixed)
 *   – Summer         (5 days, staggered by resource index so teams don't all leave at once)
 *   – Christmas/NYE  (5 days, fixed)
 */

import { PrismaClient } from "@prisma/client";
import { loadWorkspaceEnv } from "./load-workspace-env.js";
import { assertSafeSeedTarget } from "./safe-destructive-env.js";

loadWorkspaceEnv();

const prisma = new PrismaClient();

// ─── Helpers ──────────────────────────────────────────────────────────────────

/** ISO date string → Date at midnight UTC */
function d(iso: string): Date {
  return new Date(iso + "T00:00:00.000Z");
}

/** Add calendar days to a Date */
function addDays(date: Date, n: number): Date {
  const r = new Date(date);
  r.setUTCDate(r.getUTCDate() + n);
  return r;
}

// ─── Vacation blocks per year ─────────────────────────────────────────────────
// Each block is { start, end } of a Mon–Fri week (5 working days).
// Summer has multiple offsets so resources are staggered (offset chosen by index % 4).

const BLOCKS: Record<
  number,
  {
    spring: { start: string; end: string };
    summer: { start: string; end: string }[];
    christmas: { start: string; end: string };
  }
> = {
  2025: {
    spring:   { start: "2025-04-14", end: "2025-04-18" }, // Mon–Fri Easter week
    summer:   [
      { start: "2025-07-07", end: "2025-07-11" },
      { start: "2025-07-21", end: "2025-07-25" },
      { start: "2025-08-04", end: "2025-08-08" },
      { start: "2025-08-18", end: "2025-08-22" },
    ],
    christmas: { start: "2025-12-22", end: "2025-12-26" }, // Mon–Fri
  },
  2026: {
    spring:   { start: "2026-03-30", end: "2026-04-03" }, // Mon–Fri Easter week
    summer:   [
      { start: "2026-07-06", end: "2026-07-10" },
      { start: "2026-07-20", end: "2026-07-24" },
      { start: "2026-08-03", end: "2026-08-07" },
      { start: "2026-08-17", end: "2026-08-21" },
    ],
    christmas: { start: "2026-12-21", end: "2026-12-25" }, // Mon–Fri
  },
  2027: {
    // Partial year — spring only (for future view context)
    spring:   { start: "2027-03-29", end: "2027-04-02" },
    summer:   [
      { start: "2027-07-05", end: "2027-07-09" },
      { start: "2027-07-19", end: "2027-07-23" },
      { start: "2027-08-02", end: "2027-08-06" },
      { start: "2027-08-16", end: "2027-08-20" },
    ],
    christmas: { start: "2027-12-20", end: "2027-12-24" },
  },
};

const YEARS = [2025, 2026, 2027];

// ─── Main ─────────────────────────────────────────────────────────────────────

async function main() {
  assertSafeSeedTarget("db:seed:vacations");
  // Get admin user to act as approver (fall back to manager, then any user)
  const admin =
    (await prisma.user.findFirst({ where: { systemRole: "ADMIN" }, select: { id: true } })) ??
    (await prisma.user.findFirst({ where: { systemRole: "MANAGER" }, select: { id: true } })) ??
    (await prisma.user.findFirst({ select: { id: true } }));
  if (!admin) {
    throw new Error("No users found — run the main seed first.");
  }

  // Get all resources ordered by eid for stable staggering
  const resources = await prisma.resource.findMany({
    where: { isActive: true },
    select: { id: true, eid: true },
    orderBy: { eid: "asc" },
  });

  console.log(`Found ${resources.length} active resources. Admin id: ${admin.id}`);

  // Delete existing vacations to allow re-running
  const deleted = await prisma.vacation.deleteMany({});
  console.log(`Deleted ${deleted.count} existing vacation records.`);

  let created = 0;

  for (let i = 0; i < resources.length; i++) {
    const resource = resources[i]!;
    const summerOffset = i % 4; // 0-3 → pick one of the 4 staggered summer weeks

    for (const year of YEARS) {
      const blocks = BLOCKS[year]!;
      const summerBlock = blocks.summer[summerOffset]!;

      const vacationBlocks = [
        { type: "ANNUAL" as const, ...blocks.spring },
        { type: "ANNUAL" as const, ...summerBlock },
        { type: "ANNUAL" as const, ...blocks.christmas },
      ];

      for (const block of vacationBlocks) {
        await prisma.vacation.create({
          data: {
            resourceId:   resource.id,
            type:         block.type,
            status:       "APPROVED",
            startDate:    d(block.start),
            endDate:      d(block.end),
            requestedById: admin.id,
            approvedById:  admin.id,
            approvedAt:    new Date(),
            note:          `${year} annual leave`,
          },
        });
        created++;
      }
    }

    console.log(`  ✓ ${resource.eid} — ${YEARS.length * 3} vacation blocks`);
  }

  console.log(`\nDone! Created ${created} vacation records.`);
  console.log(`  ${resources.length} resources × ${YEARS.length} years × 3 blocks = ${resources.length * YEARS.length * 3} expected`);
}

main()
  .catch((e) => {
    console.error(e);
    process.exit(1);
  })
  .finally(() => void prisma.$disconnect());