import { describe, it, expect, afterEach } from "vitest";
import prisma from "../config/database";
import { createOffer, getOfferTotals } from "../services/offers.service";
import {
  createInvoice,
  getInvoiceListTotals,
} from "../services/invoices.service";

/**
 * Per-item Sleva (% discount) must reduce the line NET — and on invoices the
 * VAT is computed on the discounted net. Hits the real `app_test` DB through the
 * service layer (suite convention), mirroring offer-invoice-totals.test.ts.
 */

const MARKER = "SLEVA-TOTALS-2096";
const YEAR = 2096;
const MONTH = 8; // invoice issue_date window [2096-08-01, 2096-09-01)
const dateStr = `${YEAR}-0${MONTH}-15`;

const offerIds: number[] = [];
const invoiceIds: number[] = [];

afterEach(async () => {
  for (const id of offerIds)
    await prisma.quotations.deleteMany({ where: { id } });
  for (const id of invoiceIds)
    await prisma.invoices.deleteMany({ where: { id } });
  offerIds.length = 0;
  invoiceIds.length = 0;
  await prisma.number_sequences.deleteMany({
    where: { type: { in: ["offer", "invoice"] } },
  });
});

const amountFor = (
  totals: { currency: string; amount: number }[],
  currency: string,
): number | undefined => totals.find((t) => t.currency === currency)?.amount;

describe("offer per-item discount", () => {
  it("reduces the offer NET total by the per-item percentage", async () => {
    // 2 × 1000 with 10% off => 1800 net.
    const res = await createOffer({
      status: "draft",
      currency: "CZK",
      project_code: MARKER,
      items: [
        { description: "X", quantity: 2, unit_price: 1000, discount: 10 },
      ],
    });
    if ("error" in res) throw new Error(JSON.stringify(res));
    offerIds.push(res.id);

    const { totals } = await getOfferTotals({ search: MARKER });
    expect(amountFor(totals, "CZK")).toBe(1800);
  });
});

describe("invoice per-item discount", () => {
  it("computes VAT on the discounted net (gross = discounted net + VAT)", async () => {
    // 2 × 1000 with 10% off => net 1800, VAT@21% = 378, gross 2178.
    const inv = await createInvoice({
      status: "draft",
      currency: "CZK",
      vat_rate: 21,
      apply_vat: true,
      issue_date: dateStr,
      items: [
        { description: "X", quantity: 2, unit_price: 1000, discount: 10 },
      ],
    });
    invoiceIds.push(inv.id);

    const { totals } = await getInvoiceListTotals({ month: MONTH, year: YEAR });
    expect(amountFor(totals, "CZK")).toBe(2178);
  });

  it("treats a 100% discount line as zero", async () => {
    const inv = await createInvoice({
      status: "draft",
      currency: "CZK",
      vat_rate: 21,
      apply_vat: true,
      issue_date: dateStr,
      items: [
        { description: "Free", quantity: 5, unit_price: 200, discount: 100 },
      ],
    });
    invoiceIds.push(inv.id);

    const { totals } = await getInvoiceListTotals({ month: MONTH, year: YEAR });
    expect(amountFor(totals, "CZK")).toBeUndefined(); // zero totals are dropped
  });
});