import { describe, expect, it } from "vitest";
import { buildBook } from "./book";
import { lotDetail } from "./fixtures.spec-helper";

const movement = (id: string, createdAt: string, quantity: number, type = "TREATMENT" as const) => ({
  id,
  type,
  quantity,
  treatmentId: null,
  reason: null,
  userId: null,
  createdAt,
});

describe("buildBook", () => {
  it("lists the newest booking first and ends at the receipt", () => {
    const rows = buildBook(
      lotDetail({
        quantity: 20,
        movements: [movement("b", "2026-08-12T08:00:00.000Z", -3), movement("a", "2026-08-10T08:00:00.000Z", -8)],
      }),
    );

    expect(rows.map((row) => row.label)).toEqual(["Behandlung", "Behandlung", "Eingang"]);
    expect(rows.map((row) => row.balance)).toEqual([9, 12, 20]);
  });

  it("keeps the running rest exact to the thousandth", () => {
    const rows = buildBook(
      lotDetail({
        quantity: 1,
        movements: [movement("a", "2026-08-10T08:00:00.000Z", -0.1), movement("b", "2026-08-11T08:00:00.000Z", -0.2)],
      }),
    );

    expect(rows[0].balance).toBe(0.7);
  });

  it("lets a rest fall below zero and keeps the sign", () => {
    const rows = buildBook(lotDetail({ quantity: 2, movements: [movement("a", "2026-08-10T08:00:00.000Z", -5)] }));

    expect(rows[0].balance).toBe(-3);
  });

  it("reads the day of a booking as the Berlin calendar day", () => {
    const rows = buildBook(lotDetail({ movements: [movement("a", "2026-08-10T22:30:00.000Z", -1)] }));

    expect(rows[0].day).toBe("2026-08-11");
  });
});