import { describe, expect, it } from "vitest";
import { cumulative, overviewRange, weekday } from "./overview";

describe("overviewRange", () => {
  it("haftalık: Pazartesi–Pazar, bugünü içerir", () => {
    // 2026-11-07 Cumartesi.
    expect(weekday("2026-11-07")).toBe(5);
    const r = overviewRange("week", "2026-11-07");
    expect(r).toMatchObject({ granularity: "day", from: "2026-11-02", to: "2026-11-08" });
    expect(r.buckets).toHaveLength(7);
    // Ay sınırını aşan hafta.
    expect(overviewRange("week", "2026-12-01").from).toBe("2026-11-30");
  });

  it("aylık: bütçe ayının günleri (başlangıç günü 15)", () => {
    const r = overviewRange("month", "2026-11-07", 15);
    expect(r.from).toBe("2026-10-15");
    expect(r.to).toBe("2026-11-14");
    expect(r.buckets).toHaveLength(31);
    expect(overviewRange("month", "2026-11-07").buckets).toHaveLength(30);
  });

  it("altı aylık ve yıllık: bu ay dahil son 6 / 12 bütçe ayı", () => {
    const half = overviewRange("half", "2026-11-07");
    expect(half).toMatchObject({ granularity: "month", from: "2026-06-01", to: "2026-11-30" });
    expect(half.buckets).toEqual([
      "2026-06",
      "2026-07",
      "2026-08",
      "2026-09",
      "2026-10",
      "2026-11",
    ]);
    const year = overviewRange("year", "2026-01-20", 15);
    expect(year.buckets[0]).toBe("2025-02");
    expect(year.buckets.at(-1)).toBe("2026-01");
  });
});

describe("cumulative", () => {
  it("seriler ayrı birikir; boş nokta boş kalır, toplamı bozmaz", () => {
    const out = cumulative([
      { key: "a", plannedIncome: 100, budget: 50, actual: 10 },
      { key: "b", plannedIncome: 0, budget: null, actual: 20 },
      { key: "c", plannedIncome: 50, budget: 30, actual: null },
    ]);
    expect(out.map((p) => [p.plannedIncome, p.budget, p.actual])).toEqual([
      [100, 50, 10],
      [100, null, 30],
      [150, 80, null],
    ]);
  });
});