import { describe, expect, it } from "vitest"

import { calculateNumberOfNights } from "./calculateNumberOfNights"

describe("calculateNumberOfNights", () => {
  it("returns 0 when fromDate is undefined", () => {
    expect(calculateNumberOfNights(undefined, "2023-01-02")).toBe(0)
  })

  it("returns 0 when toDate is undefined", () => {
    expect(calculateNumberOfNights("2023-01-01", undefined)).toBe(0)
  })

  it("returns 0 for the same date (string)", () => {
    expect(calculateNumberOfNights("2023-01-01", "2023-01-01")).toBe(0)
  })

  it("calculates nights for string date inputs", () => {
    expect(calculateNumberOfNights("2023-01-01", "2023-01-05")).toBe(4)
  })

  it("calculates nights for Date object inputs", () => {
    expect(
      calculateNumberOfNights(
        new Date("2023-02-10T00:00:00Z"),
        new Date("2023-02-12T00:00:00Z")
      )
    ).toBe(2)
  })

  it("handles mixed Date and string inputs", () => {
    expect(calculateNumberOfNights(new Date("2023-03-01"), "2023-03-04")).toBe(
      3
    )
  })

  it("returns a negative number when fromDate is after toDate", () => {
    expect(calculateNumberOfNights("2023-01-05", "2023-01-01")).toBe(-4)
  })
})