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

import { longestCommonPrefix, parentDir, splitPath } from "./paths.js";

describe("splitPath", () => {
  it("splits on the last slash, keeping it with the directory", () => {
    expect(splitPath("/home/n/wo")).toEqual({ dir: "/home/n/", prefix: "wo" });
    expect(splitPath("/home/n/")).toEqual({ dir: "/home/n/", prefix: "" });
  });

  it("treats a slash-free value as all prefix", () => {
    expect(splitPath("work")).toEqual({ dir: "", prefix: "work" });
    expect(splitPath("")).toEqual({ dir: "", prefix: "" });
  });
});

describe("longestCommonPrefix", () => {
  it("returns the shared head", () => {
    expect(longestCommonPrefix(["maestro", "maestro-web"])).toBe("maestro");
    expect(longestCommonPrefix(["abc"])).toBe("abc");
  });

  it("is empty when nothing is shared", () => {
    expect(longestCommonPrefix(["abc", "xyz"])).toBe("");
    expect(longestCommonPrefix([])).toBe("");
  });

  it("preserves on-disk casing rather than folding it", () => {
    expect(longestCommonPrefix(["Alpha", "alpha"])).toBe("");
  });
});

describe("parentDir", () => {
  it("drops the last segment", () => {
    expect(parentDir("/home/user/tea/maestro")).toBe("/home/user/tea");
    expect(parentDir("/home/user/tea/maestro/")).toBe("/home/user/tea");
  });

  it("keeps the root for a top-level path", () => {
    expect(parentDir("/maestro")).toBe("/");
    expect(parentDir("/")).toBe("/");
  });

  it("is empty for a bare name", () => {
    expect(parentDir("maestro")).toBe("");
  });
});