import { describe, expect, it } from "vitest";
import { DEFAULT_LIST_STATE, parseListState, serializeListState, toQueryString, withRange } from "@/lib/url-state";

const parse = (qs: string) => parseListState(new URLSearchParams(qs));

describe("parseListState", () => {
  it("defaults to every calendar except Birthdays, upcoming, by start", () => {
    expect(parse("")).toEqual({ calendarIds: [1, 2, 4, 3], range: "future", sort: "start_asc", query: "" });
  });

  it("reads calendars by slug, dropping unknown ones and duplicates", () => {
    expect(parse("cal=choir,nope,birthdays,choir").calendarIds).toEqual([4, 5]);
  });

  it("keeps an explicitly empty selection", () => {
    expect(parse("cal=").calendarIds).toEqual([]);
  });

  it("sorts the past newest first by default", () => {
    expect(parse("range=past").sort).toBe("start_desc");
    expect(parse("range=past&sort=start_asc").sort).toBe("start_asc");
  });

  it("falls back to defaults for unknown range and sort", () => {
    expect(parse("range=soon&sort=random")).toMatchObject({ range: "future", sort: "start_asc" });
  });

  it("reads range, sort and search", () => {
    expect(parse("range=past&sort=created_desc&q=probe")).toMatchObject({
      range: "past",
      sort: "created_desc",
      query: "probe",
    });
  });
});

describe("serializeListState", () => {
  it("leaves the default view out of the URL", () => {
    expect(serializeListState(DEFAULT_LIST_STATE).toString()).toBe("");
  });

  it("treats the default calendars in another order as the default", () => {
    expect(serializeListState({ ...DEFAULT_LIST_STATE, calendarIds: [3, 4, 2, 1] }).toString()).toBe("");
  });

  it("round-trips a non-default view", () => {
    const state = { calendarIds: [5], range: "all" as const, sort: "start_desc" as const, query: "geburtstag" };
    expect(parseListState(serializeListState(state))).toEqual(state);
  });

  it("writes an empty selection as cal=", () => {
    expect(serializeListState({ ...DEFAULT_LIST_STATE, calendarIds: [] }).toString()).toBe("cal=");
  });
});

describe("withRange", () => {
  it("swaps a default sort for the new range's default, keeping the URL clean", () => {
    const past = withRange(DEFAULT_LIST_STATE, "past");
    expect(past.sort).toBe("start_desc");
    expect(serializeListState(past).toString()).toBe("range=past");
    expect(withRange(past, "all").sort).toBe("start_asc");
  });

  it("keeps a sort someone picked", () => {
    const picked = { ...DEFAULT_LIST_STATE, sort: "created_desc" as const };
    expect(withRange(picked, "past").sort).toBe("created_desc");
  });
});

describe("toQueryString", () => {
  it("keeps the calendar list readable but escapes commas in the search", () => {
    const qs = toQueryString({ ...DEFAULT_LIST_STATE, calendarIds: [1, 4], query: "a,b" });
    expect(qs).toBe("cal=public,choir&q=a%2Cb");
    expect(parseListState(new URLSearchParams(qs))).toMatchObject({ calendarIds: [1, 4], query: "a,b" });
  });
});