// @vitest-environment jsdom
// jsdom: the order language comes from the account's stored one, checked against i18n's languages.
import { describe, expect, it } from "vitest";
import { placeByPriority, priorityChoices } from "./channelOrder";

const row = (id: string, priority: number, title: string | null = id) => ({ id, priority, title });
const ids = (rows: { id: string }[]) => rows.map((r) => r.id);
const EN = { language: "en" };
const HU = { language: "hu" };

describe("placeByPriority", () => {
  const list = [row("a", 10), row("b", 5), row("c", 5), row("d", 0), row("e", 0)];

  it("bubbles a raised channel up to the first row it now outranks", () => {
    expect(
      ids(placeByPriority([...list.slice(0, 4), { ...list[4]!, priority: 5 }], "e", EN)),
    ).toEqual(["a", "b", "c", "e", "d"]);
  });

  it("sinks a lowered channel below every row it no longer outranks", () => {
    expect(ids(placeByPriority([{ ...list[0]!, priority: 0 }, ...list.slice(1)], "a", EN))).toEqual(
      ["b", "c", "a", "d", "e"],
    );
  });

  it("orders equal priorities by title, case-folded, a missing title last", () => {
    const rows = [row("x", 3, "beta"), row("y", 3, null), row("z", 3, "Alpha")];
    expect(ids(placeByPriority(rows, "z", EN))).toEqual(["z", "x", "y"]);
    expect(ids(placeByPriority([row("y", 3, null), row("x", 3, "beta")], "y", EN))).toEqual([
      "x",
      "y",
    ]);
  });

  it("leaves every other row where it was, even ones out of the server's order", () => {
    const rows = [row("p", 0), row("q", 9), row("r", 2)];
    // r lands before the first row it outranks; p and q keep their (unsorted) order.
    expect(ids(placeByPriority(rows, "r", EN))).toEqual(["r", "p", "q"]);
  });

  it("returns an unknown id's list unchanged", () => {
    expect(ids(placeByPriority(list, "nope", EN))).toEqual(ids(list));
  });

  it("places a title in the reader's alphabet, as the server's collation does", () => {
    const rows = [row("e", 0, "Ecset"), row("f", 0, "Fa"), row("m", 5, "Életrajz")];
    const moved = [...rows.slice(0, 2), { ...rows[2]!, priority: 0 }];
    expect(ids(placeByPriority(moved, "m", HU))).toEqual(["e", "m", "f"]);
    const cs = [row("u", 0, "Cukor"), row("x", 0, "Dob"), row("c", 5, "Csiga")];
    expect(ids(placeByPriority([...cs.slice(0, 2), { ...cs[2]!, priority: 0 }], "c", HU))).toEqual([
      "u",
      "c",
      "x",
    ]);
  });

  it("places by the STORED language, whatever the screen shows: the server sorts by that", () => {
    const cs = [row("u", 0, "Cukor"), row("x", 0, "Dob"), row("c", 5, "Csiga")];
    const moved = [...cs.slice(0, 2), { ...cs[2]!, priority: 0 }];
    // None stored (a Hungarian screen picked while signed out): the server's English order.
    expect(ids(placeByPriority(moved, "c", {}))).toEqual(["c", "u", "x"]);
    expect(ids(placeByPriority(moved, "c", { language: "de" }))).toEqual(["c", "u", "x"]);
  });
});

describe("priorityChoices", () => {
  it("offers the fixed steps, and an off-scale current value in its place", () => {
    expect(priorityChoices(3)).toEqual([10, 5, 3, 2, 1, 0]);
    expect(priorityChoices(7)).toEqual([10, 7, 5, 3, 2, 1, 0]);
    expect(priorityChoices(-2)).toEqual([10, 5, 3, 2, 1, 0, -2]);
  });
});