import { describe, expect, it, beforeEach, afterEach } from "vitest";
import { mkdtempSync, writeFileSync, rmSync, cpSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { NowPlayingWatcher } from "../src/nowplaying.ts";

let tmpRoot: string;

beforeEach(() => {
  tmpRoot = mkdtempSync(join(tmpdir(), "denpa-np-"));
  cpSync("tests/fixtures/now-playing", join(tmpRoot, "now-playing"), { recursive: true });
  cpSync("tests/fixtures/library", join(tmpRoot, "library"), { recursive: true });
});

afterEach(() => {
  rmSync(tmpRoot, { recursive: true, force: true });
});

describe("NowPlayingWatcher", () => {
  it("reads initial state from disk", async () => {
    const watcher = new NowPlayingWatcher({
      station: "minecraft",
      nowPlayingDir: join(tmpRoot, "now-playing"),
      libraryDir: join(tmpRoot, "library"),
    });
    await watcher.start();
    const state = watcher.current();
    expect(state).not.toBeNull();
    expect(state!.title).toBe("Sweden");
    expect(state!.cover_url).toMatch(/^\/cover\?path=/);
    expect(state!.up_next).toHaveLength(1);
    watcher.stop();
  });

  it("rewrites cover_path to /cover?path=… url", async () => {
    const watcher = new NowPlayingWatcher({
      station: "minecraft",
      nowPlayingDir: join(tmpRoot, "now-playing"),
      libraryDir: join(tmpRoot, "library"),
    });
    await watcher.start();
    expect(watcher.current()!.cover_url).toContain(
      encodeURIComponent("/library/minecraft/tracks/Volume Alpha/cover.jpg"),
    );
    watcher.stop();
  });

  it("emits change events on file rewrite", async () => {
    const watcher = new NowPlayingWatcher({
      station: "minecraft",
      nowPlayingDir: join(tmpRoot, "now-playing"),
      libraryDir: join(tmpRoot, "library"),
    });
    await watcher.start();

    let changes = 0;
    watcher.on("change", () => changes++);

    const newPayload = JSON.stringify({
      station: "minecraft",
      title: "Pigstep",
      artist: "Lena Raine",
      album: "Nether Update",
      filename: "/library/minecraft/tracks/Nether/01. Pigstep.flac",
      duration: "148",
      started_at: "1730358500",
      cover_path: "",
      up_next: [],
    });
    writeFileSync(join(tmpRoot, "now-playing", "minecraft.json"), newPayload);

    await new Promise((r) => setTimeout(r, 200));
    expect(changes).toBeGreaterThan(0);
    expect(watcher.current()!.title).toBe("Pigstep");
    watcher.stop();
  });

  it("falls back to station cover when track cover missing", async () => {
    const payload = JSON.stringify({
      station: "minecraft",
      title: "Untagged Track",
      artist: "?",
      album: "?",
      filename: "/library/minecraft/tracks/UnknownAlbum/track.flac",
      duration: "120",
      started_at: "1730358000",
      cover_path: "",
      up_next: [],
    });
    writeFileSync(join(tmpRoot, "now-playing", "minecraft.json"), payload);

    const watcher = new NowPlayingWatcher({
      station: "minecraft",
      nowPlayingDir: join(tmpRoot, "now-playing"),
      libraryDir: join(tmpRoot, "library"),
    });
    await watcher.start();
    expect(watcher.current()!.cover_url).toContain(
      encodeURIComponent("/library/minecraft/cover.jpg"),
    );
    watcher.stop();
  });
});