/**
 * The loader is chosen from the backend's `transport` tag, never from the URL.
 *
 * TRACES: UR-079 | DR-224 | UT-213
 */

import { describe, expect, it } from "vitest";
import { elementSrcFor, videoLoaderFor, type LoaderCapabilities } from "./streamTransport";
import type { StreamSelection, Transport } from "$lib/api/bindings";

const MODERN: LoaderCapabilities = { hlsJsSupported: true, nativeHlsSupported: false };
const SAFARI: LoaderCapabilities = { hlsJsSupported: false, nativeHlsSupported: true };
const NEITHER: LoaderCapabilities = { hlsJsSupported: false, nativeHlsSupported: false };

function selection(transport: Transport, url: string): Pick<StreamSelection, "url" | "transport"> {
  return { url, transport };
}

describe("videoLoaderFor", () => {
  it("attaches hls.js when the backend says HLS and hls.js is available", () => {
    expect(videoLoaderFor(selection({ type: "hls" }, "https://s/master.m3u8"), MODERN)).toBe(
      "hlsjs",
    );
  });

  it("falls back to the element's own HLS loader when hls.js is unavailable", () => {
    expect(videoLoaderFor(selection({ type: "hls" }, "https://s/master.m3u8"), SAFARI)).toBe(
      "nativeHls",
    );
  });

  it("loads a progressive stream directly", () => {
    expect(
      videoLoaderFor(
        selection({ type: "progressive" }, "https://s/Videos/1/stream?static=true"),
        MODERN,
      ),
    ).toBe("direct");
  });

  it("loads a local file directly", () => {
    expect(
      videoLoaderFor(selection({ type: "localFile" }, "http://127.0.0.1:9/media/x.mkv"), MODERN),
    ).toBe("direct");
  });

  // ---------------------------------------------------------------------
  // The two cases the `.m3u8` substring check gets wrong. These are the
  // reason the field exists; both fail against a URL-sniffing implementation.
  // ---------------------------------------------------------------------

  it("does NOT attach hls.js to a progressive stream whose URL happens to end .m3u8", () => {
    // A direct play served from a path containing the substring — nothing stops
    // a server, a proxy, or a local cache from producing this.
    expect(
      videoLoaderFor(selection({ type: "progressive" }, "https://s/files/movie.m3u8.mp4"), MODERN),
    ).toBe("direct");
    expect(
      videoLoaderFor(selection({ type: "progressive" }, "https://s/x?name=master.m3u8"), MODERN),
    ).toBe("direct");
  });

  it("DOES attach hls.js to an HLS stream whose URL does not contain .m3u8", () => {
    // Jellyfin's own transcoding URLs are not required to end in `.m3u8`, and a
    // DASH or query-routed playlist endpoint never would.
    expect(videoLoaderFor(selection({ type: "hls" }, "https://s/Videos/1/hls"), MODERN)).toBe(
      "hlsjs",
    );
    expect(
      videoLoaderFor(selection({ type: "hls" }, "https://s/stream?format=playlist"), SAFARI),
    ).toBe("nativeHls");
  });

  it("falls back to direct when HLS is requested but nothing can play it", () => {
    expect(videoLoaderFor(selection({ type: "hls" }, "https://s/master.m3u8"), NEITHER)).toBe(
      "direct",
    );
  });
});

describe("elementSrcFor", () => {
  it("empties the element's src only when hls.js drives it", () => {
    expect(elementSrcFor(selection({ type: "hls" }, "https://s/master.m3u8"), MODERN)).toBe("");
    expect(elementSrcFor(selection({ type: "hls" }, "https://s/master.m3u8"), SAFARI)).toBe(
      "https://s/master.m3u8",
    );
  });

  it("keeps the src for a progressive stream that looks like a playlist", () => {
    const s = selection({ type: "progressive" }, "https://s/files/movie.m3u8.mp4");
    expect(elementSrcFor(s, MODERN)).toBe("https://s/files/movie.m3u8.mp4");
  });
});