// The caption-track rule (lib/videoStatus.ts): which English VTT a video's
// transcript is read from, by name and then by content.
//
// Run with: node_modules/.bin/tsx --test common/lib/captionTrack.test.ts

import { after, test } from "node:test";
import assert from "node:assert/strict";
import { mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import path from "node:path";
import {
  CAPTION_TRACK_RULE_VERSION,
  TRANSCRIPT_PIN_FILENAME,
  captionInputs,
  englishVttsByPreference,
  readEnglishVttCues,
  readSubTracks,
  resolvePrimaryVtt,
} from "./videoStatus";

const ROOT = mkdtempSync(path.join(tmpdir(), "caption-track-"));
after(() => rmSync(ROOT, { recursive: true, force: true }));

const fixture = (name: string) =>
  readFileSync(path.join(import.meta.dirname, "__fixtures__", name), "utf8");

const ROLLING = fixture("vtt-rolling.vtt");
const CUE_BLOCKS = fixture("vtt-cue-blocks.vtt");
const EMPTY = "WEBVTT\nKind: captions\nLanguage: en\n\n";

let n = 0;
function videoDir(files: Record<string, string>): string {
  const dir = path.join(ROOT, `v${n++}`);
  mkdirSync(dir, { recursive: true });
  for (const [name, body] of Object.entries(files)) writeFileSync(path.join(dir, name), body);
  return dir;
}

test("en-orig ranks above en; regional above auto-translated; translations are not English", () => {
  const entries = [
    "transcript.en-en-US.vtt",
    "transcript.en.vtt",
    "transcript.es-en-US.vtt",
    "transcript.en-GB.vtt",
    "transcript.en-orig.vtt",
    "transcript.json",
  ];
  assert.deepEqual(englishVttsByPreference(entries), [
    "transcript.en-orig.vtt",
    "transcript.en.vtt",
    "transcript.en-GB.vtt",
    "transcript.en-en-US.vtt",
  ]);
  assert.equal(resolvePrimaryVtt(entries), "transcript.en-orig.vtt");
  assert.equal(resolvePrimaryVtt(["transcript.en.vtt", "transcript.en-US.vtt"]), "transcript.en.vtt");
  assert.equal(resolvePrimaryVtt(["transcript.es.vtt"]), null);
});

test("the operator's pin puts transcript.en.vtt first, and is a caption input", () => {
  const entries = ["transcript.en-orig.vtt", "transcript.en.vtt", TRANSCRIPT_PIN_FILENAME];
  assert.equal(resolvePrimaryVtt(entries), "transcript.en.vtt");
  assert.deepEqual(captionInputs(entries), [
    "transcript.en.vtt",
    "transcript.en-orig.vtt",
    TRANSCRIPT_PIN_FILENAME,
  ]);
  // A pin with no English VTT is no input.
  assert.deepEqual(captionInputs([TRANSCRIPT_PIN_FILENAME]), []);
});

test("readEnglishVttCues reads en-orig when both tracks have text", async () => {
  const dir = videoDir({
    "transcript.en.vtt": CUE_BLOCKS,
    "transcript.en-orig.vtt": ROLLING,
  });
  const got = await readEnglishVttCues(dir);
  assert.equal(got?.filename, "transcript.en-orig.vtt");
  assert.equal(got?.cues[0].text, "are talking about the harbor");
});

test("readEnglishVttCues falls back past a track with no cues", async () => {
  const dir = videoDir({
    "transcript.en-orig.vtt": EMPTY,
    "transcript.en.vtt": CUE_BLOCKS,
  });
  const got = await readEnglishVttCues(dir);
  assert.equal(got?.filename, "transcript.en.vtt");
  assert.equal(got?.cues.length, 7);
});

test("readEnglishVttCues: every track empty is the first track with no cues; none is null", async () => {
  const dir = videoDir({
    "transcript.en-orig.vtt": EMPTY,
    "transcript.en.vtt": EMPTY,
  });
  assert.deepEqual(await readEnglishVttCues(dir), { filename: "transcript.en-orig.vtt", cues: [] });
  assert.equal(await readEnglishVttCues(videoDir({ "transcript.es.vtt": ROLLING })), null);
});

test("readSubTracks lists no English VTT: those are caption tracks (lib/captionTracks.ts)", async () => {
  const dir = videoDir({
    "transcript.en.vtt": CUE_BLOCKS,
    "transcript.en-orig.vtt": ROLLING,
    "transcript.es.vtt": ROLLING,
  });
  const tracks = (await readSubTracks(dir)).map((t) => t.track).sort();
  assert.deepEqual(tracks, ["es"]);
});

test("umtool's copy of the caption-track rule version matches", () => {
  const src = readFileSync(
    path.join(import.meta.dirname, "..", "..", "umtool", "report-to-video", "cues.mjs"),
    "utf8",
  );
  const m = src.match(/export const CAPTION_TRACK_RULE_VERSION = (\d+);/);
  assert.equal(Number(m?.[1]), CAPTION_TRACK_RULE_VERSION);
});