import { test } from 'node:test';
import assert from 'node:assert/strict';
import {
  type Segment,
  formatTime,
  buildTimeline,
  mainOffsetMs,
  segmentIndexAtVirtualMs,
  chapterToVirtualMs,
} from './media-player.logic.ts';

// A main file A split around an insertion, then a second main file B:
//   [ main A 10s ][ ad 5s ][ main A 8s ][ main B 6s ]
const segs: Segment[] = [
  { url: 'A', duration_ms: 10_000, segment_type: 'main' },
  { url: 'X', duration_ms: 5_000, segment_type: 'ad' },
  { url: 'A', duration_ms: 8_000, segment_type: 'main' },
  { url: 'B', duration_ms: 6_000, segment_type: 'main' },
];

test('formatTime formats m:ss and h:mm:ss', () => {
  assert.equal(formatTime(0), '0:00');
  assert.equal(formatTime(65), '1:05');
  assert.equal(formatTime(3661), '1:01:01');
  assert.equal(formatTime(NaN), '0:00');
});

test('buildTimeline gives cumulative starts + total', () => {
  const { segStarts, totalMs } = buildTimeline(segs);
  assert.deepEqual(segStarts, [0, 10_000, 15_000, 23_000]);
  assert.equal(totalMs, 29_000);
});

test('mainOffsetMs is the offset within a split main URL', () => {
  assert.equal(mainOffsetMs(segs, 0), 0); // A's first appearance
  assert.equal(mainOffsetMs(segs, 1), 0); // insertion → 0
  assert.equal(mainOffsetMs(segs, 2), 10_000); // A's second slice sits 10s into A
  assert.equal(mainOffsetMs(segs, 3), 0); // B's first appearance
});

test('segmentIndexAtVirtualMs finds the containing segment and clamps past end', () => {
  const { segStarts, totalMs } = buildTimeline(segs);
  assert.equal(segmentIndexAtVirtualMs(segStarts, segs, 0), 0);
  assert.equal(segmentIndexAtVirtualMs(segStarts, segs, 12_000), 1);
  assert.equal(segmentIndexAtVirtualMs(segStarts, segs, 15_000), 2);
  assert.equal(segmentIndexAtVirtualMs(segStarts, segs, totalMs + 1), 3);
});

test('chapterToVirtualMs maps main-only time across insertions', () => {
  // 5s into main lands at 5s virtual (nothing precedes it).
  assert.equal(chapterToVirtualMs(segs, 5_000), 5_000);
  // 12s of main = all of A1 (10s) + 2s of A2; virtual = 10s A1 + 5s ad + 2s = 17s.
  assert.equal(chapterToVirtualMs(segs, 12_000), 17_000);
});