/**
 * The Composition tab (#417). A sprite dragged in from the Assets panel becomes an item, 3 s long
 * and picked, so the inspector shows its TIMING; a second one dropped onto the first lands there,
 * over it. The end of the first, covered by the second, lights up under the pointer and is dragged
 * past it. An animation dragged in becomes a clip that moves the item it overlaps in the picture.
 * The hierarchy lists what is alive at the playhead, Delete takes an item with its object, and Play
 * runs the playhead to the end. The video of an item about to begin is opened ahead, so the cut to
 * it shows its picture at once, and Play waits for a video whose player is still loading. A copied
 * item is pasted under the pointer or at the playhead. A video dragged in wears a sprite the
 * composition keeps to itself. An item dragged in the picture follows the pointer while the button
 * is down. A band picks items, with Alt clips, and copied clips are pasted where they fit. A sound
 * dragged in is an audio item, heard while the playhead runs; the handle of its fade in drags out a
 * fade its bus rises along. A video item's sprite reads as driven by the composition and goes into
 * its bus, which has a node in the master routing; after a hitch the sound is started again where
 * the playhead is.
 *
 * Everything it adds carries a `ct69` id and goes again at the end.
 */
import { readFileSync } from 'node:fs';
import { uploadVideo } from '../lib/projects.mjs';

const CUT = 'ct69-cut';
const BOX = 'ct69-box';
const SLIDE = 'ct69-slide';
const VIDEO = 'ct69-video';
const SCREEN = 'ct69-screen';

export async function compositionTab(t) {
  const { check, sleep, json, evaluate, mutate, mouse, drag, press, showTab } = t;
  /** Drags a row of the Assets panel to a point step by step: the drop only exists while the button is down. */
  const dragAsset = async (assetId, to) => {
    // A press on the row of the drag before, this soon, would read as a double-click that opens it.
    await sleep(450);
    const from = await json(`__gm.assetRow(${JSON.stringify(assetId)})`);
    await mouse('mouseMoved', from.x, from.y);
    await mouse('mousePressed', from.x, from.y);
    for (let i = 1; i <= 8; i++) {
      await mouse(
        'mouseMoved',
        from.x + ((to.x - from.x) * i) / 8,
        from.y + ((to.y - from.y) * i) / 8,
        'left',
        {
          buttons: 1,
        },
      );
      await sleep(16);
    }
    const drop = await json('__gm.composition.drop()');
    await mouse('mouseReleased', to.x, to.y);
    await sleep(200);
    return drop;
  };
  const model = () =>
    json(`(() => {
      const c = __gm.state.project.assets.find((a) => a.id === '${CUT}');
      return { objects: c.objects.map((o) => o.id), items: c.items, clips: c.clips };
    })()`);

  await press('Escape');
  await showTab('scene');
  // Ten frames a second keeps the numbers small: an item of 3 s is 30 frames, the slide 5.
  await mutate(`
    const p = __gm.state.project;
    p.assets.push(
      { id: '${CUT}', type: 'composition', name: 'Cut 69', props: { fps: 10, loop: false }, objects: [], groups: [],
        tracks: [{ id: 'ct69-t1', name: 'Front' }, { id: 'ct69-t2', name: 'Back' }], items: [], clips: [] },
      { id: '${BOX}', type: 'sprite', name: 'Box 69', props: { width: 100, height: 100, color: 0xff0000, texture: '' } },
      { id: '${SLIDE}', type: 'animation', name: 'Slide 69', props: { fps: 10, playback: 'once' }, root: '${BOX}',
        tracks: [{ id: 'ct69-row', target: '', property: 'x', keys: [{ frame: 0, value: 0 }, { frame: 5, value: 100 }] }] },
    );`);
  await evaluate(`__gm.state.openAsset('${CUT}')`);
  await sleep(300);
  const opened = await json(`{ tab: __gm.tab(), current: __gm.composition.current() }`);
  check(
    'opening a composition brings up its tab',
    opened.tab === 'composition' && opened.current === CUT,
    JSON.stringify(opened),
  );

  // 69a. A sprite dropped on the first track at frame 5 is an item there, 3 s long, picked.
  const first = await dragAsset(BOX, await json(`__gm.composition.laneAt('ct69-t1', 5)`));
  let m = await model();
  const a = m.items[0];
  const picked = await json('__gm.state.selection');
  check(
    'a sprite dragged onto a track becomes an item where it is let go, 3 s long and picked',
    first?.what === 'item' &&
      first.rejection === '' &&
      m.items.length === 1 &&
      a.start === 5 &&
      a.length === 30 &&
      a.fitMedia === true &&
      JSON.stringify(m.objects) === JSON.stringify([a.id]) &&
      picked?.kind === 'object' &&
      picked.holderId === CUT &&
      picked.objectId === a.id,
    JSON.stringify({ first, m, picked }),
  );
  const timing = await json(`__gm.section('TIMING')`);
  check('the inspector shows the picked item’s TIMING', timing !== null, JSON.stringify(timing));

  // 69b. A second one let go over the first lands where it is let go, over the first.
  await dragAsset(BOX, await json(`__gm.composition.laneAt('ct69-t1', 20)`));
  m = await model();
  const b = m.items.find((i) => i.id !== a.id);
  check(
    'one dropped onto an item lands where it is let go, over it',
    m.items.length === 2 && b?.start === 20 && b.length === 30,
    JSON.stringify(m.items),
  );

  // 69c. The first item's end, under the second, lights up with a resize cursor and is dragged past it.
  const box = await json(`__gm.composition.box('${a.id}')`);
  const end = { x: box.x + box.w - 2, y: box.y + box.h / 2 };
  await mouse('mouseMoved', end.x - 20, end.y);
  await mouse('mouseMoved', end.x, end.y);
  await sleep(80);
  const hovered = await json('__gm.composition.view()');
  const far = await json(`__gm.composition.laneAt('ct69-t1', 60)`);
  await drag(end.x, end.y, far.x, end.y);
  await sleep(150);
  m = await model();
  const resized = m.items.find((i) => i.id === a.id);
  check(
    'the covered end of an item lights up with a resize cursor, and is dragged past the item over it',
    hovered.hover?.id === a.id &&
      hovered.hover.part === 'end' &&
      hovered.cursor === 'ew-resize' &&
      resized?.length === 55 &&
      resized.fitMedia === undefined,
    JSON.stringify({ hover: hovered.hover, cursor: hovered.cursor, resized }),
  );

  // 69d. The animation dropped at frame 5 is a clip one pass long that moves the item in the picture.
  const clipDrop = await dragAsset(SLIDE, await json(`__gm.composition.laneAt('ct69-t1', 5)`));
  m = await model();
  const x = async (frame) => {
    await evaluate(`__gm.composition.scrub(${frame})`);
    await sleep(60);
    return (await json('__gm.composition.shown()')).find((o) => o.id === a.id)?.x ?? null;
  };
  const xs = [await x(5), await x(8), await x(20)];
  check(
    'an animation dragged onto a track becomes a clip, and moves the item it overlaps in the picture',
    clipDrop?.what === 'clip' &&
      m.clips.length === 1 &&
      m.clips[0].start === 5 &&
      m.clips[0].animation === SLIDE &&
      xs[0] === 0 &&
      xs[1] === 60 &&
      xs[2] === 100,
    JSON.stringify({ clipDrop, clips: m.clips, xs }),
  );

  // 69e. The hierarchy lists what is alive at the playhead – read off the rows it shows.
  const rowsAt = async (frame) => {
    await evaluate(`__gm.composition.scrub(${frame})`);
    await sleep(80);
    const shown = await json(`[${m.items.map((i) => `__gm.hierarchyRow('${i.id}')`).join(',')}]`);
    return m.items.filter((_, n) => shown[n] !== null).map((i) => i.id);
  };
  const rows = [await rowsAt(2), await rowsAt(10), await rowsAt(40)];
  check(
    'the hierarchy lists the items alive at the playhead',
    rows[0].length === 0 &&
      JSON.stringify(rows[1]) === JSON.stringify([a.id]) &&
      JSON.stringify(rows[2]) === JSON.stringify([a.id, b.id]),
    JSON.stringify(rows),
  );

  // 69f. Delete takes the picked item with its object; undo brings both back.
  await evaluate(`__gm.state.select({ kind: 'object', holderId: '${CUT}', objectId: '${b.id}' })`);
  await press('Delete');
  await sleep(150);
  const gone = await model();
  await press('z', { ctrl: true });
  await sleep(150);
  const back = await model();
  check(
    'Delete takes an item with its object, undo brings both back',
    !gone.items.some((i) => i.id === b.id) &&
      !gone.objects.includes(b.id) &&
      back.items.some((i) => i.id === b.id) &&
      back.objects.includes(b.id),
    JSON.stringify({ gone, back }),
  );

  // 69g. Play runs the playhead from the start to the end of the last item, and stops there.
  await evaluate(`__gm.composition.scrub(0)`);
  const playAt = await json('__gm.composition.playAt()');
  await mouse('mouseMoved', playAt.x, playAt.y);
  await mouse('mousePressed', playAt.x, playAt.y);
  await mouse('mouseReleased', playAt.x, playAt.y);
  await sleep(500);
  const running = await json('__gm.composition.view()');
  let ended = running;
  for (let i = 0; i < 40 && ended.playing; i++) {
    await sleep(150);
    ended = await json('__gm.composition.view()');
  }
  check(
    'Play runs the playhead to the end and stops there',
    running.playing && running.playhead > 0 && !ended.playing && ended.playhead === 60,
    JSON.stringify({ running, ended }),
  );

  // 69h. Two video items back to back: the second one's video is opened a second ahead, so the cut
  // draws its picture in the very redraw it begins – loaded only then, it was left out until it came.
  const uploaded = await uploadVideo(
    t.baseUrl,
    readFileSync(new URL('./fixtures/colors.webm', import.meta.url)),
    'colors.webm',
  );
  await mutate(`
    const p = __gm.state.project;
    p.assets.push(
      { id: '${VIDEO}', type: 'video', name: 'Colors 69', props: {}, file: ${JSON.stringify(uploaded.file)},
        width: 320, height: 180, duration: 2, fps: 30, audio: true },
      { id: '${SCREEN}', type: 'sprite', name: 'Screen 69', props: { width: 160, height: 90, color: 0xffffff, texture: '${VIDEO}' } },
    );
    const c = p.assets.find((a) => a.id === '${CUT}');
    const object = (id) => ({ ...structuredClone(c.objects[0]), id, assetId: '${SCREEN}', overrides: {}, instanceEdits: {} });
    c.objects = [object('ct69-v1'), object('ct69-v2')];
    c.items = [
      { id: 'ct69-v1', track: 'ct69-t1', start: 0, length: 20, offset: 0 },
      { id: 'ct69-v2', track: 'ct69-t1', start: 20, length: 10, offset: 1 },
    ];
    c.clips = [];`);
  const second = `__gm.videos().find((v) => v.key.endsWith(':ct69-v2')) ?? null`;
  await evaluate(`__gm.composition.scrub(5)`);
  await sleep(300);
  const early = await json(second);
  await evaluate(`__gm.composition.scrub(12)`);
  let ahead = null;
  // Settled: a seek still landing would hold the view a frame, which is no picture missing.
  for (let i = 0; i < 40 && !(ahead?.ready && !ahead.seeking && !ahead.landing); i++) {
    await sleep(150);
    ahead = await json(second);
  }
  const cut = await json(
    `(() => { __gm.composition.scrub(20); return __gm.composition.drawn('ct69-v2'); })()`,
  );
  check(
    'a coming video item is opened a second ahead, at its offset, and drawn in the redraw it begins',
    early === null && ahead?.ready && ahead.paused && Math.abs(ahead.time - 1) < 0.05 && cut !== null,
    JSON.stringify({ early, ahead, cut }),
  );

  // 69i. Play at the end starts over at 0, where the item's video was never opened: the playhead
  // waits for its first picture, so its first frames are seen – it ran on without them before.
  await mutate(`
    const c = __gm.state.project.assets.find((a) => a.id === '${CUT}');
    c.objects = [{ ...structuredClone(c.objects[0]), id: 'ct69-v3' }];
    c.items = [{ id: 'ct69-v3', track: 'ct69-t1', start: 0, length: 20, offset: 0 }];`);
  await evaluate(`__gm.composition.scrub(20)`);
  await sleep(200);
  await mouse('mousePressed', playAt.x, playAt.y);
  await mouse('mouseReleased', playAt.x, playAt.y);
  const wait = JSON.parse(
    await evaluate(`new Promise((done) => {
      const loading = [];
      const step = () => {
        const player = __gm.videos().find((v) => v.key.endsWith(':ct69-v3'));
        const { playhead } = __gm.composition.view();
        if (player?.ready) return done(JSON.stringify({ loading, ready: playhead }));
        if (player) loading.push(playhead);
        if (loading.length > 300) return done(JSON.stringify({ loading, ready: null }));
        requestAnimationFrame(step);
      };
      step();
    })`),
  );
  await sleep(500);
  const after = await json('__gm.composition.view()');
  check(
    'Play waits at a video item whose player is still loading, then runs on',
    wait.loading.length > 0 &&
      wait.loading.every((at) => at === 0) &&
      wait.ready !== null &&
      wait.ready < 0.5 &&
      after.playhead > 2,
    JSON.stringify({ frames: wait.loading.length, ready: wait.ready, after: after.playhead }),
  );

  // 69j. Ctrl+C copies the picked item. Ctrl+V pastes it under the pointer while that is over the
  // lanes, on the track there; with the pointer off the lanes at the playhead, on the picked track.
  for (let i = 0; i < 30 && (await json('__gm.composition.view()')).playing; i++) await sleep(150);
  await mutate(`
    const c = __gm.state.project.assets.find((a) => a.id === '${CUT}');
    c.objects = [{ ...structuredClone(c.objects[0]), id: 'ct69-p1', assetId: '${BOX}' }];
    c.items = [{ id: 'ct69-p1', track: 'ct69-t1', start: 0, length: 30, offset: 0 }];`);
  const original = await json(`__gm.composition.box('ct69-p1')`);
  await t.click(original.x + original.w / 2, original.y + original.h / 2);
  await press('c', { ctrl: true });
  const lane = await json(`__gm.composition.laneAt('ct69-t2', 50)`);
  await mouse('mouseMoved', lane.x, lane.y);
  await press('v', { ctrl: true });
  await evaluate(`__gm.composition.scrub(12)`);
  await mouse('mouseMoved', playAt.x, playAt.y);
  await press('v', { ctrl: true });
  m = await model();
  const copies = m.items.filter((i) => i.id !== 'ct69-p1');
  const pickedNow = await json('__gm.state.selection');
  check(
    'Ctrl+V pastes a copied item under the pointer, else at the playhead on the picked track',
    m.items.length === 3 &&
      m.objects.length === 3 &&
      copies[0]?.track === 'ct69-t2' &&
      copies[0].start === 50 &&
      copies[0].length === 30 &&
      copies[1]?.track === 'ct69-t2' &&
      copies[1].start === 12 &&
      pickedNow?.objectIds?.[0] === copies[1].id,
    JSON.stringify({ copies, picked: pickedNow?.objectIds }),
  );

  // 69k. A video dragged straight onto a track (#419) is an item as long as the video, wearing a sprite
  // the composition keeps and the Assets panel leaves out; a second drop shares it, and undoing both
  // takes the sprite along.
  const kept = (id) =>
    json(`(() => {
      const p = __gm.state.project;
      const c = p.assets.find((a) => a.id === '${CUT}');
      const object = c.objects.find((o) => o.id === ${JSON.stringify(id)});
      const sprite = object && p.assets.find((a) => a.id === object.assetId);
      return { item: c.items.find((i) => i.id === ${JSON.stringify(id)}) ?? null,
        sprite: sprite ? { id: sprite.id, type: sprite.type, owner: sprite.owner, texture: sprite.props.texture } : null,
        owned: p.assets.filter((a) => a.owner === '${CUT}').length };
    })()`);
  const videoDrop = await dragAsset(VIDEO, await json(`__gm.composition.laneAt('ct69-t2', 70)`));
  const one = await kept((await json('__gm.state.selection'))?.objectIds?.[0] ?? '');
  const row = one.sprite ? await json(`__gm.assetRow('${one.sprite.id}')`) : 'none';
  await dragAsset(VIDEO, await json(`__gm.composition.laneAt('ct69-t2', 100)`));
  const two = await kept((await json('__gm.state.selection'))?.objectIds?.[0] ?? '');
  await evaluate('__gm.state.undo()');
  await evaluate('__gm.state.undo()');
  const undone = await kept('');
  check(
    'a video dropped on a track wears a sprite the composition keeps, shared by a second drop',
    videoDrop?.what === 'item' &&
      videoDrop.rejection === '' &&
      one.item?.track === 'ct69-t2' &&
      one.item.start === 70 &&
      one.item.length === 20 &&
      one.sprite?.type === 'sprite' &&
      one.sprite.owner === CUT &&
      one.sprite.texture === VIDEO &&
      row === null &&
      two.item?.start === 100 &&
      two.sprite?.id === one.sprite.id &&
      two.owned === 1 &&
      undone.owned === 0,
    JSON.stringify({ videoDrop, one, row, two, undone }),
  );

  // 69l. An item dragged in the picture follows the pointer while the button is down, not only when
  // it is let go: the drag's preview each frame does not build the picture again from the document.
  await evaluate('__gm.composition.scrub(15)');
  await sleep(100);
  const front = (await json('__gm.composition.shown()')).at(-1)?.id ?? '';
  const startAt = await json(`__gm.composition.objectScreen('${front}')`);
  const objectX = () =>
    json(
      `__gm.state.project.assets.find((a) => a.id === '${CUT}').objects.find((o) => o.id === '${front}').position.x`,
    );
  const xBefore = await objectX();
  await mouse('mouseMoved', startAt.x, startAt.y);
  await mouse('mousePressed', startAt.x, startAt.y);
  for (let i = 1; i <= 6; i++) {
    await mouse('mouseMoved', startAt.x + i * 10, startAt.y, 'left', { buttons: 1 });
    await sleep(16);
  }
  await sleep(100);
  const during = await json(`__gm.composition.objectScreen('${front}')`);
  await mouse('mouseReleased', startAt.x + 60, startAt.y);
  await sleep(150);
  const xAfter = await objectX();
  check(
    'an item dragged in the picture follows the pointer while dragged and keeps the place let go',
    Math.abs(during.x - startAt.x - 60) < 2 && xAfter > xBefore,
    JSON.stringify({ front, startAt, during, xBefore, xAfter }),
  );

  // 69m. A band from an empty spot picks the items it touches, with Alt – from anywhere, an item too –
  // the clips. Ctrl+C and Ctrl+V take the clips under the pointer; a second paste onto the first
  // moves on until the clips fit, as clips of a track never overlap.
  await mutate(`
    const c = __gm.state.project.assets.find((a) => a.id === '${CUT}');
    const like = structuredClone(c.objects[0]);
    c.objects = ['ct69-b1', 'ct69-b2', 'ct69-b3'].map((id) => ({ ...like, id, assetId: '${BOX}' }));
    c.items = [
      { id: 'ct69-b1', track: 'ct69-t1', start: 0, length: 30, offset: 0 },
      { id: 'ct69-b2', track: 'ct69-t1', start: 40, length: 30, offset: 0 },
      { id: 'ct69-b3', track: 'ct69-t2', start: 0, length: 30, offset: 0 },
    ];
    c.clips = [
      { id: 'ct69-k1', track: 'ct69-t1', animation: '${SLIDE}', start: 0 },
      { id: 'ct69-k2', track: 'ct69-t2', animation: '${SLIDE}', start: 10 },
    ];`);
  await sleep(100);
  const empty = await json(`__gm.composition.laneAt('ct69-t2', 90)`);
  const into = await json(`__gm.composition.laneAt('ct69-t1', 25)`);
  await drag(empty.x, empty.y, into.x, into.y);
  const banded = await json('__gm.state.selection');
  const k1 = await json(`__gm.composition.box('ct69-k1')`);
  const k2 = await json(`__gm.composition.box('ct69-k2')`);
  await drag(k1.x + 1, k1.y - 3, k2.x + k2.w + 3, k2.y + k2.h - 1, { modifiers: { alt: true } });
  const altBanded = await json('__gm.state.selection');
  await press('c', { ctrl: true });
  const pasteAt = await json(`__gm.composition.laneAt('ct69-t1', 50)`);
  await mouse('mouseMoved', pasteAt.x, pasteAt.y);
  await press('v', { ctrl: true });
  const firstPaste = (await model()).clips.slice(2);
  await press('v', { ctrl: true });
  m = await model();
  const secondPaste = m.clips.slice(4);
  const pastedPick = await json('__gm.state.selection');
  check(
    'a band picks the items it touches, with Alt the clips, and copied clips paste where they fit',
    JSON.stringify([...(banded?.objectIds ?? [])].sort()) ===
      JSON.stringify(['ct69-b1', 'ct69-b2', 'ct69-b3']) &&
      altBanded?.kind === 'composition' &&
      JSON.stringify([...altBanded.clipIds].sort()) === JSON.stringify(['ct69-k1', 'ct69-k2']) &&
      firstPaste.length === 2 &&
      firstPaste[0].track === 'ct69-t1' &&
      firstPaste[0].start === 50 &&
      firstPaste[1].track === 'ct69-t2' &&
      firstPaste[1].start === 60 &&
      secondPaste.length === 2 &&
      secondPaste[0].start - firstPaste[0].start >= 5 &&
      secondPaste[0].start - firstPaste[0].start <= 6 &&
      secondPaste[1].start - secondPaste[0].start === 10 &&
      JSON.stringify(pastedPick?.clipIds) === JSON.stringify(secondPaste.map((c) => c.id)),
    JSON.stringify({ banded: banded?.objectIds, altBanded, firstPaste, secondPaste, pastedPick }),
  );

  // 69n. A dragged item takes the clips that begin on it along; with Alt pressed once the drag runs
  // it goes alone. The clip of the item next to it stays where it is.
  await mutate(`
    const c = __gm.state.project.assets.find((a) => a.id === '${CUT}');
    c.items = [
      { id: 'ct69-b1', track: 'ct69-t1', start: 0, length: 30, offset: 0 },
      { id: 'ct69-b2', track: 'ct69-t1', start: 70, length: 30, offset: 0 },
      { id: 'ct69-b3', track: 'ct69-t2', start: 0, length: 30, offset: 0 },
    ];
    c.clips = [
      { id: 'ct69-k1', track: 'ct69-t1', animation: '${SLIDE}', start: 5 },
      { id: 'ct69-k2', track: 'ct69-t1', animation: '${SLIDE}', start: 75 },
    ];`);
  await sleep(100);
  const frameWidth =
    ((await json(`__gm.composition.laneAt('ct69-t1', 100)`)).x -
      (await json(`__gm.composition.laneAt('ct69-t1', 0)`)).x) /
    100;
  /** Drags the item by `frames` from its middle – where no clip lies –, Alt held only while it moves. */
  const dragItem = async (id, frames, alt) => {
    const box = await json(`__gm.composition.box('${id}')`);
    const from = { x: box.x + box.w / 2, y: box.y + box.h / 2 };
    const to = from.x + frames * frameWidth;
    await mouse('mouseMoved', from.x, from.y);
    await mouse('mousePressed', from.x, from.y);
    for (let i = 1; i <= 12; i++) {
      await mouse('mouseMoved', from.x + ((to - from.x) * i) / 12, from.y, 'left', {
        buttons: 1,
        modifiers: alt ? 1 : 0,
      });
      await sleep(16);
    }
    await mouse('mouseReleased', to, from.y);
    await sleep(150);
    const now = await model();
    return {
      from,
      picked: (await json('__gm.state.selection'))?.objectIds,
      item: now.items.find((i) => i.id === id)?.start,
      clips: Object.fromEntries(now.clips.map((c) => [c.id, c.start])),
    };
  };
  const along = await dragItem('ct69-b1', 20, false);
  const alone = await dragItem('ct69-b1', -15, true);
  check(
    'a dragged item takes the clips that begin on it along, with Alt it goes alone',
    along.item === 20 &&
      along.clips['ct69-k1'] === 25 &&
      along.clips['ct69-k2'] === 75 &&
      alone.item === 5 &&
      alone.clips['ct69-k1'] === 25 &&
      alone.clips['ct69-k2'] === 75,
    JSON.stringify({ frameWidth, along, alone }),
  );

  // 69o (#418). A sound dragged onto a track is an audio item as long as one pass of it, picked on
  // the composition, the inspector naming it. Played from the middle, the composition plans it as a
  // clip that far into the sound, on the item's own bus and to the item's end; Pause ends it, and a
  // scrub plays nothing.
  const sounds = await evaluate(`fetch('/feuerwerk/api/index.php?r=sounds').then((r) => r.json())`);
  const blip = sounds.find((item) => item.bytes === 4044);
  await mutate(`
    const p = __gm.state.project;
    p.assets.push({ id: 'ct69-sound', type: 'sound', name: 'Blip 69', props: {}, file: ${JSON.stringify(blip?.file ?? '')} });
    const c = p.assets.find((a) => a.id === '${CUT}');
    c.objects = [];
    c.items = [];
    c.clips = [];`);
  const seconds = await evaluate(`__gm.sound.load(${JSON.stringify(blip?.file ?? '')})`);
  const soundDrop = await dragAsset('ct69-sound', await json(`__gm.composition.laneAt('ct69-t2', 10)`));
  m = await model();
  const tone = m.items[0];
  const tonePick = await json('__gm.state.selection');
  const toneSection = await json(`__gm.section('SOUND ITEM')`);
  await mutate(`
    const c = __gm.state.project.assets.find((a) => a.id === '${CUT}');
    c.items[0].length = 20;`);
  await evaluate('__gm.composition.scrub(15)');
  await sleep(200);
  const scrubbed = (await json('__gm.sound.playbacks()')).filter((p) => p.name === `composition:${CUT}`);
  const toneAt = await json('__gm.composition.playAt()');
  await mouse('mouseMoved', toneAt.x, toneAt.y);
  await t.click(toneAt.x, toneAt.y);
  let heard = [];
  for (let i = 0; i < 40 && !heard.some((p) => p.name === `composition:${CUT}` && p.clips.length > 0); i++) {
    await sleep(50);
    heard = await json('__gm.sound.playbacks()');
  }
  const toneView = await json('__gm.composition.view()');
  const toneSound = await json('__gm.composition.sound()');
  const playing = heard.find((p) => p.name === `composition:${CUT}`);
  const toneClip = playing?.clips[0];
  await t.click(toneAt.x, toneAt.y);
  await sleep(300);
  const paused = (await json('__gm.sound.playbacks()')).filter((p) => p.name === `composition:${CUT}`);
  check(
    'a sound dragged onto a track is an audio item, heard from the playhead on its own bus until the item ends',
    seconds > 0 &&
      soundDrop?.what === 'item' &&
      tone?.audio?.kind === 'sound' &&
      tone.audio.asset === 'ct69-sound' &&
      tone.audio.bus === '#composition' &&
      tone.start === 10 &&
      tone.length === Math.max(1, Math.round(seconds * 10)) &&
      m.objects.length === 0 &&
      tonePick?.kind === 'composition' &&
      JSON.stringify(tonePick.itemIds) === JSON.stringify([tone.id]) &&
      toneSection !== null &&
      scrubbed.length === 0 &&
      toneClip?.sound === 'ct69-sound' &&
      toneClip.bus === `composition:${CUT}:${tone.id}` &&
      toneSound.playing &&
      toneSound.playings.includes(playing.id) &&
      toneClip.offset > 0.5 &&
      toneClip.offset < 0.8 &&
      Math.abs(toneClip.offset + toneClip.duration - 2) < 0.002 &&
      paused.length === 0,
    JSON.stringify({
      seconds,
      soundDrop,
      tone,
      tonePick,
      scrubbed,
      toneClip,
      paused: paused.length,
      toneView,
      heard,
      toneSection,
      toneSound,
    }),
  );

  // 69o-ii. A pattern and a song leave the Assets panel as well and land as audio items as long as
  // their preview promised – the panel once let only sounds go.
  await mutate(`
    const p = __gm.state.project;
    p.assets.push(
      { id: 'ct69-pattern', type: 'pattern', name: 'Riff 69', props: { bars: 1 }, notes: [] },
      { id: 'ct69-song', type: 'song', name: 'Song 69', props: {}, tracks: [], items: [], graph: { nodes: [], edges: [] } },
    );
    p.assets.find((a) => a.id === '${CUT}').items = [];`);
  const patternDrop = await dragAsset('ct69-pattern', await json(`__gm.composition.laneAt('ct69-t1', 10)`));
  const songDrop = await dragAsset('ct69-song', await json(`__gm.composition.laneAt('ct69-t2', 10)`));
  m = await model();
  const kinds = m.items.map((i) => ({
    kind: i.audio?.kind,
    asset: i.audio?.asset,
    start: i.start,
    length: i.length,
  }));
  const landed = (drop, kind) =>
    drop?.what === 'item' &&
    kinds.some(
      (i) => i.kind === kind && i.asset === drop.assetId && i.start === 10 && i.length === drop.length,
    );
  check(
    'a pattern and a song dragged onto a track are audio items as long as their preview',
    landed(patternDrop, 'pattern') && landed(songDrop, 'song') && m.items.length === 2,
    JSON.stringify({ patternDrop, songDrop, kinds }),
  );

  // 69p. The handle on the top left corner of a sound item lights up under the pointer and drags
  // its fade in out to 10 frames; played from the item's start, its bus rises from silence over that
  // second and stays up.
  await mutate(`
    __gm.state.project.assets.find((a) => a.id === '${CUT}').items = [
      { id: 'ct69-fade', track: 'ct69-t2', start: 10, length: 40, offset: 0,
        audio: { kind: 'sound', asset: 'ct69-sound', volume: 0, bus: '' } },
    ];`);
  await evaluate('__gm.composition.scrub(0)');
  await sleep(100);
  const fadeBox = await json(`__gm.composition.box('ct69-fade')`);
  const perFrame = (await json('__gm.composition.view()')).pxPerTick;
  await mouse('mouseMoved', fadeBox.x + 1, fadeBox.y + 3);
  await sleep(50);
  const fadeHover = (await json('__gm.composition.view()')).hover;
  await drag(fadeBox.x + 1, fadeBox.y + 3, fadeBox.x + 10 * perFrame, fadeBox.y + 3);
  const faded = (await model()).items[0];
  await evaluate('__gm.composition.scrub(10)');
  const fadeAt = await json('__gm.composition.playAt()');
  await t.click(fadeAt.x, fadeAt.y);
  const levels = [];
  for (let i = 0; i < 16; i++) {
    await sleep(100);
    const bus = (await json('__gm.song.buses()')).find((b) =>
      b.name.endsWith(`composition:${CUT}:ct69-fade`),
    );
    levels.push(bus ? Number(bus.level.toFixed(3)) : null);
  }
  await t.click(fadeAt.x, fadeAt.y);
  const heardLevels = levels.filter((l) => l !== null);
  check(
    'the fade handle of a sound item drags its fade in, and its bus rises from silence over it',
    fadeHover?.id === 'ct69-fade' &&
      fadeHover.part === 'fadeIn' &&
      faded?.fadeIn === 10 &&
      faded.fadeOut === undefined &&
      heardLevels[0] < 0.5 &&
      heardLevels.some((l) => l > 0.1 && l < 0.9) &&
      heardLevels.at(-1) > 0.99,
    JSON.stringify({ fadeBox, perFrame, fadeHover, faded, levels }),
  );

  // 69q. A video dragged in: its sprite's Video clock reads as driven by the composition, its Video
  // time – the composition's – is not shown, its Video bus goes into the composition by default. The
  // composition has a node of its own in the master routing, linked to the master.
  await mutate(`
    const c = __gm.state.project.assets.find((a) => a.id === '${CUT}');
    c.objects = [];
    c.items = [];`);
  await dragAsset(SCREEN, await json(`__gm.composition.laneAt('ct69-t1', 0)`));
  const screenItem = (await model()).items[0];
  // A row is looked for once it is scrolled into view: the inspector is taller than the window.
  const videoRows = await json(`({
    driven: __gm.inspectorField('Video clock') !== null && __gm.locate('Driven (by composition)') !== null,
    time: __gm.inspectorField('Video time'),
    volume: __gm.inspectorField('Video volume') !== null,
    bus: __gm.inspectorField('Video bus') !== null && __gm.locate('To composition') !== null,
    stored: __gm.state.project.assets.find((a) => a.id === '${CUT}').objects[0]?.overrides ?? null,
  })`);
  const routing = await json('__gm.routing.graph()');
  const node = routing.nodes.find((n) => n.id === CUT);
  const links = routing.edges.filter((e) => e.from.node === CUT).map((e) => e.to.node);
  check(
    'a video item reads as driven by the composition, goes into its bus, and the composition is routed',
    screenItem !== undefined &&
      videoRows.driven &&
      videoRows.time === null &&
      videoRows.volume &&
      videoRows.bus &&
      videoRows.stored?.videoClock === undefined &&
      node?.params.kind === 'composition' &&
      JSON.stringify(links) === JSON.stringify(['#master']),
    JSON.stringify({ screenItem, videoRows, node, links }),
  );

  // 69r. A hitch of half a second while the tab plays: the playhead counts a tenth of it at most, the
  // sound ran on – it is started again where the playhead is, and the two keep together after.
  await mutate(`
    const c = __gm.state.project.assets.find((a) => a.id === '${CUT}');
    c.objects = [];
    c.items = [{ id: 'ct69-long', track: 'ct69-t2', start: 0, length: 100, offset: 0,
      audio: { kind: 'sound', asset: 'ct69-sound', volume: 0, bus: '' } }];`);
  await evaluate('__gm.composition.scrub(0)');
  const longAt = await json('__gm.composition.playAt()');
  await t.click(longAt.x, longAt.y);
  let hitchBefore = null;
  for (let i = 0; i < 40 && !(hitchBefore?.playing && hitchBefore.ahead !== null); i++) {
    await sleep(50);
    hitchBefore = await json('__gm.composition.sound()');
  }
  await sleep(300);
  hitchBefore = await json('__gm.composition.sound()');
  await evaluate(`{ const until = performance.now() + 500; while (performance.now() < until); null; }`);
  await sleep(400);
  const hitchAfter = await json('__gm.composition.sound()');
  await t.click(longAt.x, longAt.y);
  check(
    'after a hitch the sound of the tab is started again where the playhead is',
    hitchBefore?.playing &&
      Math.abs(hitchBefore.ahead) < 0.06 &&
      hitchAfter.resyncs > hitchBefore.resyncs &&
      hitchAfter.playing &&
      Math.abs(hitchAfter.ahead) < 0.06,
    JSON.stringify({ hitchBefore, hitchAfter }),
  );

  await showTab('scene');
  await mutate(`
    const p = __gm.state.project;
    p.assets = p.assets.filter((a) => !a.id.startsWith('ct69-') && !a.owner?.startsWith('ct69-'));`);
}