/**
 * Render layers and overlay cameras (#302). The main camera sees only `Default`, an overlay camera
 * 2000 units to the right sees only `UI`. Each draws its own picture, the overlay's laid on top:
 * a green sprite of the overlay with z -10 covers a red one of the main camera with z 1000, and
 * what a camera does not see stays away – a yellow `UI` sprite in front of the main camera, a blue
 * `Default` one in front of the overlay. Switched to no overlay, the second camera draws nothing.
 * `Is hovered` and `Mouse position` find the mouse through the overlay camera too (#304), and a
 * graph moves a sprite onto another layer while the game runs (#305).
 * Then the main camera wears a shader over its picture (#299), in the Game tab and, switched on in
 * the eye, in the scene view.
 *
 * Everything it adds carries an `rl63` id and goes again at the end.
 */
import { MAKE_OBJECT } from './lib/scaffold.mjs';

const OVERLAY = 'rl63-cam';

export async function renderLayers(t) {
  const { check, json, evaluate, mutate, sleep, shot, showTab, play, stop, clickText, press } = t;
  await showTab('scene');

  await mutate(`
    const p = __gm.state.project;
    const scene = __gm.state.activeScene;
    const main = scene.objects.find((o) => o.id === 'o3');
    window.__rl63 = { layers: p.renderLayers, overrides: structuredClone(main.overrides) };
    p.renderLayers = ['Default', 'UI'];
    main.overrides = { ...main.overrides, sees: 0b01 };
    ${MAKE_OBJECT}
    const sprite = p.assets.find((a) => a.type === 'sprite');
    const square = (id, name, dx, z, size, color, layer, from) => {
      const o = make(id, sprite.id, '', 0, name);
      Object.assign(o.position, { x: from.x + dx, y: from.y, z });
      o.overrides = { width: size, height: size, color, texture: '', shader: '', renderLayer: layer };
      return o;
    };
    const overlay = structuredClone(main);
    Object.assign(overlay, { id: '${OVERLAY}', name: 'Overlay 63', instanceEdits: {} });
    overlay.position = { ...main.position, x: main.position.x + 2000 };
    overlay.overrides = { ...main.overrides, overlay: true, sees: 0b10 };
    scene.objects.push(
      overlay,
      square('rl63-a', 'A 63', 70, 1000, 60, 0xff0000, -1, main.position),
      square('rl63-d', 'D 63', -70, 1000, 60, 0xffff00, 1, main.position),
      square('rl63-b', 'B 63', 0, -10, 40, 0x00ff00, 1, overlay.position),
      square('rl63-c', 'C 63', 70, 1000, 60, 0x0000ff, 0, overlay.position),
    );
  `);
  await evaluate('__gm.state.select(null)');
  await showTab('game');
  await sleep(300);

  const channels = (hex) => [1, 3, 5].map((i) => parseInt(hex.slice(i, i + 2), 16));
  const is = (hex, [r, g, b]) => {
    const [pr, pg, pb] = channels(hex);
    return Math.abs(pr - r) < 30 && Math.abs(pg - g) < 30 && Math.abs(pb - b) < 30;
  };
  /** The three points of the picture the squares sit on: the centre and 70 units either side. */
  const picture = async () => {
    const { frame, scale } = await json('__gm.gameScale()');
    const cx = Math.round(frame.x + frame.w / 2);
    const cy = Math.round(frame.y + frame.h / 2);
    const at = (dx) => json(`__gm.pixelAt(${Math.round(cx + dx * scale)}, ${cy})`);
    return {
      centre: await at(0),
      right: await at(70),
      left: await at(-70),
      main: await json('__gm.gameDrawOrder()'),
      overlays: await json('__gm.gameOverlays()'),
    };
  };
  const GREEN = [0, 255, 0];
  const RED = [255, 0, 0];
  const YELLOW = [255, 255, 0];
  const stacked = (seen) =>
    seen.overlays.length === 1 &&
    seen.overlays[0].camera === OVERLAY &&
    seen.overlays[0].drawOrder.includes('rl63-b') &&
    !seen.overlays[0].drawOrder.includes('rl63-c') &&
    seen.main.includes('rl63-a') &&
    !seen.main.includes('rl63-d') &&
    !seen.main.includes('rl63-b') &&
    is(seen.centre, GREEN) &&
    is(seen.right, RED) &&
    !is(seen.left, YELLOW);

  // 63a. The preview of the Game tab: each camera draws what it sees, the overlay on top.
  const preview = await picture();
  await shot('63-overlay-preview');
  check(
    'each camera draws only its layers, and the overlay lies on top whatever the z',
    stacked(preview),
    JSON.stringify(preview),
  );

  // 63b. Without Overlay the second camera is a plain one after the first: it draws nothing.
  await mutate(`
    const cam = __gm.state.activeScene.objects.find((o) => o.id === '${OVERLAY}');
    cam.overrides = { ...cam.overrides, overlay: false };
  `);
  await sleep(200);
  const plain = await picture();
  check(
    'two plain cameras switched on draw through the first one only',
    plain.overlays.length === 0 && !is(plain.centre, GREEN) && is(plain.right, RED),
    JSON.stringify(plain),
  );
  await mutate(`
    const cam = __gm.state.activeScene.objects.find((o) => o.id === '${OVERLAY}');
    cam.overrides = { ...cam.overrides, overlay: true };
  `);

  // 63c. The running game stacks them the same way.
  await play();
  await sleep(400);
  const running = await picture();
  check(
    'the running game lays the overlay camera on top the same way',
    stacked(running),
    JSON.stringify(running),
  );
  await stop();

  // 63c2. (#304) The mouse through the overlay camera, zoomed 2x: 30 units right of the centre of
  //       the picture it lies 15 units right of the overlay's centre, on the 40 wide square B. Through
  //       the main camera nothing is there. Logged each tick: hovered through it, without it, its x.
  const node = (id, type, x, params = {}) => ({ id, type, x, y: 0, params });
  const edge = (id, from, fromPort, to, toPort) => ({
    id,
    from: { node: from, port: fromPort },
    to: { node: to, port: toPort },
  });
  const hoverGraph = {
    nodes: [
      node('rl63-tick', 'OnUpdate', 0),
      node('rl63-b-find', 'ObjectByName', 0, { name: 'B 63' }),
      node('rl63-cam-find', 'ObjectByName', 0, { name: 'Overlay 63' }),
      node('rl63-through', 'IsHovered', 200),
      node('rl63-plain', 'IsHovered', 200),
      node('rl63-mouse', 'MousePosition', 200),
      node('rl63-log1', 'Log', 400),
      node('rl63-log2', 'Log', 600),
      node('rl63-log3', 'Log', 800),
    ],
    edges: [
      edge('rl63-e1', 'rl63-tick', 'exec', 'rl63-log1', 'exec'),
      edge('rl63-e2', 'rl63-log1', 'exec', 'rl63-log2', 'exec'),
      edge('rl63-e3', 'rl63-log2', 'exec', 'rl63-log3', 'exec'),
      edge('rl63-e4', 'rl63-b-find', 'object', 'rl63-through', 'object'),
      edge('rl63-e5', 'rl63-cam-find', 'object', 'rl63-through', 'camera'),
      edge('rl63-e6', 'rl63-b-find', 'object', 'rl63-plain', 'object'),
      edge('rl63-e7', 'rl63-cam-find', 'object', 'rl63-mouse', 'camera'),
      edge('rl63-e8', 'rl63-through', 'result', 'rl63-log1', 'message'),
      edge('rl63-e9', 'rl63-plain', 'result', 'rl63-log2', 'message'),
      edge('rl63-e10', 'rl63-mouse', 'x', 'rl63-log3', 'message'),
    ],
  };
  await mutate(`
    const p = __gm.state.project;
    const scene = __gm.state.activeScene;
    p.assets.push({ id: 'rl63-hover', type: 'behavior', name: 'Hover 63', props: { enabled: true, runInEditor: false }, variables: [], graph: ${JSON.stringify(hoverGraph)} });
    ${MAKE_OBJECT}
    scene.objects.push(make('rl63-logic', 'rl63-hover', '', 0, 'Hover 63'));
    const cam = scene.objects.find((o) => o.id === '${OVERLAY}');
    window.__rl63.overlay = structuredClone(cam.overrides);
    cam.overrides = { ...cam.overrides, zoom: 2 };
  `);
  await play();
  await sleep(300);
  const game = await json('__gm.gameScale()');
  const centre = { x: game.frame.x + game.frame.w / 2, y: game.frame.y + game.frame.h / 2 };
  await t.mouse('mouseMoved', centre.x + 30 * game.scale, centre.y);
  await sleep(300);
  const ran = await json('__gm.world()');
  const hovered = ran?.log.slice(-3) ?? [];
  const overlayX = ran?.entities.find((e) => e.objectId === OVERLAY)?.worldX;
  await stop();
  await mutate(`
    const p = __gm.state.project;
    const scene = __gm.state.activeScene;
    scene.objects = scene.objects.filter((o) => o.id !== 'rl63-logic');
    p.assets = p.assets.filter((a) => a.id !== 'rl63-hover');
    scene.objects.find((o) => o.id === '${OVERLAY}').overrides = window.__rl63.overlay;
  `);
  check(
    'Is hovered through the overlay camera finds what only it shows, through the main one not',
    hovered[0] === 'true' && hovered[1] === 'false' && Math.abs(Number(hovered[2]) - (overlayX + 15)) < 1,
    JSON.stringify({ hovered, overlayX }),
  );

  // 63c3. (#305) A graph moves the red square A onto `UI` with a Properties node once the game runs:
  //       the main camera no longer draws it, and `Render layer of` names its new layer.
  const switchGraph = {
    nodes: [
      node('rl63-start', 'OnStart', 0),
      node('rl63-a-find', 'ObjectByName', 0, { name: 'A 63' }),
      {
        ...node('rl63-set', 'Properties', 200, { objectType: 'sprite', renderLayer: 1 }),
        ports: [{ key: 'renderLayer', kind: 'number', write: true }],
      },
      node('rl63-of', 'RenderLayerOf', 200),
      node('rl63-name', 'Log', 400),
      node('rl63-number', 'Log', 600),
    ],
    edges: [
      edge('rl63-s1', 'rl63-start', 'exec', 'rl63-set', 'exec'),
      edge('rl63-s2', 'rl63-set', 'exec', 'rl63-name', 'exec'),
      edge('rl63-s3', 'rl63-name', 'exec', 'rl63-number', 'exec'),
      edge('rl63-s4', 'rl63-a-find', 'object', 'rl63-set', 'object'),
      edge('rl63-s5', 'rl63-a-find', 'object', 'rl63-of', 'object'),
      edge('rl63-s6', 'rl63-of', 'name', 'rl63-name', 'message'),
      edge('rl63-s7', 'rl63-of', 'number', 'rl63-number', 'message'),
    ],
  };
  await mutate(`
    const p = __gm.state.project;
    const scene = __gm.state.activeScene;
    p.assets.push({ id: 'rl63-switch', type: 'behavior', name: 'Switch 63', props: { enabled: true, runInEditor: false }, variables: [], graph: ${JSON.stringify(switchGraph)} });
    ${MAKE_OBJECT}
    scene.objects.push(make('rl63-switcher', 'rl63-switch', '', 0, 'Switch 63'));
  `);
  await play();
  await sleep(400);
  const switched = await picture();
  const named = (await json('__gm.world()'))?.log.slice(-2) ?? [];
  await stop();
  await mutate(`
    const p = __gm.state.project;
    const scene = __gm.state.activeScene;
    scene.objects = scene.objects.filter((o) => o.id !== 'rl63-switcher');
    p.assets = p.assets.filter((a) => a.id !== 'rl63-switch');
  `);
  check(
    'a graph moves a sprite onto UI while the game runs, and Render layer of names it',
    !switched.main.includes('rl63-a') && !is(switched.right, RED) && JSON.stringify(named) === '["UI","1"]',
    JSON.stringify({ switched, named }),
  );

  // 63d. The project settings list the render layers, apart from the collision layers.
  await t.clickToolbar('menu');
  await clickText('Project settings…');
  const opened = await json('__gm.renderLayers()');
  await clickText('Add render layer');
  const added = await json('__gm.renderLayers()');
  const collision = await json('__gm.collisionLayers()');
  await press('Escape');
  await sleep(150);
  check(
    'the project settings list the render layers and add one at the end',
    JSON.stringify(opened.dialog) === JSON.stringify(['Default', 'UI']) &&
      JSON.stringify(added.dialog) === JSON.stringify(['Default', 'UI', 'Layer 2']) &&
      !collision.dialog.includes('UI'),
    JSON.stringify({ opened, added, collision }),
  );

  // 63e. (#299) The main camera wears a shader over its whole picture. One that changes nothing
  //      draws the picture byte for byte as before, the right way up: a blue square 100 units above
  //      the centre stays above it. At 100 % so the picture's pixels sit on the screen's.
  await showTab('game');
  const scaleBefore = await json('__gm.state.gameScale');
  await mutate(`
    ${MAKE_OBJECT}
    const p = __gm.state.project;
    const scene = __gm.state.activeScene;
    const main = scene.objects.find((o) => o.id === 'o3');
    const sprite = p.assets.find((a) => a.type === 'sprite');
    const o = make('rl63-e', sprite.id, '', 0, 'E 63');
    Object.assign(o.position, { x: main.position.x, y: main.position.y - 100, z: 0 });
    o.overrides = { width: 30, height: 30, color: 0x3366ff, texture: '', shader: '', renderLayer: 0 };
    scene.objects.push(o);
    __gm.state.setGameScale(1);
  `);
  const shaderOf = (id, nodes, edges) => ({
    id,
    type: 'shader',
    name: id,
    props: {},
    graph: { nodes, edges },
  });
  const link = (from, out, to, port) => ({ from: { node: from, port: out }, to: { node: to, port } });
  const PASS = shaderOf('rl63-pass', [{ id: 'out', type: 'ShaderOutput', x: 0, y: 0, params: {} }], []);
  const FLAT_RED = shaderOf(
    'rl63-red',
    [
      { id: 'red', type: 'ShaderColor', x: 0, y: 0, params: { value: 0xff0000 } },
      { id: 'one', type: 'ShaderNumber', x: 0, y: 80, params: { value: 1 } },
      { id: 'out', type: 'ShaderOutput', x: 200, y: 0, params: {} },
    ],
    [link('red', 'color', 'out', 'color'), link('one', 'value', 'out', 'alpha')],
  );
  // Red is the width, green the height, both in thousandths: 640 × 360 comes out as 163 / 92.
  const SIZE = shaderOf(
    'rl63-size',
    [
      { id: 'size', type: 'ShaderTextureSize', x: 0, y: 0, params: {} },
      { id: 'red', type: 'ShaderColor', x: 0, y: 80, params: { value: 0xff0000 } },
      { id: 'green', type: 'ShaderColor', x: 0, y: 160, params: { value: 0x00ff00 } },
      { id: 'milli', type: 'ShaderNumber', x: 0, y: 240, params: { value: 0.001 } },
      { id: 'one', type: 'ShaderNumber', x: 0, y: 320, params: { value: 1 } },
      { id: 'w', type: 'ShaderMultiply', x: 200, y: 0, params: {} },
      { id: 'h', type: 'ShaderMultiply', x: 200, y: 160, params: {} },
      { id: 'sum', type: 'ShaderAdd', x: 400, y: 0, params: {} },
      { id: 'scaled', type: 'ShaderMultiply', x: 600, y: 0, params: {} },
      { id: 'out', type: 'ShaderOutput', x: 800, y: 0, params: {} },
    ],
    [
      link('red', 'color', 'w', 'a'),
      link('size', 'width', 'w', 'b'),
      link('green', 'color', 'h', 'a'),
      link('size', 'height', 'h', 'b'),
      link('w', 'result', 'sum', 'a'),
      link('h', 'result', 'sum', 'b'),
      link('sum', 'result', 'scaled', 'a'),
      link('milli', 'value', 'scaled', 'b'),
      link('scaled', 'result', 'out', 'color'),
      link('one', 'value', 'out', 'alpha'),
    ],
  );
  /** Puts `shader` on the main camera (null takes it off), with `resolution` as its row. */
  const wear = (shader, resolution = 'screen') =>
    mutate(`
      const p = __gm.state.project;
      p.assets = p.assets.filter((a) => !a.id.startsWith('rl63-'));
      const shader = ${JSON.stringify(shader)};
      if (shader) p.assets.push(shader);
      const main = __gm.state.activeScene.objects.find((o) => o.id === 'o3');
      main.overrides = { ...main.overrides, shader: shader ? shader.id : '', shaderResolution: '${resolution}' };
    `);
  /** Two rows of the picture, through the centre and through the blue square, and the square's spot. */
  const rows = async () => {
    const { frame, scale } = await json('__gm.gameScale()');
    const cx = Math.round(frame.x + frame.w / 2);
    const cy = Math.round(frame.y + frame.h / 2);
    const row = (dy) =>
      json(`__gm.pixelRow(${Math.round(frame.x)}, ${Math.round(cy + dy * scale)}, ${Math.round(frame.w)})`);
    return {
      centre: await row(0),
      above: await row(-100),
      blueAbove: await json(`__gm.pixelAt(${cx}, ${Math.round(cy - 100 * scale)})`),
      blueBelow: await json(`__gm.pixelAt(${cx}, ${Math.round(cy + 100 * scale)})`),
      pixels: await json('__gm.cameraShaderPixels()'),
    };
  };
  const same = (a, b) => JSON.stringify([a.centre, a.above]) === JSON.stringify([b.centre, b.above]);
  const unshaded = await rows();
  await wear(PASS);
  const handedThrough = await rows();
  const differing = handedThrough.above.filter((hex, i) => hex !== unshaded.above[i]).length;
  check(
    'a camera shader that changes nothing draws the game picture byte for byte, the right way up',
    unshaded.pixels === null &&
      handedThrough.pixels !== null &&
      is(unshaded.blueAbove, [0x33, 0x66, 0xff]) &&
      !is(unshaded.blueBelow, [0x33, 0x66, 0xff]) &&
      same(handedThrough, unshaded),
    JSON.stringify({ differing, pixels: handedThrough.pixels, blue: handedThrough.blueAbove }),
  );

  // 63f. A flat red fills the main camera's whole picture, corners included; the overlay camera's
  //      UI square lies on top of it in its own green (the proof moved here from #302).
  await wear(FLAT_RED);
  const { frame } = await json('__gm.gameScale()');
  const corners = await json(
    `__gm.pixels(${JSON.stringify([
      { x: frame.x + 2, y: frame.y + 2 },
      { x: frame.x + frame.w - 3, y: frame.y + 2 },
      { x: frame.x + 2, y: frame.y + frame.h - 3 },
      { x: frame.x + frame.w - 3, y: frame.y + frame.h - 3 },
    ])})`,
  );
  const reddened = await picture();
  await shot('63-camera-shader-red');
  check(
    'a flat red fills the whole game picture, and the overlay camera’s UI keeps its colour',
    corners.every((hex) => is(hex, RED)) && is(reddened.left, RED) && is(reddened.centre, GREEN),
    JSON.stringify({ corners, reddened }),
  );

  // 63g. `Texture size` is the camera's raster in either resolution – a pixel counts as a camera
  //      pixel (the user's choice, #299) – while Screen pixels draws the picture with as many pixels
  //      as it covers on screen. Fitted, so that is not 640 by chance.
  await mutate(`__gm.state.setGameScale('fit')`);
  const measured = {};
  for (const resolution of ['screen', 'camera']) {
    await wear(SIZE, resolution);
    measured[resolution] = {
      colour: (await picture()).left,
      pixels: await json('__gm.cameraShaderPixels()'),
    };
  }
  const fitted = await json('__gm.gameScale()');
  const ratio = (await json('__gm.pixelGrid()')).resolution;
  // Tight: counted in screen pixels the fitted 670 would come out as 171 / 96, close to the real thing.
  const exactly = (hex, rgb) => channels(hex).every((v, i) => Math.abs(v - rgb[i]) <= 2);
  check(
    'Texture size is View width × View height in both resolutions, and only Camera pixels draws 640 × 360',
    ['screen', 'camera'].every((r) => exactly(measured[r].colour, [163, 92, 0])) &&
      measured.camera.pixels?.w === 640 &&
      measured.camera.pixels?.h === 360 &&
      measured.screen.pixels?.w === Math.round(fitted.frame.w * ratio) &&
      measured.screen.pixels?.w !== 640,
    JSON.stringify({ measured, frame: fitted.frame, ratio }),
  );

  // 63h. Taken off again, the camera draws as before and lays no picture over its view.
  await mutate(`__gm.state.setGameScale(1)`);
  await wear(null);
  const back = await rows();
  check(
    'a camera without a shader draws as it did before',
    back.pixels === null && same(back, unshaded),
    JSON.stringify({ pixels: back.pixels }),
  );

  // 63i. The scene view lays the shader over the main camera's frame only while the eye's Shader
  //      switch is on – a real click on it – and never past the frame.
  await wear(FLAT_RED);
  await showTab('scene');
  await evaluate(`(() => {
    const main = __gm.state.activeScene.objects.find((o) => o.id === 'o3');
    __gm.lookAt(main.position.x, main.position.y);
  })()`);
  await sleep(150);
  const sceneSpots = async () => {
    const r = await json('__gm.objectRect("o3")');
    const [inside, outside] = await json(
      `__gm.pixels(${JSON.stringify([
        { x: Math.round(r.x - r.w * 0.3), y: Math.round(r.y - r.h * 0.3) },
        { x: Math.round(r.x - r.w * 0.7), y: Math.round(r.y - r.h * 0.3) },
      ])})`,
    );
    return { inside, outside, pixels: await json(`__gm.cameraShaderPixels('scene')`) };
  };
  const switchedOff = await sceneSpots();
  const eye = await json(`__gm.sceneHeaderAt('visibility')`);
  await t.click(eye.x, eye.y);
  const shaderSwitch = (await json('__gm.visibilityPopup()')).find(
    (e) => e.type === 'camera' && e.part === 'shader',
  );
  await t.click(shaderSwitch.x, shaderSwitch.y);
  await press('Escape');
  await sleep(150);
  const switchedOn = await sceneSpots();
  await shot('63-camera-shader-scene');
  check(
    'the scene view shows the camera shader over the frame only while the eye switch is on',
    shaderSwitch.on === false &&
      switchedOff.pixels === null &&
      !is(switchedOff.inside, RED) &&
      switchedOn.pixels !== null &&
      is(switchedOn.inside, RED) &&
      !is(switchedOn.outside, RED),
    JSON.stringify({ switchedOff, switchedOn, shaderSwitch }),
  );

  // Clean up.
  await showTab('scene');
  await mutate(`
    const p = __gm.state.project;
    const scene = __gm.state.activeScene;
    scene.objects = scene.objects.filter((o) => !o.id.startsWith('rl63-'));
    scene.objects.find((o) => o.id === 'o3').overrides = window.__rl63.overrides;
    p.renderLayers = window.__rl63.layers;
    p.assets = p.assets.filter((a) => !a.id.startsWith('rl63-'));
    __gm.state.setSceneVisibility('camera', 'shader', false);
    __gm.state.setGameScale(${JSON.stringify(scaleBefore)});
  `);
}