/**
 * A drag writes the model on every pointer move but tells the editor once per frame (#213): the
 * model event rebuilds panels and pictures, and a mouse reports faster than the screen draws.
 */
import { type Application, CanvasTextMetrics } from 'pixi.js';
import { beforeAll, beforeEach, describe, expect, it, vi } from 'vitest';
import { buildAsset } from '../../src/core/commands/assetCommands';
import type { Command } from '../../src/core/commands/Command';
import type {
  CurveAsset,
  GraphAsset,
  PaletteAsset,
  PixelArtAsset,
  VectorArtAsset,
  VectorGradient,
} from '../../src/core/model/Asset';
import { PALETTE_KEY } from '../../src/core/model/pixelart';
import { createEmptyProject } from '../../src/core/model/Project';
import { CurveCanvas } from '../../src/editor/curve/CurveCanvas';
import { FramePreview } from '../../src/editor/framePreview';
import { GraphDrags } from '../../src/editor/graph/graphDrags';
import type { GraphCanvasHost } from '../../src/editor/graph/graphHost';
import type { InspectorHost } from '../../src/editor/inspector/host';
import { previewingHandlers } from '../../src/editor/inspector/previewHandlers';
import { buildShapeSection, currentGradientBar } from '../../src/editor/inspector/shapeSection';
import { PixelArtCanvas } from '../../src/editor/pixelart/PixelArtCanvas';
import { PixelArtSide } from '../../src/editor/pixelart/PixelArtSide';
import { PixelThumbs } from '../../src/editor/pixelart/PixelThumbs';
import { EditorState } from '../../src/editor/state';
import { VStack } from '../../src/ui';
import { initRenderLoop, resetRenderLoop } from '../../src/ui/render';
import { PaintCache } from '../../src/viewport/vectorArtPicture';
import { allShapes } from '../../src/core/model/vectorTree';

/** One frame of the render loop, the way the ticker runs it. */
function frames(): () => void {
  const added: Array<() => void> = [];
  const app = {
    render(): void {},
    ticker: {
      add: (fn: () => void) => added.push(fn),
      remove: () => undefined,
    },
  };
  initRenderLoop(app as unknown as Application);
  return () => added.forEach((fn) => fn());
}

function fakeState() {
  return {
    selectedAnnotationIds: [] as string[],
    selectedNodeIds: ['n1'],
    preview: vi.fn(),
    execute: vi.fn(() => true),
  };
}

describe('FramePreview', () => {
  beforeEach(() => resetRenderLoop());

  it('turns any number of requests in one frame into a single preview', () => {
    const tick = frames();
    const state = fakeState();
    const preview = new FramePreview(state, 'drag');
    for (let i = 0; i < 5; i++) preview.request();
    expect(state.preview).not.toHaveBeenCalled();
    tick();
    expect(state.preview).toHaveBeenCalledTimes(1);
    tick();
    expect(state.preview).toHaveBeenCalledTimes(1);
  });

  it('drops the waiting preview on cancel', () => {
    const tick = frames();
    const state = fakeState();
    const preview = new FramePreview(state, 'drag');
    preview.request();
    preview.cancel();
    tick();
    expect(state.preview).not.toHaveBeenCalled();
  });

  it('keeps two gestures of the same name apart', () => {
    const tick = frames();
    const a = fakeState();
    const b = fakeState();
    new FramePreview(a, 'drag').request();
    new FramePreview(b, 'drag').request();
    tick();
    expect(a.preview).toHaveBeenCalledTimes(1);
    expect(b.preview).toHaveBeenCalledTimes(1);
  });
});

describe('dragging a node in the graph', () => {
  beforeEach(() => resetRenderLoop());

  function rig() {
    const state = fakeState();
    const asset = {
      id: 'b',
      graph: { nodes: [{ id: 'n1', type: 'Add', x: 0, y: 0, params: {} }], edges: [] },
    } as unknown as GraphAsset;
    const host = {
      state: state as unknown as EditorState,
      assetId: () => 'b',
      asset: () => asset,
      nodeBoxes: () => [{ id: 'n1', x: 0, y: 0, w: 100, h: 40 }],
      toGraph: (p: { x: number; y: number }) => ({ x: p.x, y: p.y }),
      zoom: () => 1,
      snapping: () => false,
      moved: vi.fn(),
    } as unknown as GraphCanvasHost;
    return { state, host, node: asset.graph.nodes[0]!, drags: new GraphDrags(host) };
  }

  it('moves the node with every pointer move, and the canvas follows once a frame', () => {
    const tick = frames();
    const { host, node, drags } = rig();
    drags.grabNodes({ x: 10, y: 10 });
    for (let i = 1; i <= 5; i++) {
      drags.move({ x: 10 + i * 10, y: 10 });
      expect(node.x).toBe(i * 10);
    }
    expect(host.moved).not.toHaveBeenCalled();
    tick();
    expect(host.moved).toHaveBeenCalledTimes(1);
  });

  it('does not announce a changed project while the drag runs (#292)', () => {
    const tick = frames();
    const { state, drags } = rig();
    drags.grabNodes({ x: 10, y: 10 });
    drags.move({ x: 50, y: 30 });
    tick();
    expect(state.preview).not.toHaveBeenCalled();
  });

  it('leaves nothing for the frame after the release: the command has the last word', () => {
    const tick = frames();
    const { state, host, node, drags } = rig();
    drags.grabNodes({ x: 10, y: 10 });
    drags.move({ x: 50, y: 30 });
    drags.releaseNodes();
    expect(state.execute).toHaveBeenCalledTimes(1);
    expect(node.x).toBe(0);
    tick();
    expect(host.moved).not.toHaveBeenCalled();
  });
});

describe('editing an inspector row (#274)', () => {
  beforeEach(() => resetRenderLoop());

  function rig() {
    const state = fakeState();
    const target = { x: 1 };
    const commit = vi.fn((value: number) => ({ value }) as unknown as Command);
    const handlers = previewingHandlers<typeof target, number>(
      { state: state as unknown as EditorState },
      { target: () => target, read: (t) => t.x, write: (t, value) => (t.x = value), commit },
    );
    return { state, target, commit, handlers };
  }

  it('writes every input into the model and previews once a frame', () => {
    const tick = frames();
    const { state, target, handlers } = rig();
    for (let i = 2; i <= 6; i++) {
      handlers.onInput(i);
      expect(target.x).toBe(i);
    }
    expect(state.preview).not.toHaveBeenCalled();
    tick();
    expect(state.preview).toHaveBeenCalledTimes(1);
  });

  it('commits from the value before the scrub and leaves nothing for the next frame', () => {
    const tick = frames();
    const { state, target, commit, handlers } = rig();
    handlers.onInput(5);
    handlers.onChange(7);
    expect(target.x).toBe(1);
    expect(commit).toHaveBeenCalledWith(7);
    expect(state.execute).toHaveBeenCalledTimes(1);
    tick();
    expect(state.preview).not.toHaveBeenCalled();
  });
});

describe('dragging a colour stop of a gradient (#274)', () => {
  beforeAll(() => {
    CanvasTextMetrics.measureText = (() => ({ width: 10, height: 10, lines: [], lineWidths: [] })) as never;
    PaintCache.prototype.gradient = (() => null) as never;
  });
  beforeEach(() => resetRenderLoop());

  function rig() {
    const state = new EditorState();
    state.loadProject(createEmptyProject('p', 'P'), 1);
    const asset = buildAsset('vectorart', 'Drawing') as VectorArtAsset;
    asset.layers[0]!.items.push({
      id: 's',
      name: 'Sky',
      fill: 0x0000ff,
      opacity: 1,
      rings: [],
      paint: {
        type: 'linear',
        from: { x: 0, y: 0 },
        to: { x: 100, y: 0 },
        stops: [
          { offset: 0, color: 0x0000ff, alpha: 1 },
          { offset: 1, color: 0xffffff, alpha: 1 },
        ],
      },
    });
    state.project.assets.push(asset);
    const host: InspectorHost = {
      state,
      body: new VStack(),
      fields: new Map(),
      nameField: null,
      project: () => state.project,
      liveVariables: () => null,
    };
    buildShapeSection(host, asset.id, 's', ['s']);
    const bar = currentGradientBar('fill')!;
    // 100 px between the outermost markers, which stand 6 px in from either end.
    bar.resize(112, 32);
    const pointer = (type: string, x: number) =>
      bar.emit(type, { button: 0, global: { x, y: 25 }, stopPropagation: () => undefined });
    const offsets = () => (allShapes(asset)[0]!.paint as VectorGradient).stops.map((stop) => stop.offset);
    return { state, preview: vi.spyOn(state, 'preview'), pointer, offsets };
  }

  it('moves the stop with every pointer move and previews once a frame', () => {
    const tick = frames();
    const { preview, pointer, offsets } = rig();
    pointer('pointerdown', 6);
    for (let i = 1; i <= 5; i++) {
      pointer('globalpointermove', 6 + i * 10);
      expect(offsets()[0]).toBeCloseTo(i / 10);
    }
    expect(preview).not.toHaveBeenCalled();
    tick();
    expect(preview).toHaveBeenCalledTimes(1);
  });

  it('leaves nothing for the frame after the release, and the drag is one undo step', () => {
    const tick = frames();
    const { state, preview, pointer, offsets } = rig();
    pointer('pointerdown', 6);
    pointer('globalpointermove', 56);
    pointer('pointerup', 56);
    expect(offsets()[0]).toBeCloseTo(0.5);
    tick();
    expect(preview).not.toHaveBeenCalled();
    state.undo();
    expect(offsets()[0]).toBe(0);
  });
});

describe('the side panel of the pixel art tab (#274)', () => {
  beforeAll(() => {
    CanvasTextMetrics.measureText = (() => ({ width: 10, height: 10, lines: [], lineWidths: [] })) as never;
    // Canvas and thumbnails paint onto browser canvases, which Node has none of.
    PixelArtCanvas.prototype.redraw = () => undefined;
    PixelThumbs.prototype.paint = () => undefined;
  });
  beforeEach(() => resetRenderLoop());

  function rig() {
    const state = new EditorState();
    state.loadProject(createEmptyProject('p', 'P'), 1);
    const palette = buildAsset('palette', 'Palette') as PaletteAsset;
    const art = buildAsset('pixelart', 'Art') as PixelArtAsset;
    art.props[PALETTE_KEY] = palette.id;
    state.project.assets.push(palette, art);
    const canvas = new PixelArtCanvas(state);
    const side = new PixelArtSide(state, canvas);
    canvas.show(art.id);
    canvas.setColor(1);
    const layer = art.layers[0]!;
    // The row's number field calls these two; the list keeps them to itself.
    const opacity = side as unknown as {
      previewOpacity(layerId: string, opacity: number): void;
      commitOpacity(layerId: string, opacity: number): void;
    };
    return { state, palette, art, layer, side, opacity, preview: vi.spyOn(state, 'preview') };
  }

  it('writes every colour under the picker into the palette and previews once a frame', () => {
    const tick = frames();
    const { state, palette, side, preview } = rig();
    const first = palette.colors[0]!;
    for (const color of [0x111111, 0x222222, 0x333333]) {
      side.colorField.onInput?.(color);
      expect(palette.colors[0]).toBe(color);
    }
    expect(preview).not.toHaveBeenCalled();
    tick();
    expect(preview).toHaveBeenCalledTimes(1);
    side.colorField.onInput?.(0x444444);
    side.colorField.onChange?.(0x555555);
    tick();
    expect(preview).toHaveBeenCalledTimes(1);
    expect(palette.colors[0]).toBe(0x555555);
    state.undo();
    expect(palette.colors[0]).toBe(first);
  });

  it('says so when the picker ends on the colour it started from', () => {
    const tick = frames();
    const { palette, side, preview } = rig();
    const first = palette.colors[0]!;
    side.colorField.onInput?.(0x111111);
    tick();
    side.colorField.onChange?.(first);
    expect(palette.colors[0]).toBe(first);
    expect(preview).toHaveBeenCalledTimes(2);
  });

  it('writes every step of an opacity scrub into the layer and previews once a frame', () => {
    const tick = frames();
    const { state, art, layer, opacity, preview } = rig();
    for (const value of [0.9, 0.8, 0.7]) {
      opacity.previewOpacity(layer.id, value);
      expect(layer.opacity).toBe(value);
    }
    expect(preview).not.toHaveBeenCalled();
    tick();
    expect(preview).toHaveBeenCalledTimes(1);
    opacity.previewOpacity(layer.id, 0.6);
    opacity.commitOpacity(layer.id, 0.5);
    tick();
    expect(preview).toHaveBeenCalledTimes(1);
    expect(art.layers[0]!.opacity).toBe(0.5);
    state.undo();
    expect(art.layers[0]!.opacity).toBe(1);
  });
});

describe('the place fields of the curve tab (#274)', () => {
  beforeAll(() => {
    CanvasTextMetrics.measureText = (() => ({ width: 10, height: 10, lines: [], lineWidths: [] })) as never;
  });
  beforeEach(() => resetRenderLoop());

  function rig() {
    const state = new EditorState();
    state.loadProject(createEmptyProject('p', 'P'), 1);
    const curve = buildAsset('curve', 'Ease') as CurveAsset;
    state.project.assets.push(curve);
    const canvas = new CurveCanvas(state);
    canvas.show(curve.id);
    (canvas as unknown as { picked: number }).picked = 1;
    return { state, curve, canvas, preview: vi.spyOn(state, 'preview') };
  }

  it('moves the picked point with every input and previews once a frame', () => {
    const tick = frames();
    const { state, curve, canvas, preview } = rig();
    const before = curve.points[1]!.y;
    for (const v of [0.9, 0.8, 0.7]) {
      canvas.movePicked({ x: 1, y: v }, false);
      expect(canvas.pickedPlace?.y).toBeCloseTo(v);
    }
    expect(preview).not.toHaveBeenCalled();
    tick();
    expect(preview).toHaveBeenCalledTimes(1);
    canvas.movePicked({ x: 1, y: 0.6 }, false);
    canvas.movePicked({ x: 1, y: 0.5 }, true);
    tick();
    expect(preview).toHaveBeenCalledTimes(1);
    expect(curve.points[1]!.y).toBeCloseTo(0.5);
    state.undo();
    expect(curve.points[1]!.y).toBe(before);
  });
});