import { describe, expect, it } from 'vitest';
import { AppState } from '../src/lib/app-state.svelte';

const image = { width: 100, height: 80, data: new Uint8ClampedArray(100 * 80 * 4) };

function withImage() {
  const app = new AppState();
  app.setImage(image);
  return app;
}

describe('AppState', () => {
  it('starts with sensible defaults', () => {
    const app = new AppState();
    expect(app.marginMm).toBe(-2);
    expect(app.mode).toBe('auto');
    expect(app.tool).toBe('none');
    expect(app.shapePx).toBeNull();
    expect(app.exportShape).toBeNull();
  });

  it('sets the scale from two clicks, then leaves the scale tool', () => {
    const app = withImage();
    app.tool = 'scale';
    app.handleImageClick({ x: 10, y: 10 });
    expect(app.tool).toBe('scale');
    app.handleImageClick({ x: 70, y: 10 });
    expect(app.tool).toBe('none');
    app.lengthMm = 30;
    expect(app.pxPerMm).toBeCloseTo(2);
    expect(app.marginPx).toBeCloseTo(-4);
  });

  it('restarts the scale line on a third click', () => {
    const app = withImage();
    app.tool = 'scale';
    app.handleImageClick({ x: 10, y: 10 });
    app.handleImageClick({ x: 70, y: 10 });
    app.tool = 'scale';
    app.handleImageClick({ x: 5, y: 5 });
    expect(app.scalePoints).toEqual([{ x: 5, y: 5 }]);
    expect(app.pxPerMm).toBeNull();
  });

  it('flags an invalid scale and keeps the margin at 0 until the scale is valid', () => {
    const app = withImage();
    app.tool = 'scale';
    app.handleImageClick({ x: 10, y: 10 });
    app.handleImageClick({ x: 10, y: 10 });
    app.lengthMm = 50;
    expect(app.scaleInvalid).toBe(true);
    expect(app.marginPx).toBe(0);
  });

  it('ignores clicks outside the image', () => {
    const app = withImage();
    app.tool = 'seed';
    app.handleImageClick({ x: -1, y: 10 });
    app.handleImageClick({ x: 50, y: 80 });
    expect(app.seed).toBeNull();
    expect(app.tool).toBe('seed');
  });

  it('sets the seed and leaves the seed tool', () => {
    const app = withImage();
    app.tool = 'seed';
    app.handleImageClick({ x: 20, y: 30 });
    expect(app.seed).toEqual({ x: 20, y: 30 });
    expect(app.tool).toBe('none');
  });

  it('draws an outline then holes, switching to manual mode', () => {
    const app = withImage();
    app.tool = 'draw';
    [{ x: 1, y: 1 }, { x: 90, y: 1 }, { x: 90, y: 70 }].forEach((p) => app.handleImageClick(p));
    app.finishPolygon();
    expect(app.manualOuter).toHaveLength(3);
    expect(app.mode).toBe('manual');
    [{ x: 20, y: 20 }, { x: 30, y: 20 }, { x: 30, y: 30 }].forEach((p) => app.handleImageClick(p));
    app.finishPolygon();
    expect(app.manualHoles).toHaveLength(1);
    expect(app.drawing).toEqual([]);
  });

  it('discards a polygon with fewer than 3 points', () => {
    const app = withImage();
    app.tool = 'draw';
    app.handleImageClick({ x: 1, y: 1 });
    app.finishPolygon();
    expect(app.manualOuter).toEqual([]);
    expect(app.mode).toBe('auto');
  });

  it('clearManual returns to auto mode', () => {
    const app = withImage();
    app.tool = 'draw';
    [{ x: 1, y: 1 }, { x: 90, y: 1 }, { x: 90, y: 70 }].forEach((p) => app.handleImageClick(p));
    app.finishPolygon();
    app.clearManual();
    expect(app.mode).toBe('auto');
    expect(app.manualOuter).toEqual([]);
    expect(app.tool).toBe('none');
  });

  it('a new image resets scale, seed and manual work', () => {
    const app = withImage();
    app.tool = 'scale';
    app.handleImageClick({ x: 10, y: 10 });
    app.seed = { x: 5, y: 5 };
    app.manualOuter = [{ x: 1, y: 1 }, { x: 2, y: 2 }, { x: 3, y: 1 }];
    app.mode = 'manual';
    app.setImage(image);
    expect(app.scalePoints).toEqual([]);
    expect(app.seed).toBeNull();
    expect(app.manualOuter).toEqual([]);
    expect(app.mode).toBe('auto');
    expect(app.tool).toBe('none');
    expect(app.threshold).toBe(128);
  });
});