import { describe, it, expect } from 'vitest';
import { drawOverlay } from './renderer';
import type { Segment, RenderStyle } from '../types';

class FakeCtx {
  calls: string[] = [];
  strokeStyle = '';
  lineWidth = 0;
  beginPath() { this.calls.push('begin'); }
  setLineDash(d: number[]) { this.calls.push(`dash:${d.length}`); }
  moveTo(x: number, y: number) { this.calls.push(`move:${x},${y}`); }
  lineTo(x: number, y: number) { this.calls.push(`line:${x},${y}`); }
  stroke() { this.calls.push(`stroke:${this.strokeStyle}`); }
}

const STYLE: RenderStyle = { cutColor: '#cut', rapidColor: '#rapid', lineWidth: 2 };

describe('drawOverlay', () => {
  it('strokes a cut as a solid polyline in the cut colour', () => {
    const ctx = new FakeCtx();
    const segs: Segment[] = [{ kind: 'cut', points: [[0, 0], [5, 5], [10, 0]] }];
    drawOverlay(ctx as unknown as CanvasRenderingContext2D, segs, STYLE);
    expect(ctx.calls).toEqual(['begin', 'dash:0', 'move:0,0', 'line:5,5', 'line:10,0', 'stroke:#cut']);
  });

  it('strokes a rapid dashed in the rapid colour', () => {
    const ctx = new FakeCtx();
    const segs: Segment[] = [{ kind: 'rapid', points: [[0, 0], [5, 0]] }];
    drawOverlay(ctx as unknown as CanvasRenderingContext2D, segs, STYLE);
    expect(ctx.calls).toContain('dash:2');
    expect(ctx.calls).toContain('stroke:#rapid');
  });

  it('skips degenerate segments', () => {
    const ctx = new FakeCtx();
    drawOverlay(ctx as unknown as CanvasRenderingContext2D, [{ kind: 'cut', points: [[1, 1]] }], STYLE);
    expect(ctx.calls).toEqual([]);
  });
});