// Painter 的 Canvas 2D 实现。Cocos 版本换成 Graphics + Label 即可，HexBoardView 不用改。
import type { Point } from '../src/geom';
import type { Painter } from '../src/painter';

export class CanvasPainter implements Painter {
  private readonly ctx: CanvasRenderingContext2D;
  private readonly fontFamily =
    '"SF Pro Rounded", "PingFang SC", "Helvetica Neue", "Segoe UI", system-ui, -apple-system, sans-serif';

  constructor(ctx: CanvasRenderingContext2D) {
    this.ctx = ctx;
  }

  private path(pts: Point[]): void {
    const ctx = this.ctx;
    ctx.beginPath();
    ctx.moveTo(pts[0].x, pts[0].y);
    for (let i = 1; i < pts.length; i++) ctx.lineTo(pts[i].x, pts[i].y);
    ctx.closePath();
  }

  fillPolygon(pts: Point[], color: string, alpha = 1): void {
    if (alpha <= 0 || pts.length < 3) return;
    const ctx = this.ctx;
    ctx.globalAlpha = alpha;
    ctx.fillStyle = color;
    this.path(pts);
    ctx.fill();
    ctx.globalAlpha = 1;
  }

  strokePolygon(pts: Point[], color: string, lineWidth: number, alpha = 1): void {
    if (alpha <= 0 || pts.length < 2) return;
    const ctx = this.ctx;
    ctx.globalAlpha = alpha;
    ctx.strokeStyle = color;
    ctx.lineWidth = lineWidth;
    ctx.lineJoin = 'round';
    this.path(pts);
    ctx.stroke();
    ctx.globalAlpha = 1;
  }

  line(x1: number, y1: number, x2: number, y2: number, width: number, color: string, alpha = 1): void {
    if (alpha <= 0) return;
    const ctx = this.ctx;
    ctx.globalAlpha = alpha;
    ctx.strokeStyle = color;
    ctx.lineWidth = width;
    ctx.lineCap = 'round';
    ctx.beginPath();
    ctx.moveTo(x1, y1);
    ctx.lineTo(x2, y2);
    ctx.stroke();
    ctx.globalAlpha = 1;
  }

  fillCircle(cx: number, cy: number, radius: number, color: string, alpha = 1): void {
    if (alpha <= 0) return;
    const ctx = this.ctx;
    ctx.globalAlpha = alpha;
    ctx.fillStyle = color;
    ctx.beginPath();
    ctx.arc(cx, cy, radius, 0, Math.PI * 2);
    ctx.fill();
    ctx.globalAlpha = 1;
  }

  text(s: string, cx: number, cy: number, size: number, color: string, bold = false, alpha = 1): void {
    if (alpha <= 0) return;
    const ctx = this.ctx;
    ctx.globalAlpha = alpha;
    ctx.fillStyle = color;
    ctx.font = `${bold ? '700' : '500'} ${size}px ${this.fontFamily}`;
    ctx.textAlign = 'center';
    ctx.textBaseline = 'middle';
    ctx.fillText(s, cx, cy + size * 0.04);
    ctx.globalAlpha = 1;
  }
}