import type { Vec4 } from '../../../renderers/webgl/internal/ShaderUtils.js';

export function roundRect(
  ctx: CanvasRenderingContext2D | Path2D,
  x: number,
  y: number,
  width: number,
  height: number,
  radius: Vec4,
) {
  if (ctx.roundRect !== undefined) {
    ctx.roundRect(x, y, width, height, radius);
    return;
  }
  const { 0: tl, 1: tr, 2: br, 3: bl } = radius;
  ctx.moveTo(x + tl, y);
  ctx.lineTo(x + width - tr, y);
  ctx.ellipse(x + width - tr, y + tr, tr, tr, 0, 1.5 * Math.PI, 2 * Math.PI);
  ctx.lineTo(x + width, y - height - br);
  ctx.ellipse(x + width - br, y + height - br, br, br, 0, 0, 0.5 * Math.PI);
  ctx.lineTo(x + bl, y + height);
  ctx.ellipse(x + bl, y + height - bl, bl, bl, 0, 0.5 * Math.PI, Math.PI);
  ctx.lineTo(x, y + tl);
  ctx.ellipse(x + tl, y + tl, tl, tl, 0, Math.PI, 1.5 * Math.PI);
}

export function roundedRectWithBorder(
  ctx: CanvasRenderingContext2D,
  x: number,
  y: number,
  width: number,
  height: number,
  radius: Vec4,
  borderGap: number,
  outerX: number,
  outerY: number,
  outerW: number,
  outerH: number,
  outerBorderRadius: Vec4,
  innerX: number,
  innerY: number,
  innerW: number,
  innerH: number,
  innerBorderRadius: Vec4,
  borderColor: string,
  renderContext: () => void,
) {
  outerX += x;
  outerY += y;
  outerW += width;
  outerH += height;

  innerX += x;
  innerY += y;
  innerW += width;
  innerH += height;

  //draw node content first
  ctx.save();
  ctx.beginPath();
  roundRect(ctx, x, y, width, height, radius);
  ctx.clip();
  renderContext();
  ctx.restore();

  //draw border by clipping inner area from outer area
  ctx.save();
  const borderPath = new Path2D();
  roundRect(borderPath, outerX, outerY, outerW, outerH, outerBorderRadius);
  roundRect(borderPath, innerX, innerY, innerW, innerH, innerBorderRadius);
  ctx.fillStyle = borderColor;
  ctx.fill(borderPath, 'evenodd');
  ctx.restore();
}

export function shadow(
  ctx: CanvasRenderingContext2D,
  x: number,
  y: number,
  width: number,
  height: number,
  color: string,
  projection: Vec4,
  radius: Vec4,
  pixelRatio: number,
) {
  ctx.save();
  const cw = ctx.canvas.width;
  const ch = ctx.canvas.height;
  const scaleFactor = (2 * projection[3] + width) / width;
  ctx.scale(scaleFactor, scaleFactor);
  ctx.shadowColor = color;
  ctx.shadowBlur = projection[2] * pixelRatio;
  ctx.shadowOffsetX = projection[0] + cw * pixelRatio - projection[3] * 0.5;
  ctx.shadowOffsetY = projection[1] + ch * pixelRatio - projection[3] * 0.5;

  const spreadFactor = projection[3];
  ctx.beginPath();
  roundRect(
    ctx,
    (x - spreadFactor - cw) / scaleFactor,
    (y - spreadFactor - ch) / scaleFactor,
    width + spreadFactor,
    height + spreadFactor,
    radius,
  );
  ctx.fillStyle = color;
  ctx.fill();
  ctx.restore();
}

export function strokeLine(
  ctx: CanvasRenderingContext2D,
  x: number,
  y: number,
  x2: number,
  y2: number,
  lineWidth: number,
) {
  ctx.beginPath();
  ctx.lineWidth = lineWidth;
  ctx.moveTo(x, y);
  ctx.lineTo(x2, y2);
  ctx.stroke();
}