// import {Texture} from '@pixi/core';
// import {Sprite} from '@pixi/sprite';

import {bresenham, createNoise2D, TAU} from '@/util/math.js';

const simplex2D = createNoise2D();

// TODO - 3d noise around a circumference of length polygon perimeter

export function createLayerMask(layer) {
  const {area, hulls, tileSize} = layer;
  const canvas = window.document.createElement('canvas');
  if (0 === hulls.length) {
    return Texture.from(canvas);
  }
  [canvas.width, canvas.height] = [area.x * tileSize.x, area.y * tileSize.y];
  const ctx = canvas.getContext('2d');
  ctx.fillStyle = 'rgba(0, 0, 0, 1)';
  ctx.fillRect(0, 0, canvas.width, canvas.height);
  ctx.fillStyle = 'rgba(255, 255, 255, 1)';
  for (let i = 0; i < hulls.length; ++i) {
    const hull = [...hulls[i]];
    hull.push(hull[0]);
    ctx.beginPath();
    ctx.moveTo(hull[0].x, hull[0].y);
    for (let j = 0; j < hull.length - 1; j++) {
      const p0 = hull[j + 0];
      const p1 = hull[j + 1];
      const points = bresenham(p0, p1);
      const isReversed = (
        (p0.x > p1.x && points[0].x < points[points.length - 1].x)
        || (p0.y > p1.y && points[0].y < points[points.length - 1].y)
      );
      for (
        let k = (isReversed ? points.length - 1 : 0);
        (isReversed ? k >= 0 : k < points.length);
        k += (isReversed ? -1 : 1)
      ) {
        const {x, y} = points[k];
        const ANGLE_SCALE = 1000;
        const WALK_SCALE = 10;
        const MAGNITUDE = ((tileSize.x + tileSize.y) / 2) * simplex2D(x * 100, y * 100);
        const w = simplex2D(x * WALK_SCALE, y * WALK_SCALE);
        const r = TAU * simplex2D(x * ANGLE_SCALE, y * ANGLE_SCALE)
        ctx.lineTo(
          x + Math.cos(r) * w * MAGNITUDE,
          y + -Math.sin(r) * w * MAGNITUDE,
        );
      }
    }
    ctx.closePath();
    ctx.fill();
  }
  return Texture.from(canvas);
}