import { Universe, Cell } from "rust-wasm";
import { memory } from "rust-wasm/rust_wasm_bg";

const CELL_SIZE = 5; // px
const GRID_COLOR = "#CCCCCC";
const COLOURS = ["#FFF", "#FF8", "#FF0", "#F80", "#F00", "#800", "#000"];

// Construct the universe, and get its width and height.
const universe = Universe.new();
universe.init();
const width = universe.width();
const height = universe.height();

// Give the canvas room for all of our cells and a 1px border
// around each of them.
const infochaos = document.getElementById("chaos");
const infomax = document.getElementById("max");
const infoavg = document.getElementById("avg");
var maxstress = 0;
var avgstress = 31000;
const canvas = document.getElementById("game-of-life-canvas");
canvas.height = (CELL_SIZE + 1) * height + 1;
canvas.width = (CELL_SIZE + 1) * width + 1;

const ctx = canvas.getContext('2d');

const renderLoop = () => {
  universe.tick();

  //drawGrid();
  drawCells();

  const st = universe.stress();
  if (st > maxstress) maxstress = st;
  avgstress = 0.999 * avgstress + 0.001 * st
  infochaos.innerHTML = st;
  infomax.innerHTML = maxstress;
  infoavg.innerHTML = Math.round(avgstress);

  // setTimeout(renderLoop, 200);
  requestAnimationFrame(renderLoop);
};

// setTimeout(renderLoop, 1);
requestAnimationFrame(renderLoop);

const drawGrid = () => {
  ctx.beginPath();
  ctx.strokeStyle = GRID_COLOR;

  // Vertical lines.
  for (let i = 0; i <= width; i++) {
    ctx.moveTo(i * (CELL_SIZE + 1) + 1, 0);
    ctx.lineTo(i * (CELL_SIZE + 1) + 1, (CELL_SIZE + 1) * height + 1);
  }

  // Horizontal lines.
  for (let j = 0; j <= height; j++) {
    ctx.moveTo(0,                           j * (CELL_SIZE + 1) + 1);
    ctx.lineTo((CELL_SIZE + 1) * width + 1, j * (CELL_SIZE + 1) + 1);
  }

  ctx.stroke();
};

const getIndex = (row, column) => {
  return row * width + column;
};

const drawCells = () => {
  const cellsPtr = universe.cells();
  const cells = new Uint8Array(memory.buffer, cellsPtr, width * height);

  ctx.beginPath();

  for (let row = 0; row < height; row++) {
    for (let col = 0; col < width; col++) {
      const idx = getIndex(row, col);
      const rat = Math.round(COLOURS.length * cells[idx] / 101);
      const colour = COLOURS[rat];

      ctx.fillStyle = colour;

      ctx.fillRect(
        col * (CELL_SIZE + 1) + 1,
        row * (CELL_SIZE + 1) + 1,
        CELL_SIZE,
        CELL_SIZE
      );
    }
  }

  ctx.stroke();
};