'use strict';

// Draws small moving gradient boxes and repeats them.
const Mirrors = function (modulation, width, height, renderer) {
  let response = [];

  let scale = 2 + Math.round(Math.random() * 4);
  let scaledHeight = Math.floor(height / scale);
  let scaledWidth = Math.floor(width / scale);

  for (let i = 0; i < scaledHeight; i++) {
    let row = [];
    for (let j = 0; j < scaledWidth; j++) {
      let red = ((modulation + i) * 255 / height) % 255;
      let blue = ((modulation + j) * 255 / width) % 255;
      let green = ((modulation + i * j) * 255 / (width * height)) % 255;

      let cell = [renderer(red, blue, green), ' '];
      row.push(cell.join(''));
    }

    let rowText = '';
    for (let j = 0; j < scale; j++) {
      rowText += row.reverse().join('');
    }

    for (let j = 1; j < scale; j++) {
      response[j * i] = rowText;
      response[(height - 1 - (j * i))] = rowText;
    }
  }

  return response.join('\n');
};

module.exports = Mirrors;