import React from "react";
import PropTypes from "prop-types";

import { geyser } from "@bufferapp/components/style/color";

import { color as metricsColor } from "../style";

const iconSize = 7;
const base = 10;
const style = {
  display: "inline-block",
  verticalAlign: "baseline",
  width: `${iconSize}px`,
  height: `${iconSize}px`,
  marginRight: `${0.5 * base}px`,

  borderWidth: "2px",
  borderStyle: "solid",
};

function lightenDarkenColor(color, amt) {
  let usePound = false;
  if (color[0] === "#") {
    color = color.slice(1);
    usePound = true;
  }

  /* eslint-disable no-bitwise */
  const num = parseInt(color, 16);
  let r = (num >> 16) + amt;
  if (r > 255) r = 255;
  else if (r < 0) r = 0;

  let b = ((num >> 8) & 0x00ff) + amt;
  if (b > 255) b = 255;
  else if (b < 0) b = 0;

  let g = (num & 0x0000ff) + amt;
  if (g > 255) g = 255;
  else if (g < 0) g = 0;

  return `${usePound ? "#" : ""}${(g | (b << 8) | (r << 16)).toString(16)}`;
}

function getIconStyle(metric) {
  const color = metric.color
    ? metric.color
    : metricsColor[metric.key] || geyser;
  return Object.assign({}, style, {
    background: lightenDarkenColor(color, 90),
    borderColor: color,
    borderRadius: `${metric.squaredIcon ? 0 : base}px`,
  });
}

const MetricIcon = ({ metric }) => <span style={getIconStyle(metric)} />;

MetricIcon.propTypes = {
  metric: PropTypes.shape({
    color: PropTypes.string,
    key: PropTypes.string,
  }).isRequired,
};

export default MetricIcon;