1import React from 'react';
 2import gql from 'graphql-tag';
 3import { makeStyles } from '@material-ui/styles';
 4import {
 5  getContrastRatio,
 6  darken,
 7} from '@material-ui/core/styles/colorManipulator';
 8import { common } from '@material-ui/core/colors';
 9
10// Minimum contrast between the background and the text color
11const contrastThreshold = 2.5;
12
13// Guess the text color based on the background color
14const getTextColor = background =>
15  getContrastRatio(background, common.white) >= contrastThreshold
16    ? common.white // White on dark backgrounds
17    : common.black; // And black on light ones
18
19const _rgb = color => 'rgb(' + color.R + ',' + color.G + ',' + color.B + ')';
20
21// Create a style object from the label RGB colors
22const createStyle = color => ({
23  backgroundColor: _rgb(color),
24  color: getTextColor(_rgb(color)),
25  borderBottomColor: darken(_rgb(color), 0.2),
26});
27
28const useStyles = makeStyles(theme => ({
29  label: {
30    ...theme.typography.body2,
31    padding: '0 6px',
32    fontSize: '0.9em',
33    margin: '0 1px',
34    borderRadius: '3px',
35    display: 'inline-block',
36    borderBottom: 'solid 1.5px',
37    verticalAlign: 'bottom',
38  },
39}));
40
41function Label({ label }) {
42  const classes = useStyles();
43  return (
44    <span className={classes.label} style={createStyle(label.color)}>
45      {label.name}
46    </span>
47  );
48}
49
50Label.fragment = gql`
51  fragment Label on Label {
52    name
53    color {
54      R
55      G
56      B
57    }
58  }
59`;
60
61export default Label;