First version of avatar

.gitignore

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+node_modules
+*.log
+test.html

README.md

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-# avatar
+# avatar
+
+Avatar as a microservice generates beautiful generated avatars for your app or homepage.

helper.js

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+function djb2(str) {
+  let hash = 5381
+  for (let i = 0; i < str.length; i++) {
+    hash = ((hash << 5) + hash) + str.charCodeAt(i)
+  }
+  return hash
+}
+
+function shouldChangeColor(color) {
+  const rgb = color.rgb().array()
+  const val = 765 - (rgb[0] + rgb[1] + rgb[2])
+  if (val < 250) {
+    return true
+  }
+  return false
+}
+
+exports.hashStringToColor = function (str) {
+  const hash = djb2(str)
+  const r = (hash & 0xFF0000) >> 16
+  const g = (hash & 0x00FF00) >> 8
+  const b = hash & 0x0000FF
+  return '#' + ('0' + r.toString(16)).substr(-2) + ('0' + g.toString(16)).substr(-2) + ('0' + b.toString(16)).substr(-2)
+}
+
+exports.getMatchingColor = function (firstColor) {
+  let color = firstColor
+  if (color.dark()) {
+    color = color.saturate(0.3).rotate(90)
+  } else {
+    color = color.desaturate(0.3).rotate(90)
+  }
+  if (shouldChangeColor(color)) {
+    color = color.rotate(-200).saturate(0.5)
+  }
+  return color
+}

index.js

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+const crypto = require('crypto')
+const url = require('url')
+
+const sharp = require('sharp')
+const Color = require('color')
+
+const svg = require('./svg')
+const helper = require('./helper')
+
+module.exports = (req, res) => {
+  const {pathname, query} = url.parse(req.url, true)
+  let imageSize = 150
+  const maxSize = 1000
+
+  if (pathname === '/favicon.ico') {
+    return ''
+  }
+  res.setHeader('Cache-Control', 'max-age=2592000, public')
+  if (query.type === 'svg') {
+    res.setHeader('Content-Type', 'svg+xml')
+  } else {
+    res.setHeader('Content-Type', 'image/png')
+  }
+
+  const hash = crypto.createHash('md5').update(pathname).digest('hex')
+
+  let firstColor = helper.hashStringToColor(hash)
+  firstColor = new Color(firstColor).saturate(0.5)
+
+  let avatar = svg.replace('$FIRST', firstColor.hex())
+  avatar = avatar.replace('$SECOND', helper.getMatchingColor(firstColor).hex())
+
+  if (query.type === 'svg') {
+    return avatar
+  }
+
+  if (query.size && query.size.match(/^-?\d+$/) && query.size <= maxSize) {
+    imageSize = parseInt(query.size, 10)
+  }
+
+  const png = sharp(new Buffer(avatar)).resize(imageSize, imageSize).png()
+  return png
+}

package.json

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+{
+  "name": "avatar",
+  "version": "1.0.0",
+  "main": "index.js",
+  "repository": "tobiaslins/avatar",
+  "scripts": {
+    "start": "micro"
+  },
+  "author": "Tobias Lins <tobias@lins.in>",
+  "license": "MIT",
+  "dependencies": {
+    "color": "^1.0.3",
+    "micro": "^7.0.3",
+    "sharp": "^0.17.1",
+    "url": "^0.11.0"
+  },
+  "devDependencies": {
+    "eslint-config-xo-react": "^0.10.0",
+    "xo": "^0.17.1"
+  },
+  "xo": {
+    "esnext": true,
+    "semicolon": false,
+    "space": true,
+    "env": [
+      "node"
+    ]
+  }
+}

svg.js

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+module.exports = `<?xml version="1.0" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg width="120" height="120" viewBox="120 120 120 120" version="1.1" xmlns="http://www.w3.org/2000/svg">
+  <g>
+    <defs>
+      <linearGradient id="avatar" x1="0" y1="0" x2="1" y2="1">
+        <stop offset="0%" stop-color="$FIRST"/>
+        <stop offset="100%" stop-color="$SECOND"/>
+      </linearGradient>
+    </defs>
+
+    <rect fill="url(#avatar)" x="120" y="120" width="120" height="120"/>
+  </g>
+</svg>
+`