Use different wallpaper collection, dedupe images, add loading spinner

components/ImagePicker.js

@@ -120,7 +120,9 @@ export default class extends React.Component {
         </div>
         <hr />
         <div className="random-image">
-          <span>Or use a random unsplash image:</span>
+          <span>
+            Or use a random <a href="https://unsplash.com/">Unsplash</a> image:
+          </span>
           <RandomImage onChange={this.selectImage} />
         </div>
         <style jsx>{`
@@ -139,6 +141,10 @@ export default class extends React.Component {
             margin-bottom: 16px;
           }
 
+          a {
+            text-decoration: underline;
+          }
+
           hr {
             border-bottom: none;
             margin-bottom: 0;

components/RandomImage.js

@@ -1,21 +1,30 @@
 import React from 'react'
 import axios from 'axios'
+import Spinner from 'react-spinner'
 
 import { range, fileToDataURL } from '../lib/util'
 
 const RAND_RANGE = 1000000
-const UPDATE_SIZE = 10
-const WALLPAPER_COLLECTION_ID = 1065396
+const UPDATE_SIZE = 20
+const WALLPAPER_COLLECTION_ID = 136026
 const RANDOM_WALLPAPER_URL = `https://source.unsplash.com/collection/${WALLPAPER_COLLECTION_ID}/240x320`
 
 const largerImage = url => url.replace(/w=\d+/, 'w=1920').replace(/&h=\d+/, '')
 const smallerImage = url => url.replace(/w=\d+/, 'w=240')
 
+const imageUrls = {}
+let cache = []
+
 async function getImage() {
   // circumvent browser caching
   const sig = Math.floor(Math.random() * RAND_RANGE)
 
   const res = await axios.get(`${RANDOM_WALLPAPER_URL}?sig=${sig}`, { responseType: 'blob' })
+
+  // image already in cache?
+  if (imageUrls[res.request.responseURL]) return
+
+  imageUrls[res.request.responseURL] = true
   return {
     url: res.request.responseURL,
     dataURL: await fileToDataURL(res.data)
@@ -25,40 +34,48 @@ async function getImage() {
 export default class extends React.Component {
   constructor() {
     super()
-    this.state = { cache: [] }
+    this.state = { cacheIndex: 0, loading: false }
     this.selectImage = this.selectImage.bind(this)
     this.updateCache = this.updateCache.bind(this)
     this.nextImage = this.nextImage.bind(this)
   }
 
-  // update in browser (we require window.FileReader)
+  // fetch images in browser (we require window.FileReader)
   componentDidMount() {
+    // clear cache when remounted
+    cache = []
     this.updateCache()
   }
 
   selectImage() {
+    this.setState({ loading: true })
     axios
-      .get(largerImage(this.state.cache[0].url), { responseType: 'blob' })
+      .get(largerImage(cache[this.state.cacheIndex].url), { responseType: 'blob' })
       .then(res => res.data)
       .then(this.props.onChange)
+      .then(() => this.setState({ loading: false }))
   }
 
   updateCache() {
-    Promise.all(range(UPDATE_SIZE).map(getImage)).then(imgs =>
-      this.setState({ cache: this.state.cache.concat(imgs) })
-    )
+    this.setState({ loading: true })
+    Promise.all(range(UPDATE_SIZE).map(getImage))
+      .then(imgs => imgs.filter(img => img)) // remove null
+      .then(imgs => (cache = cache.concat(imgs)))
+      .then(() => this.setState({ loading: false }))
   }
 
   nextImage() {
-    this.setState({ cache: this.state.cache.slice(1) })
+    if (this.state.loading) return
+
+    this.setState({ cacheIndex: this.state.cacheIndex + 1 })
 
-    if (this.state.cache.length < 3) {
+    if (this.state.cacheIndex > cache.length - 2) {
       this.updateCache()
     }
   }
 
   render() {
-    const bgImage = this.state.cache[0] && this.state.cache[0].dataURL
+    const bgImage = cache[this.state.cacheIndex] && cache[this.state.cacheIndex].dataURL
 
     return (
       <div className="random-image-container">
@@ -66,7 +83,7 @@ export default class extends React.Component {
           <span onClick={this.selectImage}>Use Image</span>
           <span onClick={this.nextImage}>Try Another</span>
         </div>
-        <div className="image" />
+        <div className="image">{this.state.loading && <Spinner />}</div>
         <style jsx>{`
           .image {
             width: 100%;
@@ -83,7 +100,8 @@ export default class extends React.Component {
           }
 
           span {
-            cursor: pointer;
+            opacity: ${this.state.loading ? 0.5 : 1};
+            cursor: ${this.state.loading ? 'not-allowed' : 'pointer'};
             user-select: none;
           }
         `}</style>