From 54b1b9f744ed03a97457719ff6a0cad60db5c4b0 Mon Sep 17 00:00:00 2001
From: "Rico Sta. Cruz" <rstacruz@users.noreply.github.com>
Date: Mon, 23 Oct 2017 13:38:51 +0800
Subject: [PATCH] Initial buggy implementation of search backend

---
 _js/search/index.js | 122 ++++++++++++++++++++++++++++++++++++++++++++
 package.json        |   2 +
 yarn.lock           |   6 ++-
 3 files changed, 129 insertions(+), 1 deletion(-)
 create mode 100644 _js/search/index.js

diff --git a/_js/search/index.js b/_js/search/index.js
new file mode 100644
index 000000000..93789939b
--- /dev/null
+++ b/_js/search/index.js
@@ -0,0 +1,122 @@
+/**
+ * Lunr-based searching
+ *
+ * @example
+ *
+ *     <meta name="search:index" content="https://search.devhints.io/index.json">
+ *
+ *     s = new Search()
+ *     s.inferFromMeta()
+ *     s.search('hello').then(() => ...)
+ *
+ *     s.loadFromData({ index, store })
+ */
+
+class Search {
+  constructor (opts) {
+    const once = require('once')
+    const Emitter = require('events')
+
+    this.indexPath = opts && opts.index
+    this.load = once(this.load)
+    this.index = null
+    this.store = null
+    this.emitter = new Emitter()
+  }
+
+  load () {
+    return this.loadRemote()
+  }
+
+  /**
+   * Infers `indexPath` from meta tags.
+   */
+
+  inferFromMeta () {
+    // Safeguard, in case we're not loaded in a browser context
+    if (typeof document === 'undefined') return this
+
+    const meta = document.querySelector('meta[name="search:index"]')
+    if (!meta) return this
+
+    const value = meta.getAttribute('content')
+    this.indexPath = value
+    return this
+  }
+
+  /**
+   * Loads the search index remotely (via `indexPath`).
+   */
+
+  loadRemote () {
+    return window.fetch(this.indexPath)
+      .then(res => res.json())
+      .then(data => {
+        this.loadFromData(data)
+      })
+  }
+
+  /**
+   * Loads the search index locally.
+   */
+
+  loadFromData (data) {
+    const lunr = require('lunr')
+
+    const { index, store } = data
+    this.index = lunr.Index.load(index)
+    this.store = store
+    this.emitter.emit('load')
+  }
+
+  /**
+   * Waits until the data is loaded, then resolves.
+   *
+   * - When called when the data is still loading, it'll wait until the data is
+   *   loaded.
+   */
+
+  loaded () {
+    return new Promise((resolve, reject) => {
+      if (this.index) return resolve(this)
+
+      this.emitter.on('load', () => {
+        resolve(this)
+      })
+
+      this.load()
+    })
+  }
+
+  /*
+   * Searches for keywords.
+   */
+
+  async search (keywords) {
+    await this.loaded()
+    const results = this.index.search(keywords)
+    const fullResults = results.map(result => {
+      return {
+        ...result,
+        object: this.store[result.ref]
+      }
+    })
+
+    return fullResults
+  }
+}
+
+/*
+ * The primary instance
+ */
+
+const search = new Search().inferFromMeta()
+
+/*
+ * Export
+ */
+
+module.exports = {
+  Search,
+  search
+}
diff --git a/package.json b/package.json
index e99648117..bb83b7e9d 100644
--- a/package.json
+++ b/package.json
@@ -38,6 +38,8 @@
     "hint.css": "2.5.0",
     "isotope-layout": "3.0.4",
     "jquery": "3.2.1",
+    "lunr": "2.1.4",
+    "once": "1.4.0",
     "onmount": "1.3.0",
     "prismjs": "1.8.1",
     "sanitize.css": "5.0.0"
diff --git a/yarn.lock b/yarn.lock
index e645b3cf9..93007aac8 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4536,6 +4536,10 @@ lru-cache@^4.0.1:
     pseudomap "^1.0.2"
     yallist "^2.1.2"
 
+lunr@2.1.4:
+  version "2.1.4"
+  resolved "https://registry.yarnpkg.com/lunr/-/lunr-2.1.4.tgz#52be0a9d068321909a7fb46575620e24417d5591"
+
 macaddress@^0.2.8:
   version "0.2.8"
   resolved "https://registry.yarnpkg.com/macaddress/-/macaddress-0.2.8.tgz#5904dc537c39ec6dbefeae902327135fa8511f12"
@@ -4980,7 +4984,7 @@ on-finished@~2.3.0:
   dependencies:
     ee-first "1.1.1"
 
-once@^1.3.0, once@^1.3.3, once@^1.4.0:
+once@1.4.0, once@^1.3.0, once@^1.3.3, once@^1.4.0:
   version "1.4.0"
   resolved "https://registry.yarnpkg.com/once/-/once-1.4.0.tgz#583b1aa775961d4b113ac17d9c50baef9dd76bd1"
   dependencies: