Move Docusaurus 1 files into directory (#966)

* Move Docusaurus 1 into v1 directory

* Update Circle CI commands for new v1 dir

* Remove OC

* Fix tests

v1/lib/server/readCategories.js

@@ -0,0 +1,110 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+const fs = require('fs');
+
+const Metadata = require('../core/metadata.js');
+
+const CWD = process.cwd();
+let languages;
+if (fs.existsSync(`${CWD}/languages.js`)) {
+  languages = require(`${CWD}/languages.js`);
+} else {
+  languages = [
+    {
+      enabled: true,
+      name: 'English',
+      tag: 'en',
+    },
+  ];
+}
+
+// returns data broken up into categories for a sidebar
+function readCategories(sidebar) {
+  const enabledLanguages = languages
+    .filter(lang => lang.enabled)
+    .map(lang => lang.tag);
+
+  const allCategories = {};
+
+  for (let k = 0; k < enabledLanguages.length; ++k) {
+    const language = enabledLanguages[k];
+
+    const metadatas = [];
+    Object.keys(Metadata).forEach(id => {
+      const metadata = Metadata[id];
+      if (metadata.sidebar === sidebar && metadata.language === language) {
+        metadatas.push(metadata);
+      }
+    });
+
+    // Build a hashmap of article_id -> metadata
+    const articles = {};
+    for (let i = 0; i < metadatas.length; ++i) {
+      const metadata = metadatas[i];
+      articles[metadata.id] = metadata;
+    }
+
+    // Build a hashmap of article_id -> previous_id
+    const previous = {};
+    for (let i = 0; i < metadatas.length; ++i) {
+      const metadata = metadatas[i];
+      if (metadata.next) {
+        if (!articles[metadata.next]) {
+          throw new Error(
+            metadata.version
+              ? `Improper sidebars file for version ${
+                  metadata.version
+                }, document with id '${
+                  metadata.next
+                }' not found. Make sure that all documents with ids specified in this version's sidebar file exist and that no ids are repeated.`
+              : `Improper sidebars.json file, document with id '${
+                  metadata.next
+                }' not found. Make sure that documents with the ids specified in sidebars.json exist and that no ids are repeated.`,
+          );
+        }
+        previous[articles[metadata.next].id] = metadata.id;
+      }
+    }
+
+    // Find the first element which doesn't have any previous
+    let first = null;
+    for (let i = 0; i < metadatas.length; ++i) {
+      const metadata = metadatas[i];
+      if (!previous[metadata.id]) {
+        first = metadata;
+        break;
+      }
+    }
+
+    const categories = [];
+    let currentCategory = null;
+
+    let metadata = first;
+    let i = 0;
+    while (metadata && i++ < 1000) {
+      if (!currentCategory || metadata.category !== currentCategory.name) {
+        if (currentCategory) {
+          categories.push(currentCategory);
+        }
+        currentCategory = {
+          name: metadata.category,
+          links: [],
+        };
+      }
+      currentCategory.links.push(metadata);
+      metadata = articles[metadata.next];
+    }
+    categories.push(currentCategory);
+
+    allCategories[language] = categories;
+  }
+
+  return allCategories;
+}
+
+module.exports = readCategories;