Reading index file and ignoring already indexed content.

config/default.js

@@ -19,7 +19,7 @@ module.exports = {
         index: {
             file: '$base/index',
             format: 'tsv',
-            keys: ['postId', 'subreddit', 'postDate', 'postTitle', 'url'],
+            keys: ['postId', 'subreddit', 'postDate', 'postTitle', 'url', 'hostId'],
         },
         booleans: {
             extracted: 'extracted-',

src/app.js

@@ -48,11 +48,12 @@ async function initApp() {
 
         await ep.open();
         await fetchSavePosts(userPosts, ep);
-
-        return ep.close();
+        await ep.close();
     } catch (error) {
         console.error(error);
     }
+
+    return true;
 }
 
 initApp();

src/curate/posts.js

@@ -60,16 +60,18 @@ function curatePost(accUserPosts, post, user, index, processed, args) {
         subreddit: post.subreddit.display_name,
         preview: post.preview ? post.preview.images.map(image => image.source) : null,
         host,
-        hash: hashPost(post)
+        hash: hashPost(post),
     });
 }
 
-const curatePosts = (userPosts, args) => {
-    const processed = new Set();
+const curatePosts = (userPosts, args) => Object.values(userPosts).reduce((accPosts, user) => {
+    const indexedHostIds = user.indexed.map(entry => entry.hostId); // already downloaded
+    const processed = new Set(indexedHostIds);
 
-    return Object.values(userPosts).reduce((accPosts, user) => {
-        return { ...accPosts, [user.name]: { ...user, posts: user.posts.reduce((accUserPosts, post, index) => curatePost(accUserPosts, post, user, index, processed, args), []) } };
-    }, {});
-};
+    const posts = user.posts.reduce((accUserPosts, post, index) =>
+        curatePost(accUserPosts, post, user, index, processed, args), []);
+
+    return { ...accPosts, [user.name]: { ...user, posts } };
+}, {});
 
 module.exports = curatePosts;

src/save/writeToIndex.js

@@ -3,16 +3,16 @@
 const config = require('config');
 const fs = require('fs-extra');
 const Promise = require('bluebird');
-
 const csvStringify = Promise.promisify(require('csv').stringify);
 
 const interpolate = require('../interpolate.js');
 
 async function writeToIndex(posts, user) {
     const filename = interpolate(config.library.index.file, user, null, false);
-    const data = posts.map(post => config.library.index.keys.map(key => interpolate(`$${key}`, user, post, null, false, 'YYYY-MM-DDTHH:mm:ssZ')));
+    const newEntries = posts.map(post => config.library.index.keys.map(key => interpolate(`$${key}`, user, post, null, false, 'YYYY-MM-DDTHH:mm:ssZ')));
+    const fullEntries = newEntries.concat(user.indexed.map(entry => Object.values(entry)));
 
-    const tsvString = await csvStringify(data, { delimiter: '\t', header: true, columns: config.library.index.keys });
+    const tsvString = await csvStringify(fullEntries, { delimiter: '\t', header: true, columns: config.library.index.keys });
 
     return fs.writeFile(filename, tsvString);
 }

src/sources/getUserPosts.js

@@ -1,8 +1,13 @@
 'use strict';
 
+const config = require('config');
 const Promise = require('bluebird');
+const fs = require('fs-extra');
+const csvParse = Promise.promisify(require('csv').parse);
+
 const getArchivePostIds = require('../archives/getArchivePostIds.js');
 const curateUser = require('../curate/user.js');
+const interpolate = require('../interpolate.js');
 
 async function getUser(username, reddit) {
     try {
@@ -40,24 +45,42 @@ async function getArchivedPosts(username, posts, reddit) {
     return Promise.all(postIds.map(postId => reddit.getSubmission(postId).fetch()));
 }
 
+async function getIndexedPosts(user) {
+    const indexFilePath = interpolate(config.library.index.file, user, null, null, false);
+
+    try {
+        const indexFile = await fs.readFile(indexFilePath, 'utf8');
+
+        return await csvParse(indexFile, { delimiter: '\t', columns: true, cast: true });
+    } catch (error) {
+        console.log('\x1b[33m%s\x1b[0m', `Could not load index file for '${user.name}' at '${indexFilePath}': ${error}`);
+
+        return [];
+    }
+}
+
 function getUserPostsWrap(reddit, args) {
-    return function getUserPosts(usernames) {
-        return Promise.props(usernames.reduce(async (userPosts, username) => {
+    return async function getUserPosts(usernames) {
+        const users = await Promise.map(usernames, async (username) => {
             const [user, posts] = await Promise.all([
                 getUser(username, reddit),
                 getPosts(username, reddit, args),
             ]);
 
+            const indexed = await getIndexedPosts(user);
+
             if (args.archives) {
                 posts.push(...await getArchivedPosts(username, posts, reddit));
             }
 
             if (posts.length) {
-                return { ...userPosts, [user.name]: { ...user, posts } };
+                return { ...user, posts, indexed };
             }
 
-            return userPosts;
-        }, {}));
+            return null;
+        });
+
+        return users.reduce((userPosts, user) => (user ? { ...userPosts, [user.name]: user } : userPosts), {});
     };
 }