Refactoring code and structure

server/db.js

@@ -0,0 +1,109 @@
+const uuid = require('uuid')
+const { logger } = require('./logger')
+const { existsInProc } = require('./procUtils')
+
+const db = require('better-sqlite3')('downloads.db')
+
+/**
+ * Inits the repository, the tables.
+ */
+async function init() {
+    try {
+        db.exec(`CREATE TABLE downloads (
+            uid varchar(36) NOT NULL,
+            url text NOT NULL,
+            title text,
+            thumbnail text,
+            created date,
+            size text,
+            process_pid int NOT NULL,
+            PRIMARY KEY (uid)
+        )`)
+    } catch (e) {
+        logger('db', 'Table already created, ignoring')
+    }
+}
+
+/**
+ * Get an instance of the db.
+ * @returns {BetterSqlite3.Database} Current database instance
+ */
+async function get_db() {
+    return db
+}
+
+/**
+ * Insert an new download to the database
+ * @param {string} url the video url
+ * @param {string} title the title fetched by the info process
+ * @param {string} thumbnail the thumbnail url fetched by the info process
+ * @param {string} size optional - the download size
+ * @param {number} PID the pid of the downloader
+ * @returns {Promise<string>} the download UUID
+ */
+async function insertDownload(url, title, thumbnail, size, PID) {
+    const uid = uuid.v1()
+    try {
+        db
+            .prepare(`
+                INSERT INTO downloads 
+                    (uid, url, title, thumbnail, size, process_pid) 
+                    VALUES (?, ?, ?, ?, ?, ?)`
+            )
+            .run(uid, url, title, thumbnail, size, PID)
+    } catch (error) {
+        logger('db', 'some error occourred')
+    }
+
+    return uid
+}
+
+/**
+ * Retrieve all downloads from the database
+ * @returns {ArrayLike} a collection of results
+ */
+async function retrieveAll() {
+    return db
+        .prepare('SELECT * FROM downloads')
+        .all()
+}
+
+/**
+ * Delete a download by its uuid
+ * @param {string} uid the to-be-deleted download uuid
+ */
+async function deleteDownloadById(uid) {
+    db.prepare(`DELETE FROM downloads WHERE uid=${uid}`).run()
+}
+
+/**
+ * Delete a download by its pid
+ * @param {string} pid the to-be-deleted download pid
+ */
+async function deleteDownloadByPID(PID) {
+    db.prepare(`DELETE FROM downloads WHERE process_pid=${PID}`).run()
+}
+
+/**
+ * Deletes the downloads that aren't active anymore
+ * @returns {Promise<ArrayLike>}
+ */
+async function pruneDownloads() {
+    const all = await retrieveAll()
+    return all.map(job => {
+        if (existsInProc(job.process_pid)) {
+            return job
+        }
+        deleteDownloadByPID(job.process_pid)
+    })
+}
+
+module.exports = {
+    init: init,
+    getDB: get_db,
+    insertDownload: insertDownload,
+    retrieveAll: retrieveAll,
+    deleteDownloadById: deleteDownloadById,
+    deleteDownloadByPID: deleteDownloadByPID,
+    pruneDownloads: pruneDownloads,
+}