Created the download server

server/download.js

@@ -0,0 +1,86 @@
+const express = require('express');
+const fs = require('fs');
+
+const {checkToken} = require('../middlewares/authenticate');
+const {getUserByName, getUserById} = require("../controller/user");
+const {getAddonFromUser, updateAddonById} = require("../controller/addon");
+const {getReleaseByAddonId, getLatestReleaseByAddonId, updateReleaseById} = require("../controller/release");
+const {ownsItem} = require("../controller/boughtItem");
+
+// Create a new express app
+const app = express();
+let dl_folder;
+
+// Register routes
+app.get('/:author/:addon/:version.addon', async (req, res) => {
+    // Get author
+    const author = await getUserByName(req.params.author);
+    if (author === null) return res.status(404).json({code: 1, message: "The provided addon does not exist"});
+
+    // Get addon
+    const addon = await getAddonFromUser(author._id, req.params.addon);
+    if (addon === null) return res.status(404).json({code: 1, message: "The provided addon does not exist"});
+
+    // Get release
+    const release = req.params.version === "latest" ? await getLatestReleaseByAddonId(addon._id)
+        : await getReleaseByAddonId(addon._id, req.params.version);
+    if (release === null) return res.status(404).json({
+        code: 2, message: req.params.version === "latest"
+            ? "Currently, there are no releases for this addon" : "The provided release version does not exist"
+    });
+
+    // Check price
+    if (addon.price !== undefined && addon.price !== 0) {
+        const token = await checkToken(req, res);
+        if (!token.token) return;
+
+        const user = await getUserById(token.user_id);
+        if (user === null) return res.status(500).json({code: 4, message: "An internal error occurred"});
+
+        if (!await ownsItem(user._id, addon._id)) return res.status(402).json({
+            code: 3,
+            message: "You don't own this addon"
+        });
+    }
+
+    let addonPath = dl_folder + "/" + release._id;
+    if (!fs.existsSync(addonPath)) return res.status(404).json({
+        code: 5,
+        message: "The author didn't upload the release file yet"
+    });
+
+    // Update download stats
+    await updateAddonById(addon._id, {$inc: {downloads: 1}});
+    await updateReleaseById(release._id, {$inc: {downloads: 1}});
+
+    try {
+        res.sendFile(addonPath);
+    } catch (e) {
+        res.status(500).json({message: "The file could not be delivered"});
+    }
+});
+
+// Register 404 route
+app.use("*", (req, res) => {
+    res.status(400).json({message: "You need to use the correct url schema"});
+});
+
+
+// Start the express server
+module.exports.startServer = (port = 8355, release_folder = "/mnt/data/download") => {
+    dl_folder = release_folder;
+    app.listen(port, () => log(`Listening to port ${port}`));
+}
+
+// Stop the express server
+module.exports.stopServer = () => {
+    app.close();
+    console.log("Closed the server");
+}
+
+// Log something in the express server
+const log = (msg) => {
+    console.log(`[Download] ${msg}`);
+}
+
+module.exports.server = app;