From 1a2ea34bb406f25fd71e2d87cfa8f23965c7af37 Mon Sep 17 00:00:00 2001
From: Jesse Chan <jc@linux.com>
Date: Sun, 6 Sep 2020 00:36:44 +0800
Subject: [PATCH] server: also modify torrent file on "Set Tracker"

---
 package-lock.json                      |  8 +++++++
 package.json                           |  1 +
 server/constants/torrentListPropMap.js |  5 +++++
 server/models/client.js                |  4 ++++
 server/util/torrentFileUtil.js         | 29 ++++++++++++++++++++++++++
 5 files changed, 47 insertions(+)
 create mode 100644 server/util/torrentFileUtil.js

diff --git a/package-lock.json b/package-lock.json
index a153c9b8..859cda3d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -3298,6 +3298,14 @@
         "tweetnacl": "^0.14.3"
       }
     },
+    "bencode": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/bencode/-/bencode-2.0.1.tgz",
+      "integrity": "sha512-2uhEl8FdjSBUyb69qDTgOEeeqDTa+n3yMQzLW0cOzNf1Ow5bwcg3idf+qsWisIKRH8Bk8oC7UXL8irRcPA8ZEQ==",
+      "requires": {
+        "safe-buffer": "^5.1.1"
+      }
+    },
     "big.js": {
       "version": "5.2.2",
       "resolved": "https://registry.npmjs.org/big.js/-/big.js-5.2.2.tgz",
diff --git a/package.json b/package.json
index 7316d5de..98c2aaa9 100644
--- a/package.json
+++ b/package.json
@@ -49,6 +49,7 @@
     "axios": "^0.20.0",
     "babel-eslint": "^10.1.0",
     "babel-loader": "^8.0.6",
+    "bencode": "^2.0.1",
     "body-parser": "^1.18.3",
     "case-sensitive-paths-webpack-plugin": "2.3.0",
     "chalk": "^4.1.0",
diff --git a/server/constants/torrentListPropMap.js b/server/constants/torrentListPropMap.js
index bc7f5baa..970e4674 100644
--- a/server/constants/torrentListPropMap.js
+++ b/server/constants/torrentListPropMap.js
@@ -249,4 +249,9 @@ torrentListPropMap.set('peersTotal', {
   transformValue: (value) => Number(value.substr(0, value.indexOf('|||'))),
 });
 
+torrentListPropMap.set('session', {
+  methodCall: 'cat=(session.path), (d.hash)',
+  transformValue: defaultTransformer,
+});
+
 module.exports = torrentListPropMap;
diff --git a/server/models/client.js b/server/models/client.js
index 662a6301..8f25bd45 100644
--- a/server/models/client.js
+++ b/server/models/client.js
@@ -10,6 +10,7 @@ const fileUtil = require('../util/fileUtil');
 const settings = require('./settings');
 const torrentFilePropsMap = require('../../shared/constants/torrentFilePropsMap');
 const torrentPeerPropsMap = require('../../shared/constants/torrentPeerPropsMap');
+const torrentFileUtil = require('../util/torrentFileUtil');
 const torrentStatusMap = require('../../shared/constants/torrentStatusMap');
 const torrentTrackerPropsMap = require('../../shared/constants/torrentTrackerPropsMap');
 
@@ -385,6 +386,9 @@ const client = {
 
     request.setTracker(data);
     request.onComplete((response, error) => {
+      // Modify tracker URL in torrent files
+      torrentFileUtil.setTracker(services, data);
+
       // Fetch the latest torrent list to re-index trackerURI.
       services.torrentService.fetchTorrentList();
       callback(response, error);
diff --git a/server/util/torrentFileUtil.js b/server/util/torrentFileUtil.js
new file mode 100644
index 00000000..60f3a244
--- /dev/null
+++ b/server/util/torrentFileUtil.js
@@ -0,0 +1,29 @@
+const bencode = require('bencode');
+const fs = require('fs');
+
+const setTracker = (services, options) => {
+  const {tracker, hashes} = options;
+
+  [...new Set(hashes)].forEach((hash) => {
+    const torrent = services.torrentService.getTorrent(hash).session.concat('.torrent');
+    fs.readFile(torrent, (err, data) => {
+      if (err) {
+        return;
+      }
+
+      const torrentData = bencode.decode(data);
+
+      if (torrentData.announce != null) {
+        torrentData.announce = Buffer.from(tracker);
+
+        fs.writeFileSync(torrent, bencode.encode(torrentData));
+      }
+    });
+  });
+};
+
+const torrentFileUtil = {
+  setTracker,
+};
+
+module.exports = torrentFileUtil;