Implement DeleteDuplicateMods option (#190)

Adds `DeleteDuplicateMods` option to the launcher config which, well,
deletes mods with the same name if their hashes mismatch. Useful for
development where client mod hashes can frequently change.

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include/Network/network.hpp

@@ -30,6 +30,7 @@ extern uint64_t UDPSock;
 extern uint64_t TCPSock;
 extern std::string Branch;
 extern std::string CachingDirectory;
+extern bool deleteDuplicateMods;
 extern bool TCPTerminate;
 extern std::string LastIP;
 extern std::string MStatus;

src/Config.cpp

@@ -15,6 +15,7 @@ namespace fs = std::filesystem;
 
 std::string Branch;
 std::string CachingDirectory = "./Resources";
+bool deleteDuplicateMods = false;
 
 void ParseConfig(const nlohmann::json& d) {
     if (d["Port"].is_number()) {
@@ -42,6 +43,11 @@ void ParseConfig(const nlohmann::json& d) {
         options.no_launch = dev;
         options.no_update = dev;
     }
+
+    if (d.contains(("DeleteDuplicateMods")) && d["DeleteDuplicateMods"].is_boolean()) {
+        deleteDuplicateMods = d["DeleteDuplicateMods"].get<bool>();
+    }
+
 }
 
 void ConfigInit() {

src/Network/Resources.cpp

@@ -475,10 +475,31 @@ void NewSyncResources(SOCKET Sock, const std::string& Mods, const std::vector<Mo
 
     info("Syncing...");
 
+    std::vector<std::pair<std::string, std::filesystem::path>> CachedMods = {};
+    if (deleteDuplicateMods) {
+        for (const auto& entry : fs::directory_iterator(CachingDirectory)) {
+            const std::string filename = entry.path().filename().string();
+            if (entry.is_regular_file() && entry.path().extension() == ".zip" && filename.length() > 10) {
+                CachedMods.push_back(std::make_pair(filename.substr(0, filename.length() - 13) + ".zip", entry.path()));
+            }
+        }
+    }
+
     int ModNo = 0;
     int TotalMods = ModInfos.size();
     for (auto ModInfoIter = ModInfos.begin(), AlsoModInfoIter = ModInfos.begin(); ModInfoIter != ModInfos.end() && !Terminate; ++ModInfoIter, ++AlsoModInfoIter) {
         ++ModNo;
+        if (deleteDuplicateMods) {
+            for (auto& CachedMod : CachedMods) {
+                const bool cachedModExists = CachedMod.first == ModInfoIter->FileName;
+                const bool cachedModIsNotNewestVersion = CachedMod.second.stem().string() + ".zip" != std::filesystem::path(ModInfoIter->FileName).stem().string() + "-" + ModInfoIter->Hash.substr(0, 8) + ".zip";
+                if (cachedModExists && cachedModIsNotNewestVersion) {
+                    debug("Found duplicate mod '" + CachedMod.second.stem().string() + ".zip" + "' in cache, removing it");
+                    std::filesystem::remove(CachedMod.second);
+                    break;
+                }
+            }
+        }
         if (ModInfoIter->Hash.length() < 8 || ModInfoIter->HashAlgorithm != "sha256") {
             error("Unsupported hash algorithm or invalid hash for '" + ModInfoIter->FileName + "'");
             Terminate = true;