Delete mods on next start using preLaunch hook

Closes #91

Signed-off-by: DeathsGun <deathsgun@protonmail.com>

Author: DeathsGun

src/main/kotlin/xyz/deathsgun/modmanager/ModManager.kt

@@ -68,7 +68,6 @@ class ModManager : ClientModInitializer {
         provider[modrinth.getName().lowercase()] = modrinth
         updateProvider[modrinth.getName().lowercase()] = modrinth
         GlobalScope.launch {
-            update.fullyDeleteMods()
             update.checkUpdates()
             icons.cleanupCache()
         }

src/main/kotlin/xyz/deathsgun/modmanager/PreLaunchHook.kt

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2021 DeathsGun
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package xyz.deathsgun.modmanager
+
+import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.decodeFromString
+import kotlinx.serialization.json.Json
+import net.fabricmc.loader.api.FabricLoader
+import net.fabricmc.loader.api.entrypoint.PreLaunchEntrypoint
+import org.apache.logging.log4j.LogManager
+import java.nio.file.Files
+import kotlin.io.path.Path
+import kotlin.io.path.deleteIfExists
+
+class PreLaunchHook : PreLaunchEntrypoint {
+
+    private val logger = LogManager.getLogger("ModManager")
+
+    override fun onPreLaunch() {
+        val filesToDelete = try {
+            loadFiles()
+        } catch (e: Exception) {
+            ArrayList()
+        }
+        for (file in filesToDelete) {
+            logger.info("Deleting {}", file)
+            val path = Path(file)
+            Files.delete(path)
+        }
+    }
+
+    @OptIn(ExperimentalSerializationApi::class)
+    private fun loadFiles(): ArrayList<String> {
+        val configFile = FabricLoader.getInstance().configDir.resolve(".modmanager.delete.json")
+        if (Files.notExists(configFile)) {
+            return ArrayList()
+        }
+        val data = Files.readString(configFile, Charsets.UTF_8)
+        configFile.deleteIfExists()
+        return Json.decodeFromString(data)
+    }
+
+}

src/main/kotlin/xyz/deathsgun/modmanager/update/UpdateManager.kt

@@ -21,6 +21,7 @@ import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.launch
 import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.decodeFromString
+import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
 import net.fabricmc.loader.api.FabricLoader
 import net.fabricmc.loader.api.metadata.ModMetadata
@@ -47,7 +48,6 @@ import java.net.http.HttpRequest
 import java.net.http.HttpResponse
 import java.nio.file.Files
 import java.nio.file.Path
-import java.nio.file.StandardOpenOption
 import java.security.MessageDigest
 import java.time.Duration
 import java.util.zip.ZipFile
@@ -59,8 +59,13 @@ class UpdateManager {
     private val logger = LogManager.getLogger("UpdateCheck")
     private val blockedIds = arrayOf("java", "minecraft", "fabricloader")
     private val http: HttpClient = HttpClient.newBuilder().connectTimeout(Duration.ofSeconds(15)).build()
+    private val deletableMods = ArrayList<String>()
     val updates = ArrayList<Update>()
 
+    init {
+        Runtime.getRuntime().addShutdownHook(Thread(this::saveDeletableFiles))
+    }
+
     //region Update Checking
 
     suspend fun checkUpdates() = coroutineScope {
@@ -372,6 +377,18 @@ class UpdateManager {
         return ids
     }
 
+    @OptIn(ExperimentalSerializationApi::class)
+    private fun saveDeletableFiles() {
+        if (deletableMods.isEmpty()) {
+            return
+        }
+        logger.info("Deleting {} mods on the next start.", deletableMods.size)
+        val configFile = FabricLoader.getInstance().configDir.resolve(".modmanager.delete.json")
+        val data = json.encodeToString(deletableMods)
+        Files.writeString(configFile, data, Charsets.UTF_8)
+    }
+
+
     private fun getCheckableMods(): List<ModMetadata> {
         return FabricLoader.getInstance().allMods.map { it.metadata }.filter {
             !it.id.startsWith("fabric-") &&
@@ -394,7 +411,7 @@ class UpdateManager {
             Files.delete(this)
         } catch (e: Exception) {
             logger.info("Error while deleting {} trying on restart again", this.absolutePathString())
-            Files.writeString(this, "MODMANAGER", StandardOpenOption.WRITE)
+            deletableMods.add(this.absolutePathString())
         }
     }
 
@@ -425,21 +442,4 @@ class UpdateManager {
         return URI("dummy", url.replace("\t", ""), null).rawSchemeSpecificPart
     }
 
-    fun fullyDeleteMods() {
-        val jars =
-            FileUtils.listFiles(FabricLoader.getInstance().gameDir.resolve("mods").toFile(), arrayOf("jar"), true)
-        for (jar in jars) {
-            val content = try {
-                Files.readString(jar.toPath())
-            } catch (e: Exception) {
-                ""
-            }
-            if (content != "MODMANGER") {
-                continue
-            }
-            logger.info("Deleting {}", jar.absolutePath)
-            jar.delete()
-        }
-    }
-
 }

src/main/resources/fabric.mod.json

@@ -22,9 +22,15 @@
 		"value": "xyz.deathsgun.modmanager.ModManager"
 	  }
 	],
+	"preLaunch": [
+	  {
+		"adapter": "kotlin",
+		"value": "xyz.deathsgun.modmanager.PreLaunchHook"
+	  }
+	],
 	"modmenu": [
 	  "xyz.deathsgun.modmanager.ModMenuEntrypoint"
-    ]
+	]
   },
   "custom": {
     "modmanager": {