Merge pull request #17 from simplecloudapp/refactor/ConfigFactory

feat: ConfigFactory.kt

Author: niklasnieberler

plugin-shared/src/main/kotlin/app/simplecloud/plugin/api/shared/config/ConfigFactory.kt

@@ -1,37 +1,41 @@
 package app.simplecloud.plugin.api.shared.config
 
+import app.simplecloud.plugin.api.shared.exception.ConfigurationException
 import app.simplecloud.plugin.api.shared.repository.GenericEnumSerializer
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.delay
-import kotlinx.coroutines.isActive
-import kotlinx.coroutines.launch
+import kotlinx.coroutines.*
 import org.spongepowered.configurate.ConfigurationOptions
 import org.spongepowered.configurate.kotlin.objectMapperFactory
-import org.spongepowered.configurate.kotlin.toNode
 import org.spongepowered.configurate.yaml.NodeStyle
 import org.spongepowered.configurate.yaml.YamlConfigurationLoader
 import java.io.File
-import java.nio.file.FileSystems
-import java.nio.file.Files
-import java.nio.file.Path
-import java.nio.file.StandardWatchEventKinds
+import java.nio.file.*
+import kotlin.coroutines.CoroutineContext
 
 /**
- * @author Niklas Nieberler
+ * A configuration factory that loads, saves and watches configuration files.
+ * The factory automatically reloads the configuration when the file changes.
+ *
+ * Usage:
+ * ```
+ * // Using create
+ * val factory = ConfigFactory.create<MyConfig>(File("config.yaml"))
+ *
+ * // Using create with custom coroutineContext
+ * val factory = ConfigFactory.create<MyConfig>(File("config.json"), Dispatchers.Default)
+ * ```
  */
-
-class ConfigFactory<E>(
+class ConfigFactory(
     private val file: File,
-    private val defaultConfig: E
-) {
+    private val configClass: Class<*>,
+    private val coroutineContext: CoroutineContext = Dispatchers.IO
+) : AutoCloseable {
 
-    private var config = defaultConfig
-    private val path = file.toPath()
+    private var config: Any? = null
+    private val path: Path = file.toPath()
+    private var watchJob: Job? = null
 
     private val configurationLoader = YamlConfigurationLoader.builder()
-        .path(this.path)
+        .path(path)
         .nodeStyle(NodeStyle.BLOCK)
         .defaultOptions { options ->
             options.serializers { builder ->
@@ -41,60 +45,94 @@ class ConfigFactory<E>(
         }
         .build()
 
-    fun loadOrCreate() {
-        registerWatcher()
-        if (this.file.exists()) {
+    fun loadOrCreate(defaultConfig: Any) {
+        if (!configClass.isInstance(defaultConfig)) {
+            throw IllegalArgumentException("Default config must be an instance of ${configClass.name}")
+        }
+
+        if (file.exists()) {
             loadConfig()
-            return
+        } else {
+            createDefaultConfig(defaultConfig)
         }
-        createDefaultConfig()
+
+        registerWatcher()
     }
 
-    private fun createDefaultConfig() {
-        this.path.parent?.let { Files.createDirectories(it) }
-        Files.createFile(this.path)
+    private fun createDefaultConfig(defaultConfig: Any) {
+        path.parent?.let { Files.createDirectories(it) }
+        Files.createFile(path)
 
-        val configurationNode = this.configurationLoader.load(ConfigurationOptions.defaults())
-        this.defaultConfig!!.toNode(configurationNode)
-        this.configurationLoader.save(configurationNode)
+        val node = configurationLoader.createNode()
+        node.set(configClass, defaultConfig)
+        configurationLoader.save(node)
+        config = defaultConfig
     }
 
-    fun getConfig(): E = this.config
+    @Suppress("UNCHECKED_CAST")
+    fun <T> getConfig(): T {
+        return config as? T ?: throw IllegalStateException("Configuration not loaded or invalid type")
+    }
 
+    @Throws(ConfigurationException::class)
     private fun loadConfig() {
-        val configurationNode = this.configurationLoader.load(ConfigurationOptions.defaults())
-        this.config = configurationNode.get(this.defaultConfig!!::class.java)
-            ?: throw IllegalStateException("Config could not be loaded")
+        try {
+            val node = configurationLoader.load(ConfigurationOptions.defaults())
+            config = node.get(configClass)
+                ?: throw ConfigurationException("Failed to parse configuration file")
+        } catch (e: Exception) {
+            throw ConfigurationException("Failed to load configuration", e)
+        }
     }
 
     private fun registerWatcher(): Job {
         val watchService = FileSystems.getDefault().newWatchService()
-        this.path.register(
+        path.parent?.register(
             watchService,
             StandardWatchEventKinds.ENTRY_CREATE,
             StandardWatchEventKinds.ENTRY_MODIFY
         )
 
-        return CoroutineScope(Dispatchers.IO).launch {
-            while (isActive) {
-                val key = watchService.take()
-
-                key.pollEvents().forEach { event ->
-                    val path = event.context() as? Path ?: return@forEach
-                    if (!file.name.contains(path.toString())) return@launch
-
-                    when (event.kind()) {
-                        StandardWatchEventKinds.ENTRY_CREATE,
-                        StandardWatchEventKinds.ENTRY_MODIFY -> {
-                            delay(100)
-                            loadConfig()
-                        }
+        return CoroutineScope(coroutineContext).launch {
+            watchService.use { watchService ->
+                while (isActive) {
+                    val key = watchService.take()
+                    key.pollEvents().forEach { event ->
+                        handleWatchEvent(event)
+                    }
+                    if (!key.reset()) {
+                        break
                     }
                 }
+            }
+        }.also { watchJob = it }
+    }
 
-                key.reset()
+    private suspend fun handleWatchEvent(event: WatchEvent<*>) {
+        val path = event.context() as? Path ?: return
+        if (!file.name.contains(path.toString())) return
+
+        when (event.kind()) {
+            StandardWatchEventKinds.ENTRY_CREATE,
+            StandardWatchEventKinds.ENTRY_MODIFY -> {
+                delay(100)
+                try {
+                    loadConfig()
+                } catch (e: ConfigurationException) {
+                    println("Failed to reload configuration: ${e.message}")
+                }
             }
         }
     }
 
+    override fun close() {
+        watchJob?.cancel()
+    }
+
+    companion object {
+        inline fun <reified T : Any> create(
+            file: File,
+            coroutineContext: CoroutineContext = Dispatchers.IO
+        ): ConfigFactory = ConfigFactory(file, T::class.java, coroutineContext)
+    }
 }

plugin-shared/src/main/kotlin/app/simplecloud/plugin/api/shared/exception/ConfigurationException.kt

@@ -0,0 +1,4 @@
+package app.simplecloud.plugin.api.shared.exception
+
+class ConfigurationException(message: String, cause: Throwable? = null) :
+    Exception(message, cause)