Feature/make config settings changeable during runtime (#545)

* Add logic to update config during runtime

* Update ConfigModule to always use the latest config

* Make ServerConfig settings re-assignable

AndroidCompat/Config/src/main/java/xyz/nulldev/ts/config/ConfigManager.kt

@@ -11,6 +11,9 @@ import ch.qos.logback.classic.Level
 import com.typesafe.config.Config
 import com.typesafe.config.ConfigFactory
 import com.typesafe.config.ConfigRenderOptions
+import com.typesafe.config.ConfigValue
+import com.typesafe.config.ConfigValueFactory
+import com.typesafe.config.parser.ConfigDocumentFactory
 import mu.KotlinLogging
 import java.io.File
 
@@ -18,15 +21,17 @@ import java.io.File
  * Manages app config.
  */
 open class ConfigManager {
+    val logger = KotlinLogging.logger {}
     private val generatedModules = mutableMapOf<Class<out ConfigModule>, ConfigModule>()
-    val config by lazy { loadConfigs() }
+    private val userConfigFile = File(ApplicationRootDir, "server.conf")
+    private var internalConfig = loadConfigs()
+    val config: Config
+        get() = internalConfig
 
     // Public read-only view of modules
     val loadedModules: Map<Class<out ConfigModule>, ConfigModule>
         get() = generatedModules
 
-    val logger = KotlinLogging.logger {}
-
     /**
      * Get a config module
      */
@@ -54,7 +59,7 @@ open class ConfigManager {
 
         // Load user config
         val userConfig =
-            File(ApplicationRootDir, "server.conf").let {
+            userConfigFile.let {
                 ConfigFactory.parseFile(it)
             }
 
@@ -86,6 +91,20 @@ open class ConfigManager {
             registerModule(it)
         }
     }
+
+    private fun updateUserConfigFile(path: String, value: ConfigValue) {
+        val userConfigDoc = ConfigDocumentFactory.parseFile(userConfigFile)
+        val updatedConfigDoc = userConfigDoc.withValue(path, value)
+        val newFileContent = updatedConfigDoc.render()
+        userConfigFile.writeText(newFileContent)
+    }
+
+    fun updateValue(path: String, value: Any) {
+        val configValue = ConfigValueFactory.fromAnyRef(value)
+
+        updateUserConfigFile(path, configValue)
+        internalConfig = internalConfig.withValue(path, configValue)
+    }
 }
 
 object GlobalConfigManager : ConfigManager()

AndroidCompat/Config/src/main/java/xyz/nulldev/ts/config/ConfigModule.kt

@@ -15,19 +15,23 @@ import kotlin.reflect.KProperty
  * Abstract config module.
  */
 @Suppress("UNUSED_PARAMETER")
-abstract class ConfigModule(config: Config)
+abstract class ConfigModule(getConfig: () -> Config)
 
 /**
  * Abstract jvm-commandline-argument-overridable config module.
  */
-abstract class SystemPropertyOverridableConfigModule(config: Config, moduleName: String) : ConfigModule(config) {
-    val overridableConfig = SystemPropertyOverrideDelegate(config, moduleName)
+abstract class SystemPropertyOverridableConfigModule(getConfig: () -> Config, moduleName: String) : ConfigModule(getConfig) {
+    val overridableConfig = SystemPropertyOverrideDelegate(getConfig, moduleName)
 }
 
 /** Defines a config property that is overridable with jvm `-D` commandline arguments prefixed with [CONFIG_PREFIX] */
-class SystemPropertyOverrideDelegate(val config: Config, val moduleName: String) {
+class SystemPropertyOverrideDelegate(val getConfig: () -> Config, val moduleName: String) {
+    operator fun <R> setValue(thisRef: R, property: KProperty<*>, value: Any) {
+        GlobalConfigManager.updateValue("$moduleName.${property.name}", value)
+    }
+
     inline operator fun <R, reified T> getValue(thisRef: R, property: KProperty<*>): T {
-        val configValue: T = config.getValue(thisRef, property)
+        val configValue: T = getConfig().getValue(thisRef, property)
 
         val combined = System.getProperty(
             "$CONFIG_PREFIX.$moduleName.${property.name}",