Reload config at runtime via command + attachment

This implements #10, but I want to write tests before closing that.

src/main/kotlin/moe/kageru/kagebot/features/Features.kt

@@ -6,20 +6,23 @@ class Features(
     val welcome: WelcomeFeature?,
     debug: DebugFeature,
     help: HelpFeature,
-    getConfig: GetConfigFeature
+    getConfig: GetConfigFeature,
+    setConfig: SetConfigFeature
 ) {
     constructor(rawFeatures: RawFeatures) : this(
         rawFeatures.welcome?.let(::WelcomeFeature),
         DebugFeature(),
         HelpFeature(),
-        GetConfigFeature()
+        GetConfigFeature(),
+        SetConfigFeature()
     )
 
     private val featureMap = mapOf(
         "help" to help,
         "debug" to debug,
         "welcome" to welcome,
-        "getConfig" to getConfig
+        "getConfig" to getConfig,
+        "setConfig" to setConfig
     )
 
     fun findByString(feature: String) = featureMap[feature]

src/main/kotlin/moe/kageru/kagebot/features/SetConfigFeature.kt

@@ -0,0 +1,44 @@
+package moe.kageru.kagebot.features
+
+import moe.kageru.kagebot.Log
+import moe.kageru.kagebot.MessageUtil
+import moe.kageru.kagebot.config.ConfigParser
+import moe.kageru.kagebot.config.RawConfig
+import org.javacord.api.event.message.MessageCreateEvent
+import java.lang.IllegalArgumentException
+
+class SetConfigFeature : MessageFeature() {
+    @ExperimentalStdlibApi
+    override fun handleInternal(message: MessageCreateEvent) {
+        if (message.messageAttachments.size != 1) {
+            message.channel.sendMessage("Error: please attach the new config to your message.")
+            return
+        }
+        val newConfig = message.messageAttachments[0].url.openStream().readAllBytes().decodeToString()
+        val rawConfig = try {
+            RawConfig.readFromString(newConfig)
+        } catch (e: IllegalStateException) {
+            MessageUtil.sendEmbed(
+                message.channel,
+                MessageUtil.getEmbedBuilder()
+                    .addField(
+                        "An unexpected error occured. This is probably caused by a malformed config file. Perhaps this can help:",
+                        "```$e: ${e.message}"
+                    )
+            )
+            Log.log.info("Could not parse new config: $e: ${e.message}")
+            return
+        }
+        try {
+            ConfigParser.reloadLocalization(rawConfig)
+            ConfigParser.reloadFeatures(rawConfig)
+            ConfigParser.reloadCommands(rawConfig)
+        } catch (e: IllegalArgumentException) {
+            MessageUtil.sendEmbed(
+                message.channel,
+                MessageUtil.getEmbedBuilder()
+                    .addField("Error", "```${e.message}```")
+            )
+        }
+    }
+}

src/main/resources/config.toml

@@ -110,3 +110,7 @@ feature = "help"
 [[command]]
 trigger = "!getConfig"
 feature = "getConfig"
+
+[[command]]
+trigger = "!setConfig"
+feature = "setConfig"