Pull event handling into interface

src/main/kotlin/moe/kageru/kagebot/Kagebot.kt

@@ -1,13 +1,11 @@
 package moe.kageru.kagebot
 
 import moe.kageru.kagebot.Util.checked
-import moe.kageru.kagebot.Util.failed
 import moe.kageru.kagebot.config.Config
 import moe.kageru.kagebot.config.ConfigParser
 import moe.kageru.kagebot.config.RawConfig
 import org.javacord.api.DiscordApiBuilder
 import org.javacord.api.event.message.MessageCreateEvent
-import org.javacord.api.event.server.member.ServerMemberJoinEvent
 import java.io.File
 import kotlin.system.exitProcess
 
@@ -17,7 +15,7 @@ fun main() {
 
 object Kagebot {
     fun MessageCreateEvent.process() {
-         if (messageAuthor.isBotUser) {
+        if (messageAuthor.isBotUser) {
             if (messageAuthor.isYourself) {
                 val loggedMessage =
                     if (readableMessageContent.isBlank()) "[embed]" else readableMessageContent
@@ -33,18 +31,6 @@ object Kagebot {
         }
     }
 
-    fun welcomeUser(event: ServerMemberJoinEvent) {
-        Config.features.welcome!!.run {
-            val message = event.user.sendMessage(embed)
-            // If the user disabled direct messages, try the fallback (if defined)
-            if (message.failed() && hasFallback()) {
-                fallbackChannel!!.sendMessage(
-                    fallbackMessage!!.replace("@@", MessageUtil.mention(event.user))
-                )
-            }
-        }
-    }
-
     private fun getSecret() = File("secret").readText().trim()
 
     fun init() {
@@ -61,10 +47,6 @@ object Kagebot {
         })
         Log.info("kagebot Mk II running")
         Globals.api.addMessageCreateListener { checked { it.process() } }
-        Config.features.welcome?.let {
+        Config.features.eventFeatures().forEach { it.register(Globals.api) }
-            Globals.api.addServerMemberJoinListener {
-                checked { welcomeUser(it) }
-            }
-        }
     }
 }

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

@@ -9,9 +9,9 @@ import java.lang.management.ManagementFactory
 import java.time.Duration
 import java.time.temporal.ChronoUnit
 
-class DebugFeature : MessageFeature() {
+class DebugFeature : MessageFeature {
 
-    override fun handleInternal(message: MessageCreateEvent) {
+    override fun handle(message: MessageCreateEvent) {
         if (message.messageAuthor.isBotOwner) {
             MessageUtil.sendEmbed(message.channel, getPerformanceStats())
         }

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

@@ -0,0 +1,12 @@
+package moe.kageru.kagebot.features
+
+import org.javacord.api.DiscordApi
+import org.javacord.api.event.message.MessageCreateEvent
+
+interface MessageFeature {
+    fun handle(message: MessageCreateEvent)
+}
+
+interface EventFeature {
+    fun register(api: DiscordApi)
+}

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

@@ -17,6 +17,7 @@ class Features(
         SetConfigFeature()
     )
 
+    private val all = listOf(welcome, debug, help, getConfig, setConfig)
     private val featureMap = mapOf(
         "help" to help,
         "debug" to debug,
@@ -26,4 +27,5 @@ class Features(
     )
 
     fun findByString(feature: String) = featureMap[feature]
+    fun eventFeatures() = all.filterIsInstance<EventFeature>()
 }

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

@@ -6,8 +6,8 @@ import org.javacord.api.event.message.MessageCreateEvent
 /**
  * Simple message handler to send the current config file via message attachment.
  */
-class GetConfigFeature : MessageFeature() {
+class GetConfigFeature : MessageFeature {
-    override fun handleInternal(message: MessageCreateEvent) {
+    override fun handle(message: MessageCreateEvent) {
         message.channel.sendMessage(ConfigParser.configFile)
     }
 }

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

@@ -5,8 +5,8 @@ import moe.kageru.kagebot.command.MatchType
 import moe.kageru.kagebot.config.Config
 import org.javacord.api.event.message.MessageCreateEvent
 
-class HelpFeature : MessageFeature() {
+class HelpFeature : MessageFeature {
-    override fun handleInternal(message: MessageCreateEvent) {
+    override fun handle(message: MessageCreateEvent) {
         message.channel.sendEmbed {
             addField("Commands:", listCommands(message))
         }

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

@@ -1,11 +0,0 @@
-package moe.kageru.kagebot.features
-
-import org.javacord.api.event.message.MessageCreateEvent
-
-abstract class MessageFeature {
-    fun handle(message: MessageCreateEvent) {
-        handleInternal(message)
-    }
-
-    internal abstract fun handleInternal(message: MessageCreateEvent)
-}

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

@@ -7,9 +7,9 @@ import moe.kageru.kagebot.config.RawConfig
 import org.javacord.api.entity.channel.TextChannel
 import org.javacord.api.event.message.MessageCreateEvent
 
-class SetConfigFeature : MessageFeature() {
+class SetConfigFeature : MessageFeature {
     @ExperimentalStdlibApi
-    override fun handleInternal(message: MessageCreateEvent) {
+    override fun handle(message: MessageCreateEvent) {
         if (message.messageAttachments.size != 1) {
             message.channel.sendMessage("Error: please attach the new config to your message.")
             return

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

@@ -2,13 +2,33 @@ package moe.kageru.kagebot.features
 
 import moe.kageru.kagebot.MessageUtil
 import moe.kageru.kagebot.Util
+import moe.kageru.kagebot.Util.checked
+import moe.kageru.kagebot.Util.failed
 import moe.kageru.kagebot.config.RawWelcomeFeature
+import org.javacord.api.DiscordApi
 import org.javacord.api.entity.channel.TextChannel
 import org.javacord.api.entity.message.embed.EmbedBuilder
 import org.javacord.api.event.message.MessageCreateEvent
+import org.javacord.api.event.server.member.ServerMemberJoinEvent
 
-class WelcomeFeature(rawWelcome: RawWelcomeFeature) : MessageFeature() {
+class WelcomeFeature(rawWelcome: RawWelcomeFeature) : MessageFeature, EventFeature {
-    override fun handleInternal(message: MessageCreateEvent) {
+    override fun register(api: DiscordApi) {
+        api.addServerMemberJoinListener { event ->
+            checked { welcomeUser(event) }
+        }
+    }
+
+    fun welcomeUser(event: ServerMemberJoinEvent) {
+        val message = event.user.sendMessage(embed)
+        // If the user disabled direct messages, try the fallback (if defined)
+        if (message.failed() && hasFallback()) {
+            fallbackChannel!!.sendMessage(
+                fallbackMessage!!.replace("@@", MessageUtil.mention(event.user))
+            )
+        }
+    }
+
+    override fun handle(message: MessageCreateEvent) {
         embed?.let {
             MessageUtil.sendEmbed(message.channel, it)
         }

src/test/kotlin/moe/kageru/kagebot/ConfigTest.kt

@@ -8,6 +8,7 @@ import io.mockk.mockk
 import moe.kageru.kagebot.config.Config
 import moe.kageru.kagebot.features.SetConfigFeature
 
+@ExperimentalStdlibApi
 class ConfigTest : ShouldSpec({
     TestUtil.prepareTestEnvironment()
     "should properly parse test config" {

src/test/kotlin/moe/kageru/kagebot/features/WelcomeFeatureTest.kt

@@ -4,16 +4,16 @@ import io.kotlintest.shouldBe
 import io.kotlintest.specs.StringSpec
 import io.mockk.every
 import io.mockk.mockk
-import moe.kageru.kagebot.config.Config
-import moe.kageru.kagebot.Kagebot
 import moe.kageru.kagebot.TestUtil
+import moe.kageru.kagebot.config.Config
 import org.javacord.api.entity.message.embed.EmbedBuilder
 
+@ExperimentalStdlibApi
 class WelcomeFeatureTest : StringSpec({
     TestUtil.prepareTestEnvironment()
     "should send welcome" {
         val sentMessages = mutableListOf<EmbedBuilder>()
-        Kagebot.welcomeUser(
+        Config.features.welcome!!.welcomeUser(
             mockk {
                 every { user } returns mockk {
                     every { sendMessage(capture(sentMessages)) } returns mockk {
@@ -28,7 +28,7 @@ class WelcomeFeatureTest : StringSpec({
     "should send welcome fallback if DMs are disabled" {
         val message = mutableListOf<String>()
         TestUtil.prepareTestEnvironment(sentMessages = message)
-        Kagebot.welcomeUser(
+        Config.features.welcome!!.welcomeUser(
             mockk {
                 every { user } returns mockk {
                     every { id } returns 123