support @mention of author in response

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

@@ -1,15 +1,22 @@
 package moe.kageru.kagebot
 
+import org.javacord.api.entity.message.MessageAuthor
+import moe.kageru.kagebot.Util.doIf
+
+private const val AUTHOR_PLACEHOLDER = "@@"
+
 class Command(trigger: String?, response: String?, matchType: MatchType?) {
     val trigger: String = trigger!!
-    val regex: Regex? = if (matchType == MatchType.REGEX) Regex.fromLiteral(trigger!!) else null
+    val regex: Regex? = if (matchType == MatchType.REGEX) Regex(trigger!!) else null
     private val response: String = response!!
     private val matchType: MatchType = matchType ?: MatchType.PREFIX
 
     constructor(cmd: Command) : this(cmd.trigger, cmd.response, cmd.matchType)
 
     fun matches(msg: String) = this.matchType.matches(msg, this)
-    fun respond() = this.response
+    fun respond(author: MessageAuthor) = this.response.doIf({ it.contains(AUTHOR_PLACEHOLDER) }) {
+        it.replace(AUTHOR_PLACEHOLDER, MessageUtil.mention(author))
+    }
 }
 
 enum class MatchType {

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

@@ -0,0 +1,9 @@
+package moe.kageru.kagebot
+
+import org.javacord.api.entity.message.MessageAuthor
+
+object MessageUtil {
+    fun mention(user: MessageAuthor): String {
+        return "<@${user.id}>"
+    }
+}

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

@@ -0,0 +1,7 @@
+package moe.kageru.kagebot
+
+object Util {
+    inline fun <T> T.doIf(condition: (T) -> Boolean, op: (T) -> T): T {
+        return if (condition(this)) op(this) else this
+    }
+}

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

@@ -25,7 +25,7 @@ fun createBot() {
     api.addMessageCreateListener { event ->
         for (command in config.commands) {
             if (command.matches(event.messageContent)) {
-                event.channel.sendMessage(command.respond())
+                event.channel.sendMessage(command.respond(event.messageAuthor))
                 break
             }
         }

src/main/resources/config.toml

@@ -11,4 +11,10 @@ response = "pong"
 [[commands]]
 trigger = "somewhere"
 response = "found it"
-matchType = "CONTAINS"
+matchType = "CONTAINS"
+
+[[commands]]
+trigger = "^[^`]*([()|DoOvVcC][-=^']?;|;[-=^']?[()|DoOpPvVcC3]|:wink:|😉)[^`]*$"
+response = "@@ Oboe!"
+matchType = "REGEX"
+deleteMessage = true

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

@@ -0,0 +1,2 @@
+package moe.kageru.kagebot
+