feat: Improve arguments

* Add UserConverter
* Add a way to specify default value

bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/GeneralModule.kt

@@ -1,5 +1,6 @@
 package io.github.null2264.tsukumogami.bot.core.module
 
+import io.github.null2264.tsukumogami.bot.core.module.arguments.Test2Arguments
 import io.github.null2264.tsukumogami.bot.core.module.arguments.TestArguments
 import io.github.null2264.tsukumogami.core.module.api.botModules
 import kotlinx.datetime.Clock
@@ -13,7 +14,7 @@ val generalModule = botModules("General") {
     }
 
     groups("group") {
-        commands("test", arguments = ::TestArguments) { ctx, args -> ctx.send("Hello world ${args.test}") }
+        commands("test", arguments = ::Test2Arguments) { ctx, args -> ctx.send("Hello world ${args.user}") }
     }
 
     commands("test", arguments = ::TestArguments) { ctx, args -> ctx.send("Hello world ${args.test}") }

bot/src/main/kotlin/io/github/null2264/tsukumogami/bot/core/module/arguments/TestArguments.kt

@@ -2,7 +2,14 @@ package io.github.null2264.tsukumogami.bot.core.module.arguments
 
 import io.github.null2264.tsukumogami.core.commands.Arguments
 import io.github.null2264.tsukumogami.core.commands.ext.string
+import io.github.null2264.tsukumogami.core.commands.ext.user
 
 class TestArguments : Arguments() {
-    val test by string("Test")
+    val test by string("Test") {
+        default("Lmao")
+    }
+}
+
+class Test2Arguments : Arguments() {
+    val user by user("User")
 }

core/src/main/kotlin/io/github/null2264/tsukumogami/core/Bot.kt

@@ -69,7 +69,7 @@ open class Bot internal constructor(): IGroup {
     private fun getContext(message: Message): Context {
         val candidate = message.content.parsePrefixCommandAndArguments()
         val context = Context(this, message, candidate?.first, candidate?.second?.toMutableList())
-        context.command = getCommand(context.candidate?.removeAt(0))
+        context.command = getCommand(context.pullCandidateOrNull())
         return context
     }
 

core/src/main/kotlin/io/github/null2264/tsukumogami/core/Context.kt

@@ -7,7 +7,7 @@ import dev.kord.rest.builder.message.allowedMentions
 import io.github.null2264.tsukumogami.core.commands.Command
 
 class Context(
-    private val bot: Bot,
+    val bot: Bot,
     private val message: Message,
     /**
      * The prefix that used to invoke the command
@@ -19,6 +19,9 @@ class Context(
     val candidate: MutableList<String>?,
 ) {
 
+    /**
+     * The user that invoked the command
+     */
     val author get() = message.author
 
     /**
@@ -26,6 +29,13 @@ class Context(
      */
     var command: Command? = null
 
+    fun getCandidateOrNull() = candidate?.getOrNull(0)
+    fun pullCandidateOrNull() = candidate?.removeFirstOrNull()
+    fun pullCandidateIf(predicate: () -> Boolean): String? {
+        if (predicate()) return candidate?.removeFirstOrNull()
+        return null
+    }
+
     suspend fun send(content: String) = message.channel.createMessage(content)
 
     suspend fun reply(content: String, mentionsAuthor: Boolean = false) = message.channel.createMessage {

core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Arguments.kt

@@ -1,5 +1,6 @@
 package io.github.null2264.tsukumogami.core.commands
 
+import io.github.null2264.tsukumogami.core.Context
 import io.github.null2264.tsukumogami.core.commands.converters.Converter
 
 abstract class Arguments {
@@ -15,17 +16,13 @@ abstract class Arguments {
         return converter
     }
 
-    suspend fun parse(values: List<String>?) {
+    suspend fun parse(context: Context) {
-        val currentValues = values?.toMutableList()
+        val currentValues = context.candidate?.toMutableList()
 
         run {
             args.forEach { arg ->
-                val value = try {
+                val value = currentValues?.removeFirstOrNull() ?: return@run
-                    currentValues?.removeAt(0)
+                arg.converter.parse(context, value)
-                } catch (e: Exception) {
-                    null
-                } ?: return@run
-                arg.converter.parse(value)
             }
         }
     }

core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Command.kt

@@ -13,7 +13,7 @@ open class Command(
 
     open suspend fun invoke(context: Context) {
         val parsedArguments = arguments.call()
-        parsedArguments.parse(context.candidate)
+        parsedArguments.parse(context)
         handler.invoke(context, parsedArguments)
     }
 }

core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/Group.kt

@@ -19,9 +19,9 @@ class Group(
     override val allCommands: MutableMap<String, Command> = mutableMapOf()
 
     override suspend fun invoke(context: Context) {
-        val command = allCommands[context.candidate?.get(0)] ?: return
+        val command = allCommands[context.getCandidateOrNull()]
-        context.candidate?.removeAt(0)
+        context.pullCandidateIf { command != null } ?: return
-        context.command = command
+        context.command = command!!
         command.invoke(context)
     }
 }

core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/Converter.kt

@@ -1,5 +1,6 @@
 package io.github.null2264.tsukumogami.core.commands.converters
 
+import io.github.null2264.tsukumogami.core.Context
 import io.github.null2264.tsukumogami.core.commands.Argument
 import io.github.null2264.tsukumogami.core.commands.Arguments
 import kotlin.reflect.KProperty
@@ -10,9 +11,14 @@ abstract class Converter<OutputType: Any?> {
 
     abstract var parsed: OutputType
 
-    abstract suspend fun parse(input: String): OutputType
+    abstract suspend fun parse(context: Context, input: String): OutputType
 
     operator fun getValue(thisRef: Arguments, property: KProperty<*>): OutputType {
-        return parsed
+        return this.parsed
+    }
+
+    fun default(defaultValue: OutputType): OutputType {
+        this.parsed = defaultValue
+        return this.parsed
     }
 }

core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/impl/StringConverter.kt

@@ -1,12 +1,13 @@
 package io.github.null2264.tsukumogami.core.commands.converters.impl
 
+import io.github.null2264.tsukumogami.core.Context
 import io.github.null2264.tsukumogami.core.commands.converters.Converter
 
 class StringConverter : Converter<String>() {
 
     override var parsed: String = ""
 
-    override suspend fun parse(input: String): String {
+    override suspend fun parse(context: Context, input: String): String {
         this.parsed = input
         return input
     }

core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/converters/impl/UserConverter.kt

@@ -0,0 +1,57 @@
+package io.github.null2264.tsukumogami.core.commands.converters.impl
+
+import dev.kord.common.entity.Snowflake
+import dev.kord.core.entity.User
+import io.github.null2264.tsukumogami.core.Context
+import io.github.null2264.tsukumogami.core.annotation.TsukumogamiInternalApi
+import io.github.null2264.tsukumogami.core.commands.converters.Converter
+import io.github.null2264.tsukumogami.core.exceptions.CommandException
+import io.github.null2264.tsukumogami.core.ext.users
+import kotlinx.coroutines.flow.firstOrNull
+
+class UserConverter : Converter<User>() {
+
+    override lateinit var parsed: User
+
+    override suspend fun parse(context: Context, input: String): User {
+        if (input.equals("me", true)) {
+            val user = context.author
+            if (user != null) {
+                this.parsed = user
+                return this.parsed
+            }
+        }
+        if (input.equals("you", true)) {
+            this.parsed = context.bot.client.getSelf()
+            return this.parsed
+        }
+
+        this.parsed = context.findUser(input) ?:
+            throw CommandException("User not found")
+
+        return this.parsed
+    }
+
+    private suspend fun Context.findUser(arg: String): User? =
+        if (arg.startsWith("<@") && arg.endsWith(">")) {
+            val id: String = arg.substring(2, arg.length - 1).replace("!", "")
+
+            try {
+                bot.client.getUser(Snowflake(id))
+            } catch (_: NumberFormatException) {
+                throw CommandException("Invalid user ID")
+            }
+        } else {
+            try {
+                bot.client.getUser(Snowflake(arg))
+            } catch (_: NumberFormatException) {
+                if (!arg.contains("#")) {
+                    null
+                } else {
+                    bot.client.users.firstOrNull { user ->
+                        user.tag.equals(arg, true)
+                    }
+                }
+            }
+        }
+}

core/src/main/kotlin/io/github/null2264/tsukumogami/core/commands/ext/ArgumentsExtensions.kt

@@ -1,6 +1,19 @@
 package io.github.null2264.tsukumogami.core.commands.ext
 
+import dev.kord.core.entity.User
 import io.github.null2264.tsukumogami.core.commands.Arguments
+import io.github.null2264.tsukumogami.core.commands.converters.Converter
 import io.github.null2264.tsukumogami.core.commands.converters.impl.StringConverter
+import io.github.null2264.tsukumogami.core.commands.converters.impl.UserConverter
 
-fun Arguments.string(name: String) = args(name, StringConverter())
+fun Arguments.string(name: String, declaration: Converter<String>.() -> Unit = {}): Converter<String> {
+    val converter = StringConverter()
+    declaration(converter)
+    return args(name, converter)
+}
+
+fun Arguments.user(name: String, declaration: Converter<User>.() -> Unit = {}): Converter<User> {
+    val converter = UserConverter()
+    declaration(converter)
+    return args(name, converter)
+}

core/src/main/kotlin/io/github/null2264/tsukumogami/core/ext/KordExtensions.kt

@@ -0,0 +1,6 @@
+package io.github.null2264.tsukumogami.core.ext
+
+import dev.kord.core.Kord
+import dev.kord.core.supplier.EntitySupplyStrategy
+
+val Kord.users get() = with(EntitySupplyStrategy.cache).users

core/src/main/kotlin/io/github/null2264/tsukumogami/core/module/BotModule.kt

@@ -4,7 +4,7 @@ import io.github.null2264.tsukumogami.core.Bot
 import io.github.null2264.tsukumogami.core.commands.Command
 import io.github.null2264.tsukumogami.core.commands.IGroup
 
-class BotModule internal constructor(val name: String) : IGroup {
+open class BotModule constructor(val name: String) : IGroup {
 
     override val allCommands: MutableMap<String, Command> = mutableMapOf()