Allow bot owner to print debug stats

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

@@ -3,9 +3,11 @@ package moe.kageru.kagebot
 import moe.kageru.kagebot.config.Config
 import org.javacord.api.DiscordApi
 import org.javacord.api.entity.server.Server
+import java.util.concurrent.atomic.AtomicInteger
 
 object Globals {
     lateinit var server: Server
     lateinit var api: DiscordApi
     lateinit var config: Config
+    var commandCounter: AtomicInteger = AtomicInteger(0)
 }

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

@@ -67,5 +67,12 @@ object Kagebot {
                 }
             }
         }
+        Globals.config.features.debug?.let { debug ->
+            if (debug.enabled) {
+                Globals.api.addMessageCreateListener {
+                    checked { debug.handle(it) }
+                }
+            }
+        }
     }
 }

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

@@ -1,5 +1,6 @@
 package moe.kageru.kagebot.command
 
+import moe.kageru.kagebot.Globals
 import moe.kageru.kagebot.Globals.config
 import moe.kageru.kagebot.MessageUtil
 import moe.kageru.kagebot.Util.doIf
@@ -36,6 +37,7 @@ class Command(cmd: RawCommand) {
             }
             return
         }
+        Globals.commandCounter.incrementAndGet()
         this.actions?.run(message, this)
         this.response?.let {
             message.channel.sendMessage(respond(message.messageAuthor, it))

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

@@ -42,10 +42,11 @@ class RawCommand(
 class RawPermissions(val hasOneOf: List<String>?, val hasNoneOf: List<String>?, val onlyDM: Boolean)
 class RawMessageActions(val delete: Boolean, val redirect: RawRedirect?)
 class RawRedirect(val target: String?, val anonymous: Boolean)
-class RawFeatures(val welcome: RawWelcomeFeature?)
+class RawFeatures(val welcome: RawWelcomeFeature?, val debug: RawDebugFeatures?)
 class RawWelcomeFeature(
     val enabled: Boolean,
     val content: Map<String, String>?,
     val fallbackChannel: String?,
     val fallbackMessage: String?
-)
+)
+class RawDebugFeatures(var enabled: Boolean)

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

@@ -0,0 +1,77 @@
+package moe.kageru.kagebot.features
+
+import com.sun.management.OperatingSystemMXBean
+import moe.kageru.kagebot.Globals
+import moe.kageru.kagebot.MessageUtil
+import moe.kageru.kagebot.config.RawDebugFeatures
+import org.javacord.api.entity.message.embed.EmbedBuilder
+import org.javacord.api.event.message.MessageCreateEvent
+import java.lang.management.ManagementFactory
+import java.time.Duration
+import java.time.temporal.ChronoUnit
+
+class DebugFeatures(rawDebugFeatures: RawDebugFeatures) {
+    fun handle(message: MessageCreateEvent) {
+        if (message.messageAuthor.isBotOwner) {
+            if (message.readableMessageContent.startsWith("!debugstats")) {
+                message.channel.sendMessage(getPerformanceStats())
+            }
+        }
+    }
+
+    private fun getPerformanceStats(): EmbedBuilder {
+        val osBean = ManagementFactory.getPlatformMXBean(OperatingSystemMXBean::class.java)
+        val runtime = Runtime.getRuntime()
+        return MessageUtil.mapToEmbed(
+            mapOf(
+                Pair(
+                    "Bot:",
+                    getBotStats()
+                ),
+                Pair(
+                    "Memory:",
+                    getMemoryInfo(runtime, osBean)
+                ),
+                Pair(
+                    "CPU:",
+                    getCpuInfo(osBean)
+                ),
+                Pair(
+                    "System:",
+                    getOsInfo()
+                )
+            )
+        )
+    }
+
+    private fun getBotStats() = "kagebot has been running for ${getBotUptime()}.\n" +
+            "During this time, ${Globals.commandCounter.incrementAndGet()} commands have been executed."
+
+    private fun getBotUptime(): String {
+        val uptime = Duration.of(ManagementFactory.getRuntimeMXBean().uptime, ChronoUnit.MILLIS)
+        return String.format(
+            "%d days, %d hours, %d minutes, %d seconds",
+            uptime.toDaysPart(),
+            uptime.toHoursPart(),
+            uptime.toMinutesPart(),
+            uptime.toSecondsPart()
+        )
+    }
+
+    private fun getMemoryInfo(runtime: Runtime, osBean: OperatingSystemMXBean): String {
+        val mb = 1024 * 1024
+        return "Memory usage: ${(runtime.totalMemory() - runtime.freeMemory()) / mb} MB.\n" +
+                "Total system memory: ${osBean.committedVirtualMemorySize / mb}/" +
+                "${osBean.totalPhysicalMemorySize / mb} MB."
+    }
+
+    private fun getCpuInfo(osBean: OperatingSystemMXBean) =
+        "The bot is currently using ${String.format("%.4f", osBean.processCpuLoad * 100)}% of the CPU with " +
+                "${Thread.activeCount()} active threads.\n" +
+                "Total system load is ${String.format("%.2f", osBean.systemCpuLoad * 100)}%."
+
+    private fun getOsInfo() = "Running on ${System.getProperty("os.name")} " +
+            "${System.getProperty("os.version")}-${System.getProperty("os.arch")}.\n"
+
+    val enabled: Boolean = rawDebugFeatures.enabled
+}

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

@@ -2,11 +2,14 @@ package moe.kageru.kagebot.features
 
 import moe.kageru.kagebot.config.RawFeatures
 
-class Features(val welcome: WelcomeFeature?) {
+class Features(val welcome: WelcomeFeature?, val debug: DebugFeatures?) {
 
-    constructor(rawFeatures: RawFeatures) : this(rawFeatures.welcome?.let(::WelcomeFeature))
+    constructor(rawFeatures: RawFeatures) : this(
+        rawFeatures.welcome?.let(::WelcomeFeature),
+        rawFeatures.debug?.let(::DebugFeatures)
+    )
 
     companion object {
-        val NONE = Features(null)
+        val NONE = Features(null, null)
     }
 }

src/main/resources/config.toml

@@ -22,6 +22,10 @@ fallbackMessage = "@@ I would like to greet you, but I can’t. :("
 "Welcome to the Server" = "This is the content of the first paragraph"
 "Second paragraph heading" = "Second paragraph content"
 
+# allow the bot owner to get debug stats
+[feature.debug]
+enabled = true
+
 [[command]]
 trigger = "!ping"
 response = "pong"

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

@@ -0,0 +1,32 @@
+package moe.kageru.kagebot.features
+
+import io.kotlintest.specs.StringSpec
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.verify
+import moe.kageru.kagebot.TestUtil
+import moe.kageru.kagebot.config.RawDebugFeatures
+import org.javacord.api.entity.message.embed.EmbedBuilder
+import org.javacord.api.event.message.MessageCreateEvent
+
+class DebugFeatureTest : StringSpec({
+    TestUtil.prepareTestEnvironment()
+    // this will fail if the bot tries to execute more than it should
+    // because the mock does not provide the necessary methods
+    "should ignore regular users" {
+        val message = mockk<MessageCreateEvent> {
+            every { messageAuthor.isBotOwner } returns false
+        }
+        DebugFeatures(RawDebugFeatures(true)).handle(message)
+        verify(exactly = 0) { message.channel.sendMessage(any<EmbedBuilder>()) }
+    }
+    "should return something" {
+        val message = mockk<MessageCreateEvent> {
+            every { messageAuthor.isBotOwner } returns true
+            every { readableMessageContent } returns "!debugstats something"
+            every { channel.sendMessage(any<EmbedBuilder>()) } returns mockk()
+        }
+        DebugFeatures(RawDebugFeatures(true)).handle(message)
+        verify(exactly = 1) { message.channel.sendMessage(any<EmbedBuilder>()) }
+    }
+})

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

@@ -1,9 +1,12 @@
-package moe.kageru.kagebot
+package moe.kageru.kagebot.features
 
 import io.kotlintest.shouldBe
 import io.kotlintest.specs.StringSpec
 import io.mockk.every
 import io.mockk.mockk
+import moe.kageru.kagebot.Globals
+import moe.kageru.kagebot.Kagebot
+import moe.kageru.kagebot.TestUtil
 import org.javacord.api.entity.message.embed.EmbedBuilder
 
 class WelcomeFeatureTest : StringSpec({