Move conditional shutdown hook to a service

Author: freya022

src/main/kotlin/io/github/freya022/botcommands/internal/core/BContextImpl.kt

@@ -20,7 +20,6 @@ import io.github.freya022.botcommands.api.core.utils.awaitShutdown
 import io.github.freya022.botcommands.api.core.utils.loggerOf
 import io.github.freya022.botcommands.internal.commands.application.ApplicationCommandsContextImpl
 import io.github.freya022.botcommands.internal.commands.text.TextCommandsContextImpl
-import io.github.freya022.botcommands.internal.core.service.SpringServiceContainer
 import io.github.freya022.botcommands.internal.utils.takeIfFinite
 import io.github.freya022.botcommands.internal.utils.unwrap
 import io.github.oshai.kotlinlogging.KotlinLogging
@@ -70,16 +69,6 @@ internal class BContextImpl internal constructor(
 
     private val statusLock: ReentrantLock = ReentrantLock()
     private val statusCondition: Condition = statusLock.newCondition()
-    private val shutdownHook: Thread? = when {
-        // Spring has its own shutdown hook that will fire a shutdown event, we handle that
-        serviceContainer is SpringServiceContainer -> null
-        config.enableShutdownHook -> Thread(::shutdownNow)
-        else -> null
-    }
-
-    init {
-        shutdownHook?.let { Runtime.getRuntime().addShutdownHook(it) }
-    }
 
     override fun dispatchException(message: String, t: Throwable?, extraContext: Map<String, Any?>) {
         if (config.disableExceptionsInDMs) return //Don't send DM exceptions in dev mode
@@ -166,8 +155,8 @@ internal class BContextImpl internal constructor(
 
     override fun shutdown() {
         if (status == Status.SHUTTING_DOWN || status == Status.SHUTDOWN) return
-        removeShutdownHook()
 
+        // Shutdown hook will be removed by [[DefaultShutdownHook]] if we use the built-in DI
         runBlocking { setStatus(Status.SHUTTING_DOWN) }
 
         scheduleShutdownSignal(afterShutdownSignal = {
@@ -181,8 +170,8 @@ internal class BContextImpl internal constructor(
     override fun shutdownNow() {
         // Do not call shutdown(), more precisely do not call scheduleShutdownSignal() twice
         if (status == Status.SHUTTING_DOWN || status == Status.SHUTDOWN) return
-        removeShutdownHook()
 
+        // Shutdown hook will be removed by [[DefaultShutdownHook]] if we use the built-in DI
         runBlocking { setStatus(Status.SHUTTING_DOWN) }
 
         scheduleShutdownSignal(afterShutdownSignal = {
@@ -272,16 +261,6 @@ internal class BContextImpl internal constructor(
         return true
     }
 
-    private fun removeShutdownHook() {
-        if (shutdownHook == null) return
-
-        try {
-            Runtime.getRuntime().removeShutdownHook(shutdownHook)
-        } catch (_: IllegalStateException) {
-
-        }
-    }
-
     private fun shutdownJDA(now: Boolean) {
         val jda = jdaOrNull ?: return logger.debug { "Ignoring JDA shutdown as there is no JDA instance registered" }
 

src/main/kotlin/io/github/freya022/botcommands/internal/core/service/DefaultShutdownHook.kt

@@ -0,0 +1,51 @@
+package io.github.freya022.botcommands.internal.core.service
+
+import io.github.freya022.botcommands.api.core.BContext
+import io.github.freya022.botcommands.api.core.annotations.BEventListener
+import io.github.freya022.botcommands.api.core.config.BConfig
+import io.github.freya022.botcommands.api.core.events.BStatusChangeEvent
+import io.github.freya022.botcommands.api.core.events.PostLoadEvent
+import io.github.freya022.botcommands.api.core.service.ConditionalServiceChecker
+import io.github.freya022.botcommands.api.core.service.ServiceContainer
+import io.github.freya022.botcommands.api.core.service.annotations.BService
+import io.github.freya022.botcommands.api.core.service.annotations.ConditionalService
+import io.github.freya022.botcommands.api.core.service.annotations.Lazy
+import io.github.freya022.botcommands.api.core.service.annotations.RequiresDefaultInjection
+import io.github.freya022.botcommands.api.core.service.getService
+
+@Lazy
+@BService
+@ConditionalService(DefaultShutdownHook.ActivationCondition::class)
+@RequiresDefaultInjection
+internal class DefaultShutdownHook internal constructor(
+    context: BContext,
+) {
+
+    private val hook = Thread { context.shutdownNow() }
+
+    @BEventListener
+    internal fun registerShutdownHook(event: PostLoadEvent) {
+        Runtime.getRuntime().addShutdownHook(hook)
+    }
+
+    @BEventListener
+    internal fun onShuttingDown(event: BStatusChangeEvent) {
+        if (event.newStatus == BContext.Status.SHUTTING_DOWN) {
+            Runtime.getRuntime().removeShutdownHook(hook)
+        }
+    }
+
+    internal object ActivationCondition : ConditionalServiceChecker {
+
+        override fun checkServiceAvailability(
+            serviceContainer: ServiceContainer,
+            checkedClass: Class<*>
+        ): String? {
+            if (!serviceContainer.getService<BConfig>().enableShutdownHook) {
+                return "Default shutdown hook is disabled"
+            }
+
+            return null
+        }
+    }
+}