Implement optional automatic update mechanism.

foundation-core/src/main/kotlin/gay/pizza/foundation/core/features/update/UpdateCommand.kt

@@ -3,15 +3,22 @@ package gay.pizza.foundation.core.features.update
 import org.bukkit.command.Command
 import org.bukkit.command.CommandExecutor
 import org.bukkit.command.CommandSender
+import org.bukkit.plugin.Plugin
 
-class UpdateCommand : CommandExecutor {
+class UpdateCommand(val plugin: Plugin) : CommandExecutor {
   override fun onCommand(
     sender: CommandSender,
     command: Command,
     label: String,
     args: Array<out String>
   ): Boolean {
-    UpdateService.updatePlugins(sender)
+    val shouldRestart = args.isNotEmpty() && args[0] == "restart"
+    UpdateService.updatePlugins(plugin, sender, onFinish = { updated ->
+      if (!updated) return@updatePlugins
+      if (shouldRestart) {
+        sender.server.shutdown()
+      }
+    })
     return true
   }
 }

foundation-core/src/main/kotlin/gay/pizza/foundation/core/features/update/UpdateConfig.kt

@@ -0,0 +1,13 @@
+package gay.pizza.foundation.core.features.update
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class UpdateConfig(
+  val autoUpdateSchedule: AutoUpdateSchedule
+)
+
+@Serializable
+class AutoUpdateSchedule(
+  val cron: String = ""
+)

foundation-core/src/main/kotlin/gay/pizza/foundation/core/features/update/UpdateFeature.kt

@@ -1,9 +1,41 @@
 package gay.pizza.foundation.core.features.update
 
 import gay.pizza.foundation.core.abstraction.Feature
+import gay.pizza.foundation.core.features.scheduler.cancel
+import gay.pizza.foundation.core.features.scheduler.cron
+import org.koin.core.component.inject
+import org.koin.core.module.Module
+import org.koin.dsl.module
 
 class UpdateFeature : Feature() {
+  private val config by inject<UpdateConfig>()
+  lateinit var autoUpdateScheduleId: String
+
   override fun enable() {
-    plugin.registerCommandExecutor("fupdate", UpdateCommand())
+    plugin.registerCommandExecutor("fupdate", UpdateCommand(plugin))
+
+    if (config.autoUpdateSchedule.cron.isNotEmpty()) {
+      autoUpdateScheduleId = scheduler.cron(config.autoUpdateSchedule.cron) {
+        plugin.server.scheduler.runTask(plugin) { ->
+          plugin.server.dispatchCommand(plugin.server.consoleSender, "fupdate restart")
+        }
+      }
+    }
+  }
+
+  override fun disable() {
+    if (::autoUpdateScheduleId.isInitialized) {
+      scheduler.cancel(autoUpdateScheduleId)
+    }
+  }
+
+  override fun module(): Module = module {
+    single {
+      plugin.loadConfigurationWithDefault(
+        plugin,
+        UpdateConfig.serializer(),
+        "update.yaml"
+      )
+    }
   }
 }

foundation-core/src/main/kotlin/gay/pizza/foundation/core/features/update/UpdatePlan.kt

@@ -4,5 +4,6 @@ import gay.pizza.foundation.concrete.ExtensibleManifestItem
 import org.bukkit.plugin.Plugin
 
 class UpdatePlan(
-  val items: Map<ExtensibleManifestItem, Plugin?>
+  val installedSet: Map<ExtensibleManifestItem, Plugin?>,
+  val updateSet: Map<ExtensibleManifestItem, Plugin?>
 )

foundation-core/src/main/kotlin/gay/pizza/foundation/core/features/update/UpdateResolver.kt

@@ -34,7 +34,20 @@ class UpdateResolver {
         installSet[newDependency] = null
       }
     }
-    return UpdatePlan(installSet)
+
+    val updateSet = installSet.filter { entry ->
+      if (entry.value == null) {
+        true
+      } else {
+        val installed = entry.value!!.description.version
+        if (installed == "DEV") {
+          false
+        } else {
+          entry.key.version != installed
+        }
+      }
+    }
+    return UpdatePlan(installSet, updateSet)
   }
 
   companion object {

foundation-core/src/main/kotlin/gay/pizza/foundation/core/features/update/UpdateService.kt

@@ -1,11 +1,21 @@
 package gay.pizza.foundation.core.features.update
 
 import org.bukkit.command.CommandSender
+import org.bukkit.plugin.Plugin
+import java.util.concurrent.atomic.AtomicBoolean
 import kotlin.io.path.name
 import kotlin.io.path.toPath
 
 object UpdateService {
-  fun updatePlugins(sender: CommandSender, onFinish: (() -> Unit)? = null) {
+  private val running = AtomicBoolean(false)
+
+  fun updatePlugins(plugin: Plugin, sender: CommandSender, onFinish: (Boolean) -> Unit = {}) {
+    if (!running.compareAndSet(false, true)) {
+      sender.sendMessage("Update is already running, skipping the requested update.")
+      onFinish(false)
+
+      return
+    }
     val updateDir = sender.server.pluginsFolder.resolve("update")
     updateDir.mkdir()
     if (!updateDir.exists()) {
@@ -15,26 +25,37 @@ object UpdateService {
     val updatePath = updateDir.toPath()
 
     Thread {
-      val resolver = UpdateResolver()
-      val manifest = resolver.fetchCurrentManifest()
-      val plan = resolver.resolve(manifest, sender.server)
-      sender.sendMessage("Updates:")
-      plan.items.forEach { (item, plugin) ->
-        val pluginJarFileItem = item.files.firstOrNull { it.type == "plugin-jar" }
-        if (pluginJarFileItem == null) {
-          sender.sendMessage("WARNING: ${item.name} is required but plugin-jar file not found in manifest. Skipping.")
-          return@forEach
+      try {
+        val resolver = UpdateResolver()
+        val manifest = resolver.fetchCurrentManifest()
+        val plan = resolver.resolve(manifest, sender.server)
+        if (plan.updateSet.isEmpty()) {
+          onFinish(false)
+          running.set(false)
+          return@Thread
         }
-        val maybeExistingPluginFileName = plugin?.javaClass?.protectionDomain?.codeSource?.location?.toURI()?.toPath()?.name
-        val fileName = maybeExistingPluginFileName ?: "${item.name}.jar"
-        val artifactPath = pluginJarFileItem.path
+        sender.sendMessage("Updates:")
+        plan.updateSet.forEach { (item, plugin) ->
+          val pluginJarFileItem = item.files.firstOrNull { it.type == "plugin-jar" }
+          if (pluginJarFileItem == null) {
+            sender.sendMessage("WARNING: ${item.name} is required but plugin-jar file not found in manifest. Skipping.")
+            return@forEach
+          }
+          val maybeExistingPluginFileName = plugin?.javaClass?.protectionDomain?.codeSource?.location?.toURI()?.toPath()?.name
+          val fileName = maybeExistingPluginFileName ?: "${item.name}.jar"
+          val artifactPath = pluginJarFileItem.path
 
-        sender.sendMessage("${item.name}: Updating ${plugin?.description?.version ?: "[not-installed]"} to ${item.version}")
-        UpdateUtil.downloadArtifact(artifactPath, updatePath.resolve(fileName))
+          sender.sendMessage("${item.name}: Updating ${plugin?.description?.version ?: "[not-installed]"} to ${item.version}")
+          UpdateUtil.downloadArtifact(artifactPath, updatePath.resolve(fileName))
+        }
+        sender.sendMessage("Restart for updates to take effect.")
+        onFinish(true)
+      } catch (e: Exception) {
+        plugin.slF4JLogger.error("Failed to update Foundation.", e)
+        onFinish(false)
+      } finally {
+        running.set(false)
       }
-      sender.sendMessage("Restart for updates to take effect.")
-
-      if (onFinish != null) onFinish()
-    }.start()
+    }.apply { name = "Plugin Updater" }.start()
   }
 }

foundation-core/src/main/kotlin/gay/pizza/foundation/core/features/update/UpdateUtil.kt

@@ -17,24 +17,6 @@ object UpdateUtil {
       .resolve(path)
       .toString()
 
-  private inline fun <reified T> fetchFile(url: String, strategy: DeserializationStrategy<T>): T {
-    val request = HttpRequest
-      .newBuilder()
-      .GET()
-      .uri(URI.create(url))
-      .build()
-
-    val response = client.send(
-      request,
-      HttpResponse.BodyHandlers.ofString()
-    )
-
-    return Json.decodeFromString(
-      strategy,
-      response.body()
-    )
-  }
-
   fun downloadArtifact(path: String, outPath: Path) {
     val uri = URI.create(getUrl(path))
     val request = HttpRequest

foundation-core/src/main/resources/update.yaml

@@ -0,0 +1,3 @@
+# Automatic update schedule.
+autoUpdateSchedule:
+  cron: ""