fix(scripting): fix hotreload when renaming agents.

arc-scripting/src/main/kotlin/ScriptHotReload.kt

@@ -20,6 +20,7 @@ import java.io.IOException
 import java.nio.file.FileSystems
 import java.nio.file.StandardWatchEventKinds.*
 import java.nio.file.WatchService
+import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.Executors.newCachedThreadPool
 import java.util.concurrent.Executors.newFixedThreadPool
 import java.util.concurrent.atomic.AtomicBoolean
@@ -35,6 +36,8 @@ class ScriptHotReload(
 ) : Closeable {
     private val log = LoggerFactory.getLogger(this.javaClass)
 
+    private val agentToFileMappings = ConcurrentHashMap<File, Set<String>>()
+
     private val fileWatcher = lazy {
         try {
             val watchService = FileSystems.getDefault().newWatchService()
@@ -52,24 +55,42 @@ class ScriptHotReload(
                 when (event) {
                     is FileEvent.Created -> {
                         if (event.file.isDirectory) return@watch
-                        scriptAgentLoader.loadAgents(event.file)
+                        val loadedAgents = scriptAgentLoader.loadAgents(event.file)
                         scriptFunctionLoader.loadFunctions(event.file)
+                        removeRemovedAgents(loadedAgents)
                     }
 
                     is FileEvent.Modified -> {
                         if (event.file.isDirectory) return@watch
-                        scriptAgentLoader.loadAgents(event.file)
+                        val loadedAgents = scriptAgentLoader.loadAgents(event.file)
                         scriptFunctionLoader.loadFunctions(event.file)
+                        removeRemovedAgents(loadedAgents)
                     }
 
                     is FileEvent.Deleted -> {
-                        // TODO
+                        if (event.file.isDirectory) return@watch
+                        removeRemovedAgents(mapOf(event.file to emptySet()))
                     }
                 }
             }.onFailure { logError(it) }
         }
     }
 
+    /**
+     * Removes agents that were removed from the script files.
+     */
+    private fun removeRemovedAgents(loadedAgents: Map<File, Set<String>>) {
+        loadedAgents.forEach { (file, agents) ->
+            val previousAgents = agentToFileMappings[file] ?: emptySet()
+            val removedAgents = previousAgents - agents
+            if (removedAgents.isNotEmpty()) {
+                log.info("Removing agents ${removedAgents.joinToString()} from file ${file.name}")
+                removedAgents.forEach { scriptAgentLoader.removeAgent(it) }
+            }
+            agentToFileMappings[file] = agents
+        }
+    }
+
     private fun logError(ex: Exception) {
         log.error("Unexpected Error while hot-loading Agent scripts!", ex)
     }

arc-scripting/src/main/kotlin/agents/ScriptingAgentLoader.kt

@@ -12,6 +12,7 @@ import org.eclipse.lmos.arc.agents.events.EventPublisher
 import org.eclipse.lmos.arc.core.Failure
 import org.eclipse.lmos.arc.core.Result
 import org.eclipse.lmos.arc.core.Success
+import org.eclipse.lmos.arc.core.map
 import org.eclipse.lmos.arc.core.onFailure
 import org.eclipse.lmos.arc.scripting.ScriptFailedException
 import org.slf4j.LoggerFactory
@@ -38,15 +39,17 @@ class ScriptingAgentLoader(
 
     /**
      * Loads the agents defined in an Agent DSL script.
+     * @return a Result containing the names of the loaded agents or an error if the script failed.
      */
-    fun loadAgent(agentScript: String): Result<ResultValue?, ScriptFailedException> {
+    fun loadAgent(agentScript: String): Result<Set<String>, ScriptFailedException> {
         val context = BasicAgentDefinitionContext(agentFactory)
         val result = agentScriptEngine.eval(agentScript, context)
         if (result is Success && context.agents.isNotEmpty()) {
             log.info("Discovered the following agents (scripting): ${context.agents.joinToString { it.name }}")
             agents.putAll(context.agents.associateBy { it.name })
+            return result.map { context.agents.map { it.name }.toSet() }
         }
-        return result
+        return result.map { emptySet<String>() }
     }
 
     fun loadCompiledAgent(compiledAgentScript: CompiledAgentLoader) {
@@ -60,18 +63,24 @@ class ScriptingAgentLoader(
 
     /**
      * Loads the agents defined in a list of Agent DSL script files.
+     * @return a Map containing the file and the names of the loaded agents.
      */
-    fun loadAgents(vararg files: File) {
+    fun loadAgents(vararg files: File): Map<File, Set<String>> = buildMap {
         files
             .asSequence()
             .filter { it.name.endsWith(".agent.kts") }
-            .map { it.name to it.readText() }
-            .forEach { (name, script) ->
+            .map { it to it.readText() }
+            .forEach { (file, script) ->
+                val name = file.name
                 val result = loadAgent(script).onFailure {
                     log.warn("Failed to load agents from script: $name!", it)
                 }
                 when (result) {
-                    is Success -> eventPublisher?.publish(AgentLoadedEvent(name))
+                    is Success -> {
+                        put(file, result.value)
+                        eventPublisher?.publish(AgentLoadedEvent(name))
+                    }
+
                     is Failure -> eventPublisher?.publish(
                         AgentLoadedEvent(
                             name,
@@ -88,4 +97,12 @@ class ScriptingAgentLoader(
     fun loadAgentsFromFolder(folder: File) {
         folder.walk().filter { it.isFile }.forEach { loadAgents(it) }
     }
+
+    /**
+     * Removes the agent with the given name.
+     */
+    fun removeAgent(name: String): Boolean {
+        val agent = agents.remove(name)
+        return agent != null
+    }
 }