Add completely broken automatic subsystem init

base/src/main/java/de/staropensource/sosengine/base/Engine.java

@@ -33,15 +33,24 @@ import de.staropensource.sosengine.base.logging.CrashHandler;
 import de.staropensource.sosengine.base.logging.Logger;
 import de.staropensource.sosengine.base.logging.LoggerInstance;
 import de.staropensource.sosengine.base.types.CodePart;
+import de.staropensource.sosengine.base.types.DependencyVector;
+import de.staropensource.sosengine.base.types.ImmutableMap;
+import de.staropensource.sosengine.base.utility.DependencyResolver;
 import de.staropensource.sosengine.base.utility.Miscellaneous;
 import de.staropensource.sosengine.base.utility.PlaceholderEngine;
 import de.staropensource.sosengine.base.utility.ShortcodeConverter;
 import lombok.Getter;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Range;
+import org.reflections.Reflections;
+import org.reflections.scanners.Scanners;
+import org.reflections.util.ClasspathHelper;
+import org.reflections.util.ConfigurationBuilder;
 
+import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * sos!engine management object.<br/>
@@ -114,12 +123,8 @@ public final class Engine implements SubsystemMainClass {
         // Only allow one instance
         if (instance == null)
             instance = this;
-        else {
-            instance.logger.crash("sos!engine tried to initialize twice");
-            //noinspection DataFlowIssue
-            logger = null;
+        else
             return;
-        }
 
         long initTime = Miscellaneous.measureExecutionTime(() -> {
             // Initialize variables
@@ -140,6 +145,16 @@ public final class Engine implements SubsystemMainClass {
 
             // Start threads
             startThreads();
+
+            // Collect subsystems
+            collectSubsystems();
+
+            // Initialize subsystems
+            try {
+                initializeSubsystems();
+            } catch (Exception exception) {
+                logger.crash("Subsystem dependency resolution failed");
+            }
         });
 
         logger.info("Initialized sos!engine v%engine_version% (commit %engine_git_commit_id_long%-%engine_git_branch%, dirty %engine_git_dirty%) in " + initTime + "ms");
@@ -221,7 +236,7 @@ public final class Engine implements SubsystemMainClass {
      *
      * @since 1-alpha0
      */
-    public void precomputeEventListeners() {
+    private void precomputeEventListeners() {
         // Internal events
         EventHelper.precomputeEventListeners(InternalEngineShutdownEvent.class);
 
@@ -231,6 +246,65 @@ public final class Engine implements SubsystemMainClass {
         EventHelper.precomputeEventListeners(LogEvent.class);
     }
 
+    /**
+     * Collects all subsystems by their {@link EngineSubsystem} annotation.
+     *
+     * @since 1-alpha1
+     */
+    private void collectSubsystems() {
+        Map<@NotNull Class<? extends SubsystemMainClass>, @NotNull DependencyVector> subsystemsMap = new HashMap<>();
+
+        // Scan entire classpath through Reflections library
+        Reflections reflections = new Reflections(
+                new ConfigurationBuilder()
+                        .setUrls(ClasspathHelper.forJavaClassPath())
+                        .setScanners(Scanners.TypesAnnotated)
+        );
+
+        // Get annotated methods
+        Set<@NotNull Class<?>> annotatedClasses = reflections.getTypesAnnotatedWith(EngineSubsystem.class);
+
+        // Add to 'subsystemsMap'
+        for (Class<?> clazz : annotatedClasses) {
+            try {
+                //noinspection unchecked
+                subsystemsMap.put((Class<? extends SubsystemMainClass>) clazz, (DependencyVector) clazz.getMethod("getDependencyVector").invoke(null));
+            } catch (Exception ignored) {}
+        }
+
+        // Remove null values
+        for (Class<? extends SubsystemMainClass> subsystem : subsystemsMap.keySet())
+            if (subsystemsMap.get(subsystem) == null)
+                subsystemsMap.remove(subsystem);
+
+        subsystems = new ImmutableMap<>(subsystemsMap);
+    }
+
+    /**
+     * Initializes all subsystems.
+     *
+     * @throws Exception exceptions thrown by the {@link DependencyResolver}
+     * @since 1-alpha1
+     */
+    private void initializeSubsystems() throws Exception {
+        DependencyResolver resolver = new DependencyResolver();
+
+        for (Class<? extends SubsystemMainClass> subsystem : subsystems.keySet())
+            resolver.addVector(subsystems.get(subsystem));
+
+        /*
+        try {
+            resolver.resolve();
+        } catch (Exception exception) {
+            logger.crash("An error occurred trying to initialize engine subsystems: " + exception.getClass().getName() + (exception.getMessage() == null ? "" : ": " + exception.getMessage()));
+            throw exception;
+        }
+         */
+
+        for (Class<? extends SubsystemMainClass> subsystem : subsystems.keySet())
+            subsystem.getDeclaredConstructor().newInstance();
+    }
+
     /**
      * Starts engine threads.
      *
@@ -261,6 +335,17 @@ public final class Engine implements SubsystemMainClass {
         Runtime.getRuntime().exit(exitCode);
     }
 
+    /**
+     * Returns the {@link DependencyVector} for this subsystem.
+     *
+     * @see DependencyVector
+     * @since 1-alpha1
+     */
+    @Override
+    public DependencyVector getDependencyVector() {
+        return new DependencyVector("engine", StarOpenSourceVersioningSystem.class, EngineInformation.getInstance().getVersioningString());
+    }
+
     /**
      * Shuts the engine and JVM down.
      *

testapp/src/main/java/de/staropensource/sosengine/testapp/Main.java

@@ -27,9 +27,6 @@ import de.staropensource.sosengine.base.types.Vec2i;
 import de.staropensource.sosengine.graphics.GraphicsSubsystem;
 import de.staropensource.sosengine.graphics.classes.ApiMainClass;
 import de.staropensource.sosengine.graphics.classes.ApiManagementClass;
-import de.staropensource.sosengine.graphics.opengl.OpenGlSubsystem;
-import de.staropensource.sosengine.graphics.vulkan.VulkanSubsystem;
-import de.staropensource.sosengine.slf4j_compat.Slf4jCompatibilitySubsystem;
 import lombok.Getter;
 import lombok.SneakyThrows;
 
@@ -101,12 +98,6 @@ public class Main {
         // Say hello to the world!
         logger.info("Hello world!");
 
-        // Initialize subsystems
-        new Slf4jCompatibilitySubsystem();
-        new GraphicsSubsystem();
-        new OpenGlSubsystem();
-        new VulkanSubsystem();
-
         // Choose Graphics API to use
         if (!GraphicsSubsystem.getInstance().setGraphicsApi()) {
             logger.crash("No Graphics API is compatible");