addon dependency sorting

common/implementation/src/main/java/com/dfsek/terra/AbstractPlatform.java

@@ -13,11 +13,13 @@ import java.io.OutputStream;
 import java.io.UncheckedIOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
 import com.dfsek.terra.addon.BootstrapAddonLoader;
+import com.dfsek.terra.addon.DependencySorter;
 import com.dfsek.terra.api.Platform;
 import com.dfsek.terra.api.addon.BaseAddon;
 import com.dfsek.terra.api.command.CommandManager;
@@ -137,8 +139,6 @@ public abstract class AbstractPlatform implements Platform {
         
         logger().info("Initializing Terra...");
         
-        getPlatformAddon().ifPresent(addon -> addonRegistry.register(addon.getID(), addon));
-        
         try(InputStream stream = getClass().getResourceAsStream("/config.yml")) {
             File configFile = new File(getDataFolder(), "config.yml");
             if(!configFile.exists()) {
@@ -192,13 +192,17 @@ public abstract class AbstractPlatform implements Platform {
             profiler.start();
         }
         
+        List<BaseAddon> addonList = new ArrayList<>();
+        
         InternalAddon internalAddon = new InternalAddon();
         
-        addonRegistry.register(internalAddon.getID(), internalAddon);
+        addonList.add(internalAddon);
+        
+        getPlatformAddon().ifPresent(addonList::add);
         
         platformAddon().ifPresent(baseAddon -> {
             baseAddon.initialize();
-            addonRegistry.register(baseAddon.getID(), baseAddon);
+            addonList.add(baseAddon);
         });
         
         BootstrapAddonLoader bootstrapAddonLoader = new BootstrapAddonLoader(this);
@@ -212,13 +216,17 @@ public abstract class AbstractPlatform implements Platform {
                             .forEach(bootstrap -> {
                                 platformInjector.inject(bootstrap);
                                 bootstrap.loadAddons(addonsFolder, getClass().getClassLoader())
-                                         .forEach(addon -> {
-                                             platformInjector.inject(addon);
-                                             addon.initialize();
-                                             addonRegistry.register(addon.getID(), addon);
-                                         });
+                                         .forEach(addonList::add);
                             });
         
+        DependencySorter sorter = new DependencySorter();
+        addonList.forEach(sorter::add);
+        sorter.sort().forEach(addon -> {
+            platformInjector.inject(addon);
+            addon.initialize();
+            addonRegistry.register(addon.getID(), addon);
+        });
+        
         eventManager
                 .getHandler(FunctionalEventHandler.class)
                 .register(internalAddon, PlatformInitializationEvent.class)

common/implementation/src/main/java/com/dfsek/terra/InternalAddon.java

@@ -1,11 +1,20 @@
 package com.dfsek.terra;
 
+import ca.solostudios.strata.Versions;
+import ca.solostudios.strata.version.Version;
+
 import com.dfsek.terra.api.addon.BaseAddon;
 
 
 public class InternalAddon implements BaseAddon {
+    private static final Version VERSION = Versions.getVersion(1, 0, 0);
     @Override
     public String getID() {
         return "terra";
     }
+    
+    @Override
+    public Version getVersion() {
+        return VERSION;
+    }
 }

common/implementation/src/main/java/com/dfsek/terra/addon/DependencySorter.java

@@ -0,0 +1,73 @@
+package com.dfsek.terra.addon;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import com.dfsek.terra.addon.dependency.CircularDependencyException;
+import com.dfsek.terra.addon.dependency.DependencyException;
+import com.dfsek.terra.addon.dependency.DependencyVersionException;
+import com.dfsek.terra.api.addon.BaseAddon;
+
+
+public class DependencySorter {
+    private final Map<String, BaseAddon> addons = new HashMap<>();
+    private final Map<BaseAddon, Boolean> visited = new HashMap<>();
+    
+    private final List<BaseAddon> addonList = new ArrayList<>();
+    
+    public void add(BaseAddon addon) {
+        addons.put(addon.getID(), addon);
+        visited.put(addon, false);
+        addonList.add(addon);
+    }
+    
+    private void sortDependencies(BaseAddon addon, List<BaseAddon> sort) {
+        addon.getDependencies().forEach((id, range) -> {
+            if(!addons.containsKey(id)) {
+                throw new DependencyException("Addon " + addon.getID() + " specifies dependency on " + id + ", versions " + range + ", but no such addon is installed.");
+            }
+            
+            BaseAddon dependency = addons.get(id);
+            
+            if(!range.isSatisfiedBy(dependency.getVersion())) {
+                throw new DependencyVersionException("Addon " + addon.getID() + " specifies dependency on " + id + ", versions " + range + ", but non-matching version " + dependency.getVersion() + " is installed..");
+            }
+            
+            if(!visited.get(dependency)) { // if we've not visited it yet
+                visited.put(dependency, true); // we've visited it now
+                
+                if(!dependency.getDependencies().isEmpty()) { // if this addon has dependencies...
+                    sortDependencies(dependency, sort); // sort them first.
+                }
+                
+                if(sort.contains(dependency)) {
+                    throw new CircularDependencyException("Addon " + addon.getID() + " has circular dependency beginning with " + dependency.getID());
+                }
+                
+                sort.add(dependency); // add it to the list.
+            }
+        });
+    }
+    
+    public List<BaseAddon> sort() {
+        List<BaseAddon> sorted = new ArrayList<>();
+        
+        for(int i = addonList.size() - 1; i >= 0; i--) {
+            BaseAddon addon = addonList.get(i);
+            addonList.remove(i);
+            
+            if(!visited.get(addon)) { // if we've not visited it yet
+                visited.put(addon, true); // we've visited it now
+                if(!addon.getDependencies().isEmpty()) { // if this addon has dependencies...
+                    sortDependencies(addon, sorted);
+                }
+            }
+            
+            sorted.add(addon);
+        }
+        
+        return sorted;
+    }
+}

common/implementation/src/main/java/com/dfsek/terra/addon/dependency/CircularDependencyException.java

@@ -0,0 +1,11 @@
+package com.dfsek.terra.addon.dependency;
+
+public class CircularDependencyException extends DependencyException{
+    public CircularDependencyException(String message) {
+        super(message);
+    }
+    
+    public CircularDependencyException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/implementation/src/main/java/com/dfsek/terra/addon/dependency/DependencyException.java

@@ -0,0 +1,13 @@
+package com.dfsek.terra.addon.dependency;
+
+
+
+public class DependencyException extends RuntimeException {
+    public DependencyException(String message) {
+        super(message);
+    }
+    
+    public DependencyException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/implementation/src/main/java/com/dfsek/terra/addon/dependency/DependencyVersionException.java

@@ -0,0 +1,11 @@
+package com.dfsek.terra.addon.dependency;
+
+public class DependencyVersionException extends DependencyException{
+    public DependencyVersionException(String message) {
+        super(message);
+    }
+    
+    public DependencyVersionException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}