implement ephemeral addons for platform version comparison

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

@@ -18,6 +18,10 @@
 package com.dfsek.terra;
 
 import com.dfsek.tectonic.loading.TypeRegistry;
+
+import com.dfsek.terra.addon.EphemeralAddon;
+import com.dfsek.terra.addon.InternalAddon;
+
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
 import org.slf4j.Logger;
@@ -33,9 +37,9 @@ import java.io.UncheckedIOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 
 import com.dfsek.terra.addon.BootstrapAddonLoader;
 import com.dfsek.terra.addon.DependencySorter;
@@ -102,8 +106,8 @@ public abstract class AbstractPlatform implements Platform {
         return manager;
     }
     
-    protected Optional<BaseAddon> platformAddon() {
-        return Optional.empty();
+    protected Iterable<BaseAddon> platformAddon() {
+        return Collections.emptySet();
     }
     
     protected void load() {
@@ -175,7 +179,7 @@ public abstract class AbstractPlatform implements Platform {
         
         addonList.add(internalAddon);
         
-        platformAddon().ifPresent(addonList::add);
+        platformAddon().forEach(addonList::add);
         
         BootstrapAddonLoader bootstrapAddonLoader = new BootstrapAddonLoader();
         
@@ -214,7 +218,9 @@ public abstract class AbstractPlatform implements Platform {
         sorter.sort().forEach(addon -> {
             platformInjector.inject(addon);
             addon.initialize();
-            addonRegistry.register(addon.getID(), addon);
+            if(!(addon instanceof EphemeralAddon)) { // ephemeral addons exist only for version checking
+                addonRegistry.register(addon.getID(), addon);
+            }
         });
     
         eventManager.getHandler(FunctionalEventHandler.class)

common/implementation/base/src/main/java/com/dfsek/terra/addon/EphemeralAddon.java

@@ -0,0 +1,26 @@
+package com.dfsek.terra.addon;
+
+import ca.solostudios.strata.version.Version;
+
+import com.dfsek.terra.api.addon.BaseAddon;
+
+
+public class EphemeralAddon implements BaseAddon {
+    private final Version version;
+    private final String id;
+    
+    public EphemeralAddon(Version version, String id) {
+        this.version = version;
+        this.id = id;
+    }
+    
+    @Override
+    public Version getVersion() {
+        return version;
+    }
+    
+    @Override
+    public String getID() {
+        return id;
+    }
+}

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

@@ -15,7 +15,7 @@
  * along with Terra.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-package com.dfsek.terra;
+package com.dfsek.terra.addon;
 
 import ca.solostudios.strata.Versions;
 import ca.solostudios.strata.version.Version;

platforms/fabric/src/main/java/com/dfsek/terra/fabric/PlatformImpl.java

@@ -17,15 +17,26 @@
 
 package com.dfsek.terra.fabric;
 
+import ca.solostudios.strata.Versions;
+import ca.solostudios.strata.parser.tokenizer.ParseException;
+import ca.solostudios.strata.version.Version;
 import com.dfsek.tectonic.exception.LoadException;
 import com.dfsek.tectonic.loading.TypeRegistry;
+
+import com.dfsek.terra.addon.EphemeralAddon;
+
 import net.fabricmc.loader.api.FabricLoader;
+import net.minecraft.MinecraftVersion;
 import net.minecraft.server.world.ServerWorld;
 import net.minecraft.util.Identifier;
 import net.minecraft.util.registry.BuiltinRegistries;
 
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 
@@ -40,9 +51,12 @@ import com.dfsek.terra.fabric.handle.FabricItemHandle;
 import com.dfsek.terra.fabric.handle.FabricWorldHandle;
 import com.dfsek.terra.fabric.util.ProtoBiome;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 
 public class PlatformImpl extends AbstractPlatform {
-    
+    private static final Logger LOGGER = LoggerFactory.getLogger(PlatformImpl.class);
     private final ItemHandle itemHandle = new FabricItemHandle();
     private final WorldHandle worldHandle = new FabricWorldHandle();
     private final Lazy<File> dataFolder = Lazy.lazy(() -> new File(FabricLoader.getInstance().getConfigDir().toFile(), "Terra"));
@@ -72,8 +86,33 @@ public class PlatformImpl extends AbstractPlatform {
     }
     
     @Override
-    protected Optional<BaseAddon> platformAddon() {
-        return Optional.of(new FabricAddon(this));
+    protected Iterable<BaseAddon> platformAddon() {
+        List<BaseAddon> addons = new ArrayList<>();
+        
+        addons.add(new FabricAddon(this));
+        
+        String mcVersion = MinecraftVersion.CURRENT.getReleaseTarget();
+        try {
+            addons.add(new EphemeralAddon(Versions.parseVersion(mcVersion), "minecraft"));
+        } catch(ParseException e) {
+            try {
+                addons.add(new EphemeralAddon(Versions.parseVersion(mcVersion + ".0"), "minecraft"));
+            } catch(ParseException ex) {
+                LOGGER.warn("Failed to parse Minecraft version", e);
+            }
+        }
+        
+        FabricLoader.getInstance().getAllMods().forEach(mod -> {
+            if(mod.getMetadata().getId().equals("terra")) return;
+            try {
+                Version version = Versions.parseVersion(mod.getMetadata().getVersion().getFriendlyString());
+                addons.add(new EphemeralAddon(version, "fabric:" + mod.getMetadata().getId()));
+            } catch(ParseException e) {
+                LOGGER.warn("Mod {}, version {} does not follow semantic versioning specification.", mod.getMetadata().getId(), mod.getMetadata().getVersion().getFriendlyString());
+            }
+        });
+        
+        return addons;
     }
     
     @Override