Change how GroupRegistry deals with Wildcard Generics

17 files changed, 215 insertions, 185 deletions

diff --git a/src/main/java/net/cshift/api/transit/Transit.java b/src/main/java/net/cshift/api/transit/Transit.java
index adc9f25..6d0523d 100644
--- a/src/main/java/net/cshift/api/transit/Transit.java
+++ b/src/main/java/net/cshift/api/transit/Transit.java
@@ -26,10 +26,9 @@ package net.cshift.api.transit;
 
 import net.fabricmc.api.ModInitializer;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import org.slf4j.*;
 
-import net.cshift.api.transit.type.group.SimpleGroups;
+import net.cshift.api.transit.type.group.*;
 
 /**
  * @author Kyle Gunger
@@ -38,7 +37,7 @@ import net.cshift.api.transit.type.group.SimpleGroups;
 public class Transit implements ModInitializer {
 
 	private static final Logger LOGGER = LoggerFactory.getLogger("Transit API");
-	
+
 	@Override
 	public void onInitialize() {
 		LOGGER.info("Transit API: Providing a thin wrapper over reality!");
diff --git a/src/main/java/net/cshift/api/transit/network/Channel.java b/src/main/java/net/cshift/api/transit/network/Channel.java
index bd4cdf2..3fdae88 100644
--- a/src/main/java/net/cshift/api/transit/network/Channel.java
+++ b/src/main/java/net/cshift/api/transit/network/Channel.java
@@ -25,6 +25,8 @@
 package net.cshift.api.transit.network;
 
 import net.cshift.api.transit.network.packet.IStaticPacket;
+import net.cshift.api.transit.type.group.GroupRegistry;
+import net.cshift.api.transit.type.group.TypeGroup;
 
 /**
  * @author Kyle Gunger
@@ -35,6 +37,7 @@ public final class Channel<D> {
     private INode to;
     private int id;
     private String group;
+    private Class<D> baseClass;
 
     /** This constructor should be called by a node approving a connection.  The approving node can give the connection an ID and group.
      * Negative IDs indicate a terminated connection, so do not initialize the class with a negative ID.
@@ -43,11 +46,12 @@ public final class Channel<D> {
      * @param id The channel's id, as assigned by the recieving node.  In most cases, this will match the pool ID as a way to match channels to pools.
      * @param group 
      */
-	public Channel(INode node, int id, String group)
+	public Channel(INode node, int id, String group, Class<D> baseClass)
 	{
         to = node;
         this.id = id;
         this.group = group;
+        this.baseClass = baseClass;
 	}
 
 
@@ -78,8 +82,8 @@ public final class Channel<D> {
      * 
      * @return
      */
-    public String getGroup() {
-        return group;
+    public TypeGroup<D> getGroup() {
+        return GroupRegistry.<D>groupByID(group, baseClass);
     }
 
     /** Returns true if the connection has been terminated
@@ -135,7 +139,7 @@ public final class Channel<D> {
      * @param packet the packet to send
      * @return The overflow data if the packet is only partially accepted. {@code null} otherwise.
      */
-    public IStaticPacket<D> send(IStaticPacket<D> packet)
+    public IStaticPacket send(IStaticPacket packet)
     {
         return to.accept(packet, this);
     }
diff --git a/src/main/java/net/cshift/api/transit/network/INode.java b/src/main/java/net/cshift/api/transit/network/INode.java
index 54701e7..6653e40 100644
--- a/src/main/java/net/cshift/api/transit/network/INode.java
+++ b/src/main/java/net/cshift/api/transit/network/INode.java
@@ -13,25 +13,29 @@ public interface INode
 	 */
 	public PoolManifest getManifest();
 
-	/** Get the system managing the node or {@code null} if there isn't one
-	 *
-	 */
-	public ISystem getSystem();
-
 
 
 	// ###############
 	// # Connections #
 	// ###############
 
-	/** Call this function to establish a connection with a node.
+	/** Call this function to establish a specific connection with a node.
 	 * 
 	 * @param <T> The type of connection being asked for
 	 * @param poolID The ID of the pool the channel will interface with (see PoolManifest)
 	 * @param asker The asking node
 	 * @return A channel if the node accepts the request, {@code null} otherwise
 	 */
-	public <T> Channel<T> connect(int poolID, INode asker);
+	public <T> Channel<T> connect(int poolID, String group, INode asker);
+	
+	/** Call this function to establish a default connection with a node.
+	 * 
+	 * @param <T> The type of connection being asked for
+	 * @param group The group that is being connected to
+	 * @param asker The asking node
+	 * @return A channel if the node accepts the request, {@code null} otherwise
+	 */
+	public <T> Channel<T> connectDefault(String group, INode asker);
 
 	/** Accept a packet from a channel (or not).
 	 * 
@@ -41,7 +45,7 @@ public interface INode
 	 * @param channel The channel which the packet is coming through
 	 * @return The overflow data if the packet is only partially accepted. {@code null} otherwise.
 	 */
-	public <T> IStaticPacket<T> accept(IStaticPacket<T> packet, Channel<T> channel);
+	public IStaticPacket accept(IStaticPacket packet, Channel<?> channel);
 
 	/** Pressure
 	 *
diff --git a/src/main/java/net/cshift/api/transit/network/ISystem.java b/src/main/java/net/cshift/api/transit/network/ISystem.java
deleted file mode 100644
index b7ab9bf..0000000
--- a/src/main/java/net/cshift/api/transit/network/ISystem.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package net.cshift.api.transit.network;
-
-
-/**
- * @author Kyle Gunger
- * @apiNote An ISystem represents a system of nodes which has been optimized for performance.  A node can exist on its own, but an ISystem can't exist without a node.
- */
-public interface ISystem
-{
-	/**The nodes stored by the system
-	 *
-	 * @return INode[]
-	 */
-	public INode[] getNodes();
-}
diff --git a/src/main/java/net/cshift/api/transit/network/PoolManifest.java b/src/main/java/net/cshift/api/transit/network/PoolManifest.java
index 26cbece..e539ee1 100644
--- a/src/main/java/net/cshift/api/transit/network/PoolManifest.java
+++ b/src/main/java/net/cshift/api/transit/network/PoolManifest.java
@@ -6,35 +6,37 @@ package net.cshift.api.transit.network;
  */
 public abstract class PoolManifest {
     
-    /** Represents the number of pools that the node has access to for the specified resource.
-     * @apiNote A "pool" in this context represents an independant network of resources.
+    /** Represents the number of pools that the node has access to.
+     * @apiNote A "pool" in this context represents an independent network of resources.
+     * Each network in the pool may represent a different TypeGroup.
      * Pool zero should be the default group that simple nodes will attempt to connect to.
      * @param group The TypeGroup that the pool belongs to
      */
-    public abstract int poolCount(String group);
+    public abstract int poolCount();
 
-    /** The ID of the pool.  The INode will use this in a connection attempt with the other INode.
-     * 
-     * @param group The TypeGroup the pool belongs to
-     * @param pool Array-like index for pool (gotten from poolCount)
-     */
-    public abstract int poolID(String group, int pool);
-
-    /** If the mod supports named pools, the names can be querried through this function.
+    /** If the mod supports named pools, the names can be queried through this function.
      *
      * @param group The TypeGroup the pool belongs to
      * @param pool Array-like index for pool (gotten from poolCount)
      */
-    public String poolName(String group, int pool) {
+    public String poolName(int pool) {
         return "";
     }
+    
+    /** Returns true if the pool with the given id supports the given group
+     * 
+     * @param pool The pool ID to query
+     * @param group The TypeGroup to query
+     * @return {@code true} if the pool supports the specified group, {@code false} otherwise
+     */
+    public abstract boolean poolProvides(int pool, String group);
 
     /** If the mod supports pool descriptions, they can be accessed by this method.
      * 
      * @param group The TypeGroup the pool belongs to
      * @param pool Array-like index for pool (gotten from poolCount)
     */
-    public String poolDescription(String group, int pool) {
+    public String poolDescription(int pool) {
         return "";
     }
 }
diff --git a/src/main/java/net/cshift/api/transit/network/packet/DynamicPacket.java b/src/main/java/net/cshift/api/transit/network/packet/DynamicPacket.java
index f3a6c47..3a57227 100644
--- a/src/main/java/net/cshift/api/transit/network/packet/DynamicPacket.java
+++ b/src/main/java/net/cshift/api/transit/network/packet/DynamicPacket.java
@@ -3,14 +3,14 @@ package net.cshift.api.transit.network.packet;
 import net.cshift.api.transit.type.Type;
 
 /**
- * Simple packet which stores a fluid value.
+ * Simple packet which stores a value which can change.
  *
+ * @param <D> The type parameter of the Type being transported
  * @author Kyle Gunger
- *
- * @param <D> The data type (Object) that the packet transfers
+ * 
  */
 public class DynamicPacket<D> implements IDynamicPacket<D> {
-    private D data;
+    private Object data;
     private Type<D> type;
 
     /** Constructor. Stores the given data and uses the given type.
@@ -18,20 +18,20 @@ public class DynamicPacket<D> implements IDynamicPacket<D> {
      * @param dat The packet's data
      * @param t The packet's type
      */
-    public DynamicPacket(D dat, Type<D> t)
+    public DynamicPacket(Object dat, Type<D> t)
     {
         data = dat;
         type = t;
     }
 
     @Override
-    public D getData()
+    public Object getData()
     {
         return data;
     }
 
     @Override
-    public void setData(D dat)
+    public void setData(Object dat)
     {
         data = dat;
     }
diff --git a/src/main/java/net/cshift/api/transit/network/packet/IDynamicPacket.java b/src/main/java/net/cshift/api/transit/network/packet/IDynamicPacket.java
index 334d5f6..6d80b3b 100644
--- a/src/main/java/net/cshift/api/transit/network/packet/IDynamicPacket.java
+++ b/src/main/java/net/cshift/api/transit/network/packet/IDynamicPacket.java
@@ -1,14 +1,11 @@
 package net.cshift.api.transit.network.packet;
 
-/** Interface describing a fluid packet.
+/** Interface describing a packet where the data can change as it's transferred.
+ * 
+ * @param <D> The type parameter of the Type being transported
  * @author Kyle Gunger
- *
- * @param <D> The data type (Object) that the packet transfers
  */
 public interface IDynamicPacket<D> extends IStaticPacket<D>{
-    /**Set the packet's data.
-	 *
-	 * @return <D> The packet's data
-	 */
-    public void setData(D dat);
+    /** Set the packet's data. */
+    public void setData(Object dat);
 }
diff --git a/src/main/java/net/cshift/api/transit/network/packet/IStaticPacket.java b/src/main/java/net/cshift/api/transit/network/packet/IStaticPacket.java
index ba1b17f..cdad90a 100644
--- a/src/main/java/net/cshift/api/transit/network/packet/IStaticPacket.java
+++ b/src/main/java/net/cshift/api/transit/network/packet/IStaticPacket.java
@@ -3,21 +3,21 @@ package net.cshift.api.transit.network.packet;
 import net.cshift.api.transit.type.*;
 
 /** Interface describing an unchanging packet.
- * @author Kyle Gunger
  *
- * @param <D> The data type (Object) that the packet transfers.
+ * @param <D> The type parameter of the Type being transported
+ * @author Kyle Gunger
  */
 public interface IStaticPacket<D>
 {
 	/**Get the packet's data.
 	 * 
-	 * @return <D> The packet's data
+	 * @return The packet's data
 	 */
-    public D getData();
+    public Object getData();
     
     /**Get the packet's type.
      * 
-     * @return IType<<D>> The type of the packet
+     * @return IType<?> The type of the packet
      */
     public Type<D> getType();
 }
diff --git a/src/main/java/net/cshift/api/transit/network/packet/MetaDynamicPacket.java b/src/main/java/net/cshift/api/transit/network/packet/MetaDynamicPacket.java
deleted file mode 100644
index d382645..0000000
--- a/src/main/java/net/cshift/api/transit/network/packet/MetaDynamicPacket.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package net.cshift.api.transit.network.packet;
-
-import net.cshift.api.transit.type.Type;
-
-/** Static packet with extra data attached.
- * @author Kyle Gunger
- *
- * @param <D> The data type (Object) that the packet transfers
- * @param <M> The type of metadata
-*/
-public class MetaDynamicPacket<D, M> extends DynamicPacket<D>
-{
-	private M metaData;
-
-    /** Constructor
-     *
-     * @param dat The data to store
-     * @param t The Type of the data
-     * @param meta The metadata to store
-     */
-    public MetaDynamicPacket(D dat, Type<D> t, M meta)
-    {
-        super(dat, t);
-        metaData = meta;
-    }
-
-    /** Get the metadata of the packet.
-     *
-     * @return The packet's metadata
-     */
-    public M getMetaData()
-    {
-    	return metaData;
-    }
-
-    /** Set the metadata of the packet.
-     *
-     * @param meta The packet's new metadata
-     */
-    public void setMetaData(M meta)
-    {
-        metaData = meta;
-    }
-}
diff --git a/src/main/java/net/cshift/api/transit/network/packet/MetaPacket.java b/src/main/java/net/cshift/api/transit/network/packet/MetaPacket.java
deleted file mode 100644
index aea1b83..0000000
--- a/src/main/java/net/cshift/api/transit/network/packet/MetaPacket.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package net.cshift.api.transit.network.packet;
-
-import net.cshift.api.transit.type.*;
-
-/** Static packet with extra data attached.
- * @author Kyle Gunger
- *
- * @param <D> The data type (Object) that the packet transfers
- * @param <M> The type of metadata
-*/
-public class MetaPacket<D, M> extends StaticPacket<D>
-{
-	private M metaData;
-
-    /** Constructor
-     * 
-     * @param dat The data to store
-     * @param t The Type of the data
-     * @param meta The metadata to store
-     */
-    public MetaPacket(D dat, Type<D> t, M meta)
-    {
-        super(dat, t);
-        metaData = meta;
-    }
-    
-    /** Get the metadata of the packet.
-     * 
-     * @return The packet's metadata
-     */
-    public M getMetaData()
-    {
-    	return metaData;
-    }
-}
diff --git a/src/main/java/net/cshift/api/transit/network/packet/StaticPacket.java b/src/main/java/net/cshift/api/transit/network/packet/StaticPacket.java
index 2c6a16a..5ffed26 100644
--- a/src/main/java/net/cshift/api/transit/network/packet/StaticPacket.java
+++ b/src/main/java/net/cshift/api/transit/network/packet/StaticPacket.java
@@ -9,7 +9,7 @@ import net.cshift.api.transit.type.*;
  */
 public class StaticPacket<D> implements IStaticPacket<D>
 {
-    private D data;
+    private Object data;
     private Type<D> type;
 
     /** Constructor. Stores the given data and uses the given type.
@@ -17,14 +17,14 @@ public class StaticPacket<D> implements IStaticPacket<D>
      * @param dat The packet's data
      * @param t The packet's type
      */
-    public StaticPacket(D dat, Type<D> t)
+    public StaticPacket(Object dat, Type<D> t)
     {
         data = dat;
         type = t;
     }
 
     @Override
-    public D getData()
+    public Object getData()
     {
         return data;
     }
diff --git a/src/main/java/net/cshift/api/transit/type/SimpleTypes.java b/src/main/java/net/cshift/api/transit/type/SimpleTypes.java
index 54106c7..5b4a6b8 100644
--- a/src/main/java/net/cshift/api/transit/type/SimpleTypes.java
+++ b/src/main/java/net/cshift/api/transit/type/SimpleTypes.java
@@ -27,17 +27,17 @@ package net.cshift.api.transit.type;
 public final class SimpleTypes {
 	/** Transfers energy.  Energy is stored as a numeric.
 	 */
-	public static final Type<Long> TransitJoule = new Type<Long>("Joule", "ENERGY");
+	public static final Type<Long> TransitJoule = new Type<Long>("Joule", "ENERGY", Long.class);
 	
 	/** Transfers mana.  TMana stores mana count and type.
 	 */
-	public static final Type<TMana> TransitMana = new Type<TMana>("TMana", "MANA");
+	public static final Type<TMana> TransitMana = new Type<TMana>("TMana", "MANA", TMana.class);
 
 	/** Transfers items. TItem stores an item and an item count.
 	 */
-	public static final Type<TItem> TransitItem = new Type<TItem>("TItem", "ITEM");
+	public static final Type<TItem> TransitItem = new Type<TItem>("TItem", "ITEM", TItem.class);
 
 	/** Transfers fluid. TFluid stores fluid and mB.
 	 */
-	public static final Type<TFluid> TransitFluid = new Type<TFluid>("TFluid", "FLUID");
+	public static final Type<TFluid> TransitFluid = new Type<TFluid>("TFluid", "FLUID", TFluid.class);
 }
diff --git a/src/main/java/net/cshift/api/transit/type/Type.java b/src/main/java/net/cshift/api/transit/type/Type.java
index d47cd08..f544e8f 100644
--- a/src/main/java/net/cshift/api/transit/type/Type.java
+++ b/src/main/java/net/cshift/api/transit/type/Type.java
@@ -1,3 +1,27 @@
+/*
+	MIT License
+
+	Copyright (c) 2023 Kyle Gunger
+	
+	Permission is hereby granted, free of charge, to any person obtaining a copy
+	of this software and associated documentation files (the "Software"), to deal
+	in the Software without restriction, including without limitation the rights
+	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+	copies of the Software, and to permit persons to whom the Software is
+	furnished to do so, subject to the following conditions:
+	
+	The above copyright notice and this permission notice shall be included in all
+	copies or substantial portions of the Software.
+	
+	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+	SOFTWARE.
+*/
+
 package net.cshift.api.transit.type;
 
 import net.cshift.api.transit.network.packet.*;
@@ -10,12 +34,14 @@ public class Type<T>
 {
 	protected final String typeID;
 	protected final String groupID;
+	private final Class<?> underlying;
 	
 	// Should not override, but you can if you must
-	public Type(String tID, String gID)
+	public Type(String tID, String gID, Class<?> underlying)
 	{
 		typeID = tID;
 		groupID = gID;
+		this.underlying = underlying;
 	}
 	
 
@@ -31,9 +57,13 @@ public class Type<T>
 	 * @param group The group asking for the conversion
 	 * @return The data in the group's base type
 	 */
-	public T toBase(T data, String group)
+	@SuppressWarnings("unchecked")
+	public T toBase(Object data, String group)
 	{
-		return data;
+		// Assume the underlying is the same as T for this very simple case
+		if (data.getClass().equals(this.getUnderlying()))
+			return (T) data;
+		return null;
 	}
 
 	/** Return the data formatted in the default group's base type.
@@ -41,7 +71,7 @@ public class Type<T>
 	 * @param data The data (of this type)
 	 * @return The data in the group's base type
 	 */
-	public final T toBase(T data)
+	public final T toBase(Object data)
 	{
 		return this.toBase(data, this.groupID);
 	}
@@ -54,7 +84,9 @@ public class Type<T>
 	 */
 	public final T toBase(IStaticPacket<T> packet, String group)
 	{
-		return this.toBase(packet.getData(), group);
+		if(packet.getType().equals(this))
+			return this.toBase(packet.getData(), group);
+		return null;
 	}
 
 	/** Return the packet's data formatted in the default group's base type.
@@ -78,19 +110,20 @@ public class Type<T>
 	 * 
 	 * @param data The base data
 	 * @param group The group asking for the conversion
-	 * @return The packet's data in the group's base type
+	 * @return The converted data, in the Type's underlying
 	 */
-	public T fromBase(T data, String group)
+	public Object fromBase(T data, String group)
 	{
+		// Assume T is the same as the underlying
 		return data;
 	}
 
 	/** Convert data from the default group's base type to this type.
 	 * 
 	 * @param data The base data
-	 * @return The packet's data in the group's base type
+	 * @return The converted data, in the Type's underlying
 	 */
-	public final T fromBase(T data)
+	public final Object fromBase(T data)
 	{
 		return fromBase(data, this.groupID);
 	}
@@ -99,7 +132,7 @@ public class Type<T>
 	 * 
 	 * @param data The base data
 	 * @param group The group asking for the conversion
-	 * @return The packet's data in the group's base type
+	 * @return A packet containing the converted data in the Type's underlying
 	 */
 	public final IStaticPacket<T> packetFromBase(T data, String group)
 	{
@@ -130,7 +163,7 @@ public class Type<T>
 	 * @param data The data to convert
 	 * @return The data formatted in this type
 	 */
-	public T convertFrom(Type<T> from, T data, String group) {
+	public Object convertFrom(Type<T> from, Object data, String group) {
 		return this.fromBase(from.toBase(data, group), group);
 	}
 
@@ -140,7 +173,7 @@ public class Type<T>
 	 * @param data The data to convert
 	 * @return The data formatted in this type
 	 */
-	public final T convertFrom(Type<T> from, T data) {
+	public final Object convertFrom(Type<T> from, Object data) {
 		return convertFrom(from, data, from.groupID);
 	}
 
@@ -159,7 +192,7 @@ public class Type<T>
 	 * @param packet The packet to convert
 	 * @return The new packet formatted in this type
 	 */
-	public final IStaticPacket<T> convertFrom(IStaticPacket<T> packet) {
+	public final IStaticPacket<T> convertFrom(IStaticPacket<T> packet) throws ClassCastException {
 		return this.convertFrom(packet, packet.getType().groupID);
 	}
 
@@ -176,7 +209,7 @@ public class Type<T>
 	 * @param data The data to convert
 	 * @return The data formatted in this type
 	 */
-	public final T convertTo(Type<T> to, T data, String group) {
+	public final Object convertTo(Type<T> to, Object data, String group) {
 		return to.convertFrom(this, data, group);
 	}
 
@@ -186,7 +219,7 @@ public class Type<T>
 	 * @param data The data to convert
 	 * @return The data formatted in this type
 	 */
-	public final T convertTo(Type<T> to, T data) {
+	public final Object convertTo(Type<T> to, Object data) {
 		return to.convertFrom(this, data, this.groupID);
 	}
 
@@ -232,7 +265,16 @@ public class Type<T>
 	{
 		return groupID;
 	}
-
+	
+	/** The underlying class which this Type uses to implement functionality within the mod
+	 * 
+	 * @return Class<?>
+	 */
+	public final Class<?> getUnderlying()
+	{
+		return underlying;
+	}
+	
 	@Override
 	public final String toString() {
 		return groupID + ":" + typeID;
diff --git a/src/main/java/net/cshift/api/transit/type/group/GroupRegistry.java b/src/main/java/net/cshift/api/transit/type/group/GroupRegistry.java
index 5e09e71..f74e9c5 100644
--- a/src/main/java/net/cshift/api/transit/type/group/GroupRegistry.java
+++ b/src/main/java/net/cshift/api/transit/type/group/GroupRegistry.java
@@ -1,3 +1,27 @@
+/*
+	MIT License
+
+	Copyright (c) 2023 Kyle Gunger
+	
+	Permission is hereby granted, free of charge, to any person obtaining a copy
+	of this software and associated documentation files (the "Software"), to deal
+	in the Software without restriction, including without limitation the rights
+	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+	copies of the Software, and to permit persons to whom the Software is
+	furnished to do so, subject to the following conditions:
+	
+	The above copyright notice and this permission notice shall be included in all
+	copies or substantial portions of the Software.
+	
+	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+	SOFTWARE.
+*/
+
 package net.cshift.api.transit.type.group;
 
 import java.security.InvalidKeyException;
@@ -14,8 +38,7 @@ public final class GroupRegistry {
 	
 	private GroupRegistry() {}
 	
-	public static final boolean addGroup(TypeGroup<?> group)
-	{
+	public static final boolean addGroup(TypeGroup<?> group) {
 		if (GROUPS.containsKey(group.getGroup())) {
 			LOGGER.warn("Failed to add group " + group + " to the registry. Did another mod add a group with the same name?");
 			return false;
@@ -27,24 +50,67 @@ public final class GroupRegistry {
 		return true;
 	}
 	
-	public static final <T> TypeGroup<T> groupByID(String groupID)
-	{
+	/** Get the requested type group via ID
+	 * 
+	 * @param <B> The base type of the type group
+	 * @param groupID 
+	 * @param baseClass
+	 * @throws ClassCastException if the group is not of the provided class type
+	 * @return The group (properly casted) if it exists, or null otherwise
+	 */
+	@SuppressWarnings("unchecked")
+	public static final <B> TypeGroup<B> groupByID(String groupID, Class<B> baseClass) throws ClassCastException {
 		if (GROUPS.containsKey(groupID)) {
 			TypeGroup<?> g = GROUPS.get(groupID);
-			return (TypeGroup<T>) g;
+			if (g.getBaseClass().equals(baseClass)) {
+				return (TypeGroup<B>) g;
+			} else {
+				throw new ClassCastException(
+						"Group " + g.getGroup() + " was requested as TypeGroup<" +
+						baseClass.getName() + ">, but the group is actually TypeGroup<" +
+						g.getBaseClass().getName() + ">"
+				);
+			}
 		}
 		
 		return null;
 	}
 	
-	public static final <T> Type<T> typeByIdentity(String groupID, String typeID) throws InvalidKeyException
-	{
-		TypeGroup<T> group = GroupRegistry.<T>groupByID(groupID);
+	/** Get the wildcard generic TypeGroup via the groupID
+	 * 
+	 * @param groupID The ID of the group to get
+	 * @return The group if it exists, or null otherwise
+	 */
+	public static final TypeGroup<?> groupByID(String groupID) {
+		if (GROUPS.containsKey(groupID)) {
+			return GROUPS.get(groupID);
+		}
 		
-		if(group != null)
-			return group.getType(typeID);
-
 		return null;
 	}
 	
+	/** Get the requested type via 
+	 * 
+	 * @param <B>
+	 * @param groupID
+	 * @param typeID
+	 * @param baseClass
+	 * @return
+	 * @throws ClassCastException
+	 */
+	public static final <B> Type<B> typeByIdentity(String groupID, String typeID, Class<B> baseClass) throws ClassCastException {
+		TypeGroup<B> group = GroupRegistry.<B>groupByID(groupID, baseClass);
+		
+		if(group != null && group.isInGroup(typeID)) {
+			try {
+				return group.getType(typeID);
+			} catch (InvalidKeyException e) {
+				// Should never happen, since we just checked that the type is in the group
+				LOGGER.error("Unreachable in typeByIdentity: trying to get type '" + groupID + ":" + typeID + "'");
+				e.printStackTrace();
+			}
+		}
+
+		return null;
+	}
 }
diff --git a/src/main/java/net/cshift/api/transit/type/group/SimpleGroups.java b/src/main/java/net/cshift/api/transit/type/group/SimpleGroups.java
index 66d0121..3f7d8a1 100644
--- a/src/main/java/net/cshift/api/transit/type/group/SimpleGroups.java
+++ b/src/main/java/net/cshift/api/transit/type/group/SimpleGroups.java
@@ -31,19 +31,19 @@ import net.cshift.api.transit.type.*;
 public final class SimpleGroups {
 	/** Transfers energy.  Basic unit is TJoule (Transit Joule).
 	 */
-	public static final TypeGroup<Long> ENERGY = new TypeGroup<Long>(SimpleTypes.TransitJoule);
+	public static final TypeGroup<Long> ENERGY = new TypeGroup<Long>(SimpleTypes.TransitJoule, Long.class);
 
 	/** Transfers mana.  Basic unit is TMana (Transit Mana).
 	 */
-	public static final TypeGroup<TMana> MANA = new TypeGroup<TMana>(SimpleTypes.TransitMana);
+	public static final TypeGroup<TMana> MANA = new TypeGroup<TMana>(SimpleTypes.TransitMana, TMana.class);
 
 	/** Transfers items. Basic unit is TItem.
 	 */
-	public static final TypeGroup<TItem> ITEM = new TypeGroup<TItem>(SimpleTypes.TransitItem);
+	public static final TypeGroup<TItem> ITEM = new TypeGroup<TItem>(SimpleTypes.TransitItem, TItem.class);
 
 	/** Transfers fluids.  Basic unit is TFluid.
 	 */
-	public static final TypeGroup<TFluid> FLUID = new TypeGroup<TFluid>(SimpleTypes.TransitFluid);
+	public static final TypeGroup<TFluid> FLUID = new TypeGroup<TFluid>(SimpleTypes.TransitFluid, TFluid.class);
 	
 	private static final Logger LOGGER = LoggerFactory.getLogger("Transit API/Simple Groups");
 	
diff --git a/src/main/java/net/cshift/api/transit/type/group/TypeGroup.java b/src/main/java/net/cshift/api/transit/type/group/TypeGroup.java
index fcbb3ef..426f0a8 100644
--- a/src/main/java/net/cshift/api/transit/type/group/TypeGroup.java
+++ b/src/main/java/net/cshift/api/transit/type/group/TypeGroup.java
@@ -25,7 +25,6 @@
 package net.cshift.api.transit.type.group;
 
 import java.security.InvalidKeyException;
-import java.sql.Types;
 import java.util.HashMap;
 
 import org.slf4j.*;
@@ -38,6 +37,9 @@ import net.cshift.api.transit.type.Type;
  */
 public final class TypeGroup<B>
 {
+	// The basic class of the base type which is being transferred
+	private Class<B> baseClass;
+	
 	// The base Type (provides the group's identifier)
 	private Type<B> baseType;
 
@@ -48,10 +50,11 @@ public final class TypeGroup<B>
 	private static final Logger LOGGER = LoggerFactory.getLogger("Transit API/Type Group");
 
 
-	public TypeGroup(Type<B> base)
+	public TypeGroup(Type<B> base, Class<B> baseClass)
 	{
 		TYPES = new HashMap<String, Type<B>>();
 		baseType = base;
+		this.baseClass = baseClass;
 		addType(base);
 	}
 
@@ -207,11 +210,18 @@ public final class TypeGroup<B>
 	}
 
 	/** The base group type
-	 * 	@return Type
+	 * 	@return Type<B>
 	 */
 	public final Type<B> getBase() {
 		return baseType;
 	}
+	
+	/** A Class object which represents the type that the base type uses to transfer data
+	 * @return Class<B>
+	 */
+	public final Class<B> getBaseClass() {
+		return baseClass;
+	}
 
 	@Override
 	public final String toString() {
diff --git a/src/main/resources/fabric.mod.json b/src/main/resources/fabric.mod.json
index 6f2fbd5..94912c3 100644
--- a/src/main/resources/fabric.mod.json
+++ b/src/main/resources/fabric.mod.json
@@ -1,7 +1,7 @@
 {
   "schemaVersion": 1,
   "id": "transit-api",
-  "version": "3.0.0-alpha",
+  "version": "3.0.0-alpha-2",
 
   "name": "Transit API",
   "description": "Move things about!",