Add the default implementation of wired networks

build.gradle

@@ -59,6 +59,8 @@ dependencies {
     deobfProvided "mezz.jei:jei_1.12:4.7.5.86:api"
     runtime "mezz.jei:jei_1.12:4.7.5.86"
     shade 'org.squiddev:Cobalt:0.3.1'
+
+    testCompile 'junit:junit:4.11'
 }
 
 javadoc {

src/main/java/dan200/computercraft/ComputerCraft.java

@@ -14,6 +14,9 @@
 import dan200.computercraft.api.media.IMedia;
 import dan200.computercraft.api.media.IMediaProvider;
 import dan200.computercraft.api.network.IPacketNetwork;
+import dan200.computercraft.api.network.wired.IWiredElement;
+import dan200.computercraft.api.network.wired.IWiredNode;
+import dan200.computercraft.api.network.wired.IWiredProvider;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.api.peripheral.IPeripheralProvider;
 import dan200.computercraft.api.permissions.ITurtlePermissionProvider;
@@ -57,6 +60,7 @@
 import dan200.computercraft.shared.turtle.blocks.TileTurtle;
 import dan200.computercraft.shared.turtle.upgrades.*;
 import dan200.computercraft.shared.util.*;
+import dan200.computercraft.shared.wired.WiredNode;
 import io.netty.buffer.Unpooled;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.player.EntityPlayer;
@@ -69,6 +73,7 @@
 import net.minecraft.util.NonNullList;
 import net.minecraft.util.SoundEvent;
 import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.IBlockAccess;
 import net.minecraft.world.World;
 import net.minecraftforge.common.config.ConfigCategory;
 import net.minecraftforge.common.config.Configuration;
@@ -259,6 +264,7 @@ public static class Config {
     private static List<ITurtlePermissionProvider> permissionProviders = new ArrayList<>();
     private static final Map<String, IPocketUpgrade> pocketUpgrades = new HashMap<>();
     private static final Set<ILuaAPIFactory> apiFactories = new LinkedHashSet<>();
+    private static final Set<IWiredProvider> wiredProviders = new LinkedHashSet<>();
 
     // Implementation
     @Mod.Instance( value = ComputerCraft.MOD_ID )
@@ -730,6 +736,16 @@ public static void registerAPIFactory( ILuaAPIFactory provider )
         }
     }
 
+    public static void registerWiredProvider( IWiredProvider provider )
+    {
+        if( provider != null ) wiredProviders.add( provider );
+    }
+
+    public static IWiredNode createWiredNodeForElement( IWiredElement element )
+    {
+        return new WiredNode( element );
+    }
+
     public static IPeripheral getPeripheralAt( World world, BlockPos pos, EnumFacing side )
     {
         // Try the handlers in order:
@@ -751,6 +767,24 @@ public static IPeripheral getPeripheralAt( World world, BlockPos pos, EnumFacing
         return null;
     }
 
+    public static IWiredElement getWiredElementAt( IBlockAccess world, BlockPos pos, EnumFacing side )
+    {
+        // Try the handlers in order:
+        for( IWiredProvider provider : wiredProviders )
+        {
+            try
+            {
+                IWiredElement element = provider.getElement( world, pos, side );
+                if( element != null ) return element;
+            }
+            catch( Exception e )
+            {
+                ComputerCraft.log.error( "Wired element provider " + provider + " errored.", e );
+            }
+        }
+        return null;
+    }
+
     public static int getDefaultBundledRedstoneOutput( World world, BlockPos pos, EnumFacing side )
     {
         if( WorldUtil.isBlockInWorld( world, pos ) )

src/main/java/dan200/computercraft/shared/proxy/ComputerCraftProxyCommon.java

@@ -52,6 +52,7 @@
 import dan200.computercraft.shared.turtle.blocks.TileTurtle;
 import dan200.computercraft.shared.turtle.inventory.ContainerTurtle;
 import dan200.computercraft.shared.util.*;
+import dan200.computercraft.shared.wired.DefaultWiredProvider;
 import net.minecraft.block.Block;
 import net.minecraft.creativetab.CreativeTabs;
 import net.minecraft.entity.player.EntityPlayer;
@@ -291,7 +292,7 @@ public void registerItems( RegistryEvent.Register<Item> event )
         // Command Computer
         registry.register( new ItemCommandComputer( ComputerCraft.Blocks.commandComputer ).setRegistryName( new ResourceLocation( ComputerCraft.MOD_ID, "command_computer" ) ) );
 
-        // Command Computer
+        // Advanced modem
         registry.register( new ItemAdvancedModem( ComputerCraft.Blocks.advancedModem ).setRegistryName( new ResourceLocation( ComputerCraft.MOD_ID, "advanced_modem" ) ) );
 
         // Items
@@ -482,6 +483,9 @@ private void registerTileEntities()
 
         // Register media providers
         ComputerCraftAPI.registerMediaProvider( new DefaultMediaProvider() );
+
+        // Register network providers
+        ComputerCraftAPI.registerWiredProvider( new DefaultWiredProvider() );
     }
 
     private void registerForgeHandlers()

src/main/java/dan200/computercraft/shared/wired/DefaultWiredProvider.java

@@ -0,0 +1,23 @@
+package dan200.computercraft.shared.wired;
+
+import dan200.computercraft.api.network.wired.IWiredElement;
+import dan200.computercraft.api.network.wired.IWiredElementTile;
+import dan200.computercraft.api.network.wired.IWiredProvider;
+import net.minecraft.tileentity.TileEntity;
+import net.minecraft.util.EnumFacing;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.IBlockAccess;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+public class DefaultWiredProvider implements IWiredProvider
+{
+    @Nullable
+    @Override
+    public IWiredElement getElement( @Nonnull IBlockAccess world, @Nonnull BlockPos pos, @Nonnull EnumFacing side )
+    {
+        TileEntity te = world.getTileEntity( pos );
+        return te instanceof IWiredElementTile ? ((IWiredElementTile) te).getWiredElement( side ) : null;
+    }
+}

src/main/java/dan200/computercraft/shared/wired/InvariantChecker.java

@@ -0,0 +1,46 @@
+package dan200.computercraft.shared.wired;
+
+import dan200.computercraft.ComputerCraft;
+
+/**
+ * Verifies certain elements of a network are "well formed".
+ *
+ * This adds substantial overhead to network modification, and so should only be enabled
+ * in a development environment.
+ */
+public class InvariantChecker
+{
+    private static final boolean ENABLED = false;
+
+    public static void checkNode( WiredNode node )
+    {
+        if( !ENABLED ) return;
+
+        WiredNetwork network = node.network;
+        if( network == null )
+        {
+            ComputerCraft.log.error( "Node's network is null", new Exception() );
+            return;
+        }
+
+        if( network.nodes == null || !network.nodes.contains( node ) )
+        {
+            ComputerCraft.log.error( "Node's network does not contain node", new Exception() );
+        }
+
+        for( WiredNode neighbour : node.neighbours )
+        {
+            if( !neighbour.neighbours.contains( node ) )
+            {
+                ComputerCraft.log.error( "Neighbour is missing node", new Exception() );
+            }
+        }
+    }
+
+    public static void checkNetwork( WiredNetwork network )
+    {
+        if( !ENABLED ) return;
+
+        for( WiredNode node : network.nodes ) checkNode( node );
+    }
+}