Provide an API for registering custom APIs

ILuaAPI has been moved to dan200.computercraft.api.lua. One creates
a new API by registering an instance of ILuaAPIFactory. This takes an
instance of IComputerSystem and returns such an API.

IComputerSystem is an extension of IComputerAccess, with methods to
access additional information about the the computer, such as its label
and filesystem.

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

@@ -9,6 +9,7 @@ package dan200.computercraft;
 import com.google.common.base.CaseFormat;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
+import dan200.computercraft.api.lua.ILuaAPIFactory;
 import dan200.computercraft.api.media.IMedia;
 import dan200.computercraft.api.media.IMediaProvider;
 import dan200.computercraft.api.network.IPacketNetwork;
@@ -81,10 +82,7 @@ import java.io.*;
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
-import java.util.ArrayList;
+import java.util.*;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
@@ -244,6 +242,7 @@ public class ComputerCraft
     private static List<IMediaProvider> mediaProviders = new ArrayList<>();
     private static List<ITurtlePermissionProvider> permissionProviders = new ArrayList<>();
     private static final Map<String, IPocketUpgrade> pocketUpgrades = new HashMap<>();
+    private static final Set<ILuaAPIFactory> apiFactories = new LinkedHashSet<>();
 
     // Implementation
     @Mod.Instance( value = ComputerCraft.MOD_ID )
@@ -644,6 +643,14 @@ public class ComputerCraft
         }
     }
 
+    public static void registerAPIFactory( ILuaAPIFactory provider )
+    {
+        if( provider != null )
+        {
+            apiFactories.add( provider );
+        }
+    }
+
     public static IPeripheral getPeripheralAt( World world, BlockPos pos, EnumFacing side )
     {
         // Try the handlers in order:
@@ -771,6 +778,11 @@ public class ComputerCraft
         return WirelessNetwork.getUniversal();
     }
 
+    public static Iterable<ILuaAPIFactory> getAPIFactories()
+    {
+        return apiFactories;
+    }
+
     public static int createUniqueNumberedSaveDir( World world, String parentSubPath )
     {
         return IDAssigner.getNextIDFromDirectory(new File(getWorldDir(world), parentSubPath));

src/main/java/dan200/computercraft/api/ComputerCraftAPI.java

@@ -8,6 +8,7 @@ package dan200.computercraft.api;
 
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
+import dan200.computercraft.api.lua.ILuaAPIFactory;
 import dan200.computercraft.api.media.IMedia;
 import dan200.computercraft.api.media.IMediaProvider;
 import dan200.computercraft.api.network.IPacketNetwork;
@@ -311,6 +312,22 @@ public final class ComputerCraftAPI
         return null;
     }
 
+    public static void registerAPIFactory( @Nonnull ILuaAPIFactory upgrade )
+    {
+        findCC();
+        if( computerCraft_registerAPIFactory != null )
+        {
+            try
+            {
+                computerCraft_registerAPIFactory.invoke( null, upgrade );
+            }
+            catch( Exception e )
+            {
+                // It failed
+            }
+        }
+    }
+
     // The functions below here are private, and are used to interface with the non-API ComputerCraft classes.
     // Reflection is used here so you can develop your mod without decompiling ComputerCraft and including
     // it in your solution, and so your mod won't crash if ComputerCraft is installed.
@@ -354,6 +371,9 @@ public final class ComputerCraftAPI
                 } );
                 computerCraft_getWirelessNetwork = findCCMethod( "getWirelessNetwork", new Class<?>[] {
                 } );
+                computerCraft_registerAPIFactory = findCCMethod( "registerAPIFactory", new Class<?>[] {
+                    ILuaAPIFactory.class
+                } );
             } catch( Exception e ) {
                 System.out.println( "ComputerCraftAPI: ComputerCraft not found." );
             } finally {
@@ -390,4 +410,5 @@ public final class ComputerCraftAPI
     private static Method computerCraft_registerPermissionProvider = null;
     private static Method computerCraft_registerPocketUpgrade = null;
     private static Method computerCraft_getWirelessNetwork = null;
+    private static Method computerCraft_registerAPIFactory = null;
 }

src/main/java/dan200/computercraft/api/filesystem/IFileSystem.java

@@ -0,0 +1,38 @@
+package dan200.computercraft.api.filesystem;
+
+import java.io.IOException;
+
+/**
+ * Provides a mount of the entire computer's file system.
+ *
+ * This exists for use by various APIs - one should not attempt to mount it.
+ */
+public interface IFileSystem extends IWritableMount
+{
+    /**
+     * Combine two paths together, reducing them into a normalised form.
+     *
+     * @param path  The main path.
+     * @param child The path to append.
+     * @return The combined, normalised path.
+     */
+    String combine( String path, String child );
+
+    /**
+     * Copy files from one location to another.
+     *
+     * @param from The location to copy from.
+     * @param to   The location to copy to. This should not exist.
+     * @throws IOException If the copy failed.
+     */
+    void copy( String from, String to ) throws IOException;
+
+    /**
+     * Move files from one location to another.
+     *
+     * @param from The location to move from.
+     * @param to   The location to move to. This should not exist.
+     * @throws IOException If the move failed.
+     */
+    void move( String from, String to ) throws IOException;
+}

src/main/java/dan200/computercraft/api/lua/IComputerSystem.java

@@ -0,0 +1,29 @@
+package dan200.computercraft.api.lua;
+
+import dan200.computercraft.api.filesystem.IFileSystem;
+import dan200.computercraft.api.peripheral.IComputerAccess;
+
+import javax.annotation.Nullable;
+
+/**
+ * An interface passed to {@link ILuaAPIFactory} in order to provide additional information
+ * about a computer.
+ */
+public interface IComputerSystem extends IComputerAccess
+{
+    /**
+     * Get the file system for this computer.
+     *
+     * @return The computer's file system, or {@code null} if it is not initialised.
+     */
+    @Nullable
+    IFileSystem getFileSystem();
+
+    /**
+     * Get the label for this computer
+     *
+     * @return This computer's label, or {@code null} if it is not set.
+     */
+    @Nullable
+    String getLabel();
+}

src/main/java/dan200/computercraft/api/lua/ILuaAPI.java

@@ -0,0 +1,47 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2016. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.api.lua;
+
+import dan200.computercraft.api.ComputerCraftAPI;
+
+/**
+ * Represents a {@link ILuaObject} which is stored as a global variable on computer startup.
+ *
+ * Before implementing this interface, consider alternative methods of providing methods. It is generally preferred
+ * to use peripherals to provide functionality to users.
+ *
+ * @see ILuaAPIFactory
+ * @see ComputerCraftAPI#registerAPIFactory(ILuaAPIFactory)
+ */
+public interface ILuaAPI extends ILuaObject
+{
+    /**
+     * Get the globals this API will be assigned to. This will override any other global, so you should
+     *
+     * @return A list of globals this API will be assigned to.
+     */
+    String[] getNames();
+
+    /**
+     * Called when the computer is turned on.
+     *
+     * One should only interact with the file system.
+     */
+    default void startup() { }
+
+    /**
+     * Called every time the computer is ticked. This can be used to process various.
+     */
+    default void update() { }
+
+    /**
+     * Called when the computer is turned off or unloaded.
+     *
+     * This should reset the state of the object, disposing any remaining file handles, or other resources.
+     */
+    default void shutdown() { }
+}

src/main/java/dan200/computercraft/api/lua/ILuaAPIFactory.java

@@ -0,0 +1,24 @@
+package dan200.computercraft.api.lua;
+
+import dan200.computercraft.api.ComputerCraftAPI;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+/**
+ * Construct an {@link ILuaAPI} for a specific computer.
+ *
+ * @see ILuaAPI
+ * @see ComputerCraftAPI#registerAPIFactory(ILuaAPIFactory)
+ */
+public interface ILuaAPIFactory
+{
+    /**
+     * Create a new API instance for a given computer.
+     *
+     * @param computer The computer this API is for.
+     * @return The created API, or {@code null} if one should not be injected.
+     */
+    @Nullable
+    ILuaAPI create( @Nonnull IComputerSystem computer );
+}

src/main/java/dan200/computercraft/core/apis/BitAPI.java

@@ -6,6 +6,7 @@
 
 package dan200.computercraft.core.apis;
 
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 
@@ -38,21 +39,6 @@ public class BitAPI implements ILuaAPI
         };
     }
     
-    @Override
-    public void startup( )
-    {
-    }
-
-    @Override
-    public void advance( double _dt )
-    {
-    }
-    
-    @Override
-    public void shutdown( )
-    {
-    }
-    
     @Nonnull
     @Override
     public String[] getMethodNames() {

src/main/java/dan200/computercraft/core/apis/BufferAPI.java

@@ -6,6 +6,7 @@
 
 package dan200.computercraft.core.apis;
 
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.ILuaObject;
 import dan200.computercraft.api.lua.LuaException;
@@ -100,21 +101,6 @@ public class BufferAPI implements ILuaAPI
         };
     }
 
-    @Override
-    public void startup()
-    {
-    }
-
-    @Override
-    public void advance( double _dt )
-    {
-    }
-
-    @Override
-    public void shutdown()
-    {
-    }
-
     @Nonnull
     @Override
     public String[] getMethodNames()

src/main/java/dan200/computercraft/core/apis/ComputerAccess.java

@@ -0,0 +1,155 @@
+package dan200.computercraft.core.apis;
+
+import dan200.computercraft.api.filesystem.IMount;
+import dan200.computercraft.api.filesystem.IWritableMount;
+import dan200.computercraft.api.peripheral.IComputerAccess;
+import dan200.computercraft.core.filesystem.FileSystem;
+import dan200.computercraft.core.filesystem.FileSystemException;
+
+import javax.annotation.Nonnull;
+import java.util.HashSet;
+import java.util.Set;
+
+public abstract class ComputerAccess implements IComputerAccess
+{
+    private final IAPIEnvironment m_environment;
+    private final Set<String> m_mounts = new HashSet<>();
+
+    protected ComputerAccess( IAPIEnvironment m_environment )
+    {
+        this.m_environment = m_environment;
+    }
+
+    public void unmountAll()
+    {
+        FileSystem fileSystem = m_environment.getFileSystem();
+        for( String m_mount : m_mounts )
+        {
+            fileSystem.unmount( m_mount );
+        }
+        m_mounts.clear();
+    }
+
+    @Override
+    public String mount( @Nonnull String desiredLoc, @Nonnull IMount mount )
+    {
+        return mount( desiredLoc, mount, getAttachmentName() );
+    }
+
+    @Override
+    public synchronized String mount( @Nonnull String desiredLoc, @Nonnull IMount mount, @Nonnull String driveName )
+    {
+        // Mount the location
+        String location;
+        FileSystem fileSystem = m_environment.getFileSystem();
+        if( fileSystem == null )
+        {
+            throw new IllegalStateException( "File system has not been created" );
+        }
+
+        synchronized( fileSystem )
+        {
+            location = findFreeLocation( desiredLoc );
+            if( location != null )
+            {
+                try
+                {
+                    fileSystem.mount( driveName, location, mount );
+                }
+                catch( FileSystemException ignored )
+                {
+                }
+            }
+        }
+        if( location != null )
+        {
+            m_mounts.add( location );
+        }
+        return location;
+    }
+
+    @Override
+    public String mountWritable( @Nonnull String desiredLoc, @Nonnull IWritableMount mount )
+    {
+        return mountWritable( desiredLoc, mount, getAttachmentName() );
+    }
+
+    @Override
+    public synchronized String mountWritable( @Nonnull String desiredLoc, @Nonnull IWritableMount mount, @Nonnull String driveName )
+    {
+        // Mount the location
+        String location;
+        FileSystem fileSystem = m_environment.getFileSystem();
+        if( fileSystem == null )
+        {
+            throw new IllegalStateException( "File system has not been created" );
+        }
+
+        synchronized( fileSystem )
+        {
+            location = findFreeLocation( desiredLoc );
+            if( location != null )
+            {
+                try
+                {
+                    fileSystem.mountWritable( driveName, location, mount );
+                }
+                catch( FileSystemException ignored )
+                {
+                }
+            }
+        }
+        if( location != null )
+        {
+            m_mounts.add( location );
+        }
+        return location;
+    }
+
+    @Override
+    public synchronized void unmount( String location )
+    {
+        if( location != null )
+        {
+            if( !m_mounts.contains( location ) )
+            {
+                throw new RuntimeException( "You didn't mount this location" );
+            }
+
+            m_environment.getFileSystem().unmount( location );
+            m_mounts.remove( location );
+        }
+    }
+
+    @Override
+    public synchronized int getID()
+    {
+        return m_environment.getComputerID();
+    }
+
+    @Override
+    public synchronized void queueEvent( @Nonnull final String event, final Object[] arguments )
+    {
+        m_environment.queueEvent( event, arguments );
+    }
+
+    private String findFreeLocation( String desiredLoc )
+    {
+        try
+        {
+            FileSystem fileSystem = m_environment.getFileSystem();
+            if( !fileSystem.exists( desiredLoc ) )
+            {
+                return desiredLoc;
+            }
+
+            // We used to check foo2,foo3,foo4,etc here
+            // but the disk drive does this itself now
+            return null;
+        }
+        catch( FileSystemException e )
+        {
+            return null;
+        }
+    }
+}

src/main/java/dan200/computercraft/core/apis/FSAPI.java

@@ -6,6 +6,7 @@
 
 package dan200.computercraft.core.apis;
 
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.core.apis.handles.BinaryInputHandle;
@@ -48,11 +49,6 @@ public class FSAPI implements ILuaAPI
         m_fileSystem = m_env.getFileSystem();
     }
 
-    @Override
-    public void advance( double _dt )
-    {
-    }
-    
     @Override
     public void shutdown( )
     {

src/main/java/dan200/computercraft/core/apis/HTTPAPI.java

@@ -6,6 +6,7 @@
 
 package dan200.computercraft.core.apis;
 
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.core.apis.http.HTTPCheck;
@@ -38,12 +39,7 @@ public class HTTPAPI implements ILuaAPI
     }
 
     @Override
-    public void startup( )
+    public void update()
-    {
-    }
-
-    @Override
-    public void advance( double _dt )
     {
         // Wait for all of our http requests 
         synchronized( m_httpTasks )

src/main/java/dan200/computercraft/core/apis/ILuaAPI.java

@@ -1,17 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2017. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-
-package dan200.computercraft.core.apis;
-import dan200.computercraft.api.lua.ILuaObject;
-
-public interface ILuaAPI extends ILuaObject
-{
-    String[] getNames();
-
-    void startup(); // LT
-    void advance( double _dt ); // MT
-    void shutdown(); // LT
-}

src/main/java/dan200/computercraft/core/apis/OSAPI.java

@@ -6,6 +6,7 @@
 
 package dan200.computercraft.core.apis;
 
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.shared.util.StringUtil;
@@ -102,7 +103,7 @@ public class OSAPI implements ILuaAPI
     }
     
     @Override
-    public void advance( double dt )
+    public void update()
     {
         synchronized( m_timers )
         {

src/main/java/dan200/computercraft/core/apis/PeripheralAPI.java

@@ -8,24 +8,25 @@ package dan200.computercraft.core.apis;
 
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
-import dan200.computercraft.api.peripheral.IComputerAccess;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.core.computer.Computer;
 import dan200.computercraft.core.computer.ComputerThread;
 import dan200.computercraft.core.computer.ITask;
 import dan200.computercraft.core.filesystem.FileSystem;
-import dan200.computercraft.core.filesystem.FileSystemException;
 
 import javax.annotation.Nonnull;
-import java.util.*;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
 
 import static dan200.computercraft.core.apis.ArgumentHelper.getString;
 
 public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChangeListener
 {
-    private class PeripheralWrapper implements IComputerAccess
+    private class PeripheralWrapper extends ComputerAccess
     {
         private final String m_side;
         private final IPeripheral m_peripheral;
@@ -35,10 +36,9 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         private Map<String, Integer> m_methodMap;
         private boolean m_attached;
         
-        private Set<String> m_mounts;
-        
         public PeripheralWrapper( IPeripheral peripheral, String side )
         {
+            super(m_environment);
             m_side = side;
             m_peripheral = peripheral;
             m_attached = false;
@@ -54,8 +54,6 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
                     m_methodMap.put( m_methods[i], i );
                 }
             }
-            
-            m_mounts = new HashSet<>();
         }
         
         public IPeripheral getPeripheral()
@@ -91,11 +89,7 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
             m_attached = false;
 
             // Unmount everything the detach function forgot to do
-            for( String m_mount : m_mounts )
+            unmountAll();
-            {
-                m_fileSystem.unmount( m_mount );
-            }
-            m_mounts.clear();
         }
         
         public Object[] call( ILuaContext context, String methodName, Object[] arguments ) throws LuaException, InterruptedException
@@ -119,13 +113,6 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         }
 
         // IComputerAccess implementation
-
-        @Override
-        public String mount( @Nonnull String desiredLoc, @Nonnull IMount mount )
-        {
-            return mount( desiredLoc, mount, m_side );
-        }
-
         @Override
         public synchronized String mount( @Nonnull String desiredLoc, @Nonnull IMount mount, @Nonnull String driveName )
         {
@@ -134,31 +121,7 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
                 throw new RuntimeException( "You are not attached to this Computer" );
             }
 
-            // Mount the location
+            return super.mount( desiredLoc, mount, driveName );
-            String location;
-            synchronized( m_fileSystem )
-            {
-                location = findFreeLocation( desiredLoc );
-                if( location != null )
-                {
-                    try {
-                        m_fileSystem.mount( driveName, location, mount );
-                    } catch( FileSystemException e ) {
-                        // fail and return null
-                    }
-                }
-            }
-            if( location != null )
-            {
-                m_mounts.add( location );
-            }            
-            return location;
-        }
-
-        @Override
-        public String mountWritable( @Nonnull String desiredLoc, @Nonnull IWritableMount mount )
-        {
-            return mountWritable( desiredLoc, mount, m_side );
         }
 
         @Override
@@ -169,68 +132,46 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
                 throw new RuntimeException( "You are not attached to this Computer" );
             }
 
-            // Mount the location
+            return super.mountWritable( desiredLoc, mount, driveName );
-            String location;
-            synchronized( m_fileSystem )
-            {
-                location = findFreeLocation( desiredLoc );
-                if( location != null )
-                {
-                    try {
-                        m_fileSystem.mountWritable( driveName, location, mount );
-                    } catch( FileSystemException e ) {
-                        // fail and return null
-                    }
-                }
-            }
-            if( location != null )
-            {
-                m_mounts.add( location );
-            }            
-            return location;
         }
 
         @Override
         public synchronized void unmount( String location )
         {
-            if( !m_attached ) {
+            if( !m_attached )
+            {
                 throw new RuntimeException( "You are not attached to this Computer" );
             }
 
-            if( location != null )
+            super.unmount( location );
-            {
-                if( !m_mounts.contains( location ) ) {
-                    throw new RuntimeException( "You didn't mount this location" );
-                }
-            
-                m_fileSystem.unmount( location );
-                m_mounts.remove( location );
-            }
         }
 
         @Override
         public synchronized int getID()
         {
-            if( !m_attached ) {
+            if( !m_attached )
+            {
                 throw new RuntimeException( "You are not attached to this Computer" );
             }
-            return m_environment.getComputerID();
+            return super.getID();
         }
 
         @Override
         public synchronized void queueEvent( @Nonnull final String event, final Object[] arguments )
         {
-            if( !m_attached ) {
+            if( !m_attached )
+            {
                 throw new RuntimeException( "You are not attached to this Computer" );
             }
-            m_environment.queueEvent( event, arguments );
+            super.queueEvent( event, arguments );
         }
 
         @Nonnull
         @Override
         public synchronized String getAttachmentName()
         {
-            if( !m_attached ) {
+            if( !m_attached )
+            {
                 throw new RuntimeException( "You are not attached to this Computer" );
             }
             return m_side;
@@ -353,11 +294,6 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         }
     }
     
-    @Override
-    public void advance( double _dt )
-    {
-    }
-    
     @Override
     public void shutdown( )
     {
@@ -506,25 +442,4 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         }
         return -1;
     }
-    
-    private String findFreeLocation( String desiredLoc )
-    {
-        try
-        {
-            synchronized( m_fileSystem )
-            {
-                if( !m_fileSystem.exists( desiredLoc ) )
-                {
-                    return desiredLoc;
-                }
-                // We used to check foo2,foo3,foo4,etc here
-                // but the disk drive does this itself now
-                return null;
-            }
-        }
-        catch( FileSystemException e )
-        {
-            return null;
-        }
-    }
 }

src/main/java/dan200/computercraft/core/apis/RedstoneAPI.java

@@ -6,6 +6,7 @@
 
 package dan200.computercraft.core.apis;
 
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.core.computer.Computer;
@@ -33,21 +34,6 @@ public class RedstoneAPI implements ILuaAPI
         };
     }
 
-    @Override
-    public void startup( )
-    {
-    }
-
-    @Override
-    public void advance( double _dt )
-    {
-    }
-    
-    @Override
-    public void shutdown( )
-    {
-    }
-
     @Nonnull
     @Override
     public String[] getMethodNames()

src/main/java/dan200/computercraft/core/apis/TermAPI.java

@@ -6,6 +6,7 @@
 
 package dan200.computercraft.core.apis;
 
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.core.computer.IComputerEnvironment;
@@ -36,21 +37,6 @@ public class TermAPI implements ILuaAPI
         };
     }
 
-    @Override
-    public void startup( )
-    {
-    }
-
-    @Override
-    public void advance( double _dt )
-    {
-    }
-    
-    @Override
-    public void shutdown( )
-    {
-    }
-
     @Nonnull
     @Override
     public String[] getMethodNames()

src/main/java/dan200/computercraft/core/computer/Computer.java

@@ -8,8 +8,10 @@ package dan200.computercraft.core.computer;
 
 import com.google.common.base.Objects;
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.api.filesystem.IFileSystem;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
+import dan200.computercraft.api.lua.*;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.core.apis.*;
 import dan200.computercraft.core.filesystem.FileSystem;
@@ -18,6 +20,8 @@ import dan200.computercraft.core.lua.ILuaMachine;
 import dan200.computercraft.core.lua.LuaJLuaMachine;
 import dan200.computercraft.core.terminal.Terminal;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
@@ -174,6 +178,90 @@ public class Computer
         }
     }
 
+    private static class ComputerSystem extends ComputerAccess implements IComputerSystem
+    {
+        private final IAPIEnvironment m_environment;
+
+        private ComputerSystem( IAPIEnvironment m_environment )
+        {
+            super( m_environment );
+            this.m_environment = m_environment;
+        }
+
+        @Nonnull
+        @Override
+        public String getAttachmentName()
+        {
+            return "computer";
+        }
+
+        @Nullable
+        @Override
+        public IFileSystem getFileSystem()
+        {
+            FileSystem fs = m_environment.getFileSystem();
+            return fs == null ? null : fs.getMountWrapper();
+        }
+
+        @Nullable
+        @Override
+        public String getLabel()
+        {
+            return m_environment.getLabel();
+        }
+    }
+
+    private static class APIWrapper implements ILuaAPI
+    {
+        private final ILuaAPI delegate;
+        private final ComputerSystem system;
+
+        private APIWrapper( ILuaAPI delegate, ComputerSystem system )
+        {
+            this.delegate = delegate;
+            this.system = system;
+        }
+
+        @Override
+        public String[] getNames()
+        {
+            return delegate.getNames();
+        }
+
+        @Override
+        public void startup()
+        {
+            delegate.startup();
+        }
+
+        @Override
+        public void update()
+        {
+            delegate.update();
+        }
+
+        @Override
+        public void shutdown()
+        {
+            delegate.shutdown();
+            system.unmountAll();
+        }
+
+        @Nonnull
+        @Override
+        public String[] getMethodNames()
+        {
+            return delegate.getMethodNames();
+        }
+
+        @Nullable
+        @Override
+        public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] arguments ) throws LuaException, InterruptedException
+        {
+            return delegate.callMethod( context, method, arguments );
+        }
+    }
+
     private static IMount s_romMount = null;
 
     private int m_id;
@@ -371,7 +459,7 @@ public class Computer
                 {
                     for(ILuaAPI api : m_apis)
                     {
-                        api.advance( _dt );
+                        api.update();
                     }
                 }
             }
@@ -617,6 +705,16 @@ public class Computer
         {
             m_apis.add( new HTTPAPI( m_apiEnvironment ) );
         }
+
+        for( ILuaAPIFactory factory : ComputerCraft.getAPIFactories() )
+        {
+            ComputerSystem system = new ComputerSystem( m_apiEnvironment );
+            ILuaAPI api = factory.create( system );
+            if( api != null )
+            {
+                m_apis.add( api );
+            }
+        }
     }
     
     private void initLua()
@@ -789,7 +887,7 @@ public class Computer
                     // Shutdown our APIs
                     synchronized( m_apis )
                     {
-                        for(ILuaAPI api : m_apis)
+                        for( ILuaAPI api : m_apis )
                         {
                             api.shutdown();
                         }

src/main/java/dan200/computercraft/core/filesystem/FileSystem.java

@@ -7,6 +7,7 @@
 package dan200.computercraft.core.filesystem;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.api.filesystem.IFileSystem;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
 
@@ -290,6 +291,7 @@ public class FileSystem
         }
     }
 
+    private final FileSystemMount m_wrapper = new FileSystemMount( this );
     private final Map<String, MountWrapper> m_mounts = new HashMap<>();
     private final Set<Closeable> m_openFiles = Collections.newSetFromMap( new WeakHashMap<Closeable, Boolean>() );
     
@@ -734,6 +736,11 @@ public class FileSystem
         return match;
     }
 
+    public IFileSystem getMountWrapper()
+    {
+        return m_wrapper;
+    }
+
     private static String sanitizePath( String path )
     {
         return sanitizePath( path, false );

src/main/java/dan200/computercraft/core/filesystem/FileSystemMount.java

@@ -0,0 +1,185 @@
+package dan200.computercraft.core.filesystem;
+
+import dan200.computercraft.api.filesystem.IFileSystem;
+
+import javax.annotation.Nonnull;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Collections;
+import java.util.List;
+
+public class FileSystemMount implements IFileSystem
+{
+    private final FileSystem m_filesystem;
+
+    public FileSystemMount( FileSystem m_filesystem )
+    {
+        this.m_filesystem = m_filesystem;
+    }
+
+    @Override
+    public void makeDirectory( @Nonnull String path ) throws IOException
+    {
+        try
+        {
+            m_filesystem.makeDir( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Override
+    public void delete( @Nonnull String path ) throws IOException
+    {
+        try
+        {
+            m_filesystem.delete( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Nonnull
+    @Override
+    public OutputStream openForWrite( @Nonnull String path ) throws IOException
+    {
+        try
+        {
+            return m_filesystem.openForWrite( path, false );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Nonnull
+    @Override
+    public OutputStream openForAppend( @Nonnull String path ) throws IOException
+    {
+        try
+        {
+            return m_filesystem.openForWrite( path, true );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Override
+    public long getRemainingSpace() throws IOException
+    {
+        try
+        {
+            return m_filesystem.getFreeSpace( "/" );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Override
+    public boolean exists( @Nonnull String path ) throws IOException
+    {
+        try
+        {
+            return m_filesystem.exists( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Override
+    public boolean isDirectory( @Nonnull String path ) throws IOException
+    {
+        try
+        {
+            return m_filesystem.exists( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Override
+    public void list( @Nonnull String path, @Nonnull List<String> contents ) throws IOException
+    {
+        try
+        {
+            Collections.addAll( contents, m_filesystem.list( path ) );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Override
+    public long getSize( @Nonnull String path ) throws IOException
+    {
+        try
+        {
+            return m_filesystem.getSize( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Nonnull
+    @Override
+    public InputStream openForRead( @Nonnull String path ) throws IOException
+    {
+        try
+        {
+            return m_filesystem.openForRead( path );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Override
+    public String combine( String path, String child )
+    {
+        return m_filesystem.combine( path, child );
+    }
+
+    @Override
+    public void copy( String from, String to ) throws IOException
+    {
+        try
+        {
+            m_filesystem.copy( from, to );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+
+    @Override
+    public void move( String from, String to ) throws IOException
+    {
+        try
+        {
+            m_filesystem.move( from, to );
+        }
+        catch( FileSystemException e )
+        {
+            throw new IOException( e.getMessage() );
+        }
+    }
+}

src/main/java/dan200/computercraft/core/lua/ILuaMachine.java

@@ -5,7 +5,7 @@
  */
 
 package dan200.computercraft.core.lua;
-import dan200.computercraft.core.apis.ILuaAPI;
+import dan200.computercraft.api.lua.ILuaAPI;
 
 import java.io.InputStream;
 import java.io.OutputStream;

src/main/java/dan200/computercraft/core/lua/LuaJLuaMachine.java

@@ -11,7 +11,7 @@ import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.ILuaObject;
 import dan200.computercraft.api.lua.ILuaTask;
 import dan200.computercraft.api.lua.LuaException;
-import dan200.computercraft.core.apis.ILuaAPI;
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.core.computer.Computer;
 import dan200.computercraft.core.computer.ITask;
 import dan200.computercraft.core.computer.MainThread;

src/main/java/dan200/computercraft/shared/computer/apis/CommandAPI.java

@@ -8,9 +8,9 @@ package dan200.computercraft.shared.computer.apis;
 
 import com.google.common.collect.ImmutableMap;
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
-import dan200.computercraft.core.apis.ILuaAPI;
 import dan200.computercraft.shared.computer.blocks.TileCommandComputer;
 import dan200.computercraft.shared.util.WorldUtil;
 import net.minecraft.block.Block;
@@ -49,21 +49,6 @@ public class CommandAPI implements ILuaAPI
         };
     }
 
-    @Override
-    public void startup()
-    {
-    }
-
-    @Override
-    public void advance( double dt )
-    {
-    }
-
-    @Override
-    public void shutdown()
-    {
-    }
-
     @Nonnull
     @Override
     public String[] getMethodNames()

src/main/java/dan200/computercraft/shared/computer/core/ServerComputer.java

@@ -12,7 +12,7 @@ import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.core.apis.IAPIEnvironment;
-import dan200.computercraft.core.apis.ILuaAPI;
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.core.computer.Computer;
 import dan200.computercraft.core.computer.IComputerEnvironment;
 import dan200.computercraft.shared.common.ServerTerminal;

src/main/java/dan200/computercraft/shared/pocket/apis/PocketAPI.java

@@ -7,10 +7,10 @@
 package dan200.computercraft.shared.pocket.apis;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.api.pocket.IPocketUpgrade;
-import dan200.computercraft.core.apis.ILuaAPI;
 import dan200.computercraft.shared.pocket.core.PocketServerComputer;
 import dan200.computercraft.shared.util.InventoryUtil;
 import dan200.computercraft.shared.util.WorldUtil;
@@ -39,21 +39,6 @@ public class PocketAPI implements ILuaAPI
         };
     }
 
-    @Override
-    public void startup()
-    {
-    }
-
-    @Override
-    public void advance( double dt )
-    {
-    }
-
-    @Override
-    public void shutdown()
-    {
-    }
-
     @Nonnull
     @Override
     public String[] getMethodNames()

src/main/java/dan200/computercraft/shared/turtle/apis/TurtleAPI.java

@@ -6,13 +6,13 @@
 
 package dan200.computercraft.shared.turtle.apis;
 
+import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleCommand;
 import dan200.computercraft.api.turtle.TurtleSide;
 import dan200.computercraft.core.apis.IAPIEnvironment;
-import dan200.computercraft.core.apis.ILuaAPI;
 import dan200.computercraft.shared.turtle.core.*;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
@@ -45,21 +45,6 @@ public class TurtleAPI implements ILuaAPI
         };
     }
        
-    @Override
-    public void startup( )
-    {
-    }
-
-    @Override
-    public void advance( double _dt )
-    {
-    }
-    
-    @Override
-    public void shutdown( )
-    {
-    }
-       
     @Nonnull
     @Override
     public String[] getMethodNames()