feat(java): initial (broken) VFS implementation

README.md

@@ -1,4 +1,4 @@
-[![codemp](https://codemp.dev/static/banner.png)](https://codemp.dev)
+[![codemp](https://code.mp/static/banner.png)](https://code.mp)
 
 > `codemp` is a **collaborative** text editing solution to work remotely.
 
@@ -9,9 +9,11 @@ as well as a remote virtual workspace for you and your team.
 > [!WARNING]
 > `codmep-intellij` is still under active development. It is not in a usable state yet, coming soon!
 
-This is the reference `codemp` [IntelliJ Platform](https://www.jetbrains.com/opensource/idea/) plugin, maintained by [hexedtech](https://hexed.technology).
+This is the reference `codemp` [IntelliJ Platform](https://www.jetbrains.com/opensource/idea/) plugin,
+maintained by [hexedtech](https://hexed.technology).
 
 ## Testing
 As this is not meant to be used yet, we do not provide build instructions.
 
-You may however test it using Gradle with the `runIde` task. It will open in a new window an IntelliJ IDE with the plugin installed.
+You may however test it using Gradle with the `runIde` task. It will open in a new window an IntelliJ IDE
+with the plugin installed.

build.gradle

@@ -33,7 +33,7 @@ intellij {
 shadowJar {
 	archiveClassifier.set('')
 	dependencies {
-		include(dependency(files('../../lib/java/build/libs/codemp-6645c46.jar')))
+		include(dependency(files('../../lib/java/build/libs/codemp-0.6.2.jar')))
 	}
 }
 

src/main/java/mp/code/intellij/CodeMP.java

@@ -1,9 +1,9 @@
 package mp.code.intellij;
 
+import mp.code.exceptions.ConnectionException;
 import mp.code.intellij.exceptions.ide.NotConnectedException;
 import mp.code.intellij.workspace.IJWorkspace;
 import mp.code.Client;
-import mp.code.exceptions.CodeMPException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -15,7 +15,7 @@ public class CodeMP {
 	public static final Map<String, IJWorkspace> ACTIVE_WORKSPACES =  new ConcurrentHashMap<>();
 	private static Client CLIENT = null;
 
-	public static void connect(String url, String username, String password) throws CodeMPException {
+	public static void connect(String url, String username, String password) throws ConnectionException {
 		CLIENT = Client.connect(url, username, password);
 	}
 

src/main/java/mp/code/intellij/actions/ConnectAction.java

@@ -1,19 +1,18 @@
 package mp.code.intellij.actions;
 
 import com.intellij.credentialStore.Credentials;
+import mp.code.exceptions.ConnectionException;
 import mp.code.intellij.CodeMP;
 import mp.code.intellij.settings.CodeMPSettings;
 import mp.code.intellij.util.ActionUtil;
 import com.intellij.openapi.actionSystem.AnAction;
 import com.intellij.openapi.actionSystem.AnActionEvent;
-import mp.code.exceptions.CodeMPException;
-import org.apache.commons.lang3.StringUtils;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Objects;
 
 public class ConnectAction extends AnAction {
-	public static void connect(AnActionEvent e, boolean silent) throws NullPointerException, CodeMPException {
+	public static void connect(AnActionEvent e, boolean silent) throws NullPointerException, ConnectionException {
 		CodeMPSettings.State state = Objects.requireNonNull(CodeMPSettings.getInstance().getState());
 		Credentials creds = Objects.requireNonNull(state.getCredentials());
 		CodeMP.connect(

src/main/java/mp/code/intellij/actions/workspace/WorkspaceJoinAction.java

@@ -1,20 +1,36 @@
 package mp.code.intellij.actions.workspace;
 
+import com.intellij.openapi.module.Module;
+import com.intellij.openapi.module.ModuleManager;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.roots.ModuleRootModificationUtil;
+import com.intellij.openapi.vfs.VirtualFileManager;
+import mp.code.exceptions.ConnectionException;
 import mp.code.intellij.CodeMP;
 import mp.code.intellij.util.ActionUtil;
-import mp.code.intellij.workspace.IJWorkspace;
+import mp.code.intellij.vfs.CodeMPPath;
+import mp.code.intellij.vfs.CodeMPFileSystem;
+import mp.code.intellij.vfs.CodeMPFolder;
 import com.intellij.openapi.actionSystem.AnAction;
 import com.intellij.openapi.actionSystem.AnActionEvent;
 import com.intellij.openapi.ui.Messages;
-import mp.code.exceptions.CodeMPException;
+import org.apache.logging.log4j.util.Strings;
 import org.jetbrains.annotations.NotNull;
 
+import java.io.IOException;
+
 public class WorkspaceJoinAction extends AnAction {
-	public static void join(AnActionEvent e, String workspaceId, boolean silent) throws CodeMPException {
+	public static void join(AnActionEvent e, String workspaceId, boolean silent) throws ConnectionException, IOException {
-		CodeMP.ACTIVE_WORKSPACES.put(workspaceId, new IJWorkspace(
+		CodeMP.getClient("join workspace").joinWorkspace(workspaceId);
-			workspaceId, CodeMP.getClient("join workspace"),
+		CodeMPFileSystem fs = (CodeMPFileSystem) VirtualFileManager.getInstance().getFileSystem(CodeMPFileSystem.PROTOCOL);
-			false, e.getProject() //TODO: implement remote projects
+		CodeMPFolder root = new CodeMPFolder(fs, new CodeMPPath(workspaceId, Strings.EMPTY));
-		));
+
+		Project proj = e.getProject();
+
+		assert proj != null;
+		Module someModule = ModuleManager.getInstance(proj).getModules()[0];
+
+		ModuleRootModificationUtil.addContentRoot(someModule, root);
 
 		if(!silent) ActionUtil.notify(e,
 			"Success", String.format("Joined workspace %s!", workspaceId));

src/main/java/mp/code/intellij/listeners/BufferEventListener.java

@@ -7,10 +7,8 @@ import com.intellij.openapi.editor.event.DocumentEvent;
 import com.intellij.openapi.editor.event.DocumentListener;
 import mp.code.BufferController;
 import mp.code.data.TextChange;
-import mp.code.exceptions.CodeMPException;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.Optional;
 import java.util.OptionalLong;
 
 public class BufferEventListener implements DocumentListener {

src/main/java/mp/code/intellij/listeners/WorkspaceFileOpenedListener.java

@@ -1,5 +1,6 @@
 package mp.code.intellij.listeners;
 
+import mp.code.exceptions.ConnectionException;
 import mp.code.intellij.task.BufferEventAwaiterTask;
 import mp.code.intellij.util.FileUtil;
 import com.intellij.openapi.Disposable;
@@ -11,7 +12,6 @@ import com.intellij.openapi.util.Disposer;
 import com.intellij.openapi.vfs.VirtualFile;
 import mp.code.BufferController;
 import mp.code.Workspace;
-import mp.code.exceptions.CodeMPException;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.List;
@@ -56,10 +56,11 @@ public class WorkspaceFileOpenedListener implements FileOpenedSyncListener {
 	private BufferController getBufferForPath(String path) {
 		try {
 			return this.handler.attachToBuffer(path);
-		} catch (CodeMPException ignored) {
+		} catch (ConnectionException ignored) {
 			try {
-				return this.handler.createBuffer(path);
+				this.handler.createBuffer(path);
-			} catch(CodeMPException e) {
+				return this.handler.attachToBuffer(path);
+			} catch(ConnectionException e) {
 				throw new RuntimeException(e);
 			}
 		}

src/main/java/mp/code/intellij/settings/CodeMPSettings.java

@@ -9,6 +9,7 @@ import com.intellij.openapi.components.PersistentStateComponent;
 import com.intellij.openapi.components.State;
 import com.intellij.openapi.components.Storage;
 import lombok.Getter;
+import lombok.Setter;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -33,16 +34,26 @@ public class CodeMPSettings implements PersistentStateComponent<CodeMPSettings.S
 		this.currentState = state;
 	}
 
-	private static final String KEY = "cred";
+	@Getter
-	static CredentialAttributes createCredentialAttributes() {
+	@Setter
-		return new CredentialAttributes(CredentialAttributesKt.generateServiceName("CodeMP", KEY));
+	public static class State {
+		String serverUrl;
+
+		private static CredentialAttributes createCredentialAttributes() {
+			return new CredentialAttributes(CredentialAttributesKt.generateServiceName(
+				"CodeMP",
+				"login"
+			));
 		}
 
-	public static class State {
-		@Getter String serverUrl;
 		public @Nullable Credentials getCredentials() {
 			CredentialAttributes attr = createCredentialAttributes();
 			return PasswordSafe.getInstance().get(attr);
 		}
+
+		public void setCredentials(Credentials creds) {
+			CredentialAttributes attributes = createCredentialAttributes();
+			PasswordSafe.getInstance().set(attributes, creds);
+		}
 	}
 }

src/main/java/mp/code/intellij/settings/CodeMPSettingsConfigurable.java

@@ -1,14 +1,13 @@
 package mp.code.intellij.settings;
 
-import com.intellij.credentialStore.CredentialAttributes;
 import com.intellij.credentialStore.Credentials;
 import com.intellij.credentialStore.OneTimeString;
-import com.intellij.ide.passwordSafe.PasswordSafe;
 import com.intellij.openapi.options.Configurable;
 import com.intellij.ui.components.JBLabel;
 import com.intellij.ui.components.JBPasswordField;
 import com.intellij.ui.components.JBTextField;
 import com.intellij.util.ui.FormBuilder;
+import com.intellij.util.ui.JBFont;
 import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.Nullable;
 
@@ -53,8 +52,7 @@ final class CodeMPSettingsConfigurable implements Configurable {
 	public void apply() {
 		CodeMPSettings.State state = Objects.requireNonNull(CodeMPSettings.getInstance().getState());
 		state.serverUrl = this.component.serverUrlField.getText();
-		CredentialAttributes attributes = CodeMPSettings.createCredentialAttributes();
+		state.setCredentials(new Credentials(
-		PasswordSafe.getInstance().set(attributes, new Credentials(
 			this.component.userNameField.getText(),
 			this.component.passwordField.getPassword()
 		));
@@ -70,7 +68,6 @@ final class CodeMPSettingsConfigurable implements Configurable {
 			this.component.userNameField.setText(cred.getUserName());
 			this.component.passwordField.setText(cred.getPasswordAsString());
 		}
-
 	}
 
 	@Override
@@ -86,6 +83,7 @@ final class CodeMPSettingsConfigurable implements Configurable {
 
 		Component() {
 			this.mainPanel = FormBuilder.createFormBuilder()
+				.addComponent(new JBLabel("Connection").withFont(JBFont.h2().asBold()))
 				.addLabeledComponent(new JBLabel("Server address:"), this.serverUrlField, 1, false)
 				.addLabeledComponent(new JBLabel("Username:"), this.userNameField, 1, false)
 				.addLabeledComponent(new JBLabel("Password:"), this.passwordField, 1, false)

src/main/java/mp/code/intellij/task/BufferEventAwaiterTask.java

@@ -13,8 +13,6 @@ import com.intellij.openapi.project.Project;
 import mp.code.BufferController;
 import mp.code.Workspace;
 import mp.code.data.TextChange;
-import mp.code.exceptions.CodeMPException;
-import mp.code.exceptions.DeadlockedException;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
@@ -49,10 +47,7 @@ public class BufferEventAwaiterTask extends Task.Backgroundable implements Dispo
 				Optional<TextChange> changeOptional;
 				try {
 					changeOptional = buffer.tryRecv();
-				} catch(DeadlockedException e) {
+				} catch(Exception e) {
-					CodeMP.LOGGER.error(e.getMessage());
-					continue;
-				} catch(CodeMPException e) {
 					throw new RuntimeException(e);
 				}
 

src/main/java/mp/code/intellij/task/CursorEventAwaiterTask.java

@@ -1,7 +1,6 @@
 package mp.code.intellij.task;
 
 import lombok.SneakyThrows;
-import mp.code.exceptions.DeadlockedException;
 import mp.code.intellij.CodeMP;
 import mp.code.intellij.util.ColorUtil;
 import mp.code.intellij.util.FileUtil;
@@ -18,7 +17,6 @@ import com.intellij.openapi.progress.Task;
 import com.intellij.openapi.project.Project;
 import mp.code.CursorController;
 import mp.code.data.Cursor;
-import mp.code.exceptions.CodeMPException;
 import org.jetbrains.annotations.NotNull;
 
 import java.awt.*;

src/main/java/mp/code/intellij/util/FileUtil.java

@@ -7,8 +7,13 @@ import com.intellij.openapi.project.Project;
 import com.intellij.openapi.roots.ProjectRootManager;
 import com.intellij.openapi.vfs.VfsUtilCore;
 import com.intellij.openapi.vfs.VirtualFile;
+import mp.code.BufferController;
+import mp.code.exceptions.ConnectionException;
+import mp.code.intellij.CodeMP;
+import mp.code.intellij.vfs.CodeMPPath;
 
 import java.util.Arrays;
+import java.util.Optional;
 
 public class FileUtil {
 	public static String getRelativePath(Project project, VirtualFile vf) {
@@ -29,4 +34,26 @@ public class FileUtil {
 			.findFirst()
 			.orElse(null);
 	}
+
+	/**
+	 * Will first check if such a buffer exists.
+	 * If it does, it will try to get the relevant controller and,
+	 * if necessary, will attach to the buffer.
+	 * @return the relevant {@link BufferController}, if it could be obtained
+	 */
+	public static Optional<BufferController> getRelevantBufferController(CodeMPPath path) {
+		return CodeMP.getClient("buffer access")
+			.getWorkspace(path.getWorkspaceName())
+			.flatMap(ws -> {
+				String[] matches = ws.getFileTree(Optional.of(path.getRealPath()));
+				if(matches.length == 0) return Optional.empty();
+				Optional<BufferController> controller = ws.getBuffer(path.getRealPath());
+				if(controller.isPresent()) return controller;
+				try {
+					return Optional.of(ws.attachToBuffer(path.getRealPath()));
+				} catch(ConnectionException e) {
+					return Optional.empty();
+				}
+			});
+	}
 }

src/main/java/mp/code/intellij/vfs/CodeMPFile.java

@@ -0,0 +1,111 @@
+package mp.code.intellij.vfs;
+
+import com.intellij.openapi.util.NlsSafe;
+import com.intellij.openapi.vfs.VirtualFile;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import mp.code.exceptions.ControllerException;
+import mp.code.intellij.CodeMP;
+import mp.code.intellij.util.FileUtil;
+import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.file.Path;
+import java.util.Optional;
+
+@Getter
+@RequiredArgsConstructor
+public class CodeMPFile extends VirtualFile {
+	protected final CodeMPFileSystem fileSystem;
+	protected final CodeMPPath path;
+
+	@Override
+	public @NotNull @NlsSafe String getName() {
+		return this.path.getFileName();
+	}
+
+	@Override
+	public @NonNls @NotNull String getPath() {
+		return this.path.join();
+	}
+
+	@Override
+	public boolean isWritable() {
+		return true; // TODO permissions!
+	}
+
+	@Override
+	public boolean isDirectory() {
+		return false; // TODO ????
+	}
+
+	@Override
+	public boolean isValid() {
+		return CodeMP.getClient("validity check")
+			.getWorkspace(this.path.getWorkspaceName())
+			.map(ws -> ws.getFileTree(Optional.of(this.path.getRealPath())))
+			.map(buf -> buf.length != 0)
+			.orElse(false);
+	}
+
+	@Override
+	public @Nullable CodeMPFolder getParent() {
+		return this.path.getParent()
+			.map(parent -> new CodeMPFolder(this.fileSystem, parent))
+			.orElse(null);
+	}
+
+	@Override
+	public CodeMPFile[] getChildren() {
+		return null;
+	}
+
+	@Override
+	public @NotNull OutputStream getOutputStream(Object requester, long newModificationStamp, long newTimeStamp) throws IOException {
+		throw new RuntimeException("WHAT OUTPUT");
+	}
+
+	@Override
+	public byte @NotNull [] contentsToByteArray() throws IOException {
+		return FileUtil.getRelevantBufferController(this.path).flatMap(c -> {
+			try {
+				return Optional.of(c.getContent().getBytes());
+			} catch(ControllerException e) {
+				return Optional.empty();
+			}
+		}).orElseThrow(() -> new IOException("Buffer " + this.path.join() + "did not exist or was inaccessible!"));
+	}
+
+	@Override
+	public long getTimeStamp() {
+		return System.currentTimeMillis();
+	}
+
+	@Override
+	public long getLength() {
+		try {
+			return this.contentsToByteArray().length;
+		} catch(IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	@Override
+	public void refresh(boolean asynchronous, boolean recursive, @Nullable Runnable postRunnable) {
+		// TODO
+	}
+
+	@Override
+	public @NotNull InputStream getInputStream() throws IOException {
+		throw new RuntimeException("WHAT INPUT");
+	}
+
+	@Override
+	public @NotNull Path toNioPath() {
+		return this.path.toNioPath();
+	}
+}

src/main/java/mp/code/intellij/vfs/CodeMPFileSystem.java

@@ -0,0 +1,210 @@
+package mp.code.intellij.vfs;
+
+import com.google.common.collect.Sets;
+import com.intellij.credentialStore.Credentials;
+import com.intellij.openapi.vfs.*;
+import lombok.Getter;
+import mp.code.BufferController;
+import mp.code.Workspace;
+import mp.code.data.TextChange;
+import mp.code.exceptions.ConnectionException;
+import mp.code.exceptions.ConnectionRemoteException;
+import mp.code.exceptions.ControllerException;
+import mp.code.intellij.CodeMP;
+import mp.code.intellij.exceptions.ide.NotConnectedException;
+import mp.code.intellij.settings.CodeMPSettings;
+import mp.code.intellij.util.FileUtil;
+import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.OptionalLong;
+import java.util.Set;
+import java.util.function.BiConsumer;
+
+/**
+ * VFS implementation representing a remote CodeMP workspace.
+ * TODO: KNOWN PROBLEMS
+ *  - Pretty sure we need a folder registry somewhere. Doubt he tracks them itself.
+ *  - Already open remote module will crash if not for that janky try-catch in {@link #findFileByPath(String)}, maybe
+ *    try to connect quietly?
+ */
+@Getter
+public class CodeMPFileSystem extends VirtualFileSystem {
+	public static String PROTOCOL = "codemp";
+	private final Set<VirtualFileListener> listeners;
+
+	public CodeMPFileSystem() {
+		this.listeners = Sets.newConcurrentHashSet();
+	}
+
+	@Override
+	public @NonNls @NotNull String getProtocol() {
+		return PROTOCOL; //TODO: should be same as KeyedLazyInstance.key wtf is that
+	}
+
+	@Override
+	public @Nullable CodeMPFile findFileByPath(@NotNull @NonNls String path) {
+		CodeMPPath cmpPath = new CodeMPPath(path);
+		try {
+			return CodeMP.getClient("file seek")
+				.getWorkspace(cmpPath.getWorkspaceName())
+				.filter(ws -> ws.getFileTree(Optional.of(cmpPath.getRealPath())).length != 0)
+				.map(ws -> new CodeMPFile(this, cmpPath))
+				.orElseGet(() -> new CodeMPFolder(this, cmpPath));
+		} catch(NotConnectedException ex) {
+			CodeMPSettings.State state = Objects.requireNonNull(CodeMPSettings.getInstance().getState());
+			Credentials credentials = Objects.requireNonNull(state.getCredentials());
+			try {
+				CodeMP.connect(
+					Objects.requireNonNull(state.getServerUrl()),
+					Objects.requireNonNull(credentials.getUserName()),
+					Objects.requireNonNull(credentials.getPasswordAsString())
+				);
+				return CodeMP.getClient("file seek")
+					.getWorkspace(cmpPath.getWorkspaceName())
+					.filter(ws -> ws.getFileTree(Optional.of(cmpPath.getRealPath())).length != 0)
+					.map(ws -> new CodeMPFile(this, cmpPath))
+					.orElseGet(() -> new CodeMPFolder(this, cmpPath));
+			} catch(ConnectionException e) {
+				return null;
+			} // TODO this sucks
+		}
+	}
+
+	@Override
+	public void refresh(boolean asynchronous) {
+		// TODO find out if and where ij stores filetree
+		// this is a no-op
+	}
+
+	@Override
+	public @Nullable CodeMPFile refreshAndFindFileByPath(@NotNull String path) {
+		this.refresh(false);
+		return this.findFileByPath(path);
+	}
+
+	@Override
+	public void addVirtualFileListener(@NotNull VirtualFileListener listener) {
+		this.listeners.add(listener);
+	}
+
+	@Override
+	public void removeVirtualFileListener(@NotNull VirtualFileListener listener) {
+		this.listeners.remove(listener);
+	}
+
+	@Override
+	protected void deleteFile(Object requester, @NotNull VirtualFile vFile) throws IOException {
+		if(vFile instanceof CodeMPFile cmpFile) {
+			try {
+				Optional<Workspace> ws = CodeMP.getClient("delete file")
+					.getWorkspace(cmpFile.path.getWorkspaceName());
+				if(ws.isPresent()) {
+					ws.get().deleteBuffer(vFile.getPath());
+				} else {
+					throw new IOException("failed to find workspace!"); // TODO do it better
+				}
+			} catch(ConnectionRemoteException e) {
+				throw new IOException(e);
+			}
+		}
+	}
+
+	@Override
+	protected void moveFile(Object requester, @NotNull VirtualFile vFile, @NotNull VirtualFile newParent) throws IOException {
+		throw new RuntimeException("RENAME NOT SUPPORTED YET!"); // TODO
+	}
+
+	@Override
+	protected void renameFile(Object requester, @NotNull VirtualFile vFile, @NotNull String newName) throws IOException {
+		throw new RuntimeException("RENAME NOT SUPPORTED YET!"); // TODO
+	}
+
+	@Override
+	protected @NotNull CodeMPFile createChildFile(Object requester, @NotNull VirtualFile vDir, @NotNull String fileName) throws IOException {
+		if(vDir instanceof CodeMPFolder parent) {
+			try {
+				Optional<Workspace> ws = CodeMP.getClient("delete file").getWorkspace(parent.path.getWorkspaceName());
+				if(ws.isPresent()) {
+					CodeMPPath newFilePath = parent.path.resolve(fileName);
+					ws.get().createBuffer(newFilePath.getRealPath());
+					ws.get().attachToBuffer(newFilePath.getRealPath());
+					return new CodeMPFile(this, newFilePath);
+				} else {
+					throw new IOException("failed to find workspace!"); // TODO do it better
+				}
+			} catch(ConnectionException e) {
+				throw new IOException(e);
+			}
+		} else {
+			throw new IOException("Can only create children in CodeMP folders!");
+		}
+	}
+
+	@Override
+	protected @NotNull CodeMPFolder createChildDirectory(
+		Object requester,
+		@NotNull VirtualFile vDir,
+		@NotNull String dirName
+	) throws IOException {
+		if(vDir instanceof CodeMPFolder parent) {
+			return new CodeMPFolder(
+				this,
+				parent.path.resolve(dirName)
+			);
+		} else {
+			throw new IOException("Can only create children in CodeMP folders!");
+		}
+	}
+
+	@Override
+	protected @NotNull CodeMPFile copyFile(Object requester, @NotNull VirtualFile virtualFile, @NotNull VirtualFile newParent, @NotNull String copyName) throws IOException {
+		if(virtualFile instanceof CodeMPFile cfile) {
+			try {
+				CodeMPFile newFile = this.createChildFile(requester, newParent, copyName);
+				BufferController oldController = FileUtil.getRelevantBufferController(cfile.path)
+					.orElseThrow(() -> new IOException("Non existing buffer for old file!"));
+				BufferController destinationController = FileUtil.getRelevantBufferController(cfile.path)
+					.orElseThrow(() -> new IOException("Non existing buffer for new file!"));
+				destinationController.send(new TextChange(0, 0, oldController.getContent(), OptionalLong.empty()));
+				return newFile;
+			} catch(ControllerException ex) {
+				throw new IOException(ex);
+			}
+		}
+
+		throw new IOException("Bad VirtualFile type!");
+	}
+
+	@Override
+	public boolean isReadOnly() {
+		return false; // TODO doesnt exist yet
+	}
+
+	private void dispatchEvent(
+		BiConsumer<VirtualFileListener, VirtualFileEvent> fun,
+		Object requester,
+		VirtualFile file,
+		VirtualFile parent,
+		long oldModificationStamp,
+		long newModificationStamp
+	) {
+		this.listeners.forEach(listener -> fun.accept(listener, new VirtualFileEvent(
+			requester,
+			file,
+			parent,
+			oldModificationStamp,
+			newModificationStamp
+		)));
+	}
+
+	@Override
+	public @Nullable Path getNioPath(@NotNull VirtualFile file) {
+		return file.toNioPath();
+	}
+}

src/main/java/mp/code/intellij/vfs/CodeMPFolder.java

@@ -0,0 +1,83 @@
+package mp.code.intellij.vfs;
+
+import com.intellij.openapi.vfs.VirtualFile;
+import lombok.Getter;
+import mp.code.intellij.CodeMP;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Arrays;
+import java.util.Optional;
+
+@Getter
+public class CodeMPFolder extends CodeMPFile {
+
+	public CodeMPFolder(CodeMPFileSystem fileSystem, CodeMPPath path) {
+		super(fileSystem, path);
+	}
+
+	@Override
+	public boolean isWritable() {
+		return false;
+	}
+
+	@Override
+	public boolean isDirectory() {
+		return true;
+	}
+
+	@Override
+	public boolean isValid() {
+		return true;
+	}
+
+	@Override
+	public CodeMPFile[] getChildren() {
+		return CodeMP.getClient("get folder children")
+			.getWorkspace(this.path.getWorkspaceName())
+			.map(ws ->
+				Arrays.stream(ws.getFileTree(Optional.of(this.path.getRealPath())))
+					.map(p -> new CodeMPPath(this.path.getWorkspaceName(), p))
+					.map(CodeMPPath::join)
+					.map(this.fileSystem::findFileByPath)
+					.toArray(CodeMPFile[]::new)
+			).orElseGet(() -> new CodeMPFile[0]);
+	}
+
+	@Override
+	public @NotNull OutputStream getOutputStream(Object o, long l, long l1) throws IOException {
+		throw new RuntimeException("WHAT FOLDER OUTPUT");
+	}
+
+	@Override
+	public byte @NotNull [] contentsToByteArray() throws IOException {
+		return new byte[0];
+	}
+
+	@Override
+	public long getTimeStamp() {
+		return 0;
+	}
+
+	@Override
+	public long getLength() {
+		return 0;
+	}
+
+	@Override
+	public void refresh(boolean asynchronous, boolean recursive, @Nullable Runnable postRunnable) {
+		for(CodeMPFile vf : this.getChildren()) {
+			if(recursive || !this.isDirectory()) {
+				vf.refresh(asynchronous, recursive, postRunnable);
+			}
+		}
+	}
+
+	@Override
+	public @NotNull InputStream getInputStream() throws IOException {
+		throw new RuntimeException("WHAT FOLDER INPUT");
+	}
+}

src/main/java/mp/code/intellij/vfs/CodeMPPath.java

@@ -0,0 +1,127 @@
+package mp.code.intellij.vfs;
+
+import lombok.Getter;
+import lombok.Setter;
+import org.jetbrains.annotations.NotNull;
+
+import java.nio.file.FileSystems;
+import java.nio.file.Path;
+import java.util.Optional;
+
+/**
+ * A utility class representing a path as implemented in CodeMP.
+ * To represent them in an IntelliJ-compatible way, we use the workspace name
+ * as "root folder" of all workspace contents.
+ * Thus, a CodeMP URI looks like this: <code>codemp://[workspace]/[path]</code>.
+ * This helper class manages just that.
+ */
+@Getter @Setter
+public class CodeMPPath {
+	/**
+	 * The name of the workspace that contains this path.
+	 */
+	private final String workspaceName;
+	/**
+	 * The real path. May never be null, but may be empty.
+	 * It is guaranteed to not have any trailing slashes.
+	 */
+	private final String realPath;
+
+	/**
+	 * Builds a new {@link CodeMPPath} from its separate components.
+	 * @param workspaceName the name of the workspace
+	 * @param realPath the name of the underlying path
+	 */
+	public CodeMPPath(String workspaceName, String realPath) {
+		this.workspaceName = workspaceName;
+		if(!realPath.isEmpty()) realPath = stripTrailingSlashes(realPath);
+
+		this.realPath = realPath;
+	}
+
+	/**
+	 * Builds a new {@link CodeMPPath} from a unified path containing both the real path and
+	 * the workspace name.
+	 * @param pathWithWorkspace the unified path
+	 */
+	public CodeMPPath(String pathWithWorkspace) {
+		this.workspaceName = extractWorkspace(pathWithWorkspace);
+		this.realPath = extractRealPath(pathWithWorkspace);
+	}
+
+	/**
+	 * Joins back into a single string workspace name and path.
+	 * @return the resulting string
+	 */
+	public String join() {
+		return this.workspaceName + '/' + this.realPath;
+	}
+
+	/**
+	 * Recovers just the name of the current file.
+	 * @return a string containing the name
+	 */
+	public String getFileName() {
+		int lastSlashPos = this.realPath.lastIndexOf('/');
+		if(lastSlashPos == -1) return this.realPath;
+		else return this.realPath.substring(lastSlashPos + 1, this.realPath.length() - 1);
+	}
+
+	/**
+	 * Gets the parent, if it is present.
+	 * @return the parent
+	 */
+	public Optional<CodeMPPath> getParent() {
+		int lastSlash = this.realPath.lastIndexOf('/');
+		if(this.realPath.isEmpty()) return Optional.empty();
+		else if(lastSlash == -1) return Optional.of(new CodeMPPath(this.workspaceName, ""));
+		else return Optional.of(new CodeMPPath(
+			this.workspaceName,
+			this.realPath.substring(0, lastSlash)
+		));
+	}
+
+	/**
+	 * Resolves one or multiple children against this, assuming that this
+	 * path represents a folder.
+	 * @param firstChild the first, mandatory child to resolve against
+	 * @param children other, eventual children
+	 * @return the build {@link CodeMPPath}
+	 */
+	public CodeMPPath resolve(String firstChild, String... children) {
+		StringBuilder pathBuilder = new StringBuilder(this.realPath)
+			.append('/')
+			.append(stripTrailingSlashes(firstChild));
+		if(children != null)
+			for(String c : children)
+				pathBuilder.append('/').append(stripTrailingSlashes(c));
+		return new CodeMPPath(
+			this.workspaceName,
+			pathBuilder.toString()
+		);
+	}
+
+	/**
+	 * Converts this to a {@link Path}, accounting for system differences in separator.
+	 * @return the built {@link Path}
+	 */
+	public @NotNull Path toNioPath() {
+		String currentSystemSeparator = FileSystems.getDefault().getSeparator();
+		return Path.of(this.realPath.replace("/", currentSystemSeparator));
+	}
+
+	private static String extractWorkspace(@NotNull String path) {
+		int firstSlashPosition = path.indexOf('/');
+		if(firstSlashPosition == -1) return path;
+		return path.substring(0, path.indexOf('/'));
+	}
+
+	private static String extractRealPath(@NotNull String path) {
+		return path.substring(path.indexOf('/') + 1);
+	}
+
+	private static String stripTrailingSlashes(@NotNull String s) {
+		while(s.charAt(s.length() - 1) == '/') s = s.substring(0, s.length() - 1);
+		return s;
+	}
+}

src/main/java/mp/code/intellij/workspace/IJWorkspace.java

@@ -1,63 +0,0 @@
-package mp.code.intellij.workspace;
-
-import mp.code.intellij.listeners.WorkspaceFileOpenedListener;
-import mp.code.intellij.task.BufferEventAwaiterTask;
-import mp.code.intellij.task.CursorEventAwaiterTask;
-import com.intellij.openapi.Disposable;
-import com.intellij.openapi.editor.EditorFactory;
-import com.intellij.openapi.fileEditor.FileEditorManagerListener;
-import com.intellij.openapi.fileEditor.FileOpenedSyncListener;
-import com.intellij.openapi.progress.ProgressManager;
-import com.intellij.openapi.project.Project;
-import com.intellij.util.messages.MessageBusConnection;
-import mp.code.Client;
-import mp.code.Workspace;
-import mp.code.exceptions.CodeMPException;
-import mp.code.intellij.listeners.CursorEventListener;
-import mp.code.intellij.listeners.WorkspaceFileClosedListener;
-
-public class IJWorkspace implements Disposable {
-	public final String id;
-	public final String url;
-	public final boolean isRemote;
-	public final Workspace handler;
-	public final Project project;
-	public final BufferEventAwaiterTask bufferTask;
-	public final CursorEventAwaiterTask cursorTask;
-
-	/**
-	 * The constructor, that will also take care of creating the tasks and listeners associated with it.
-	 * @param id unique id of the workspace on the server
-	 * @param client the {@link Client} to use
-	 * @param isRemote whether the project is remote
-	 * @param project the {@link Project} to use
-	 */
-	public IJWorkspace(String id, Client client, boolean isRemote, Project project) throws CodeMPException {
-		this.id = id;
-		this.url = client.getUrl();
-		this.isRemote = isRemote;
-		this.handler = client.joinWorkspace(id);
-		this.project = project;
-
-		this.cursorTask = new CursorEventAwaiterTask(project, this.handler.getCursor());
-		ProgressManager.getInstance().run(this.cursorTask);
-
-		this.bufferTask = new BufferEventAwaiterTask(project, this.handler);
-		ProgressManager.getInstance().run(this.bufferTask);
-
-		// buffer listening
-		MessageBusConnection conn = this.project.getMessageBus().connect(this);
-		conn.subscribe(FileOpenedSyncListener.TOPIC,
-			new WorkspaceFileOpenedListener(this.handler, this.bufferTask));
-		conn.subscribe(FileEditorManagerListener.Before.FILE_EDITOR_MANAGER,
-			new WorkspaceFileClosedListener(this.handler, this.bufferTask));
-
-		// cursor listening
-		EditorFactory.getInstance()
-			.getEventMulticaster()
-			.addCaretListener(new CursorEventListener(this.handler.getCursor()), this.cursorTask);
-	}
-
-	@Override
-	public void dispose() {}
-}

src/main/resources/META-INF/plugin.xml

@@ -20,6 +20,10 @@
 	</actions>
 
 	<extensions defaultExtensionNs="com.intellij">
+		<virtualFileSystem
+				id="codemp_vfs"
+				key="codemp"
+				implementationClass="mp.code.intellij.vfs.CodeMPFileSystem"/>
 		<notificationGroup id="CodeMP" displayType="BALLOON"/>
 		<applicationService serviceImplementation="mp.code.intellij.settings.CodeMPSettings"/>
 		<applicationConfigurable