feat - support readDirectory for ADT

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/lsp/CopilotLanguageClient.java

@@ -55,6 +55,7 @@
 import com.microsoft.copilot.eclipse.core.lsp.protocol.LanguageModelToolResult.ToolInvocationStatus;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.OnChangeMcpServerToolsParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.RateLimitWarningParams;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.ReadDirectoryResult;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.ReadFileResult;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.codingagent.CodingAgentMessageRequestParams;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.codingagent.CodingAgentMessageResult;
@@ -335,6 +336,15 @@ public CompletableFuture<ReadFileResult> readFile(String uri) {
     return CompletableFuture.supplyAsync(() -> FileUtils.readFileWithStats(uri));
   }
 
+  /**
+   * Reads the contents of a directory given its URI. Used by the language server to list directory entries for URIs
+   * with external content provider schemes (e.g., semanticfs://) that cannot be read from the local file system.
+   */
+  @JsonRequest("workspace/readDirectory")
+  public CompletableFuture<ReadDirectoryResult> readDirectory(String uri) {
+    return CompletableFuture.supplyAsync(() -> FileUtils.readDirectoryEntries(uri));
+  }
+
   /**
    * Handles the progress notification for chat replies.
    */

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/lsp/protocol/ReadDirectoryResult.java

@@ -0,0 +1,135 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+package com.microsoft.copilot.eclipse.core.lsp.protocol;
+
+import java.util.List;
+import java.util.Objects;
+
+import org.apache.commons.lang3.builder.ToStringBuilder;
+
+/**
+ * Result of reading a directory, containing the directory entries.
+ */
+public class ReadDirectoryResult {
+
+  private List<DirectoryEntry> entries;
+
+  /**
+   * Constructor with entries.
+   *
+   * @param entries the directory entries
+   */
+  public ReadDirectoryResult(List<DirectoryEntry> entries) {
+    this.entries = entries;
+  }
+
+  /**
+   * Gets the directory entries.
+   *
+   * @return the directory entries
+   */
+  public List<DirectoryEntry> getEntries() {
+    return entries;
+  }
+
+  /**
+   * Sets the directory entries.
+   *
+   * @param entries the directory entries
+   */
+  public void setEntries(List<DirectoryEntry> entries) {
+    this.entries = entries;
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(entries);
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (this == obj) {
+      return true;
+    }
+    if (obj == null || getClass() != obj.getClass()) {
+      return false;
+    }
+    ReadDirectoryResult other = (ReadDirectoryResult) obj;
+    return Objects.equals(entries, other.entries);
+  }
+
+  @Override
+  public String toString() {
+    return new ToStringBuilder(this).append("entries", entries).toString();
+  }
+
+  /**
+   * A single directory entry with name and file type.
+   */
+  public static class DirectoryEntry {
+
+    /** VS Code FileType constants. */
+    public static final int FILE_TYPE_UNKNOWN = 0;
+    public static final int FILE_TYPE_FILE = 1;
+    public static final int FILE_TYPE_DIRECTORY = 2;
+
+    private String name;
+    private int type;
+
+    /**
+     * Constructor with name and type.
+     *
+     * @param name the entry name
+     * @param type the file type (0=Unknown, 1=File, 2=Directory)
+     */
+    public DirectoryEntry(String name, int type) {
+      this.name = name;
+      this.type = type;
+    }
+
+    /**
+     * Gets the entry name.
+     */
+    public String getName() {
+      return name;
+    }
+
+    public void setName(String name) {
+      this.name = name;
+    }
+
+    /**
+     * Gets the file type.
+     */
+    public int getType() {
+      return type;
+    }
+
+    public void setType(int type) {
+      this.type = type;
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(name, type);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+      if (this == obj) {
+        return true;
+      }
+      if (obj == null || getClass() != obj.getClass()) {
+        return false;
+      }
+      DirectoryEntry other = (DirectoryEntry) obj;
+      return Objects.equals(name, other.name) && type == other.type;
+    }
+
+    @Override
+    public String toString() {
+      return new ToStringBuilder(this).append("name", name).append("type", type).toString();
+    }
+  }
+}

com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/utils/FileUtils.java

@@ -12,11 +12,15 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.attribute.BasicFileAttributes;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
+import org.apache.commons.lang3.StringUtils;
+import org.eclipse.core.resources.IContainer;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IFolder;
 import org.eclipse.core.resources.IResource;
@@ -33,6 +37,8 @@
 import com.microsoft.copilot.eclipse.core.lsp.protocol.DirectoryChatReference;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.FileChatReference;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.FileStat;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.ReadDirectoryResult;
+import com.microsoft.copilot.eclipse.core.lsp.protocol.ReadDirectoryResult.DirectoryEntry;
 import com.microsoft.copilot.eclipse.core.lsp.protocol.ReadFileResult;
 
 /**
@@ -302,6 +308,80 @@ public static ReadFileResult readFileWithStats(String uri) {
 
   }
 
+  /**
+   * Reads the contents of a directory given its URI. Used by workspace/readDirectory API to list directory entries.
+   * Works with local filesystem URIs, platform:/resource URIs (produced by {@link #getResourceUri(IResource)}), and
+   * virtual URIs (e.g., semanticfs://) through Eclipse's IResource API.
+   *
+   * @param uri the directory URI
+   * @return ReadDirectoryResult containing the directory entries
+   */
+  public static ReadDirectoryResult readDirectoryEntries(String uri) {
+    if (StringUtils.isBlank(uri)) {
+      return new ReadDirectoryResult(Collections.emptyList());
+    }
+
+    try {
+      URI parsedUri = new URI(uri);
+      IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
+
+      IContainer container = null;
+      if ("platform".equals(parsedUri.getScheme())) {
+        // Handle platform:/resource/... URIs by resolving via workspace path
+        String path = parsedUri.getPath();
+        String prefix = "/resource";
+        if (path != null && path.startsWith(prefix)) {
+          String workspacePath = path.substring(prefix.length());
+          IResource resource = root.findMember(workspacePath);
+          if (resource instanceof IContainer c && c.isAccessible()) {
+            container = c;
+          }
+        }
+      } else {
+        // For file://, semanticfs://, and other URIs, use location URI lookup
+        IContainer[] containers = root.findContainersForLocationURI(parsedUri);
+        if (containers != null) {
+          for (IContainer c : containers) {
+            if (c.isAccessible()) {
+              container = c;
+              break;
+            }
+          }
+        }
+      }
+
+      if (container == null) {
+        return new ReadDirectoryResult(Collections.emptyList());
+      }
+
+      IResource[] members = container.members();
+      List<DirectoryEntry> entries = new ArrayList<>();
+      for (IResource member : members) {
+        int type;
+        switch (member.getType()) {
+          case IResource.FILE:
+            type = DirectoryEntry.FILE_TYPE_FILE;
+            break;
+          case IResource.FOLDER:
+          case IResource.PROJECT:
+            type = DirectoryEntry.FILE_TYPE_DIRECTORY;
+            break;
+          default:
+            type = DirectoryEntry.FILE_TYPE_UNKNOWN;
+            break;
+        }
+        entries.add(new DirectoryEntry(member.getName(), type));
+      }
+      return new ReadDirectoryResult(entries);
+    } catch (URISyntaxException e) {
+      CopilotCore.LOGGER.error("Invalid directory URI: " + uri, e);
+      return new ReadDirectoryResult(Collections.emptyList());
+    } catch (CoreException e) {
+      CopilotCore.LOGGER.error("Failed to read directory: " + uri, e);
+      return new ReadDirectoryResult(Collections.emptyList());
+    }
+  }
+
   private static String readFileContent(IFile file) throws CoreException, IOException {
     try (InputStream is = file.getContents()) {
       return new String(is.readAllBytes(), file.getCharset());