Refactors companion VS Code extension to import & use notification schema defined in gemini-cli (#5059)

packages/vscode-ide-companion/src/open-files-manager.ts

@@ -0,0 +1,178 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as vscode from 'vscode';
+import type { File, IdeContext } from '@google/gemini-cli-core';
+
+export const MAX_FILES = 10;
+const MAX_SELECTED_TEXT_LENGTH = 16384; // 16 KiB limit
+
+/**
+ * Keeps track of the workspace state, including open files, cursor position, and selected text.
+ */
+export class OpenFilesManager {
+  private readonly onDidChangeEmitter = new vscode.EventEmitter<void>();
+  readonly onDidChange = this.onDidChangeEmitter.event;
+  private debounceTimer: NodeJS.Timeout | undefined;
+  private openFiles: File[] = [];
+
+  constructor(private readonly context: vscode.ExtensionContext) {
+    const editorWatcher = vscode.window.onDidChangeActiveTextEditor(
+      (editor) => {
+        if (editor && this.isFileUri(editor.document.uri)) {
+          this.addOrMoveToFront(editor);
+          this.fireWithDebounce();
+        }
+      },
+    );
+
+    const selectionWatcher = vscode.window.onDidChangeTextEditorSelection(
+      (event) => {
+        if (this.isFileUri(event.textEditor.document.uri)) {
+          this.updateActiveContext(event.textEditor);
+          this.fireWithDebounce();
+        }
+      },
+    );
+
+    const closeWatcher = vscode.workspace.onDidCloseTextDocument((document) => {
+      if (this.isFileUri(document.uri)) {
+        this.remove(document.uri);
+        this.fireWithDebounce();
+      }
+    });
+
+    const deleteWatcher = vscode.workspace.onDidDeleteFiles((event) => {
+      for (const uri of event.files) {
+        if (this.isFileUri(uri)) {
+          this.remove(uri);
+        }
+      }
+      this.fireWithDebounce();
+    });
+
+    const renameWatcher = vscode.workspace.onDidRenameFiles((event) => {
+      for (const { oldUri, newUri } of event.files) {
+        if (this.isFileUri(oldUri)) {
+          if (this.isFileUri(newUri)) {
+            this.rename(oldUri, newUri);
+          } else {
+            // The file was renamed to a non-file URI, so we should remove it.
+            this.remove(oldUri);
+          }
+        }
+      }
+      this.fireWithDebounce();
+    });
+
+    context.subscriptions.push(
+      editorWatcher,
+      selectionWatcher,
+      closeWatcher,
+      deleteWatcher,
+      renameWatcher,
+    );
+
+    // Just add current active file on start-up.
+    if (
+      vscode.window.activeTextEditor &&
+      this.isFileUri(vscode.window.activeTextEditor.document.uri)
+    ) {
+      this.addOrMoveToFront(vscode.window.activeTextEditor);
+    }
+  }
+
+  private isFileUri(uri: vscode.Uri): boolean {
+    return uri.scheme === 'file';
+  }
+
+  private addOrMoveToFront(editor: vscode.TextEditor) {
+    // Deactivate previous active file
+    const currentActive = this.openFiles.find((f) => f.isActive);
+    if (currentActive) {
+      currentActive.isActive = false;
+      currentActive.cursor = undefined;
+      currentActive.selectedText = undefined;
+    }
+
+    // Remove if it exists
+    const index = this.openFiles.findIndex(
+      (f) => f.path === editor.document.uri.fsPath,
+    );
+    if (index !== -1) {
+      this.openFiles.splice(index, 1);
+    }
+
+    // Add to the front as active
+    this.openFiles.unshift({
+      path: editor.document.uri.fsPath,
+      timestamp: Date.now(),
+      isActive: true,
+    });
+
+    // Enforce max length
+    if (this.openFiles.length > MAX_FILES) {
+      this.openFiles.pop();
+    }
+
+    this.updateActiveContext(editor);
+  }
+
+  private remove(uri: vscode.Uri) {
+    const index = this.openFiles.findIndex((f) => f.path === uri.fsPath);
+    if (index !== -1) {
+      this.openFiles.splice(index, 1);
+    }
+  }
+
+  private rename(oldUri: vscode.Uri, newUri: vscode.Uri) {
+    const index = this.openFiles.findIndex((f) => f.path === oldUri.fsPath);
+    if (index !== -1) {
+      this.openFiles[index].path = newUri.fsPath;
+    }
+  }
+
+  private updateActiveContext(editor: vscode.TextEditor) {
+    const file = this.openFiles.find(
+      (f) => f.path === editor.document.uri.fsPath,
+    );
+    if (!file || !file.isActive) {
+      return;
+    }
+
+    file.cursor = editor.selection.active
+      ? {
+          line: editor.selection.active.line + 1,
+          character: editor.selection.active.character,
+        }
+      : undefined;
+
+    let selectedText: string | undefined =
+      editor.document.getText(editor.selection) || undefined;
+    if (selectedText && selectedText.length > MAX_SELECTED_TEXT_LENGTH) {
+      selectedText =
+        selectedText.substring(0, MAX_SELECTED_TEXT_LENGTH) + '... [TRUNCATED]';
+    }
+    file.selectedText = selectedText;
+  }
+
+  private fireWithDebounce() {
+    if (this.debounceTimer) {
+      clearTimeout(this.debounceTimer);
+    }
+    this.debounceTimer = setTimeout(() => {
+      this.onDidChangeEmitter.fire();
+    }, 50); // 50ms
+  }
+
+  get state(): IdeContext {
+    return {
+      workspaceState: {
+        openFiles: [...this.openFiles],
+      },
+    };
+  }
+}