Add summarize selection context menu feature (#130)

* feat: add Summarize Selection context menu command

- Add new context menu item in Noted submenu for summarizing selected text
- Works in any file (not just Notes folder)
- Uses VS Code LLM API (GitHub Copilot) for AI-powered summarization
- Generates concise 2-3 sentence summary
- Inserts summary below selection with "## Summary of Selection" header
- Shows error message if Copilot is unavailable

* fix: add empty line before Summary of Selection header

* Update src/commands/summarizationCommands.ts

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* fix: pass cancellation token to summarizeSelection and simplify insertion

- Add cancellation token parameter to summarizeSelection method
- Pass token from withProgress to enable proper cancellation
- Simplify insertion logic to always insert at end of selection line

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: 3 people

package.json

@@ -681,6 +681,11 @@
         "title": "Generate Tags for Current Note",
         "icon": "$(sparkle)"
       },
+      {
+        "command": "noted.summarizeSelection",
+        "title": "Summarize Selection",
+        "icon": "$(sparkle)"
+      },
       {
         "command": "noted.batchGenerateTags",
         "title": "Noted: Batch Generate Tags",
@@ -806,15 +811,20 @@
           "when": "editorHasSelection",
           "group": "1_edit@1"
         },
+        {
+          "command": "noted.summarizeSelection",
+          "when": "editorHasSelection",
+          "group": "2_ai@1"
+        },
         {
           "command": "noted.summarizeCurrentNote",
           "when": "resourcePath =~ /Notes.*\\.(txt|md)$/",
-          "group": "2_ai@1"
+          "group": "2_ai@2"
         },
         {
           "command": "noted.generateTagsCurrentNote",
           "when": "resourcePath =~ /Notes.*\\.(txt|md)$/",
-          "group": "2_ai@2"
+          "group": "2_ai@3"
         }
       ],
       "editor/context": [

src/commands/summarizationCommands.ts

@@ -341,6 +341,66 @@ export class SummarizationCommands {
         }
     }
 
+    /**
+     * Handle summarizing selected text and inserting summary below the selection
+     */
+    public async handleSummarizeSelection(): Promise<void> {
+        const editor = vscode.window.activeTextEditor;
+        if (!editor) {
+            vscode.window.showErrorMessage('No editor is currently open');
+            return;
+        }
+
+        const selection = editor.selection;
+        if (selection.isEmpty) {
+            vscode.window.showErrorMessage('No text is selected. Please select some text to summarize.');
+            return;
+        }
+
+        const selectedText = editor.document.getText(selection);
+        if (!selectedText.trim()) {
+            vscode.window.showErrorMessage('Selected text is empty or contains only whitespace');
+            return;
+        }
+
+        try {
+            await vscode.window.withProgress(
+                {
+                    location: vscode.ProgressLocation.Notification,
+                    title: 'Summarizing selection...',
+                    cancellable: true
+                },
+                async (progress, token) => {
+                    if (token.isCancellationRequested) {
+                        return;
+                    }
+
+                    const summary = await this.summarizationService.summarizeSelection(selectedText, token);
+
+                    if (token.isCancellationRequested) {
+                        return;
+                    }
+
+                    // Insert summary at the end of the line containing the selection's end point
+                    // to ensure consistent spacing.
+                    const endLine = editor.document.lineAt(selection.end.line);
+                    const insertPosition = endLine.range.end;
+
+                    // Format the summary with header (extra blank line before header)
+                    const summaryText = `\n\n## Summary of Selection\n\n${summary}\n`;
+
+                    await editor.edit(editBuilder => {
+                        editBuilder.insert(insertPosition, summaryText);
+                    });
+
+                    vscode.window.showInformationMessage('Summary inserted below selection');
+                }
+            );
+        } catch (error) {
+            vscode.window.showErrorMessage(`Failed to generate summary: ${error instanceof Error ? error.message : String(error)}`);
+        }
+    }
+
     // ========================================================================
     // Private Helper Methods
     // ========================================================================

src/extension.ts

@@ -2081,6 +2081,10 @@ export function activate(context: vscode.ExtensionContext) {
         await summarizationCommands.handleSummarizeCurrentNote();
     });
 
+    let summarizeSelection = vscode.commands.registerCommand('noted.summarizeSelection', async () => {
+        await summarizationCommands.handleSummarizeSelection();
+    });
+
     let summarizeRecent = vscode.commands.registerCommand('noted.summarizeRecent', async () => {
         await summarizationCommands.handleSummarizeRecent();
     });
@@ -2226,7 +2230,7 @@ export function activate(context: vscode.ExtensionContext) {
         showPreview, showMarkdownToolbar,
         undoCommand, redoCommand, showUndoHistory, clearUndoHistory,
         renameSymbol,
-        summarizeNote, summarizeCurrentNote, summarizeRecent, summarizeWeek, summarizeMonth, summarizeCustomRange, clearSummaryCache, summarizeSearchResults,
+        summarizeNote, summarizeCurrentNote, summarizeSelection, summarizeRecent, summarizeWeek, summarizeMonth, summarizeCustomRange, clearSummaryCache, summarizeSearchResults,
         showSummaryHistory, compareSummaries, restoreSummaryVersion, clearSummaryHistory, showSummaryHistoryStats,
         createPromptTemplate, editPromptTemplate, deletePromptTemplate, duplicatePromptTemplate, listPromptTemplates, viewTemplateVariables,
         suggestTags,

src/services/summarizationService.ts

@@ -526,4 +526,46 @@ ${note.content}
         }
         return 'GitHub Copilot';
     }
+
+    /**
+     * Summarize selected text (concise 2-3 sentence summary)
+     */
+    async summarizeSelection(selectedText: string, token: vscode.CancellationToken): Promise<string> {
+        // Check if AI is enabled
+        if (!this.isAIEnabled()) {
+            throw new Error('AI summarization is disabled. Enable it in settings: noted.ai.enabled');
+        }
+
+        // Check if Language Model API is available
+        if (!(await this.isLanguageModelAvailable())) {
+            throw new Error('Copilot is not available. Please install and enable GitHub Copilot to use AI summarization features.');
+        }
+
+        // Truncate if too large
+        const maxChars = 16000;
+        const truncatedText = selectedText.length > maxChars
+            ? selectedText.substring(0, maxChars) + '\n\n[Text truncated for summarization]'
+            : selectedText;
+
+        // Build a concise summarization prompt
+        const prompt = `Summarize the following text in 2-3 concise sentences, capturing the main points:\n\n---\n${truncatedText}\n---\n\nProvide only the summary without any preamble or extra formatting.`;
+
+        // Call Language Model API
+        try {
+            const model = await selectAIModel();
+            const messages = [vscode.LanguageModelChatMessage.User(prompt)];
+
+            const response = await model.sendRequest(messages, {}, token);
+
+            let summary = '';
+            for await (const chunk of response.text) {
+                summary += chunk;
+            }
+
+            return summary.trim();
+
+        } catch (error) {
+            throw new Error(`Failed to generate summary: ${error instanceof Error ? error.message : String(error)}`);
+        }
+    }
 }