feat: add comprehensive logging infrastructure for embedders

- Added standardized logging methods (log, logWarning, logError) to all embedder classes
- Integrated VS Code output channel for consistent logging across OpenAI, Gemini, Mistral, and Ollama embedders
- Enhanced debug logging in CodeIndexManager and webviewMessageHandler
- Added detailed logging for embedding creation, validation, and error handling
- Updated CodeIndexServiceFactory to pass output channel to all embedders
- Fixed test files to account for new constructor signatures

This logging infrastructure provides better debugging and troubleshooting capabilities as requested in PR #7200

Author: roomote

src/core/webview/webviewMessageHandler.ts

@@ -2027,6 +2027,9 @@ export const webviewMessageHandler = async (
 
 			const settings = message.codeIndexSettings
 
+			// Debug logging for settings save
+			console.log("[DEBUG] saveCodeIndexSettingsAtomic called with settings:", JSON.stringify(settings, null, 2))
+
 			try {
 				// Check if embedder provider has changed
 				const currentConfig = getGlobalState("codebaseIndexConfig") || {}
@@ -2047,6 +2050,8 @@ export const webviewMessageHandler = async (
 					codebaseIndexSearchMinScore: settings.codebaseIndexSearchMinScore,
 				}
 
+				console.log("[DEBUG] globalStateConfig to be saved:", JSON.stringify(globalStateConfig, null, 2))
+
 				// Save global state first
 				await updateGlobalState("codebaseIndexConfig", globalStateConfig)
 
@@ -2076,26 +2081,35 @@ export const webviewMessageHandler = async (
 					)
 				}
 
+				console.log("[DEBUG] Secrets saved successfully")
+
 				// Send success response first - settings are saved regardless of validation
 				await provider.postMessageToWebview({
 					type: "codeIndexSettingsSaved",
 					success: true,
 					settings: globalStateConfig,
 				})
 
+				console.log("[DEBUG] Success response sent to webview")
+
 				// Update webview state
 				await provider.postStateToWebview()
 
 				// Then handle validation and initialization for the current workspace
 				const currentCodeIndexManager = provider.getCurrentWorkspaceCodeIndexManager()
 				if (currentCodeIndexManager) {
+					console.log("[DEBUG] CodeIndexManager found, handling settings change")
+
 					// If embedder provider changed, perform proactive validation
 					if (embedderProviderChanged) {
+						console.log("[DEBUG] Embedder provider changed, performing validation")
 						try {
 							// Force handleSettingsChange which will trigger validation
 							await currentCodeIndexManager.handleSettingsChange()
+							console.log("[DEBUG] Settings change handled successfully")
 						} catch (error) {
 							// Validation failed - the error state is already set by handleSettingsChange
+							console.log("[DEBUG] Embedder validation failed:", error)
 							provider.log(
 								`Embedder validation failed after provider change: ${error instanceof Error ? error.message : String(error)}`,
 							)
@@ -2109,10 +2123,13 @@ export const webviewMessageHandler = async (
 						}
 					} else {
 						// No provider change, just handle settings normally
+						console.log("[DEBUG] No provider change, handling settings normally")
 						try {
 							await currentCodeIndexManager.handleSettingsChange()
+							console.log("[DEBUG] Settings change handled successfully")
 						} catch (error) {
 							// Log but don't fail - settings are saved
+							console.log("[DEBUG] Settings change handling error:", error)
 							provider.log(
 								`Settings change handling error: ${error instanceof Error ? error.message : String(error)}`,
 							)
@@ -2124,11 +2141,15 @@ export const webviewMessageHandler = async (
 
 					// Auto-start indexing if now enabled and configured
 					if (currentCodeIndexManager.isFeatureEnabled && currentCodeIndexManager.isFeatureConfigured) {
+						console.log("[DEBUG] Feature enabled and configured, checking initialization")
 						if (!currentCodeIndexManager.isInitialized) {
+							console.log("[DEBUG] Manager not initialized, initializing now")
 							try {
 								await currentCodeIndexManager.initialize(provider.contextProxy)
+								console.log("[DEBUG] Code index manager initialized successfully")
 								provider.log(`Code index manager initialized after settings save`)
 							} catch (error) {
+								console.log("[DEBUG] Code index initialization failed:", error)
 								provider.log(
 									`Code index initialization failed: ${error instanceof Error ? error.message : String(error)}`,
 								)
@@ -2138,10 +2159,15 @@ export const webviewMessageHandler = async (
 									values: currentCodeIndexManager.getCurrentStatus(),
 								})
 							}
+						} else {
+							console.log("[DEBUG] Manager already initialized")
 						}
+					} else {
+						console.log("[DEBUG] Feature not enabled or not configured")
 					}
 				} else {
 					// No workspace open - send error status
+					console.log("[DEBUG] No workspace open, cannot save code index settings")
 					provider.log("Cannot save code index settings: No workspace folder open")
 					await provider.postMessageToWebview({
 						type: "indexingStatusUpdate",
@@ -2155,6 +2181,7 @@ export const webviewMessageHandler = async (
 					})
 				}
 			} catch (error) {
+				console.log("[DEBUG] Error saving code index settings:", error)
 				provider.log(`Error saving code index settings: ${error.message || error}`)
 				await provider.postMessageToWebview({
 					type: "codeIndexSettingsSaved",

src/services/code-index/embedders/__tests__/gemini.spec.ts

@@ -38,6 +38,8 @@ describe("GeminiEmbedder", () => {
 				apiKey,
 				"gemini-embedding-001",
 				2048,
+				undefined, // useFloatEncoding
+				undefined, // outputChannel
 			)
 		})
 
@@ -55,6 +57,8 @@ describe("GeminiEmbedder", () => {
 				apiKey,
 				"text-embedding-004",
 				2048,
+				undefined, // useFloatEncoding
+				undefined, // outputChannel
 			)
 		})
 

src/services/code-index/embedders/__tests__/mistral.spec.ts

@@ -38,6 +38,8 @@ describe("MistralEmbedder", () => {
 				apiKey,
 				"codestral-embed-2505",
 				8191,
+				undefined, // useFloatEncoding
+				undefined, // outputChannel
 			)
 		})
 
@@ -55,6 +57,8 @@ describe("MistralEmbedder", () => {
 				apiKey,
 				"custom-embed-model",
 				8191,
+				undefined, // useFloatEncoding
+				undefined, // outputChannel
 			)
 		})
 

src/services/code-index/embedders/gemini.ts

@@ -1,3 +1,4 @@
+import * as vscode from "vscode"
 import { OpenAICompatibleEmbedder } from "./openai-compatible"
 import { IEmbedder, EmbeddingResponse, EmbedderInfo } from "../interfaces/embedder"
 import { GEMINI_MAX_ITEM_TOKENS } from "../constants"
@@ -18,27 +19,72 @@ export class GeminiEmbedder implements IEmbedder {
 	private static readonly GEMINI_BASE_URL = "https://generativelanguage.googleapis.com/v1beta/openai/"
 	private static readonly DEFAULT_MODEL = "gemini-embedding-001"
 	private readonly modelId: string
+	private readonly outputChannel?: vscode.OutputChannel
 
 	/**
 	 * Creates a new Gemini embedder
 	 * @param apiKey The Gemini API key for authentication
 	 * @param modelId The model ID to use (defaults to gemini-embedding-001)
+	 * @param outputChannel Optional VS Code output channel for logging
 	 */
-	constructor(apiKey: string, modelId?: string) {
+	constructor(apiKey: string, modelId?: string, outputChannel?: vscode.OutputChannel) {
 		if (!apiKey) {
 			throw new Error(t("embeddings:validation.apiKeyRequired"))
 		}
 
 		// Use provided model or default
 		this.modelId = modelId || GeminiEmbedder.DEFAULT_MODEL
+		this.outputChannel = outputChannel
 
 		// Create an OpenAI Compatible embedder with Gemini's configuration
 		this.openAICompatibleEmbedder = new OpenAICompatibleEmbedder(
 			GeminiEmbedder.GEMINI_BASE_URL,
 			apiKey,
 			this.modelId,
 			GEMINI_MAX_ITEM_TOKENS,
+			undefined, // useFloatEncoding
+			this.outputChannel,
 		)
+
+		// Log construction
+		this.log("info", "Gemini Embedder constructed", {
+			modelId: this.modelId,
+			baseUrl: GeminiEmbedder.GEMINI_BASE_URL,
+		})
+	}
+
+	/**
+	 * Logs a message to the output channel if available
+	 * @param level The log level (debug, info, warn, error)
+	 * @param message The message to log
+	 * @param data Optional structured data to include
+	 */
+	private log(level: "debug" | "info" | "warn" | "error", message: string, data?: any): void {
+		if (!this.outputChannel) return
+
+		const timestamp = new Date().toISOString()
+		const prefix = `[${timestamp}] [${level.toUpperCase()}] [GEMINI]`
+
+		let logMessage = `${prefix} ${message}`
+		if (data) {
+			logMessage += `\n${JSON.stringify(data, null, 2)}`
+		}
+
+		this.outputChannel.appendLine(logMessage)
+	}
+
+	/**
+	 * Helper method for warning logs
+	 */
+	private logWarning(message: string, data?: any): void {
+		this.log("warn", message, data)
+	}
+
+	/**
+	 * Helper method for error logs
+	 */
+	private logError(message: string, data?: any): void {
+		this.log("error", message, data)
 	}
 
 	/**
@@ -51,8 +97,26 @@ export class GeminiEmbedder implements IEmbedder {
 		try {
 			// Use the provided model or fall back to the instance's model
 			const modelToUse = model || this.modelId
-			return await this.openAICompatibleEmbedder.createEmbeddings(texts, modelToUse)
+
+			this.log("debug", "Starting embedding creation", {
+				textCount: texts.length,
+				model: modelToUse,
+			})
+
+			const result = await this.openAICompatibleEmbedder.createEmbeddings(texts, modelToUse)
+
+			this.log("info", "Successfully created embeddings", {
+				count: result.embeddings.length,
+				usage: result.usage,
+			})
+
+			return result
 		} catch (error) {
+			this.logError("Failed to create embeddings", {
+				error: error instanceof Error ? error.message : String(error),
+				stack: error instanceof Error ? error.stack : undefined,
+			})
+
 			TelemetryService.instance.captureEvent(TelemetryEventName.CODE_INDEX_ERROR, {
 				error: error instanceof Error ? error.message : String(error),
 				stack: error instanceof Error ? error.stack : undefined,
@@ -68,10 +132,25 @@ export class GeminiEmbedder implements IEmbedder {
 	 */
 	async validateConfiguration(): Promise<{ valid: boolean; error?: string }> {
 		try {
+			this.log("info", "Starting configuration validation")
+
 			// Delegate validation to the OpenAI-compatible embedder
 			// The error messages will be specific to Gemini since we're using Gemini's base URL
-			return await this.openAICompatibleEmbedder.validateConfiguration()
+			const result = await this.openAICompatibleEmbedder.validateConfiguration()
+
+			if (result.valid) {
+				this.log("info", "Configuration validation successful")
+			} else {
+				this.logError("Configuration validation failed", { error: result.error })
+			}
+
+			return result
 		} catch (error) {
+			this.logError("Configuration validation error", {
+				error: error instanceof Error ? error.message : String(error),
+				stack: error instanceof Error ? error.stack : undefined,
+			})
+
 			TelemetryService.instance.captureEvent(TelemetryEventName.CODE_INDEX_ERROR, {
 				error: error instanceof Error ? error.message : String(error),
 				stack: error instanceof Error ? error.stack : undefined,