feat(chat): unify error handling and logging for chat operations, enhancing clarity and consistency in error reporting

surfsense_web/lib/chat/chat-error-classifier.ts

@@ -0,0 +1,273 @@
+export type ChatFlow = "new" | "resume" | "regenerate";
+
+export type ChatErrorKind =
+	| "premium_quota_exhausted"
+	| "auth_expired"
+	| "rate_limited"
+	| "network_offline"
+	| "stream_interrupted"
+	| "stream_parse_error"
+	| "tool_execution_error"
+	| "persist_message_failed"
+	| "server_error"
+	| "unknown";
+
+export type ChatErrorChannel = "pinned_inline" | "toast" | "silent";
+export type ChatTelemetryEvent = "chat_blocked" | "chat_error";
+export type ChatErrorSeverity = "info" | "warn" | "error";
+
+export interface NormalizedChatError {
+	kind: ChatErrorKind;
+	channel: ChatErrorChannel;
+	severity: ChatErrorSeverity;
+	telemetryEvent: ChatTelemetryEvent;
+	isExpected: boolean;
+	userMessage: string;
+	assistantMessage?: string;
+	rawMessage?: string;
+	errorCode?: string;
+	details?: Record<string, unknown>;
+}
+
+export interface RawChatErrorInput {
+	error: unknown;
+	flow: ChatFlow;
+	context?: {
+		searchSpaceId?: number;
+		threadId?: number | null;
+	};
+}
+
+export const PREMIUM_QUOTA_ASSISTANT_MESSAGE =
+	"I can’t continue with the current premium model because your premium tokens are exhausted. Switch to a free model or buy more tokens to continue.";
+
+function getErrorMessage(error: unknown): string {
+	if (error instanceof Error) return error.message;
+	if (typeof error === "string") return error;
+	try {
+		return JSON.stringify(error);
+	} catch {
+		return "Unknown error";
+	}
+}
+
+function getErrorCode(error: unknown, parsedJson: Record<string, unknown> | null): string | undefined {
+	if (error instanceof Error) {
+		const withCode = error as Error & { errorCode?: string };
+		if (withCode.errorCode) return withCode.errorCode;
+	}
+
+	if (typeof error === "object" && error !== null) {
+		const withCode = error as { errorCode?: unknown };
+		if (typeof withCode.errorCode === "string" && withCode.errorCode) {
+			return withCode.errorCode;
+		}
+	}
+
+	if (parsedJson) {
+		const topLevelCode = parsedJson.errorCode;
+		if (typeof topLevelCode === "string" && topLevelCode) {
+			return topLevelCode;
+		}
+	}
+
+	return undefined;
+}
+
+function parseEmbeddedJson(text: string): Record<string, unknown> | null {
+	const candidates = [text];
+	const firstBraceIdx = text.indexOf("{");
+	if (firstBraceIdx >= 0) {
+		candidates.push(text.slice(firstBraceIdx));
+	}
+	for (const candidate of candidates) {
+		try {
+			const parsed = JSON.parse(candidate);
+			if (typeof parsed === "object" && parsed !== null) {
+				return parsed as Record<string, unknown>;
+			}
+		} catch {
+			// noop
+		}
+	}
+	return null;
+}
+
+function inferProviderErrorType(parsedJson: Record<string, unknown> | null): string | undefined {
+	if (!parsedJson) return undefined;
+	const topLevelType = parsedJson.type;
+	if (typeof topLevelType === "string" && topLevelType) return topLevelType;
+	const nestedError = parsedJson.error;
+	if (typeof nestedError === "object" && nestedError !== null) {
+		const nestedType = (nestedError as Record<string, unknown>).type;
+		if (typeof nestedType === "string" && nestedType) return nestedType;
+	}
+	return undefined;
+}
+
+export function classifyChatError(input: RawChatErrorInput): NormalizedChatError {
+	const { error } = input;
+	const rawMessage = getErrorMessage(error);
+	const parsedJson = parseEmbeddedJson(rawMessage);
+	const errorCode = getErrorCode(error, parsedJson);
+	const providerErrorType = inferProviderErrorType(parsedJson);
+	const providerTypeNormalized = providerErrorType?.toLowerCase() ?? "";
+	const errorName = error instanceof Error ? error.name : undefined;
+
+	if (errorName === "AbortError") {
+		return {
+			kind: "stream_interrupted",
+			channel: "silent",
+			severity: "info",
+			telemetryEvent: "chat_error",
+			isExpected: true,
+			userMessage: "Request canceled.",
+			rawMessage,
+			errorCode,
+			details: { flow: input.flow },
+		};
+	}
+
+	if (errorCode === "PREMIUM_QUOTA_EXHAUSTED") {
+		return {
+			kind: "premium_quota_exhausted",
+			channel: "pinned_inline",
+			severity: "info",
+			telemetryEvent: "chat_blocked",
+			isExpected: true,
+			userMessage:
+				"Buy more tokens to continue with this model, or switch to a free model.",
+			assistantMessage: PREMIUM_QUOTA_ASSISTANT_MESSAGE,
+			rawMessage,
+			errorCode: errorCode ?? "PREMIUM_QUOTA_EXHAUSTED",
+			details: { flow: input.flow },
+		};
+	}
+
+	if (
+		errorCode === "AUTH_EXPIRED" ||
+		errorCode === "UNAUTHORIZED"
+	) {
+		return {
+			kind: "auth_expired",
+			channel: "toast",
+			severity: "warn",
+			telemetryEvent: "chat_error",
+			isExpected: true,
+			userMessage: "Your session expired. Please sign in again.",
+			rawMessage,
+			errorCode: errorCode ?? "AUTH_EXPIRED",
+			details: { flow: input.flow },
+		};
+	}
+
+	if (
+		errorCode === "RATE_LIMITED" ||
+		providerTypeNormalized === "rate_limit_error"
+	) {
+		return {
+			kind: "rate_limited",
+			channel: "toast",
+			severity: "warn",
+			telemetryEvent: "chat_blocked",
+			isExpected: true,
+			userMessage:
+				"This model is temporarily rate-limited. Please try again in a few seconds or switch models.",
+			rawMessage,
+			errorCode: errorCode ?? "RATE_LIMITED",
+			details: { flow: input.flow, providerErrorType },
+		};
+	}
+
+	if (
+		errorCode === "NETWORK_ERROR"
+	) {
+		return {
+			kind: "network_offline",
+			channel: "toast",
+			severity: "warn",
+			telemetryEvent: "chat_error",
+			isExpected: true,
+			userMessage: "Connection issue detected. Check your internet and try again.",
+			rawMessage,
+			errorCode: errorCode ?? "NETWORK_ERROR",
+			details: { flow: input.flow },
+		};
+	}
+
+	if (
+		errorCode === "STREAM_PARSE_ERROR"
+	) {
+		return {
+			kind: "stream_parse_error",
+			channel: "toast",
+			severity: "error",
+			telemetryEvent: "chat_error",
+			isExpected: false,
+			userMessage: "We hit a response formatting issue. Please try again.",
+			rawMessage,
+			errorCode: errorCode ?? "STREAM_PARSE_ERROR",
+			details: { flow: input.flow },
+		};
+	}
+
+	if (
+		errorCode === "TOOL_EXECUTION_ERROR"
+	) {
+		return {
+			kind: "tool_execution_error",
+			channel: "toast",
+			severity: "error",
+			telemetryEvent: "chat_error",
+			isExpected: false,
+			userMessage: "A tool failed while processing your request. Please try again.",
+			rawMessage,
+			errorCode: errorCode ?? "TOOL_EXECUTION_ERROR",
+			details: { flow: input.flow },
+		};
+	}
+
+	if (
+		errorCode === "PERSIST_MESSAGE_FAILED"
+	) {
+		return {
+			kind: "persist_message_failed",
+			channel: "toast",
+			severity: "error",
+			telemetryEvent: "chat_error",
+			isExpected: false,
+			userMessage: "Response generated, but saving failed. Please retry once.",
+			rawMessage,
+			errorCode: errorCode ?? "PERSIST_MESSAGE_FAILED",
+			details: { flow: input.flow },
+		};
+	}
+
+	if (
+		errorCode === "SERVER_ERROR"
+	) {
+		return {
+			kind: "server_error",
+			channel: "toast",
+			severity: "error",
+			telemetryEvent: "chat_error",
+			isExpected: false,
+			userMessage: "We couldn’t complete this response right now. Please try again.",
+			rawMessage,
+			errorCode: errorCode ?? "SERVER_ERROR",
+			details: { flow: input.flow, providerErrorType },
+		};
+	}
+
+	return {
+		kind: "unknown",
+		channel: "toast",
+		severity: "error",
+		telemetryEvent: "chat_error",
+		isExpected: false,
+		userMessage: "We couldn’t complete this response right now. Please try again.",
+		rawMessage,
+		errorCode,
+		details: { flow: input.flow, providerErrorType },
+	};
+}