import { useMemo } from "react";
import {
extractAssistantContent,
parseChatMessageOutput,
} from "@phoenix/schemas/experimentOutputSchemas";
import { useUnnestedValue } from "./useUnnestedValue";
/**
* Discriminated union for extracted output content.
* When `isExtracted` is true, `content` is guaranteed to be a string.
* When `isExtracted` is false, `content` is the original value type.
*/
export type ExtractedOutputContent<T> =
| {
/** Content was successfully extracted as a renderable string */
isExtracted: true;
/** The extracted string content */
content: string;
}
| {
/** Content could not be extracted, returning original value */
isExtracted: false;
/** The original value, unchanged */
content: T;
};
/**
* Hook that attempts to extract renderable string content from experiment outputs.
*
* Supports two formats:
* 1. Chat message format: `{ messages: [{ role: "assistant", content: "..." }] }`
* 2. Single-key object: `{ response: "..." }` or `{ output: "..." }`
*
* @param value - The experiment output value to analyze
* @returns Discriminated union - when `isExtracted` is true, `content` is a string
*
* @example
* const result = useExtractedOutputContent(output);
* if (result.isExtracted) {
* // TypeScript knows content is string here
* return <MarkdownBlock>{result.content}</MarkdownBlock>;
* }
* // TypeScript knows content is the original type here
* return <DynamicContent value={result.content} />;
*/
export function useExtractedOutputContent<T>(
value: T
): ExtractedOutputContent<T> {
// Parse both formats upfront (hooks must be called unconditionally)
const chatOutput = useMemo(() => parseChatMessageOutput(value), [value]);
const { value: unnestedValue, wasUnnested } = useUnnestedValue(value);
// Try chat message format first
if (chatOutput) {
const assistantContent = extractAssistantContent(chatOutput);
if (assistantContent !== null) {
return {
isExtracted: true,
content: assistantContent,
};
}
}
// Try single-key object format (e.g., { "response": "..." })
// useUnnestedValue returns wasUnnested: true if it was a single-key object with string value
if (wasUnnested) {
return {
isExtracted: true,
content: unnestedValue,
};
}
// Fall back to original value
return {
isExtracted: false,
content: value,
};
}
