import type { ChatMessage } from '../store/useAppStore';

/** Id of the most recent assistant message, or null when there is none. */
export function findLastAssistantId(messages: ChatMessage[]): string | null {
    for (let i = messages.length - 1; i >= 0; i--) {
        if (messages[i].role === 'assistant') return messages[i].id;
    }
    return null;
}

/** True while the model has been asked to answer but has not produced any text yet. */
export function shouldShowTypingIndicator(messages: ChatMessage[], isStreaming: boolean): boolean {
    if (!isStreaming) return false;
    const last = messages[messages.length - 1];
    return last?.role === 'assistant' && last.content === '';
}