use crate::providers::{ChatCompletionRequest, LLMProvider, Message};

pub async fn generate_topic_description(
    provider: &dyn LLMProvider,
    first_user_message: &str,
) -> Result<String, Box<dyn std::error::Error + Send + Sync>> {
    let prompt = format!(
        "请根据用户的第一句话，用简短的词语（不超过15字）描述这个对话的主题或意图。只输出描述内容，不要其他解释。\n\n用户消息：{}",
        first_user_message
    );

    let request = ChatCompletionRequest {
        messages: vec![Message::user(prompt)],
        temperature: Some(0.3),
        max_tokens: Some(50),
        tools: None,
    };

    let response = provider.chat(request).await?;
    let description = response.content.trim().to_string();

    if description.is_empty() {
        return Err("LLM returned empty description".into());
    }

    if description.len() > 50 {
        Ok(description.chars().take(50).collect())
    } else {
        Ok(description)
    }
}