use serde::{Deserialize, Serialize};

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "snake_case")]
pub enum LlmChatMessageRole {
    System,
    User,
    Assistant,
}

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
pub struct LlmChatMessagePayload {
    pub role: LlmChatMessageRole,
    pub content: String,
}

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
pub struct LlmChatCompletionRequest {
    #[serde(default)]
    pub model: Option<String>,
    #[serde(default)]
    pub stream: bool,
    pub messages: Vec<LlmChatMessagePayload>,
}

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "camelCase")]
pub struct LlmChatCompletionResponse {
    pub id: Option<String>,
    pub model: String,
    pub content: String,
    pub finish_reason: Option<String>,
}

#[cfg(test)]
mod tests {
    use super::*;
    use serde_json::json;

    #[test]
    fn llm_chat_completion_request_keeps_openai_compatible_field_names() {
        let payload = serde_json::to_value(LlmChatCompletionRequest {
            model: Some("doubao-test".to_string()),
            stream: false,
            messages: vec![
                LlmChatMessagePayload {
                    role: LlmChatMessageRole::System,
                    content: "系统".to_string(),
                },
                LlmChatMessagePayload {
                    role: LlmChatMessageRole::User,
                    content: "用户".to_string(),
                },
            ],
        })
        .expect("payload should serialize");

        assert_eq!(payload["model"], json!("doubao-test"));
        assert_eq!(payload["stream"], json!(false));
        assert_eq!(payload["messages"][0]["role"], json!("system"));
    }
}