use crate::command::adapter::{AdapterError, InputAdapter, OutputAdapter};
use crate::command::context::AdapterContext;
use crate::command::response::{CommandResponse, MessageKind};
use crate::command::Command;
use crate::protocol::WsOutbound;

/// WebSocket 输入适配器
///
/// 将 WebSocket 的 JSON 输入直接反序列化为 Command
pub struct WebSocketInputAdapter;

impl WebSocketInputAdapter {
    /// 创建新的 WebSocket 输入适配器
    pub fn new() -> Self {
        Self
    }
}

impl Default for WebSocketInputAdapter {
    fn default() -> Self {
        Self::new()
    }
}

impl InputAdapter for WebSocketInputAdapter {
    fn try_parse(
        &self,
        input: &str,
        _ctx: AdapterContext,
    ) -> Result<Option<Command>, AdapterError> {
        // 尝试将 JSON 反序列化为 Command
        // 如果失败，说明不是 Command 消息，返回 None
        match serde_json::from_str(input) {
            Ok(cmd) => Ok(Some(cmd)),
            Err(_) => Ok(None),
        }
    }
}

/// WebSocket 输出适配器
///
/// 将 CommandResponse 转换为 WsOutbound 消息列表
pub struct WebSocketOutputAdapter;

impl WebSocketOutputAdapter {
    /// 创建新的 WebSocket 输出适配器
    pub fn new() -> Self {
        Self
    }
}

impl Default for WebSocketOutputAdapter {
    fn default() -> Self {
        Self::new()
    }
}

impl OutputAdapter for WebSocketOutputAdapter {
    type Output = Vec<WsOutbound>;

    fn adapt(&self, response: CommandResponse) -> Vec<WsOutbound> {
        let mut outbounds = Vec::new();

        // 如果出错，返回错误消息
        if let Some(error) = response.error {
            outbounds.push(WsOutbound::Error {
                code: error.code,
                message: error.message,
            });
            return outbounds;
        }

        // 转换响应消息为 WsOutbound
        for msg in &response.messages {
            let outbound = match msg.kind {
                MessageKind::Text => WsOutbound::AssistantResponse {
                    id: response.request_id.to_string(),
                    content: msg.content.clone(),
                    role: "assistant".to_string(),
                },
                MessageKind::Notification => {
                    // 根据元数据判断具体类型
                    if let Some(topics_json) = response.metadata.get("topics") {
                        // Topic 列表响应 - 优先检查 topics
                        match serde_json::from_str::<Vec<crate::protocol::TopicSummary>>(topics_json) {
                            Ok(topics) => {
                                let session_id = response.metadata.get("session_id")
                                    .cloned()
                                    .unwrap_or_default();
                                WsOutbound::TopicList {
                                    topics,
                                    session_id,
                                }
                            }
                            Err(_) => WsOutbound::AssistantResponse {
                                id: response.request_id.to_string(),
                                content: msg.content.clone(),
                                role: "assistant".to_string(),
                            },
                        }
                    } else if let Some(session_id) = response.metadata.get("session_id") {
                        // 有 session_id 但没有 topic_id 的是创建会话
                        if response.metadata.get("topic_id").is_none() {
                            WsOutbound::SessionCreated {
                                session_id: session_id.clone(),
                                title: msg.content.clone(),
                            }
                        } else {
                            // 加载会话
                            let message_count = response.metadata.get("message_count")
                                .and_then(|s| s.parse().ok())
                                .unwrap_or(0);
                            WsOutbound::SessionLoaded {
                                session_id: session_id.clone(),
                                title: msg.content.clone(),
                                message_count,
                            }
                        }
                    } else if let Some(topic_id) = response.metadata.get("topic_id") {
                        // 只有 topic_id，可能是加载话题
                        let message_count = response.metadata.get("message_count")
                            .and_then(|s| s.parse().ok())
                            .unwrap_or(0);
                        WsOutbound::SessionLoaded {
                            session_id: topic_id.clone(),
                            title: msg.content.clone(),
                            message_count,
                        }
                    } else if let Some(channels_json) = response.metadata.get("channels") {
                        // 通道列表响应
                        match serde_json::from_str::<Vec<crate::protocol::Channel>>(channels_json) {
                            Ok(channels) => WsOutbound::ChannelList { channels },
                            Err(_) => WsOutbound::AssistantResponse {
                                id: response.request_id.to_string(),
                                content: msg.content.clone(),
                                role: "assistant".to_string(),
                            },
                        }
                    } else if let Some(sessions_json) = response.metadata.get("sessions") {
                        // 会话列表响应
                        match serde_json::from_str::<Vec<crate::protocol::SessionSummary>>(sessions_json) {
                            Ok(sessions) => {
                                let channel_name = response.metadata.get("channel_name").cloned();
                                WsOutbound::SessionList {
                                    sessions,
                                    current_session_id: None,
                                    channel_name,
                                }
                            }
                            Err(_) => WsOutbound::AssistantResponse {
                                id: response.request_id.to_string(),
                                content: msg.content.clone(),
                                role: "assistant".to_string(),
                            },
                        }
                    } else if let Some(topics_json) = response.metadata.get("topics") {
                        // Topic 列表响应
                        match serde_json::from_str::<Vec<crate::protocol::TopicSummary>>(topics_json) {
                            Ok(topics) => {
                                let session_id = response.metadata.get("session_id")
                                    .cloned()
                                    .unwrap_or_default();
                                WsOutbound::TopicList {
                                    topics,
                                    session_id,
                                }
                            }
                            Err(_) => WsOutbound::AssistantResponse {
                                id: response.request_id.to_string(),
                                content: msg.content.clone(),
                                role: "assistant".to_string(),
                            },
                        }
                    } else {
                        // 默认通知
                        WsOutbound::AssistantResponse {
                            id: response.request_id.to_string(),
                            content: msg.content.clone(),
                            role: "assistant".to_string(),
                        }
                    }
                }
                MessageKind::Error => WsOutbound::Error {
                    code: "RESPONSE_ERROR".to_string(),
                    message: msg.content.clone(),
                },
                _ => WsOutbound::AssistantResponse {
                    id: response.request_id.to_string(),
                    content: msg.content.clone(),
                    role: "assistant".to_string(),
                },
            };
            outbounds.push(outbound);
        }

        outbounds
    }
}

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

    #[test]
    fn test_websocket_input_adapter_valid_command() {
        let adapter = WebSocketInputAdapter::new();
        let ctx = AdapterContext::new("test");

        let json = r#"{"type":"create_session","title":"my session"}"#;
        let result = adapter.try_parse(json, ctx).unwrap();

        assert!(result.is_some());
        let cmd = result.unwrap();
        assert!(matches!(
            cmd,
            Command::CreateSession {
                title: Some(ref t)
            } if t == "my session"
        ));
    }

    #[test]
    fn test_websocket_input_adapter_invalid_json() {
        let adapter = WebSocketInputAdapter::new();
        let ctx = AdapterContext::new("test");

        let json = "not a command";
        let result = adapter.try_parse(json, ctx).unwrap();

        assert!(result.is_none());
    }

    #[test]
    fn test_websocket_output_adapter_session_created() {
        let adapter = WebSocketOutputAdapter::new();
        let request_id = uuid::Uuid::new_v4();
        let response = CommandResponse::success(request_id)
            .with_message(MessageKind::Notification, "My Session")
            .with_metadata("session_id", "abc123");

        let outbounds = adapter.adapt(response);

        assert_eq!(outbounds.len(), 1);
        assert!(matches!(outbounds[0], WsOutbound::SessionCreated { .. }));
    }
}