use crate::command::adapter::{AdapterError, InputAdapter};
use crate::command::context::AdapterContext;
use crate::command::Command;

/// Channel 输入适配器
///
/// 将 Channel 消息中的文本命令（如 "/new", "/save"）转换为 Command
pub struct ChannelInputAdapter;

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

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

impl InputAdapter for ChannelInputAdapter {
    fn try_parse(
        &self,
        input: &str,
        _ctx: AdapterContext,
    ) -> Result<Option<Command>, AdapterError> {
        let trimmed = input.trim();

        // 解析 /new 命令
        if trimmed == "/new" {
            return Ok(Some(Command::CreateSession { title: None }));
        }

        if let Some(title) = trimmed.strip_prefix("/new ") {
            let title = title.trim();
            return Ok(Some(Command::CreateSession {
                title: Some(title.to_string()),
            }));
        }

        // 解析 /save 命令 - 保存当前话题
        if trimmed == "/save" {
            return Ok(Some(Command::SaveTopic {
                filepath: None,
                include_subagents: false,
            }));
        }

        if let Some(args) = trimmed.strip_prefix("/save ") {
            let args = args.trim();
            let parts: Vec<&str> = args.split_whitespace().collect();

            // 解析参数
            let mut include_subagents = false;
            let mut filepath = None;

            for part in parts {
                if part == "+sub" {
                    include_subagents = true;
                } else if !part.is_empty() {
                    // 非特殊参数视为文件路径
                    filepath = Some(part.to_string());
                }
            }

            return Ok(Some(Command::SaveTopic {
                filepath,
                include_subagents,
            }));
        }

        // 解析 /save-session 命令 - 保存整个会话
        if trimmed == "/save-session" {
            return Ok(Some(Command::SaveSession {
                filepath: None,
                include_all: false,
                include_subagents: false,
            }));
        }

        if let Some(args) = trimmed.strip_prefix("/save-session ") {
            let args = args.trim();
            let parts: Vec<&str> = args.split_whitespace().collect();

            // 解析参数
            let mut include_all = false;
            let mut include_subagents = false;
            let mut filepath = None;

            for part in parts {
                if part == "all" {
                    include_all = true;
                } else if part == "+sub" {
                    include_subagents = true;
                } else if !part.is_empty() {
                    // 非特殊参数视为文件路径
                    filepath = Some(part.to_string());
                }
            }

            return Ok(Some(Command::SaveSession {
                filepath,
                include_all,
                include_subagents,
            }));
        }

        // 解析 /list 命令
        if trimmed == "/list" {
            return Ok(Some(Command::ListSessions {
                include_archived: false,
            }));
        }

        if trimmed == "/list all" {
            return Ok(Some(Command::ListSessions {
                include_archived: true,
            }));
        }

        // 解析 /use 命令 - 切换话题（支持 topic_id 或序号）
        if let Some(topic_id) = trimmed.strip_prefix("/use ") {
            let topic_id = topic_id.trim();
            return Ok(Some(Command::SwitchTopic {
                topic_id: topic_id.to_string(),
            }));
        }

        // 解析 /current 命令 - 获取当前会话信息
        if trimmed == "/current" {
            return Ok(Some(Command::GetCurrentSession));
        }

        // 解析 /help 命令 - 显示所有支持的命令
        if trimmed == "/help" {
            return Ok(Some(Command::Help));
        }

        // 不是命令，返回 None
        Ok(None)
    }
}