// src/agent/team/inbox.rs
//
// 团队消息邮箱系统。
// 使用 .team/{session_id}/inbox/{agent_name}.jsonl 作为 append-only 消息文件。

use chrono::Utc;
use serde::{Deserialize, Serialize};
use std::io::Write;
use std::path::{Path, PathBuf};

/// 团队消息类型
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "lowercase")]
pub enum TeamMessageType {
    Task,
    Result,
    Question,
    Answer,
    Status,
}

impl TeamMessageType {
    pub fn as_str(&self) -> &str {
        match self {
            TeamMessageType::Task => "task",
            TeamMessageType::Result => "result",
            TeamMessageType::Question => "question",
            TeamMessageType::Answer => "answer",
            TeamMessageType::Status => "status",
        }
    }
}

/// 团队消息
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TeamMessage {
    pub from: String,
    pub to: String,
    pub content: String,
    pub msg_type: TeamMessageType,
    pub timestamp: String,
}

impl TeamMessage {
    pub fn new(from: &str, to: &str, content: &str, msg_type: TeamMessageType) -> Self {
        TeamMessage {
            from: from.to_string(),
            to: to.to_string(),
            content: content.to_string(),
            msg_type,
            timestamp: Utc::now().to_rfc3339(),
        }
    }
}

/// 获取团队目录路径
pub fn team_dir(session_id: &str) -> PathBuf {
    PathBuf::from(".team").join(session_id)
}

/// 获取指定 agent 的收件箱路径
pub fn inbox_path(team_dir: &Path, agent_name: &str) -> PathBuf {
    team_dir.join("inbox").join(format!("{}.jsonl", agent_name))
}

/// 向收件箱追加一条消息
pub fn append_message(team_dir: &Path, agent_name: &str, msg: &TeamMessage) -> std::io::Result<()> {
    let inbox = inbox_path(team_dir, agent_name);
    if let Some(parent) = inbox.parent() {
        std::fs::create_dir_all(parent)?;
    }
    let line = serde_json::to_string(msg).unwrap_or_default();
    let mut file = std::fs::OpenOptions::new()
        .create(true)
        .append(true)
        .open(&inbox)?;
    file.write_all(line.as_bytes())?;
    file.write_all(b"\n")?;
    Ok(())
}

/// 读取并清空收件箱
pub fn drain_inbox(team_dir: &Path, agent_name: &str) -> Vec<TeamMessage> {
    let inbox = inbox_path(team_dir, agent_name);
    if !inbox.exists() {
        return Vec::new();
    }

    let content = match std::fs::read_to_string(&inbox) {
        Ok(c) => c,
        Err(_) => return Vec::new(),
    };

    let messages: Vec<TeamMessage> = content
        .lines()
        .filter(|l| !l.is_empty())
        .filter_map(|l| serde_json::from_str(l).ok())
        .collect();

    // 清空文件
    let _ = std::fs::write(&inbox, "");

    messages
}

/// 检查收件箱中是否有未读消息
pub fn has_pending(team_dir: &Path, agent_name: &str) -> bool {
    let inbox = inbox_path(team_dir, agent_name);
    inbox.exists() && inbox.metadata().map(|m| m.len() > 0).unwrap_or(false)
}