"""
命令片段管理：保存常用命令，快速发送到终端。
持久化到 ~/.sshclient/snippets.json
"""
import json
from pathlib import Path
from typing import List, Optional

CONFIG_DIR = Path.home() / ".sshclient"
SNIPPETS_FILE = CONFIG_DIR / "snippets.json"

# 预置片段（首次运行时自动添加）
DEFAULT_SNIPPETS = [
    {"name": "系统信息", "cmd": "uname -a && cat /etc/os-release"},
    {"name": "磁盘使用", "cmd": "df -h"},
    {"name": "内存使用", "cmd": "free -h"},
    {"name": "CPU 信息", "cmd": "lscpu | head -20"},
    {"name": "监听端口", "cmd": "ss -tlnp"},
    {"name": "所有连接", "cmd": "ss -tnp"},
    {"name": "进程 TOP10", "cmd": "ps aux --sort=-%cpu | head -11"},
    {"name": "内存 TOP10", "cmd": "ps aux --sort=-%mem | head -11"},
    {"name": "最近登录", "cmd": "last -10"},
    {"name": "系统日志", "cmd": "journalctl -n 50 --no-pager"},
    {"name": "DNS 解析", "cmd": "dig +short"},
    {"name": "网络路由", "cmd": "ip route show"},
    {"name": "网卡信息", "cmd": "ip addr show"},
    {"name": "防火墙状态", "cmd": "iptables -L -n --line-numbers"},
    {"name": "Docker 容器", "cmd": "docker ps -a"},
    {"name": "Docker 日志", "cmd": "docker logs --tail 50"},
    {"name": "systemctl 状态", "cmd": "systemctl status"},
    {"name": "重启服务", "cmd": "systemctl restart"},
    {"name": "定时任务", "cmd": "crontab -l"},
    {"name": "大文件 TOP10", "cmd": "find / -type f -size +100M 2>/dev/null | head -10"},
]


class SnippetManager:
    """命令片段的增删改查 + 持久化"""

    def __init__(self):
        CONFIG_DIR.mkdir(parents=True, exist_ok=True)
        self._snippets: List[dict] = []
        self._load()

    def _load(self):
        if SNIPPETS_FILE.exists():
            try:
                with open(SNIPPETS_FILE, "r", encoding="utf-8") as f:
                    self._snippets = json.load(f)
            except Exception:
                self._snippets = []
        if not self._snippets:
            self._snippets = [dict(s) for s in DEFAULT_SNIPPETS]
            self._save()

    def _save(self):
        with open(SNIPPETS_FILE, "w", encoding="utf-8") as f:
            json.dump(self._snippets, f, ensure_ascii=False, indent=2)

    def list_all(self) -> List[dict]:
        return list(self._snippets)

    def add(self, name: str, cmd: str) -> int:
        """添加片段，返回新索引"""
        snippet = {"name": name.strip(), "cmd": cmd}
        self._snippets.append(snippet)
        self._save()
        return len(self._snippets) - 1

    def update(self, index: int, name: str, cmd: str):
        if 0 <= index < len(self._snippets):
            self._snippets[index] = {"name": name.strip(), "cmd": cmd}
            self._save()

    def remove(self, index: int):
        if 0 <= index < len(self._snippets):
            del self._snippets[index]
            self._save()

    def move(self, index: int, direction: int):
        """direction: -1=上移, +1=下移"""
        new_idx = index + direction
        if 0 <= new_idx < len(self._snippets):
            self._snippets[index], self._snippets[new_idx] = \
                self._snippets[new_idx], self._snippets[index]
            self._save()