"""主机注册表 - 管理多台 libvirt 宿主机"""
import json
import os
import time
import uuid
import logging
from typing import Optional
from pydantic import BaseModel, Field
from app.config import settings

logger = logging.getLogger(__name__)

# 数据存储目录
DATA_DIR = os.environ.get("KVM_DATA_DIR", "/var/lib/kvm-manager")
HOSTS_FILE = os.path.join(DATA_DIR, "hosts.json")


class HostInfo(BaseModel):
    """主机信息模型"""
    id: str = Field(..., description="主机唯一ID")
    name: str = Field(..., description="主机名称")
    uri: str = Field(..., description="libvirt 连接 URI")
    type: str = Field("local", description="连接类型: local/tcp/ssh")
    ssh_key_path: Optional[str] = Field(None, description="SSH 私钥路径（ssh 模式）")
    status: str = "unknown"
    created_at: float = Field(default_factory=time.time)
    last_seen: Optional[float] = None


class HostCreate(BaseModel):
    """创建主机请求"""
    name: str = Field(..., description="主机名称")
    uri: str = Field(..., description="libvirt 连接 URI，如 qemu+tcp://192.168.1.2/system")
    ssh_key_path: Optional[str] = Field(None, description="SSH 私钥路径（ssh 模式）")


def _detect_type(uri: str) -> str:
    """根据 URI 判断连接类型"""
    if uri.startswith("qemu+ssh://"):
        return "ssh"
    elif uri.startswith("qemu+tcp://"):
        return "tcp"
    return "local"


def _ensure_data_dir():
    """确保数据目录存在"""
    os.makedirs(DATA_DIR, exist_ok=True)


def _load_hosts() -> dict:
    """从文件加载主机列表"""
    if not os.path.exists(HOSTS_FILE):
        return {}
    try:
        with open(HOSTS_FILE, "r") as f:
            return json.load(f)
    except (json.JSONDecodeError, IOError):
        return {}


def _save_hosts(data: dict):
    """保存主机列表到文件"""
    _ensure_data_dir()
    with open(HOSTS_FILE, "w") as f:
        json.dump(data, f, indent=2, ensure_ascii=False)


def _init_local_host() -> dict:
    """初始化本机默认主机"""
    return HostInfo(
        id="local",
        name="本机",
        uri=settings.LIBVIRT_URI,
        type="local",
        status="unknown",
    ).model_dump()


def list_hosts() -> list[HostInfo]:
    """列出所有已注册主机"""
    data = _load_hosts()
    if not data:
        # 首次运行，初始化本机
        local = _init_local_host()
        data["local"] = local
        _save_hosts(data)
    return [HostInfo(**h) for h in data.values()]


def get_host(host_id: str) -> Optional[HostInfo]:
    """获取单个主机信息"""
    data = _load_hosts()
    if host_id not in data:
        return None
    return HostInfo(**data[host_id])


def add_host(req: HostCreate) -> HostInfo:
    """添加新主机"""
    data = _load_hosts()
    if not data:
        data["local"] = _init_local_host()

    host_id = req.name.lower().replace(" ", "-").replace(".", "-")
    # 确保ID唯一
    if host_id in data:
        host_id = f"{host_id}-{uuid.uuid4().hex[:6]}"

    host_type = _detect_type(req.uri)

    # 构建 SSH URI
    uri = req.uri
    if host_type == "ssh" and req.ssh_key_path:
        # 在 URI 中嵌入 key 提示，实际连接时由 libvirt ssh driver 使用
        pass

    host = HostInfo(
        id=host_id,
        name=req.name,
        uri=uri,
        type=host_type,
        ssh_key_path=req.ssh_key_path,
        status="unknown",
        created_at=time.time(),
    )
    data[host_id] = host.model_dump()
    _save_hosts(data)
    return host


def remove_host(host_id: str) -> bool:
    """删除主机（local 不可删）"""
    if host_id == "local":
        return False
    data = _load_hosts()
    if host_id not in data:
        return False
    del data[host_id]
    _save_hosts(data)
    return True


def update_host_status(host_id: str, status: str):
    """更新主机在线状态"""
    data = _load_hosts()
    if host_id in data:
        data[host_id]["status"] = status
        data[host_id]["last_seen"] = time.time()
        _save_hosts(data)


def test_connection(uri: str) -> dict:
    """测试 libvirt 连接是否可用"""
    import libvirt
    try:
        conn = libvirt.openReadOnly(uri)
        if conn:
            info = conn.getInfo()
            result = {
                "success": True,
                "hostname": conn.getHostname(),
                "hypervisor": conn.getType(),
                "cpu_cores": info[2],
                "memory_mb": info[1],  # getInfo()[1] 已经是 MiB 单位
                "libvirt_version": conn.getLibVersion(),
            }
            conn.close()
            return result
        else:
            return {"success": False, "error": "无法建立连接"}
    except libvirt.libvirtError as e:
        return {"success": False, "error": str(e)}
    except Exception as e:
        return {"success": False, "error": str(e)}