"""
用户目录管理模块
管理用户工作空间和文件系统结构
"""
from pathlib import Path
from typing import List, Optional, Dict
import os
import json
import yaml

# 全局配置
_config = None
CLOUD_ROOT = None
USERS_DB_FILE = None


def load_config():
    """加载系统配置"""
    global _config, CLOUD_ROOT, USERS_DB_FILE
    if _config is None:
        config_path = Path(__file__).parent.parent.parent / "system_config.yaml"
        with open(config_path, 'r', encoding='utf-8') as f:
            _config = yaml.safe_load(f)
        
        # 项目根目录 = server的上一级
        project_root = Path(__file__).parent.parent.parent.parent
        
        # 获取 cloud_root 路径
        cloud_root_rel = _config.get('storage', {}).get('cloud_root', './cloud')
        CLOUD_ROOT = (project_root / cloud_root_rel).resolve()
        
        # 用户数据库文件在 server/ 目录下
        USERS_DB_FILE = Path(__file__).parent.parent.parent / "users.json"
    
    return _config


# 初始化配置
load_config()


def load_users_db() -> Dict:
    """加载用户数据库"""
    if not USERS_DB_FILE.exists():
        # 创建默认数据库
        default_db = {
            "users": [
                {
                    "username": "guest",
                    "display_name": "访客",
                    "created_at": "2026-01-07T00:00:00Z",
                    "active": True
                }
            ]
        }
        save_users_db(default_db)
        return default_db
    
    try:
        with open(USERS_DB_FILE, 'r', encoding='utf-8') as f:
            return json.load(f)
    except Exception as e:
        print(f"⚠️ 加载用户数据库失败: {e}")
        return {"users": []}


def save_users_db(db: Dict) -> bool:
    """保存用户数据库"""
    try:
        USERS_DB_FILE.parent.mkdir(parents=True, exist_ok=True)
        with open(USERS_DB_FILE, 'w', encoding='utf-8') as f:
            json.dump(db, f, indent=2, ensure_ascii=False)
        return True
    except Exception as e:
        print(f"⚠️ 保存用户数据库失败: {e}")
        return False


def get_active_users() -> List[str]:
    """获取所有活跃用户名列表"""
    db = load_users_db()
    return [
        user["username"] 
        for user in db.get("users", []) 
        if user.get("active", True)
    ]


def user_exists(username: str) -> bool:
    """检查用户是否存在"""
    return username in get_active_users()

def init_base_structure():
    """初始化基础文件系统结构"""
    # 创建云存储根目录
    CLOUD_ROOT.mkdir(exist_ok=True)
    
    # 创建基础目录
    base_dirs = [
        CLOUD_ROOT / "users",
        CLOUD_ROOT / "shared",
        CLOUD_ROOT / "temp",
    ]
    
    for dir_path in base_dirs:
        dir_path.mkdir(exist_ok=True)
    
    # 从数据库创建用户目录
    active_users = get_active_users()
    for user in active_users:
        create_user_workspace(user)
    
    print(f"✅ 文件系统初始化完成: {CLOUD_ROOT}")
    print(f"✅ 已激活用户: {', '.join(active_users)}")


def create_user_workspace(username: str) -> Path:
    """
    创建用户工作空间
    
    Args:
        username: 用户名
        
    Returns:
        用户根目录路径
    """
    user_root = CLOUD_ROOT / "users" / username
    user_root.mkdir(parents=True, exist_ok=True)
    
    # 创建用户子目录
    subdirs = ["data", "workflows", "results", "cache"]
    for subdir in subdirs:
        (user_root / subdir).mkdir(exist_ok=True)
    
    return user_root


def get_user_root(username: str) -> Path:
    """获取用户根目录"""
    user_root = CLOUD_ROOT / "users" / username
    if not user_root.exists():
        return create_user_workspace(username)
    return user_root


def get_user_path(username: str, relative_path: str = "") -> Path:
    """
    获取用户文件的绝对路径
    
    Args:
        username: 用户名
        relative_path: 相对路径（相对于用户根目录）
        
    Returns:
        绝对路径
    """
    user_root = get_user_root(username)
    if relative_path:
        return user_root / relative_path
    return user_root


def list_users() -> List[str]:
    """列出所有活跃用户（从数据库）"""
    return get_active_users()


class UserContext:
    """用户上下文管理"""
    
    def __init__(self, username: str):
        self.username = username
        self.root = get_user_root(username)
    
    def get_path(self, relative_path: str = "") -> Path:
        """获取相对于用户根目录的路径"""
        if relative_path:
            return self.root / relative_path
        return self.root
    
    def ensure_dir(self, relative_path: str):
        """确保目录存在"""
        path = self.get_path(relative_path)
        path.mkdir(parents=True, exist_ok=True)
        return path
    
    def list_dir(self, relative_path: str = ""):
        """列出目录内容"""
        path = self.get_path(relative_path)
        if not path.exists():
            return []
        return list(path.iterdir())