import threading
import time
import json
import os
import random
from typing import Optional, Dict, Any, List
from vs_log_macros import VSC_DEBUG, VSC_WARN, VSC_INFO, VSC_ERROR

class AccountManager:
    """
    账户管理器 (仅本地配置文件模式)
    读取 config/accounts.json
    """
    _instance = None
    _lock = threading.RLock()

    def __new__(cls):
        with cls._lock:
            if cls._instance is None:
                cls._instance = super().__new__(cls)
                cls._instance._init_data()
            return cls._instance

    @staticmethod
    def Instance():
        return AccountManager()

    def _init_data(self):
        self._accounts: Dict[str, List[Dict]] = {} # pool_name -> [account_dict]
        self._account_lock = threading.RLock()
        self._config_path = "config/accounts.json"
        
        # 初始化时加载
        self.reload_config()

    def reload_config(self):
        """(重新)加载本地配置文件"""
        if not os.path.exists(self._config_path):
            VSC_WARN("acc_mgr", f"Config file not found: {self._config_path}. Account pools are empty.")
            return

        try:
            with open(self._config_path, 'r', encoding='utf-8') as f:
                data = json.load(f)
            
            count = 0
            with self._account_lock:
                self._accounts.clear()
                for pool_name, acc_list in data.items():
                    processed_list = []
                    for acc in acc_list:
                        # 确保必要字段存在，并初始化状态
                        if "id" not in acc or "username" not in acc:
                            continue
                            
                        acc.setdefault('lock_until', 0)
                        # bound_data 用于存储绑定的预约人信息，配置文件里可以是 null
                        acc.setdefault('bound_data', None) 
                        
                        processed_list.append(acc)
                        count += 1
                    
                    self._accounts[pool_name] = processed_list
                    
            VSC_INFO("acc_mgr", f"Loaded {count} accounts from {self._config_path}")
            
        except json.JSONDecodeError:
            VSC_ERROR("acc_mgr", f"Invalid JSON format in {self._config_path}")
        except Exception as e:
            VSC_ERROR("acc_mgr", f"Failed to load config: {e}")

    def next(self, pool_name: str, lock_duration: float = 60.0) -> Optional[Dict[str, Any]]:
        """
        获取下一个可用账号 (随机策略)，并自动锁定指定时长。
        
        @param pool_name: 账号池名称
        @param lock_duration: 锁定时间(秒)，默认60秒
        @return: 账号信息字典 或 None
        """
        with self._account_lock:
            accounts = self._accounts.get(pool_name, [])
            if not accounts:
                VSC_WARN("acc_mgr", "No accounts found for pool '%s'", pool_name)
                return None

            now = time.time()
            # 筛选未锁定的账号 (lock_until 必须小于等于当前时间)
            available = [acc for acc in accounts if acc.get("lock_until", 0) <= now]
            
            if not available:
                VSC_DEBUG("acc_mgr", "Pool '%s' has %d accounts but all are locked.", pool_name, len(accounts))
                return None

            # 随机选择
            selected = random.choice(available)
            
            # === 关键修改：立即更新锁定时间 ===
            # 直接修改引用的对象，确保其他线程或其他逻辑能感知到该账号已被占用
            selected["lock_until"] = now + lock_duration
            
            VSC_DEBUG("acc_mgr", "Selected account %s (id=%s) from pool %s, locked for %.1fs", 
                      selected.get("username"), selected.get("id"), pool_name, lock_duration)
            
            # 返回账号数据的浅拷贝，防止调用者无意修改 Manager 内部的其他字段
            # (虽然 Python dict 是引用传递，但 copy 一下是个好习惯，除非你需要引用修改)
            return selected.copy()

    def lock(self, pool_name: str, account_id: int, duration_seconds: int):
        """
        锁定账号一段时间
        """
        with self._account_lock:
            accounts = self._accounts.get(pool_name, [])
            for acc in accounts:
                if acc["id"] == account_id:
                    acc["lock_until"] = time.time() + duration_seconds
                    VSC_INFO("acc_mgr", "Locked account %s (id=%d) for %ds", 
                             acc.get("username"), account_id, duration_seconds)
                    return
            VSC_WARN("acc_mgr", "Account %d not found in pool %s to lock", account_id, pool_name)

    def remove(self, pool_name: str, account_id: int, reason: str = "success", extra_data: dict = None):
        """
        从内存中移除账号 (预订成功后不再使用)
        注意：这不会修改磁盘上的 accounts.json 文件，重启程序后账号会恢复
        """
        with self._account_lock:
            accounts = self._accounts.get(pool_name, [])
            target_acc = None
            for acc in accounts:
                if acc["id"] == account_id:
                    target_acc = acc
                    break
            
            if target_acc:
                accounts.remove(target_acc)
                VSC_INFO("acc_mgr", "Removed account %s (id=%d) from memory pool %s. Reason: %s", 
                         target_acc.get("username"), account_id, pool_name, reason)
            else:
                VSC_WARN("acc_mgr", "Attempt to remove non-existent account %d from pool %s", account_id, pool_name)