using System;
using System.Collections.Generic;

/// <summary>
/// 用户数据库结构
/// 支持版本管理和用户集合
/// </summary>
[System.Serializable]
public class UserDatabase
{
    public string Version = "1.0";
    public List<UserInfo> Users = new List<UserInfo>();

    /// <summary>
    /// 查找活跃用户
    /// 用户名区分大小写
    /// </summary>
    /// <param name="username">用户名</param>
    /// <returns>用户信息，如果不存在或不活跃则返回null</returns>
    public UserInfo FindUser(string username)
    {
        // 修改为区分大小写的比较
        return Users.Find(u => u.Username == username && u.IsActive);
    }
    
    /// <summary>
    /// 获取所有活跃用户
    /// </summary>
    /// <returns>活跃用户列表</returns>
    public List<UserInfo> GetActiveUsers()
    {
        return Users.FindAll(u => u.IsActive);
    }
    
    /// <summary>
    /// 获取管理员用户列表
    /// </summary>
    /// <returns>管理员用户列表</returns>
    public List<UserInfo> GetAdminUsers()
    {
        return Users.FindAll(u => u.IsActive && u.Role == UserRole.Admin);
    }
}

/// <summary>
/// 扩展的用户信息类
/// 包含完整的用户数据和时间戳
/// </summary>
[System.Serializable]
public class UserInfo
{
    public string Username;
    public string Password;
    public UserRole Role;
    public DateTime CreatedTime;
    public DateTime LastLoginTime;
    public DateTime PasswordChangedTime;
    public bool IsActive = true;
    
    /// <summary>
    /// 获取用户显示名称
    /// </summary>
    /// <returns>包含角色信息的显示名称</returns>
    public string GetDisplayName()
    {
        string displayName = Username;
        if (Role == UserRole.Admin)
        {
            displayName += " [管理员]";
        }
        return displayName;
    }
    
    /// <summary>
    /// 检查密码是否需要更新（例如：超过指定天数）
    /// </summary>
    /// <param name="maxDays">最大天数</param>
    /// <returns>是否需要更新</returns>
    public bool IsPasswordExpired(int maxDays = 90)
    {
        if (PasswordChangedTime == default(DateTime))
        {
            // 如果从未修改过密码，使用创建时间
            return (DateTime.Now - CreatedTime).Days > maxDays;
        }
        return (DateTime.Now - PasswordChangedTime).Days > maxDays;
    }
}

/// <summary>
/// 用户操作日志事件
/// 记录用户的各种操作行为
/// </summary>
[System.Serializable]
public class UserLogEvent
{
    public int Id;
    public string Username;
    public string Operation;        // 操作类型：登录、登出、修改密码、创建用户等
    public string OperationDetails; // 操作详情
    public DateTime Timestamp;
    public string IPAddress;        // IP地址（如果需要）
    public bool IsSuccessful;       // 操作是否成功
    
    public UserLogEvent()
    {
        Timestamp = DateTime.Now;
        IsSuccessful = true;
    }
    
    public UserLogEvent(string username, string operation, string details = null, bool successful = true)
    {
        Username = username;
        Operation = operation;
        OperationDetails = details;
        IsSuccessful = successful;
        Timestamp = DateTime.Now;
    }
}

/// <summary>
/// 系统使用日志事件（保持向后兼容）
/// </summary>
[System.Serializable]
public class UseLogEvent
{
    public int Id;
    public string OperationContentText;
    public DateTime Time;
    public string Account;
    
    public UseLogEvent()
    {
        Time = DateTime.Now;
    }
    
    public UseLogEvent(string account, string operation)
    {
        Account = account;
        OperationContentText = operation;
        Time = DateTime.Now;
    }
}