using System;
using System.Collections.Generic;
using System.DirectoryServices;
using System.Linq;
using System.Runtime.InteropServices;
using System.Security.Principal;
using System.Text;
using System.Threading.Tasks;
 
namespace ADS.BLL
{
    public class ADHelper
    {
        ///
        ///域名
        ///
        private static string DomainName = ActiveDirectory.GetDomainName;
        ///
        /// LDAP 地址
        ///
        private static string LDAPDomain = "DC=" + ActiveDirectory.GetDomainName + ",DC=local";
        ///
        /// LDAP绑定路径
        ///
        private static string ADPath = "LDAP://" + ActiveDirectory.GetDomainName;
        ///
        ///登录帐号
        ///
        private static string ADUser = ActiveDirectory.GetUserName; //administrator
        ///
        ///登录密码
        ///
        private static string ADPassword = ConstantHelper.PASSWORD;
        ///
        ///扮演类实例
        ///
        private static IdentityImpersonation impersonate = new IdentityImpersonation(ADUser, ADPassword, DomainName);
 
        ///
        ///用户登录验证结果
        ///
        public enum LoginResult
        {
            ///
            ///正常登录
            ///
            LOGIN_USER_OK = 0,
            ///
            ///用户不存在
            ///
            LOGIN_USER_DOESNT_EXIST,
            ///
            ///用户帐号被禁用
            ///
            LOGIN_USER_ACCOUNT_INACTIVE,
            ///
            ///用户密码不正确
            ///
            LOGIN_USER_PASSWORD_INCORRECT
        }
 
        ///
        ///用户属性定义标志
        ///
        public enum ADS_USER_FLAG_ENUM
        {
            ///
            ///登录脚本标志。如果通过 ADSI LDAP 进行读或写操作时，该标志失效。如果通过 ADSI WINNT，该标志为只读。
            ///
            ADS_UF_SCRIPT = 0X0001,
            ///
            ///用户帐号禁用标志
            ///
            ADS_UF_ACCOUNTDISABLE = 0X0002,
            ///
            ///主文件夹标志
            ///
            ADS_UF_HOMEDIR_REQUIRED = 0X0008,
            ///
            ///过期标志
            ///
            ADS_UF_LOCKOUT = 0X0010,
            ///
            ///用户密码不是必须的
            ///
            ADS_UF_PASSWD_NOTREQD = 0X0020,
            ///
            ///密码不能更改标志
            ///
            ADS_UF_PASSWD_CANT_CHANGE = 0X0040,
            ///
            ///使用可逆的加密保存密码
            ///
            ADS_UF_ENCRYPTED_TEXT_PASSWORD_ALLOWED = 0X0080,
            ///
            ///本地帐号标志
            ///
            ADS_UF_TEMP_DUPLICATE_ACCOUNT = 0X0100,
            ///
            ///普通用户的默认帐号类型
            ///
            ADS_UF_NORMAL_ACCOUNT = 0X0200,
            ///
            ///跨域的信任帐号标志
            ///
            ADS_UF_INTERDOMAIN_TRUST_ACCOUNT = 0X0800,
            ///
            ///工作站信任帐号标志
            ///
            ADS_UF_WORKSTATION_TRUST_ACCOUNT = 0x1000,
            ///
            ///服务器信任帐号标志
            ///
            ADS_UF_SERVER_TRUST_ACCOUNT = 0X2000,
            ///
            ///密码永不过期标志
            ///
            ADS_UF_DONT_EXPIRE_PASSWD = 0X10000,
            ///
            /// MNS 帐号标志
            ///
            ADS_UF_MNS_LOGON_ACCOUNT = 0X20000,
            ///
            ///交互式登录必须使用智能卡
            ///
            ADS_UF_SMARTCARD_REQUIRED = 0X40000,
            ///
            ///当设置该标志时，服务帐号（用户或计算机帐号）将通过 Kerberos 委托信任
            ///
            ADS_UF_TRUSTED_FOR_DELEGATION = 0X80000,
            ///
            ///当设置该标志时，即使服务帐号是通过 Kerberos 委托信任的，敏感帐号不能被委托
            ///
            ADS_UF_NOT_DELEGATED = 0X100000,
            ///
            ///此帐号需要 DES 加密类型
            ///
            ADS_UF_USE_DES_KEY_ONLY = 0X200000,
            ///
            ///不要进行 Kerberos 预身份验证
            ///
            ADS_UF_DONT_REQUIRE_PREAUTH = 0X4000000,
            ///
            ///用户密码过期标志
            ///
            ADS_UF_PASSWORD_EXPIRED = 0X800000,
            ///
            ///用户帐号可委托标志
            ///
            ADS_UF_TRUSTED_TO_AUTHENTICATE_FOR_DELEGATION = 0X1000000
        }
 
        public ADHelper()
        {
            
        }
 
        #region GetDirectoryObject
 
        /// <summary>
        /// 获得DirectoryEntry对象实例,以当前用户登陆AD
        /// </summary>
        /// <returns></returns>
        private static DirectoryEntry GetDirectoryObject()
        {
            DirectoryEntry entry = new DirectoryEntry(ADPath, ADUser, ADPassword, AuthenticationTypes.Secure);
            return entry;
        }
 
        /// <summary>
        /// 根据指定用户名和密码获得相应DirectoryEntry实体
        /// </summary>
        /// <param name="userName"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        private static DirectoryEntry GetDirectoryObject(string userName, string password)
        {
            DirectoryEntry entry = new DirectoryEntry(ADPath, userName, password, AuthenticationTypes.None);
            return entry;
        }
 
        /// <summary>
        /// i.e. /CN=Users,DC=creditsights, DC=cyberelves, DC=Com
        /// </summary>
        /// <param name="domainReference"></param>
        /// <returns></returns>
        private static DirectoryEntry GetDirectoryObject(string domainReference)
        {
            DirectoryEntry entry = new DirectoryEntry(ADPath + domainReference, ADUser, ADPassword, AuthenticationTypes.Secure);
            return entry;
        }
 
        /// <summary>
        /// 获得以UserName,Password创建的DirectoryEntry
        /// </summary>
        /// <param name="domainReference"></param>
        /// <param name="userName"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        private static DirectoryEntry GetDirectoryObject(string domainReference, string userName, string password)
        {
            DirectoryEntry entry = new DirectoryEntry(ADPath + domainReference, userName, password, AuthenticationTypes.Secure);
            return entry;
        }
 
        #endregion
 
        #region GetDirectoryEntry
 
 
        /// <summary>
        ///根据用户公共名称取得用户的对象
        ///用户公共名称
        ///如果找到该用户，则返回用户的对象；否则返回 null
        /// </summary>
        /// <param name="commonName"></param>
        /// <returns></returns>
        public static DirectoryEntry GetDirectoryEntry(string commonName)
        {
            DirectoryEntry de = GetDirectoryObject();
            DirectorySearcher deSearch = new DirectorySearcher(de);
            deSearch.Filter = "(&(&(objectCategory=person)(objectClass=user))(cn=" + commonName + "))";
            deSearch.SearchScope = SearchScope.Subtree;
 
            try
            {
                SearchResult result = deSearch.FindOne();
                de = new DirectoryEntry(result.Path);
            }
            catch
            {
                de = null;
            }
            return de;
        }
 
        /// <summary>
        ///根据用户公共名称和密码取得用户的对象。
        ///用户公共名称
        ///用户密码
        ///如果找到该用户，则返回用户的 对象；否则返回null
        /// </summary>
        /// <param name="commonName"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        public static DirectoryEntry GetDirectoryEntry(string commonName, string password)
        {
            DirectoryEntry de = GetDirectoryObject(commonName, password);
            DirectorySearcher deSearch = new DirectorySearcher(de);
            deSearch.Filter = "(&(&(objectCategory=person)(objectClass=user))(cn=" + commonName + "))";
            deSearch.SearchScope = SearchScope.Subtree;
 
            try
            {
                SearchResult result = deSearch.FindOne();
                de = new DirectoryEntry(result.Path);
                return de;
            }
            catch
            {
                return null;
            }
        }
 
        /// <summary>
        ///根据用户帐号称取得用户的对象
        ///用户帐号名
        ///如果找到该用户，则返回用户的对象；否则返回null
        /// </summary>
        /// <param name="sAMAccountName"></param>
        /// <returns></returns>
        public static DirectoryEntry GetDirectoryEntryByAccount(string sAMAccountName)
        {
            DirectoryEntry de = GetDirectoryObject();
            DirectorySearcher deSearch = new DirectorySearcher(de);
            deSearch.Filter = "(&(&(objectCategory=person)(objectClass=user))(sAMAccountName=" + sAMAccountName + "))";
            deSearch.SearchScope = SearchScope.Subtree;
 
            try
            {
                SearchResult result = deSearch.FindOne();
                de = new DirectoryEntry(result.Path);
             
            }
            catch
            {
                de = null;
            }
            return de;
        }
 
        /// <summary>
        ///根据用户帐号和密码取得用户的对象
        ///用户帐号名
        ///用户密码
        ///如果找到该用户，则返回用户的 对象；否则返回null
        /// </summary>
        /// <param name="sAMAccountName"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        public static DirectoryEntry GetDirectoryEntryByAccount(string sAMAccountName, string password)
        {
            DirectoryEntry de = GetDirectoryEntryByAccount(sAMAccountName);
            if (de != null)
            {
                string commonName = de.Properties["cn"][0].ToString();
 
                if (GetDirectoryEntry(commonName, password) != null)
                    return GetDirectoryEntry(commonName, password);
                else
                    return null;
            }
            else
            {
                return null;
            }
        }
 
        /// <summary>
        ///根据组名取得用户组的对象
        ///组名
        /// </summary>
        /// <param name="groupName"></param>
        /// <returns></returns>
        public static DirectoryEntry GetDirectoryEntryOfGroup(string groupName)
        {
            DirectoryEntry de = GetDirectoryObject();
            DirectorySearcher deSearch = new DirectorySearcher(de);
            deSearch.Filter = "(&(objectClass=group)(cn=" + groupName + "))";
            deSearch.SearchScope = SearchScope.Subtree;
 
            try
            {
                SearchResult result = deSearch.FindOne();
                de = new DirectoryEntry(result.Path);
                return de;
            }
            catch
            {
                return null;
            }
        }
 
        #endregion
 
        #region GetProperty
 
        /// <summary>
        ///获得指定属性名对应的值
        ///属性名称
        ///属性值
        /// </summary>
        /// <param name="de"></param>
        /// <param name="propertyName"></param>
        /// <returns></returns>
        public static string GetProperty(DirectoryEntry de, string propertyName)
        {
            if (de.Properties.Contains(propertyName))
            {
                return de.Properties[propertyName][0].ToString();
            }
            else
            {
                return string.Empty;
            }
        }
 
        /// <summary>
        ///获得指定搜索结果中指定属性名对应的值
        ///属性名称
        ///属性值
        /// </summary>
        /// <param name="searchResult"></param>
        /// <param name="propertyName"></param>
        /// <returns></returns>
        public static string GetProperty(SearchResult searchResult, string propertyName)
        {
            if (searchResult.Properties.Contains(propertyName))
            {
                return searchResult.Properties[propertyName][0].ToString();
            }
            else
            {
                return string.Empty;
            }
        }
 
        #endregion
 
        /// <summary>
        ///设置指定的属性值
        ///属性名称
        ///属性值
        /// </summary>
        /// <param name="de"></param>
        /// <param name="propertyName"></param>
        /// <param name="propertyValue"></param>
        public static void SetProperty(DirectoryEntry de, string propertyName, string propertyValue)
        {
            if (propertyValue != string.Empty || propertyValue != "" || propertyValue != null)
            {
                if (de.Properties.Contains(propertyName))
                {
                    de.Properties[propertyName][0] = propertyValue;
                }
                else
                {
                    de.Properties[propertyName].Add(propertyValue);
                }
            }
        }
 
        /// <summary>
        ///创建新的用户
        ///DN 位置。例如：OU=共享平台 或 CN=Users
        ///公共名称
        ///帐号
        ///密码
        /// </summary>
        /// <param name="ldapDN"></param>
        /// <param name="commonName"></param>
        /// <param name="sAMAccountName"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        public static DirectoryEntry CreateNewUser(string ldapDN, string commonName, string sAMAccountName, string password)
        {
            DirectoryEntry entry = GetDirectoryObject();
            DirectoryEntry subEntry = entry.Children.Find(ldapDN);
            DirectoryEntry deUser = subEntry.Children.Add("CN=" + commonName, "user");
            deUser.Properties["sAMAccountName"].Value = sAMAccountName;
            deUser.CommitChanges();
            ADHelper.EnableUser(commonName);
            ADHelper.SetPassword(commonName, password);
            deUser.Close();
            return deUser;
        }
 
        /// <summary>
        ///创建新的用户。默认创建在Users单元下。
        ///公共名称
        ///帐号
        ///密码
        /// </summary>
        /// <param name="commonName"></param>
        /// <param name="sAMAccountName"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        public static DirectoryEntry CreateNewUser(string commonName, string sAMAccountName, string password)
        {
            return CreateNewUser("CN=Users", commonName, sAMAccountName, password);
        }
 
        /// <summary>
        ///判断指定公共名称的用户是否存在
        ///用户公共名称
        ///如果存在,返回true；否则返回false
        /// </summary>
        /// <param name="commonName"></param>
        /// <returns></returns>
        public static bool IsUserExists(string commonName)
        {
            DirectoryEntry de = GetDirectoryObject();
            DirectorySearcher deSearch = new DirectorySearcher(de);
            deSearch.Filter = "(&(&(objectCategory=person)(objectClass=user))(cn=" + commonName + "))";       // LDAP 查询串
            SearchResultCollection results = deSearch.FindAll();
 
            if (results.Count == 0)
                return false;
            else
                return true;
        }
 
        /// <summary>
        ///判断用户帐号是否激活
        ///用户帐号属性控制器
        ///如果用户帐号已经激活，返回true；否则返回false
        /// </summary>
        /// <param name="userAccountControl"></param>
        /// <returns></returns>
        public static bool IsAccountActive(int userAccountControl)
        {
            int userAccountControl_Disabled = Convert.ToInt32(ADS_USER_FLAG_ENUM.ADS_UF_ACCOUNTDISABLE);
            int flagExists = userAccountControl & userAccountControl_Disabled;
 
            if (flagExists > 0)
                return false;
            else
                return true;
        }
 
        /// <summary>
        ///判断用户与密码是否足够以满足身份验证进而登录
        ///用户公共名称
        ///密码
        ///如能可正常登录，则返回 true；否则返回 false
        /// </summary>
        /// <param name="commonName"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        public static LoginResult Login(string commonName, string password)
        {
            DirectoryEntry de = GetDirectoryEntry(commonName);
 
            if (de != null)
            {
                // 必须在判断用户密码正确前，对帐号激活属性进行判断；否则将出现异常。
                int userAccountControl = Convert.ToInt32(de.Properties["userAccountControl"][0]);
                de.Close();
 
                if (!IsAccountActive(userAccountControl))
                    return LoginResult.LOGIN_USER_ACCOUNT_INACTIVE;
 
                if (GetDirectoryEntry(commonName, password) != null)
                    return LoginResult.LOGIN_USER_OK;
                else
                    return LoginResult.LOGIN_USER_PASSWORD_INCORRECT;
            }
            else
            {
                return LoginResult.LOGIN_USER_DOESNT_EXIST;
            }
        }
 
        /// <summary>
        ///判断用户帐号与密码是否足够以满足身份验证进而登录
        ///用户帐号
        ///密码
        ///如能可正常登录，则返回true；否则返回false
        /// </summary>
        /// <param name="sAMAccountName"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        public static LoginResult LoginByAccount(string sAMAccountName, string password)
        {
            DirectoryEntry de = GetDirectoryEntryByAccount(sAMAccountName);
 
            if (de != null)
            {
                // 必须在判断用户密码正确前，对帐号激活属性进行判断；否则将出现异常。
                int userAccountControl = Convert.ToInt32(de.Properties["userAccountControl"][0]);
                de.Close();
 
                if (!IsAccountActive(userAccountControl))
                    return LoginResult.LOGIN_USER_ACCOUNT_INACTIVE;
 
                if (GetDirectoryEntryByAccount(sAMAccountName, password) != null)
                    return LoginResult.LOGIN_USER_OK;
                else
                    return LoginResult.LOGIN_USER_PASSWORD_INCORRECT;
            }
            else
            {
                return LoginResult.LOGIN_USER_DOESNT_EXIST;
            }
        }
 
 
        /// <summary>
        ///设置用户密码，管理员可以通过它来修改指定用户的密码。
        ///用户公共名称
        ///用户新密码
        /// </summary>
        /// <param name="commonName"></param>
        /// <param name="newPassword"></param>
        public static void SetPassword(string commonName, string newPassword)
        {
            DirectoryEntry de = GetDirectoryEntry(commonName);
 
            // 模拟超级管理员，以达到有权限修改用户密码
            impersonate.BeginImpersonate();
            de.Invoke("SetPassword", new object[] { newPassword });
            impersonate.StopImpersonate();
 
            de.Close();
        }
 
 
        /// <summary>
        ///设置帐号密码，管理员可以通过它来修改指定帐号的密码。
        ///用户帐号
        ///用户新密码
        ///