Imports DigitalData.Modules.Database
Imports DigitalData.Modules.Logging

Namespace SyncUsers
    Public Class SyncUsersMSSQL
        Implements ISyncUsers

        Private _logConfig As LogConfig
        Private _logger As Logger
        Private _mssql As MSSQLServer

        Private Const ADDED_WHO = "Active Directory Sync"

        Public Sub New(LogConfig As LogConfig, MSSQL As MSSQLServer)
            _logConfig = LogConfig
            _logger = LogConfig.GetLogger()
            _mssql = MSSQL
        End Sub

        Public Function SyncUsers(GroupName As String, Users As List(Of ADUser), PropertyMapping As List(Of AttributeMapping)) As List(Of ADUser) Implements ISyncUsers.SyncUsers
            Dim oGroupId As Integer
            Dim oSyncedUsers As New List(Of ADUser)

            Try
                _logger.Debug("Getting group Id for group {0}", GroupName)
                oGroupId = GetGroupId(GroupName)

                If oGroupId = 0 Then
                    _logger.Debug("Group {0} does not exist in database. Exiting.", GroupName)
                    Return oSyncedUsers
                End If

                _logger.Debug("Using group Id {0}", oGroupId)
            Catch ex As Exception
                _logger.Error(ex)
                Return oSyncedUsers
            End Try

            For Each oUser In Users
                Dim oUserId As Int64
                Dim oUserExists As Boolean = False

                ' Check if user already exists
                Try
                    _logger.Debug("Checking if user {0} exists", oUser)
                    oUserId = GetUserId(oUser.samAccountName)
                    oUserExists = oUserId > 0
                    _logger.Debug("User {0} exists in database: {1}", oUser, oUserExists)
                Catch ex As Exception
                    _logger.Error(ex)
                    _logger.Warn("Could not get UserId for user. Skipping.")
                    Continue For
                End Try

                ' I user does not exist, create a new user
                Try
                    If Not oUserExists Then
                        _logger.Debug("Creating new user for {0}", oUser)
                        oUserId = CreateUser(oUser)
                        _logger.Debug("User created with Id {0}", oUserId)
                    End If
                Catch ex As Exception
                    _logger.Error(ex)
                    _logger.Warn("Could not create user. Skipping.")
                    Continue For
                End Try

                ' Add custom attributes to user
                Try
                    AddCustomAttributesToUser(oUser, oUserId)
                Catch ex As Exception
                    _logger.Error(ex)
                    _logger.Debug("Could not add custom attributes to user {0}. Continuing.", oUser)
                End Try

                ' Add the user to group
                Try
                    AddUserToGroup(oUserId, oGroupId)
                Catch ex As Exception
                    _logger.Error(ex)
                    _logger.Warn("Could not add user {0} to group {1}. Skipping.", oUser, GroupName)
                    Continue For
                End Try

                oSyncedUsers.Add(oUser)
            Next

            Return oSyncedUsers
        End Function

        Private Sub AddUserToGroup(UserId As Integer, GroupId As Integer) Implements ISyncUsers.AddUserToGroup
            Try
                Dim oSQL = $"SELECT COUNT(*) FROM TBDD_GROUPS_USER WHERE USER_ID = {UserId} AND GROUP_ID = {GroupId}"
                Dim oResult = True
                If _mssql.NewExecuteScalar(oSQL) = 0 Then
                    oSQL = $"INSERT INTO TBDD_GROUPS_USER (USER_ID, GROUP_ID, ADDED_WHO) VALUES ({UserId}, {GroupId}, '{ADDED_WHO}')"
                    oResult = _mssql.NewExecutenonQuery(oSQL)
                Else
                    _logger.Debug($"UserGroup-Relation [{UserId}/{GroupId}] already existing")

                End If

                If oResult = False Then
                    Throw New Exception("Error while adding user to group!")
                End If
            Catch ex As Exception
                _logger.Error(ex)
                Throw ex
            End Try
        End Sub

        Private Function GetGroupId(GroupName As String) As Integer Implements ISyncUsers.GetGroupId
            Try
                Dim oSQL As String = $"SELECT GUID FROM TBDD_GROUPS WHERE UPPER(NAME) = UPPER('{GroupName}') AND AD_SYNC = 1 AND ACTIVE = 1"
                Dim oGroupId = _mssql.NewExecuteScalar(oSQL)

                If IsDBNull(oGroupId) OrElse oGroupId = 0 Then
                    _logger.Debug("Group {0} not found in database.", GroupName)
                    Return 0
                End If

                Return oGroupId
            Catch ex As Exception
                _logger.Error(ex)
                Throw ex
            End Try
        End Function

        Private Function GetUserId(UserName As String) As Integer Implements ISyncUsers.GetUserId
            Try
                Dim oSQL As String = $"SELECT GUID FROM TBDD_USER WHERE UPPER(USERNAME) = UPPER('{UserName}')"
                Dim oUserId = _mssql.NewExecuteScalar(oSQL)

                If IsDBNull(oUserId) OrElse oUserId = 0 Then
                    Return 0
                End If

                Return oUserId
            Catch ex As Exception
                _logger.Error(ex)
                Throw ex
            End Try
        End Function

        Private Function CreateUser(User As ADUser) As Integer Implements ISyncUsers.CreateUser
            Try
                Dim oUserId As Integer = GetUserId(User.samAccountName)
                If oUserId = 0 Then
                    Dim oSQL As String = $"INSERT INTO TBDD_USER (PRENAME, NAME, USERNAME, EMAIL, ADDED_WHO) VALUES ('{User.GivenName}', '{User.Surname}', UPPER('{User.samAccountName}'), '{User.Email}', '{ADDED_WHO}')"
                    Dim oResult = _mssql.NewExecutenonQuery(oSQL)

                    If oResult = True Then
                        oUserId = _mssql.NewExecuteScalar("SELECT MAX(GUID) FROM TBDD_USER")
                        Return oUserId
                    Else
                        Throw New Exception("Error while inserting user!")
                    End If
                Else
                    Return oUserId
                End If

            Catch ex As Exception
                _logger.Error(ex)
                Throw ex
            End Try
        End Function

        Public Sub AddCustomAttributesToUser(User As ADUser, UserId As Integer) Implements ISyncUsers.AddCustomAttributesToUser
            Dim oCustomAttributes = User.CustomAttributes

            _logger.Debug("Adding {0} Custom Attributes to User {1}", oCustomAttributes.Count, User)

            For Each oAttribute In oCustomAttributes
                Dim oSQL As String = $"UPDATE TBDD_USER SET {oAttribute.MSSQLColumn} = '{oAttribute.Value}', CHANGED_WHO = '{ADDED_WHO}' WHERE GUID = {UserId}"
                Dim oResult = _mssql.NewExecutenonQuery(oSQL)

                If oResult = False Then
                    _logger.Debug("Custom Attribute {0} could not be added to user {1}", oAttribute.Name, User.samAccountName)
                    Continue For
                End If
            Next
        End Sub
    End Class

End Namespace