Imports System.IO
Imports System.Threading.Tasks
Imports DigitalData.Modules.Base
Imports DigitalData.Modules.Database
Imports DigitalData.Modules.Logging

Public MustInherit Class BaseModule
    Inherits BaseClass
    Implements ISync

    Friend ReadOnly Config As Config
    Friend ReadOnly Database As MSSQLServer

    Public Const DIVIDER_TEXT = "-------------------------------------"

    Public Enum LogLevel
        Info
        Warn
        [Error]
    End Enum

    Public MustOverride Property Name As String Implements ISync.Name
    Public MustOverride Property IsLoggedIn As Boolean Implements ISync.IsLoggedIn
    Public MustOverride Async Function Run() As Task Implements ISync.Run
    Public MustOverride Function Cleanup() As Task Implements ISync.Cleanup
    Public MustOverride Function TestConfigIsComplete() As Boolean Implements ISync.TestConfigIsComplete

    Public Event OnLogEntry As EventHandler(Of Tuple(Of String, LogLevel)) Implements ISync.OnLogEntry
    Public Event OnFileProcessed As EventHandler(Of String) Implements ISync.OnFileProcessed
    Public Event OnFileError As EventHandler(Of String) Implements ISync.OnFileError

    Private DirectoryGuid As String = Guid.NewGuid.ToString()

    Public Sub New(pLogConfig As LogConfig, pDatabase As MSSQLServer, pConfig As Config)
        MyBase.New(pLogConfig)

        Database = pDatabase
        Config = pConfig
    End Sub

    Friend Sub RefreshDirectoryGuid()
        DirectoryGuid = Guid.NewGuid.ToString()
    End Sub

    Friend Async Function FetchDocIds() As Task(Of List(Of String))
        If Config.SQLQueryFetch = "" Then
            Logger.Warn("Fetch Query is not configured. Exiting.")
            Return Nothing
        End If

        Dim oTable As DataTable = Await Database.GetDatatableAsync(Config.SQLQueryFetch)

        If oTable Is Nothing Then
            Logger.Warn("Error while fetching DocIds. Exiting")
            Return Nothing
        End If

        Dim oDocIds = oTable.Rows.
            Cast(Of DataRow).
            Select(Function(r) r.Item(0).ToString()).
            ToList()

        AddInfoEntry("Found [{0}] files.", oDocIds.Count)
        Return oDocIds
    End Function

    Friend Sub EnsureOutputDirectoryExists()
        Dim oOutputDirectory As String = Config.OutputDirectory

        If Directory.Exists(oOutputDirectory) = False Then
            Throw New DirectoryNotFoundException($"Directory '{oOutputDirectory}' does not exist.")
        End If
    End Sub

    Friend Function ConvertFilenameToSlug(pFileName As String) As String
        Dim oName = Path.GetFileNameWithoutExtension(pFileName)
        Dim oExtension = Path.GetExtension(pFileName)

        Return StringEx.ConvertTextToSlug(oName) & oExtension
    End Function

    Friend Function GetFinalFileName(pFileName As String, pId As String) As String
        Dim oExtension = Path.GetExtension(pFileName)
        Return pId & oExtension
    End Function

    Friend Function GetFinalFilePath(pFileName As String) As String
        Dim oFinalDirectoryPath = Config.OutputDirectory

        If Config.AddDateSubDirectory = True Then
            Dim oSubPath = FileEx.CreateDateDirectory(oFinalDirectoryPath)
            If oSubPath Is Nothing Then
                Throw New ApplicationException("Output sub path could not be created!")
            End If
            Logger.Debug("Date Subdirectory [{0}] created.", oSubPath)
            oFinalDirectoryPath = oSubPath
        End If

        If Config.AddImportSubDirectory = True Then
            Dim oSubPath = Path.Combine(oFinalDirectoryPath, DirectoryGuid)
            Try
                Directory.CreateDirectory(oSubPath)
            Catch ex As Exception
                Throw New ApplicationException("Output subpath could not be created!")
            End Try

            Logger.Debug("Import Subdirectory [{0}] created", oSubPath)
            oFinalDirectoryPath = oSubPath
        End If

        Return Path.Combine(oFinalDirectoryPath, pFileName)
    End Function

    Friend Function CopyFileToOutputPath(pFileContents As Byte(), pFilePath As String) As Boolean
        Try
            Using oStream As New MemoryStream(pFileContents)
                Using oWriter As New FileStream(pFilePath, FileMode.Create)
                    oStream.CopyTo(oWriter)
                    Logger.Debug("File copied to document path [{0}]", pFilePath)
                End Using
            End Using

            Return True
        Catch ex As Exception
            Logger.Error(ex)
            Return False

        End Try
    End Function

    Public Function TestConfigIsCompleteBase() As Boolean
        Dim oComplete = True

        If Config.ConnectionString = String.Empty Then
            AddWarnEntry("Configuration for 'ConnectionString' is empty.")
            oComplete = False
        End If

        If Config.SQLQueryFetch = String.Empty Then
            AddWarnEntry("Configuration for 'SQLQueryFetch' is empty.")
            oComplete = False
        End If

        If Config.SQLQueryExport = String.Empty Then
            AddWarnEntry("Configuration for 'SQLQueryExport' is empty.")
            oComplete = False
        End If

        If Config.OutputDirectory = String.Empty Then
            AddWarnEntry("Configuration for 'OutputDirectory' is empty.")
            oComplete = False
        End If

        Return oComplete
    End Function

    Friend Sub AddInfoEntry(pMessage As String, ParamArray pArgs As Object())
        RaiseEvent OnLogEntry(Me, New Tuple(Of String, LogLevel)(String.Format(pMessage, pArgs), LogLevel.Info))
    End Sub

    Friend Sub AddWarnEntry(pMessage As String, ParamArray pArgs As Object())
        RaiseEvent OnLogEntry(Me, New Tuple(Of String, LogLevel)(String.Format(pMessage, pArgs), LogLevel.Warn))
    End Sub

    Friend Sub AddErrorEntry(pMessage As String, ParamArray pArgs As Object())
        RaiseEvent OnLogEntry(Me, New Tuple(Of String, LogLevel)(String.Format(pMessage, pArgs), LogLevel.Error))
    End Sub
    Friend Sub AddDivider()
        RaiseEvent OnLogEntry(Me, New Tuple(Of String, LogLevel)(DIVIDER_TEXT, LogLevel.Info))
    End Sub

    Friend Sub RaiseFileProcessed(pFilePath As String)
        RaiseEvent OnFileProcessed(Me, pFilePath)
    End Sub

    Friend Sub RaiseFileError(pFilePath As String)
        RaiseEvent OnFileError(Me, pFilePath)
    End Sub
End Class