Option Explicit

' Main entry: Validate all files and targets first. Import only if everything is OK.
Sub ImportModulesAndSheets_Safe()
    Dim fso As Object
    Set fso = CreateObject("Scripting.FileSystemObject")
    
    Const PROJECT_PATH As String = "D:\Project\upds7\vba\"
    Const MODULE_PATH As String = PROJECT_PATH & "src\sh\tuk\module"
    Const SHEET_PATH As String = PROJECT_PATH & "src\sh\tuk\sheet"
    
    ' --- Phase 1: Validation ---
    Debug.Print "[LOG] Starting validation phase..."
    Dim validationErrors As String
    validationErrors = ValidateAllFilesAndTargets(MODULE_PATH, SHEET_PATH)
    
    If validationErrors <> "" Then
        MsgBox "Validation failed. Import aborted:" & vbCrLf & vbCrLf & validationErrors, vbCritical
        Debug.Print "[LOG] Validation failed. Aborting import."
        Exit Sub
    End If
    
    ' --- Phase 2: Perform import ---
    On Error GoTo ImportError
    Application.ScreenUpdating = False
    
    Debug.Print "[LOG] Validation passed. Starting import phase..."
    ImportStandardModules MODULE_PATH
    ImportSheetCLSFiles SHEET_PATH
    
    Application.ScreenUpdating = True
    MsgBox "All .bas and .cls files imported successfully!", vbInformation
    Debug.Print "[LOG] Import completed successfully."
    Exit Sub

ImportError:
    Application.ScreenUpdating = True
    MsgBox "Error during import: " & Err.Description, vbCritical
    Debug.Print "[ERROR] Import error (" & Err.Number & "): " & Err.Description
End Sub

' Validate existence of folders, files, and target components
Private Function ValidateAllFilesAndTargets(modulePath As String, sheetPath As String) As String
    Dim fso As Object
    Set fso = CreateObject("Scripting.FileSystemObject")
    
    Dim msg As String
    
    ' Check module folder
    Debug.Print "[LOG] Validating module folder: " & modulePath
    If Not fso.FolderExists(modulePath) Then
        msg = msg & "• Module folder not found: " & modulePath & vbCrLf
        Debug.Print "[WARNING] Module folder not found."
    Else
        Dim file As Object
        For Each file In fso.GetFolder(modulePath).Files
            If LCase(fso.GetExtensionName(file.Name)) = "bas" Then
                Dim modName As String
                modName = fso.GetBaseName(file.Name)
                Debug.Print "[LOG] Found .bas file: " & file.Name & " (CodeName: " & modName & ")"
                If Not IsValidVBComponentName(modName) Then
                    msg = msg & "• Invalid module name (.bas): '" & modName & "'" & vbCrLf
                    Debug.Print "[WARNING] Invalid module name: " & modName
                End If
            End If
        Next file
    End If
    
    ' Check sheet folder
    Debug.Print "[LOG] Validating sheet folder: " & sheetPath
    If Not fso.FolderExists(sheetPath) Then
        msg = msg & "• Sheet macro folder not found: " & sheetPath & vbCrLf
        Debug.Print "[WARNING] Sheet folder not found."
    Else
        For Each file In fso.GetFolder(sheetPath).Files
            If LCase(fso.GetExtensionName(file.Name)) = "cls" Then
                Dim sheetCodeName As String
                sheetCodeName = fso.GetBaseName(file.Name)
                Debug.Print "[LOG] Found .cls file: " & file.Name & " (Target CodeName: " & sheetCodeName & ")"
                
                Dim cmp As Object
                On Error Resume Next
                Set cmp = ThisWorkbook.VBProject.VBComponents(sheetCodeName)
                On Error GoTo 0
                
                If cmp Is Nothing Then
                    msg = msg & "• No worksheet with CodeName: '" & sheetCodeName & "'" & vbCrLf
                    Debug.Print "[WARNING] Worksheet with CodeName '" & sheetCodeName & "' not found."
                ElseIf cmp.Type <> 100 Then ' 100 = xlWorksheet
                    msg = msg & "• Name exists but is not a worksheet: '" & sheetCodeName & "'" & vbCrLf
                    Debug.Print "[WARNING] Component '" & sheetCodeName & "' exists but is not a worksheet."
                End If
            End If
        Next file
    End If
    
    ValidateAllFilesAndTargets = msg
End Function

' Check if name is a valid VBA component name (ASCII only, starts with letter)
Private Function IsValidVBComponentName(name As String) As Boolean
    If name = "" Then Exit Function
    If Not (name Like "[A-Za-z]*") Then Exit Function
    Dim i As Long
    For i = 1 To Len(name)
        Dim c As String
        c = Mid(name, i, 1)
        If Not (c Like "[A-Za-z0-9_]") Then Exit Function
    Next i
    IsValidVBComponentName = True
End Function

' Import all .bas files as standard modules (assumes validation passed)
Private Sub ImportStandardModules(folderPath As String)
    Dim fso As Object, file As Object
    Set fso = CreateObject("Scripting.FileSystemObject")
    
    Debug.Print "[LOG] Starting import of standard modules from: " & folderPath
    For Each file In fso.GetFolder(folderPath).Files
        If LCase(fso.GetExtensionName(file.Name)) = "bas" Then
            Dim modName As String
            modName = fso.GetBaseName(file.Name)
            Debug.Print "[LOG] Processing module: " & file.Path
            
            ' Remove existing module if any
            On Error Resume Next
            ThisWorkbook.VBProject.VBComponents.Remove ThisWorkbook.VBProject.VBComponents(modName)
            On Error GoTo 0
            Debug.Print "[LOG] Removed existing module (if any): " & modName
            
            ' Import new one
            ThisWorkbook.VBProject.VBComponents.Import file.Path
            Debug.Print "[LOG] Successfully imported: " & file.Path
        End If
    Next file
    Debug.Print "[LOG] Finished importing standard modules."
End Sub

' Import .cls files into worksheet code modules (by CodeName)
Private Sub ImportSheetCLSFiles(folderPath As String)
    Dim fso As Object, file As Object
    Set fso = CreateObject("Scripting.FileSystemObject")
    
    Debug.Print "[LOG] Starting import of sheet code modules from: " & folderPath
    For Each file In fso.GetFolder(folderPath).Files
        If LCase(fso.GetExtensionName(file.Name)) = "cls" Then
            Dim sheetCodeName As String
            sheetCodeName = fso.GetBaseName(file.Name)
            Debug.Print "[LOG] Processing sheet code: " & file.Path & " -> " & sheetCodeName
            
            Dim cmp As Object
            Set cmp = ThisWorkbook.VBProject.VBComponents(sheetCodeName) ' Safe: already validated
            
            Dim pureCode As String
            pureCode = ExtractPureCodeFromCls(file.Path)
            
            With cmp.CodeModule
                If .CountOfLines > 0 Then .DeleteLines 1, .CountOfLines
                If Trim(pureCode) <> "" Then .AddFromString pureCode
            End With
            Debug.Print "[LOG] Successfully updated code for: " & sheetCodeName
        End If
    Next file
    Debug.Print "[LOG] Finished importing sheet code modules."
End Sub

' Extract only the VBA source code from a .cls file (skip VERSION, BEGIN, Attribute lines)
Private Function ExtractPureCodeFromCls(filePath As String) As String
    Dim fso As Object, ts As Object, line As String
    Set fso = CreateObject("Scripting.FileSystemObject")
    Set ts = fso.OpenTextFile(filePath, 1)
    
    Dim result As String
    Dim inCodeSection As Boolean: inCodeSection = False
    
    Do While Not ts.AtEndOfStream
        line = ts.ReadLine
        
        If inCodeSection Then
            result = result & line & vbCrLf
        Else
            Dim tLine As String: tLine = Trim(line)
            If tLine = "" Then
                inCodeSection = True
            ElseIf Left(tLine, 7) = "VERSION" Or _
                   Left(tLine, 5) = "BEGIN" Or _
                   Left(tLine, 3) = "END" Or _
                   Left(tLine, 9) = "Attribute" Then
                ' Skip metadata lines
            Else
                inCodeSection = True
                result = result & line & vbCrLf
            End If
        End If
    Loop
    
    ts.Close
    ExtractPureCodeFromCls = result
End Function