' Writes a 2D array to a CSV file
Sub WriteCSVFromArray( _
    ByVal filePath As String, _
    ByVal data As Variant, _
    Optional ByVal Charset As String = "shift_jis", _
    Optional ByVal alwaysQuote As Boolean = False _
)
    ' === Input validation ===
    If Not IsArray(data) Then
        Err.Raise 513, , "Input 'data' must be an array."
    End If
    
    Dim numDims As Long
    On Error Resume Next
    numDims = ArrayDimensions(data)
    On Error GoTo 0
    If numDims <> 2 Then
        Err.Raise 514, , "Input array must be 2-dimensional."
    End If
    
    Dim rows As Long, cols As Long
    rows = UBound(data, 1) - LBound(data, 1) + 1
    cols = UBound(data, 2) - LBound(data, 2) + 1
    
    If rows = 0 Or cols = 0 Then Exit Sub ' Empty array, exit early
    
    ' === Build CSV content ===
    Dim outputLines As Collection
    Set outputLines = New Collection
    
    Dim i As Long, j As Long
    Dim rowStr As String
    Dim field As String
    Dim needsQuote As Boolean
    
    For i = LBound(data, 1) To UBound(data, 1)
        Dim fields As Variant
        ReDim fields(1 To cols)
        
        For j = LBound(data, 2) To UBound(data, 2)
            ' Safely convert variant to string
            field = SafeToString(data(i, j))
            
            ' Determine if the field needs quoting (per RFC 4180)
            needsQuote = alwaysQuote Or (InStr(field, """") > 0) Or _
                                       (InStr(field, ",") > 0) Or _
                                       (InStr(field, vbLf) > 0) Or _
                                       (InStr(field, vbCrLf) > 0) Or _
                                       (InStr(field, vbCr) > 0) Or _
                                       (Left(field, 1) = " " Or Right(field, 1) = " ")
            
            If needsQuote Then
                ' Escape double quotes: "" represents a single "
                field = """" & Replace(field, """", """""") & """"
            End If
            
            fields(j - LBound(data, 2) + 1) = field
        Next j
        
        rowStr = Join(fields, ",")
        outputLines.Add rowStr
    Next i
    
    ' Concatenate all lines
    Dim finalContent As String
    finalContent = Join(CollectionToArray(outputLines), vbCrLf)
    
    ' === Write to file ===
    Dim stream As Object
    Set stream = CreateObject("ADODB.Stream")
    With stream
        .Type = 2 ' adTypeText
        .Charset = Charset
        .Open
        .WriteText finalContent, 0 ' adWriteChar
        .SaveToFile filePath, 2 ' adSaveCreateOverWrite
        .Close
    End With
End Sub

' Helper function: safely convert any Variant to a string
Private Function SafeToString(ByVal v As Variant) As String
    On Error Resume Next
    If IsNull(v) Or IsEmpty(v) Then
        SafeToString = ""
    Else
        SafeToString = CStr(v)
    End If
    On Error GoTo 0
End Function

' Helper function: get the number of dimensions of an array (1, 2, ...)
Private Function ArrayDimensions(arr As Variant) As Long
    Dim dimCount As Long
    On Error GoTo ExitPoint
    Do
        dimCount = dimCount + 1
        Dim tmp As Long
        tmp = UBound(arr, dimCount)
    Loop
ExitPoint:
    ArrayDimensions = dimCount - 1
End Function

' Helper function: convert a Collection to a 1D array (for use with Join)
Private Function CollectionToArray(col As Collection) As Variant
    If col.Count = 0 Then
        CollectionToArray = Array()
        Exit Function
    End If
    
    Dim arr() As String
    ReDim arr(1 To col.Count)
    Dim i As Long
    For i = 1 To col.Count
        arr(i) = col(i)
    Next i
    CollectionToArray = arr
End Function