(*
' *************************************************************************
' * Script name:
' *   Edit Lens Info
' *   Version: 1.2
' *
' * Description:
' *   Allows the user to update the lens metadata for selected thumbnails
' *
' * Version History:
' *   Hert van Zwietering;
' *     1.0 Initial version
' *     1.1 The script now also write Edif Tag 0xA434 (LensModel)
' *     1.2 Added progress
' *
' *************************************************************************/
*)

var
  AFNumberBox: TvxTextBox;
  AFocalLengthBox: TvxTextBox;
  ALensInfoBox: TvxTextBox;

var
  gFNumber: Double;
  gFocalLength: Double;
  gLensInfo: WideString;

  function IsRational(AVal: WideString): Boolean;
  var
    ALen, i: Integer;
  begin
    // a rational exists of numbers or a single slash (e.g. 2800/1000)...
    // NOTE: we'll also accept spaces because some tools write it (falsely) as 2800 / 1000
    ALen := Length(AVal);
    result := False;
    if ALen = 0 then exit;
    for i := 1 to ALen do
    begin
      if (AVal[i] <> '0') and
         (AVal[i] <> '1') and
         (AVal[i] <> '2') and
         (AVal[i] <> '3') and
         (AVal[i] <> '4') and
         (AVal[i] <> '5') and
         (AVal[i] <> '6') and
         (AVal[i] <> '7') and
         (AVal[i] <> '8') and
         (AVal[i] <> '9') and
         (AVal[i] <> '-') and
         (AVal[i] <> '/') and
         (AVal[i] <> ' ')
      then
        exit;
    end;
    result := True;
  end;

  function XMPRationalStringToDouble(AVal: WideString): Double;
  var
    ANumStr: WideString;
  begin
    if IsRational(Trim(AVal)) then
    begin
      ANumStr := FormatRationalToDecimal(AVal, '%d' + WideString(DecimalSeparator) + '%s', 10000000);
      try
        result := StrToFloat(ANumStr);
      except
        result := 0
      end;
    end
    else
      result := 0;
  end;

  function DoubleToXMPRationalString(AVal: Double): WideString;
  const
    cFactor = 1000000;
  begin
    result := IntToStr(Trunc(AVal * cFactor)) + '/' + IntToStr(cFactor);
  end;

  procedure HandleImage(AImage: TImageItem);
  var
    ATif: TTif;
    ATag: TTifTag;
    AXmp: TXMP;
    AFNumber: TMacroParam;
    AFLength: TMacroParam;
    ALensModel: TMacroParam;
    ACanUpdateExif, ASaveTif: Boolean;
  begin
    ASaveTif := False;

    ACanUpdateExif := AImage.CanUpdateExif;

    AXmp := TXMP.Create(False);
    ATif := TTif.Create(nil);
    try
      if ACanUpdateExif then
      begin
        // load the exif
        ATif.FileName := AImage.ExifFileName;
        ATif.Load(True, False);
      end;

      PublicCatalog.LoadXMPForImage(AImage, AXmp, PublicOptions.CachedXMP);

      AFNumber := AXmp.QuickSetProperty('http://ns.adobe.com/exif/1.0/', 'exif:FNumber', DoubleToXMPRationalString(gFNumber));
      if Assigned(AFNumber) then
      begin
        if ACanUpdateExif then
        begin
          ATag := ATif.ExifIFD.FindTag($829D);   // FNumber
          if Assigned(ATag) then
          begin
            ATag.Value := AFNumber.StrContent;
            ASaveTif := True;
          end;
        end;
      end;

      AFLength := AXmp.QuickSetProperty('http://ns.adobe.com/exif/1.0/', 'exif:FocalLength', DoubleToXMPRationalString(gFocalLength));
      if Assigned(AFLength) then
      begin
        if ACanUpdateExif then
        begin
          ATag := ATif.ExifIFD.FindTag($920A);   // FocalLength
          if Assigned(ATag) then
          begin
            ATag.Value := AFLength.StrContent;
            ASaveTif := True;
          end;
        end;
      end;

      ALensmodel := AXmp.QuickSetProperty('http://ns.adobe.com/exif/1.0/aux/', 'aux:Lens', gLensInfo);
      AXmp.QuickSetProperty('http://cipa.jp/exif/1.0/', 'exifEX:LensModel', gLensInfo);
      if Assigned(ALensModel) then
      begin
        if ACanUpdateExif then
        begin
          ATag := ATif.ExifIFD.FindTag($A434);   // LensModel
          if Assigned(ATag) then
          begin
            ATag.Value := ALensModel.StrContent;
            ASaveTif := True;
          end;
        end;
      end;

      PublicCatalog.SaveXMPForImage(AImage, AXmp, PublicOptions.CachedXMP);
      if ASaveTif then
        ATif.Save;
    except
      ATif.Free;
      AXmp.Free;
    end;
  end;

  function CreateForm: TvxSceneForm;
  const
    cSpacing = 20;
  var
    ARoot: TvxVisualObject;
    ALabel: TvxLabel;
    ATextBox: TvxTextBox;
  begin
    result := TvxSceneForm.Create(nil);
    result.Caption := UTF8Encode('Edit Lens Info');
    result.Position := poScreenCenter;
    result.Height := 200 * result.DPIFactor;

    ARoot := result.Root;

    ALabel := TvxLabel.Create(ARoot);
    ALabel.Text := 'F-Number';
    ALabel.TextAlign := vgTextAlignNear;
    ALabel.Padding.Left := 10;
    ALabel.Padding.Top := cSpacing;
    ALabel.Align := vaTop;
    ARoot.AddObject(ALabel);

    ATextBox := TvxTextBox.Create(ARoot)
    ATextBox.Padding.Left := 13;
    ATextBox.Padding.Right := 240;
    ATextBox.Padding.Top := 3;
    ATextBox.Align := vaTop;
    ATextBox.Text := '';
    ARoot.AddObject(ATextBox);
    AFNumberBox := ATextBox;

    ALabel := TvxLabel.Create(ARoot);
    ALabel.Text := 'Focal Length (mm)';
    ALabel.TextAlign := vgTextAlignNear;
    ALabel.Padding.Left := 10;
    ALabel.Padding.Top := cSpacing;
    ALabel.Align := vaTop;
    ARoot.AddObject(ALabel);

    ATextBox := TvxTextBox.Create(ARoot)
    ATextBox.Padding.Left := 13;
    ATextBox.Padding.Right := 240;
    ATextBox.Padding.Top := 3;
    ATextBox.Align := vaTop;
    ATextBox.Text := '';
    ARoot.AddObject(ATextBox);
    AFocalLengthBox := ATextBox;

    ALabel := TvxLabel.Create(ARoot);
    ALabel.Text := 'Lens Information';
    ALabel.TextAlign := vgTextAlignNear;
    ALabel.Padding.Left := 10;
    ALabel.Padding.Top := cSpacing;
    ALabel.Align := vaTop;
    ARoot.AddObject(ALabel);

    ATextBox := TvxTextBox.Create(ARoot)
    ATextBox.Padding.Left := 13;
    ATextBox.Padding.Right := 13;
    ATextBox.Padding.Top := 3;
    ATextBox.Align := vaTop;
    ATextBox.Text := '';
    ARoot.AddObject(ATextBox);
    ALensInfoBox := ATextBox;
  end;

  procedure ReadDefaults;
  var
    AImage: TImageItem;
    AXmp: TXMP;
  begin
    AImage := selected.Items[0];

    AXmp := TXMP.Create(False);
    try
      PublicCatalog.LoadXMPForImage(AImage, AXmp, PublicOptions.CachedXMP);

      AParam := AXmp.FindDesignProperty('http://ns.adobe.com/exif/1.0/', 'exif:FNumber');
      if Assigned(AParam) then
        AFNumberBox.Text := FloatToStr(XMPRationalStringToDouble(AParam.StrContent));

      AParam := AXmp.FindDesignProperty('http://ns.adobe.com/exif/1.0/', 'exif:FocalLength');
      if Assigned(AParam) then
        AFocalLengthBox.Text := FloatToStr(XMPRationalStringToDouble(AParam.StrContent));

      AParam := AXmp.FindDesignProperty('http://ns.adobe.com/exif/1.0/aux/', 'aux:Lens');
      if Assigned(AParam) then
        ALensInfoBox.Text := AParam.StrContent
      else
      begin
        AParam := AXmp.FindDesignProperty('http://cipa.jp/exif/1.0/', 'exifEX:LensModel');
        if Assigned(AParam) then
          ALensInfoBox.Text := AParam.StrContent;
      end;
    finally
      AXmp.Free;
    end;
  end;

var
  AForm: TvxSceneForm;
  AGo: Boolean;
  i: Integer;
  APro: TxomProgress;
  AImg: TImageItem;
begin
  if Selected.Count = 0 then
  begin
    Say('Please select at least one thumbnail');
    exit;
  end;

  AForm := CreateForm;
  try
    ReadDefaults;

    AForm.PrepareModal([mbOK, mbCancel]);
    AForm.ShowModal;
    if AForm.ModalResult = mrOk then
    begin
      AGo := True;
      if not IsValidNumberString(AFNumberBox.Text, False, DecimalSeparator) then
      begin
        Say('No valid "F-Number" value entered');
        AGo := False;
      end;

      if not IsValidNumberString(AFocalLengthBox.Text, False, DecimalSeparator) then
      begin
        Say('No valid "Focal Length" value entered');
        AGo := False;
      end;

      if AGo then
      begin
        gFNumber     := StrToFloat(AFNumberBox.Text);
        gFocalLength := StrToFloat(AFocalLengthBox.Text);
        gLensInfo    := ALensInfoBox.Text;

        if AskYN(
              'Are you sure you want to change the lens metadata for the ' + IntToStr(Selected.Count) + ' selected file(s)?' + CrLf +
              '' + CrLf +
              'F-Number: F' + FloatToStr(gFNumber) + CrLf +
              'Focal Length: ' + FloatToStr(gFocalLength) + 'mm' + CrLf +
              'Lens Information: ' + gLensInfo
            )
        then
        begin
          APro := TxomProgress.Create(nil);
          try
            APro.Max := Selected.Count;
            APro.Pos := 0;
            APro.Caption := 'Edit Lens Info';
            for i := 0 to Selected.Count - 1 do
            begin
              AImg := Selected.Items[i];

              APro.Pos := i + 1;
              APro.ProgressText := AImg.FileNameOnScreen(50, True);

              HandleImage(AImg);
            end;
          finally
            APro.Free;
          end;
        end;
      end;
    end;
  finally
    AForm.Free;
  end;
end;