/*
 * Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General 
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General  License for more details.
 *
 * You should have received a copy of the GNU Lesser General 
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

part of pdf;

class PdfAnnot extends PdfObject {
  /// The subtype of the outline, ie text, note, etc
  final String subtype;

  /// The size of the annotation
  final PdfRect srcRect;

  /// The text of a text annotation
  final String content;

  /// Link to the Destination page
  final PdfObject dest;

  /// If destRect is null then this is the region of the destination page shown.
  /// Otherwise they are ignored.
  final PdfRect destRect;

  /// the border for this annotation
  final PdfBorder border;

  PdfAnnot._create(PdfPage pdfPage,
      {String type,
      this.content,
      this.srcRect,
      @required this.subtype,
      this.dest,
      this.destRect,
      this.border})
      : super(pdfPage.pdfDocument, type ?? '/Annot') {
    pdfPage.annotations.add(this);
  }

  /// Creates a text annotation
  /// @param rect coordinates
  /// @param s Text for this annotation
  factory PdfAnnot.text(PdfPage pdfPage,
          {@required PdfRect rect,
          @required String content,
          PdfBorder border}) =>
      PdfAnnot._create(pdfPage,
          subtype: "/Text", srcRect: rect, content: content, border: border);

  /// Creates a link annotation
  /// @param srcRect coordinates
  /// @param dest Destination for this link. The page will fit the display.
  /// @param destRect Rectangle describing what part of the page to be displayed
  /// (must be in User Coordinates)
  factory PdfAnnot.link(PdfPage pdfPage,
          {@required PdfRect srcRect,
          @required PdfPage dest,
          PdfRect destRect,
          PdfBorder border}) =>
      PdfAnnot._create(pdfPage,
          subtype: "/Link",
          srcRect: srcRect,
          dest: dest,
          destRect: destRect,
          border: border);

  /// Output the annotation
  ///
  /// @param os OutputStream to send the object to
  @override
  void _prepare() {
    super._prepare();

    params["/Subtype"] = PdfStream.string(subtype);
    params["/Rect"] = PdfStream.string(
        "[${srcRect.l} ${srcRect.b} ${srcRect.r} ${srcRect.t}]");

    // handle the border
    if (border == null) {
      params["/Border"] = PdfStream.string("[0 0 0]");
    } else {
      params["/BS"] = border.ref();
    }

    // Now the annotation subtypes
    if (subtype == "/Text") {
      params["/Contents"] = PdfStream.text(content);
    } else if (subtype == "/Link") {
      var dests = List<PdfStream>();
      dests.add(dest.ref());
      if (destRect == null)
        dests.add(PdfStream.string("/Fit"));
      else {
        dests.add(PdfStream.string(
            "/FitR ${destRect.l} ${destRect.b} ${destRect.r} ${destRect.t}"));
      }
      params["/Dest"] = PdfStream.array(dests);
    }
  }
}