#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange
//
// Copyright (c) 2005-2017 empira Software GmbH, Cologne Area (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

using System.Diagnostics;
using PdfSharp.Fonts;
using PdfSharp.Fonts.OpenType;
using PdfSharp.Drawing;
using PdfSharp.Pdf.Filters;

namespace PdfSharp.Pdf.Advanced
{
    /// <summary>
    /// Represents a TrueType font.
    /// </summary>
    internal class PdfTrueTypeFont : PdfFont
    {
        public PdfTrueTypeFont(PdfDocument document)
            : base(document)
        { }

        /// <summary>
        /// Initializes a new instance of PdfTrueTypeFont from an XFont.
        /// </summary>
        public PdfTrueTypeFont(PdfDocument document, XFont font)
            : base(document)
        {
            Elements.SetName(Keys.Type, "/Font");
            Elements.SetName(Keys.Subtype, "/TrueType");

            // TrueType with WinAnsiEncoding only.
            OpenTypeDescriptor ttDescriptor = (OpenTypeDescriptor)FontDescriptorCache.GetOrCreateDescriptorFor(font);
            FontDescriptor = new PdfFontDescriptor(document, ttDescriptor);
            _fontOptions = font.PdfOptions;
            Debug.Assert(_fontOptions != null);

            //cmapInfo = new CMapInfo(null/*ttDescriptor*/);
            _cmapInfo = new CMapInfo(ttDescriptor);

            BaseFont = font.GlyphTypeface.GetBaseName();
     
            if (_fontOptions.FontEmbedding == PdfFontEmbedding.Always)
                BaseFont = PdfFont.CreateEmbeddedFontSubsetName(BaseFont);
            FontDescriptor.FontName = BaseFont;

            Debug.Assert(_fontOptions.FontEncoding == PdfFontEncoding.WinAnsi);
            if (!IsSymbolFont)
                Encoding = "/WinAnsiEncoding";

            Owner._irefTable.Add(FontDescriptor);
            Elements[Keys.FontDescriptor] = FontDescriptor.Reference;

            FontEncoding = font.PdfOptions.FontEncoding;
        }

        XPdfFontOptions FontOptions
        {
            get { return _fontOptions; }
        }
        readonly XPdfFontOptions _fontOptions;

        public string BaseFont
        {
            get { return Elements.GetName(Keys.BaseFont); }
            set { Elements.SetName(Keys.BaseFont, value); }
        }

        public int FirstChar
        {
            get { return Elements.GetInteger(Keys.FirstChar); }
            set { Elements.SetInteger(Keys.FirstChar, value); }
        }

        public int LastChar
        {
            get { return Elements.GetInteger(Keys.LastChar); }
            set { Elements.SetInteger(Keys.LastChar, value); }
        }

        public PdfArray Widths
        {
            get { return (PdfArray)Elements.GetValue(Keys.Widths, VCF.Create); }
        }

        public string Encoding
        {
            get { return Elements.GetName(Keys.Encoding); }
            set { Elements.SetName(Keys.Encoding, value); }
        }

        /// <summary>
        /// Prepares the object to get saved.
        /// </summary>
        internal override void PrepareForSave()
        {
            base.PrepareForSave();

            // Fonts are always embedded.
            OpenTypeFontface subSet = FontDescriptor._descriptor.FontFace.CreateFontSubSet(_cmapInfo.GlyphIndices, false);
            byte[] fontData = subSet.FontSource.Bytes;

            PdfDictionary fontStream = new PdfDictionary(Owner);
            Owner.Internals.AddObject(fontStream);
            FontDescriptor.Elements[PdfFontDescriptor.Keys.FontFile2] = fontStream.Reference;

            fontStream.Elements["/Length1"] = new PdfInteger(fontData.Length);
            if (!Owner.Options.NoCompression)
            {
                fontData = Filtering.FlateDecode.Encode(fontData, _document.Options.FlateEncodeMode);
                fontStream.Elements["/Filter"] = new PdfName("/FlateDecode");
            }
            fontStream.Elements["/Length"] = new PdfInteger(fontData.Length);
            fontStream.CreateStream(fontData);

            FirstChar = 0;
            LastChar = 255;
            PdfArray width = Widths;
            //width.Elements.Clear();
            for (int idx = 0; idx < 256; idx++)
                width.Elements.Add(new PdfInteger(FontDescriptor._descriptor.Widths[idx]));
        }

        /// <summary>
        /// Predefined keys of this dictionary.
        /// </summary>
        public new sealed class Keys : PdfFont.Keys
        {
            /// <summary>
            /// (Required) The type of PDF object that this dictionary describes;
            /// must be Font for a font dictionary.
            /// </summary>
            [KeyInfo(KeyType.Name | KeyType.Required, FixedValue = "Font")]
            public new const string Type = "/Type";

            /// <summary>
            /// (Required) The type of font; must be TrueType for a TrueType font.
            /// </summary>
            [KeyInfo(KeyType.Name | KeyType.Required)]
            public new const string Subtype = "/Subtype";

            /// <summary>
            /// (Required in PDF 1.0; optional otherwise) The name by which this font is 
            /// referenced in the Font subdictionary of the current resource dictionary.
            /// </summary>
            [KeyInfo(KeyType.Name | KeyType.Optional)]
            public const string Name = "/Name";

            /// <summary>
            /// (Required) The PostScript name of the font. For Type 1 fonts, this is usually
            /// the value of the FontName entry in the font program; for more information.
            /// The Post-Script name of the font can be used to find the font’s definition in 
            /// the consumer application or its environment. It is also the name that is used when
            /// printing to a PostScript output device.
            /// </summary>
            [KeyInfo(KeyType.Name | KeyType.Required)]
            public new const string BaseFont = "/BaseFont";

            /// <summary>
            /// (Required except for the standard 14 fonts) The first character code defined 
            /// in the font’s Widths array.
            /// </summary>
            [KeyInfo(KeyType.Integer)]
            public const string FirstChar = "/FirstChar";

            /// <summary>
            /// (Required except for the standard 14 fonts) The last character code defined
            /// in the font’s Widths array.
            /// </summary>
            [KeyInfo(KeyType.Integer)]
            public const string LastChar = "/LastChar";

            /// <summary>
            /// (Required except for the standard 14 fonts; indirect reference preferred)
            /// An array of (LastChar - FirstChar + 1) widths, each element being the glyph width
            /// for the character code that equals FirstChar plus the array index. For character
            /// codes outside the range FirstChar to LastChar, the value of MissingWidth from the 
            /// FontDescriptor entry for this font is used. The glyph widths are measured in units 
            /// in which 1000 units corresponds to 1 unit in text space. These widths must be 
            /// consistent with the actual widths given in the font program. 
            /// </summary>
            [KeyInfo(KeyType.Array, typeof(PdfArray))]
            public const string Widths = "/Widths";

            /// <summary>
            /// (Required except for the standard 14 fonts; must be an indirect reference)
            /// A font descriptor describing the font’s metrics other than its glyph widths.
            /// Note: For the standard 14 fonts, the entries FirstChar, LastChar, Widths, and 
            /// FontDescriptor must either all be present or all be absent. Ordinarily, they are
            /// absent; specifying them enables a standard font to be overridden.
            /// </summary>
            [KeyInfo(KeyType.Dictionary | KeyType.MustBeIndirect, typeof(PdfFontDescriptor))]
            public new const string FontDescriptor = "/FontDescriptor";

            /// <summary>
            /// (Optional) A specification of the font’s character encoding if different from its
            /// built-in encoding. The value of Encoding is either the name of a predefined
            /// encoding (MacRomanEncoding, MacExpertEncoding, or WinAnsiEncoding, as described in 
            /// Appendix D) or an encoding dictionary that specifies differences from the font’s
            /// built-in encoding or from a specified predefined encoding.
            /// </summary>
            [KeyInfo(KeyType.Name | KeyType.Dictionary)]
            public const string Encoding = "/Encoding";

            /// <summary>
            /// (Optional; PDF 1.2) A stream containing a CMap file that maps character
            /// codes to Unicode values.
            /// </summary>
            [KeyInfo(KeyType.Stream | KeyType.Optional)]
            public const string ToUnicode = "/ToUnicode";

            /// <summary>
            /// Gets the KeysMeta for these keys.
            /// </summary>
            internal static DictionaryMeta Meta
            {
                get { return _meta ?? (_meta = CreateMeta(typeof(Keys))); }
            }
            static DictionaryMeta _meta;
        }

        /// <summary>
        /// Gets the KeysMeta of this dictionary type.
        /// </summary>
        internal override DictionaryMeta Meta
        {
            get { return Keys.Meta; }
        }
    }
}
