#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;

namespace PdfSharp.Pdf.AcroForms
{
    /// <summary>
    /// Represents the radio button field.
    /// </summary>
    public sealed class PdfRadioButtonField : PdfButtonField
    {
        /// <summary>
        /// Initializes a new instance of PdfRadioButtonField.
        /// </summary>
        internal PdfRadioButtonField(PdfDocument document)
            : base(document)
        {
            _document = document;
        }

        internal PdfRadioButtonField(PdfDictionary dict)
            : base(dict)
        { }

        /// <summary>
        /// Gets or sets the index of the selected radio button in a radio button group.
        /// </summary>
        public int SelectedIndex
        {
            get
            {
                string value = Elements.GetString(Keys.V);
                return IndexInOptStrings(value);
            }
            set
            {
                PdfArray opt = Elements[Keys.Opt] as PdfArray;

                if (opt == null)
                    opt = Elements[Keys.Kids] as PdfArray;

                if (opt != null)
                {
                    int count = opt.Elements.Count;
                    if (value < 0 || value >= count)
                        throw new ArgumentOutOfRangeException("value");
                    Elements.SetName(Keys.V, opt.Elements[value].ToString());
                }
            }
        }

        int IndexInOptStrings(string value)
        {
            PdfArray opt = Elements[Keys.Opt] as PdfArray;
            if (opt != null)
            {
                int count = opt.Elements.Count;
                for (int idx = 0; idx < count; idx++)
                {
                    PdfItem item = opt.Elements[idx];
                    if (item is PdfString)
                    {
                        if (item.ToString() == value)
                            return idx;
                    }
                }
            }
            return -1;
        }

        /// <summary>
        /// Predefined keys of this dictionary. 
        /// The description comes from PDF 1.4 Reference.
        /// </summary>
        public new class Keys : PdfButtonField.Keys
        {
            /// <summary>
            /// (Optional; inheritable; PDF 1.4) An array of text strings to be used in
            /// place of the V entries for the values of the widget annotations representing
            /// the individual radio buttons. Each element in the array represents
            /// the export value of the corresponding widget annotation in the
            /// Kids array of the radio button field.
            /// </summary>
            [KeyInfo(KeyType.Array | KeyType.Optional)]
            public const string Opt = "/Opt";

            /// <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; }
        }
    }
}
