//Released under the MIT License.
//
//Copyright (c) 2015 Ntreev Soft co., Ltd.
//
//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.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace Ntreev.Library.Psd.Readers.LayerAndMaskInformation
{
    /// <summary>
    /// The document resource
    /// </summary>
    class DocumentResourceBlock : LazyDataReader
  {
        private static string[] doubleTypeKeys = { "LMsk", "Lr16", "Lr32", "Layr", "Mt16", "Mt32", "Mtrn", "Alph", "FMsk", "lnk2", "FEid", "FXid", "PxSD", "lnkE", "extd", };

        private IResourceBlock[] resources;

        public DocumentResourceBlock()
        {
            resources = new IResourceBlock[0];
        }

        public DocumentResourceBlock(PsdReader reader, long length)
        {
          Init(reader, length, null);
        }

        public IResourceBlock[] Resources
        {
            get
            {
                ReadData();
                return resources;
            }

            set
            {
                resources = value;
            }
        }

        protected override void ReadData(PsdReader reader, object userData)
        {
            var resources = new List<IResourceBlock>();

            while (reader.Position < this.EndPosition)
            {
                reader.ValidateSignature(true);
                string resourceID = reader.ReadType();
                long length = this.ReadLength(reader, resourceID);

                var resourceReader = ReaderCollector.CreateReader(resourceID, reader, length);
                string resourceName = ReaderCollector.GetDisplayName(resourceID);

                resources.Add(resourceReader);
            }

            Resources = resources.ToArray();
        }

        private long ReadLength(PsdReader reader, string resourceId)
        {
            long length = 0;

            if (doubleTypeKeys.Contains(resourceId) && reader.Version == 2)
            {
                length = reader.ReadInt64();
            }
            else if(reader.Version == 2)
            {
                length = reader.ReadInt64();
            }
            else
            {
                length = reader.ReadInt32();
            }

            return (length + 3) & (~3);
        }
    }
}