/*
 * QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
 * Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); 
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
*/

using System.IO;
using Ionic.Zip;

namespace QuantConnect.Lean.Engine.DataFeeds.Transport
{
    /// <summary>
    /// Represents a stream reader capable of reading lines from disk
    /// </summary>
    public class LocalFileSubscriptionStreamReader : IStreamReader
    {
        private StreamReader _streamReader;
        private readonly ZipFile _zipFile;

        /// <summary>
        /// Initializes a new instance of the <see cref="LocalFileSubscriptionStreamReader"/> class.
        /// </summary>
        /// <param name="source">The local file to be read</param>
        public LocalFileSubscriptionStreamReader(string source)
        {
            // unzip if necessary
            _streamReader = source.GetExtension() == ".zip"
                ? Compression.Unzip(source, out _zipFile)
                : new StreamReader(source);
        }

        /// <summary>
        /// Gets <see cref="SubscriptionTransportMedium.LocalFile"/>
        /// </summary>
        public SubscriptionTransportMedium TransportMedium
        {
            get { return SubscriptionTransportMedium.LocalFile; }
        }

        /// <summary>
        /// Gets whether or not there's more data to be read in the stream
        /// </summary>
        public bool EndOfStream
        {
            get { return _streamReader == null || _streamReader.EndOfStream; }
        }

        /// <summary>
        /// Gets the next line/batch of content from the stream 
        /// </summary>
        public string ReadLine()
        {
            return _streamReader.ReadLine();
        }

        /// <summary>
        /// Disposes of the stream
        /// </summary>
        public void Dispose()
        {
            if (_streamReader != null)
            {
                _streamReader.Dispose();
                _streamReader = null;
            }
            if (_zipFile != null)
            {
                _zipFile.Dispose();
            }
        }
    }
}