quantconnect--lean/ToolBox/ExchangeInfoUpdater.cs

/*
 * 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;
using System.IO;

namespace QuantConnect.ToolBox
{
    /// <summary>
    /// Base tool for pulling data from a remote source and updating existing csv file.
    /// </summary>
    public class ExchangeInfoUpdater
    {
        private readonly IExchangeInfoDownloader _eidl;

        public ExchangeInfoUpdater(IExchangeInfoDownloader eidl)
        {
            _eidl = eidl;
        }

        /// <summary>
        /// Update existing symbol properties database
        /// </summary>
        public void Run()
        {
            var directory = Path.Combine(Globals.DataFolder, "symbol-properties");
            var file = Path.Combine(directory, "symbol-properties-database.csv");
            var tmp = Path.Combine(directory, "symbol-properties-database.tmp.csv");
            if (!File.Exists(file))
            {
                throw new FileNotFoundException("Unable to locate symbol properties file: " + file);
            }

            using (var writer = new StreamWriter(tmp))
            {
                var fetch = false;
                // skip the first header line, also skip #'s as these are comment lines
                foreach (var line in File.ReadLines(file))
                {
                    if (!line.StartsWithInvariant(_eidl.Market, true))
                    {
                        writer.WriteLine(line);

                    }
                    else if (!fetch)
                    {
                        foreach (var upd in _eidl.Get())
                        {
                            writer.WriteLine(upd);
                        }
                        fetch = true;
                    }
                }

                if (!fetch)
                {
                    writer.WriteLine(Environment.NewLine);
                    foreach (var upd in _eidl.Get())
                    {
                        writer.WriteLine(upd);
                    }
                }
            }

            File.Delete(file); // Delete the existing file if exists
            File.Move(tmp, file);
        }
    }
}