/*
 * QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
 * Lean Algorithmic Trading Engine v2.0. Copyright 2026 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 QuantConnect.Util;
using QuantConnect.Interfaces;
using QuantConnect.Configuration;

namespace QuantConnect.Lean.Engine.DataFeeds.DataDownloader
{
    /// <summary>Selects the appropriate data downloader based on the data type.</summary>
    public class DataDownloaderSelector : IDisposable
    {
        private readonly IDataDownloader _baseDataDownloader;
        private readonly CanonicalDataDownloaderDecorator _canonicalDataDownloaderDecorator;

        /// <summary>Initializes a new instance of the <see cref="DataDownloaderSelector"/> class.</summary>
        /// <param name="baseDataDownloader">The base data downloader instance.</param>
        /// <param name="mapFileProvider">The map file provider used for initializing chain providers.</param>
        /// <param name="dataProvider">The data provider used for initializing chain providers.</param>
        /// <param name="factorFileProvider">The factor file provider used for initializing chain providers.</param>
        public DataDownloaderSelector(
            IDataDownloader baseDataDownloader,
            IMapFileProvider mapFileProvider,
            IDataProvider dataProvider,
            IFactorFileProvider factorFileProvider = null)
        {
            factorFileProvider ??= Composer.Instance.GetPart<IFactorFileProvider>();
            if (factorFileProvider == null)
            {
                factorFileProvider = Composer.Instance.GetExportedValueByTypeName<IFactorFileProvider>(Config.Get("factor-file-provider", "LocalDiskFactorFileProvider"));
                factorFileProvider.Initialize(mapFileProvider, dataProvider);
            }

            _baseDataDownloader = baseDataDownloader;
            _canonicalDataDownloaderDecorator = new CanonicalDataDownloaderDecorator(_baseDataDownloader, dataProvider, mapFileProvider, factorFileProvider);
        }

        /// <summary>Disposes the base downloader and the decorator if it was initialized.</summary>
        public void Dispose()
        {
            (_baseDataDownloader as IDisposable)?.DisposeSafely();
        }

        /// <summary>Returns the appropriate downloader for the given data type.</summary>
        /// <param name="dataType">The type of data to download.</param>
        /// <returns>The base downloader for common lean data types, otherwise the canonical decorator.</returns>
        public IDataDownloader GetDataDownloader(Type dataType)
        {
            return LeanData.IsCommonLeanDataType(dataType) ? _canonicalDataDownloaderDecorator : _baseDataDownloader;
        }
    }
}