/*
 * 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 System.Linq;
using Newtonsoft.Json;
using NUnit.Framework;
using QuantConnect.Commands;
using QuantConnect.Interfaces;
using System.Collections.Generic;
using System.Globalization;

namespace QuantConnect.Tests.Common.Commands
{
    [TestFixture]
    public class FileCommandHandlerTests
    {
        // NOTE: command file name should follow the file pattern "command*.json"
        private const string SingleCommandFilePath = "command.json";
        private const string MultiCommandFilePath = "commands.json";

        [Test]
        public void ReadsSingleCommandFromFile()
        {
            if (File.Exists(SingleCommandFilePath)) File.Delete(SingleCommandFilePath);
            using var queue = new TestFileCommandHandler();
            Assert.IsEmpty(queue.GetCommandsPublic());
            File.WriteAllText(SingleCommandFilePath, JsonConvert.SerializeObject(new LiquidateCommand
            {
                Ticker = "aapl",
                SecurityType = SecurityType.Equity,
                Market = Market.USA
            }, new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.All }));
            Assert.IsInstanceOf(typeof(LiquidateCommand), queue.GetCommandsPublic().Single());
        }

        [Test]
        public void ReadsMultipleCommandsFromFile()
        {
            if (File.Exists(MultiCommandFilePath)) File.Delete(MultiCommandFilePath);
            using var queue = new TestFileCommandHandler();
            Assert.IsEmpty(queue.GetCommandsPublic());
            File.WriteAllText(MultiCommandFilePath, JsonConvert.SerializeObject(new List<ICommand>
            {
                new CancelOrderCommand
                {
                    OrderId = 2342
                },
                new SpecialCommand()
            }, new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.All }));
            var list = queue.GetCommandsPublic().ToList();
            Assert.IsInstanceOf(typeof(CancelOrderCommand), list[0]);
            Assert.IsInstanceOf(typeof(SpecialCommand), list[1]);
            Assert.IsEmpty(queue.GetCommandsPublic());
        }

        [Test]
        public void ReadsFilesInOrder()
        {
            foreach (var file in FileCommandHandler.GetCommandFiles())
            {
                File.Delete(file.FullName);
            }
            using var queue = new TestFileCommandHandler();
            Assert.IsEmpty(queue.GetCommandsPublic());
            var baseName = SingleCommandFilePath.Split(".")[0];
            var commands = new List<BaseCommand>()
            {
                new LiquidateCommand(), new SpecialCommand(), new AlgorithmStatusCommand()
            };
            var fileSerialNumber = 0;
            foreach (var command in commands)
            {
                var fileName = $"{baseName}-{++fileSerialNumber}.json";
                File.WriteAllText(fileName, JsonConvert.SerializeObject(command, new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.All }));
            }
            var list = queue.GetCommandsPublic().ToList();
            Assert.AreEqual(commands.Count, list.Count);
            for (int i = 0; i < commands.Count; i++)
            {
                Assert.AreEqual(commands[i].GetType().FullName, list[i].GetType().FullName);
            }
            Assert.IsEmpty(queue.GetCommandsPublic());
        }

        private sealed class SpecialCommand : BaseCommand
        {
            public override CommandResultPacket Run(IAlgorithm algorithm)
            {
                return new CommandResultPacket(this, true);
            }
        }

        private class TestFileCommandHandler : FileCommandHandler
        {
            public IEnumerable<ICommand> GetCommandsPublic() => base.GetCommands();
        }
    }
}