/*
 * 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.ComponentModel.Composition;
using System.IO;
using System.Threading;
using QuantConnect.Configuration;
using QuantConnect.Lean.Engine;
using QuantConnect.Logging;
using QuantConnect.Packets;
using QuantConnect.Util;

namespace QuantConnect.Lean.Launcher
{
    public class Program
    {
        private const string _collapseMessage = "Unhandled exception breaking past controls and causing collapse of algorithm node. This is likely a memory leak of an external dependency or the underlying OS terminating the LEAN engine.";

        static Program()
        {
            AppDomain.CurrentDomain.AssemblyLoad += (sender, e) =>
            {
                if (e.LoadedAssembly.FullName.ToLowerInvariant().Contains("python"))
                {
                    Log.Trace($"Python for .NET Assembly: {e.LoadedAssembly.GetName()}");
                }
            };
        }

        static void Main(string[] args)
        {
            //Initialize:
            var mode = "RELEASE";
            #if DEBUG
                mode = "DEBUG";
            #endif

            if (OS.IsWindows)
            {
                Console.OutputEncoding = System.Text.Encoding.UTF8;
            }

            // expect first argument to be config file name
            if (args.Length > 0)
            {
                Config.MergeCommandLineArgumentsWithConfiguration(LeanArgumentParser.ParseArguments(args));
            }

            var environment = Config.Get("environment");
            var liveMode = Config.GetBool("live-mode");
            Log.DebuggingEnabled = Config.GetBool("debug-mode");
            Log.FilePath = Path.Combine(Config.Get("results-destination-folder"), "log.txt");
            Log.LogHandler = Composer.Instance.GetExportedValueByTypeName<ILogHandler>(Config.Get("log-handler", "CompositeLogHandler"));

            //Name thread for the profiler:
            Thread.CurrentThread.Name = "Algorithm Analysis Thread";
            Log.Trace("Engine.Main(): LEAN ALGORITHMIC TRADING ENGINE v" + Globals.Version + " Mode: " + mode + " (" + (Environment.Is64BitProcess ? "64" : "32") + "bit)");
            Log.Trace("Engine.Main(): Started " + DateTime.Now.ToShortTimeString());

            //Import external libraries specific to physical server location (cloud/local)
            LeanEngineSystemHandlers leanEngineSystemHandlers;
            try
            {
                leanEngineSystemHandlers = LeanEngineSystemHandlers.FromConfiguration(Composer.Instance);
            }
            catch (CompositionException compositionException)
            {
                Log.Error("Engine.Main(): Failed to load library: " + compositionException);
                throw;
            }

            //Setup packeting, queue and controls system: These don't do much locally.
            leanEngineSystemHandlers.Initialize();

            //-> Pull job from QuantConnect job queue, or, pull local build:
            string assemblyPath;
            var job = leanEngineSystemHandlers.JobQueue.NextJob(out assemblyPath);

            if (job == null)
            {
                const string jobNullMessage = "Engine.Main(): Sorry we could not process this algorithm request.";
                Log.Error(jobNullMessage);
                throw new ArgumentException(jobNullMessage);
            }

            LeanEngineAlgorithmHandlers leanEngineAlgorithmHandlers;
            try
            {
                leanEngineAlgorithmHandlers = LeanEngineAlgorithmHandlers.FromConfiguration(Composer.Instance);
            }
            catch (CompositionException compositionException)
            {
                Log.Error("Engine.Main(): Failed to load library: " + compositionException);
                throw;
            }

            // if the job version doesn't match this instance version then we can't process it
            // we also don't want to reprocess redelivered jobs
            if (VersionHelper.IsNotEqualVersion(job.Version) || job.Redelivered)
            {
                Log.Error("Engine.Run(): Job Version: " + job.Version + "  Deployed Version: " + Globals.Version + " Redelivered: " + job.Redelivered);
                //Tiny chance there was an uncontrolled collapse of a server, resulting in an old user task circulating.
                //In this event kill the old algorithm and leave a message so the user can later review.
                leanEngineSystemHandlers.Api.SetAlgorithmStatus(job.AlgorithmId, AlgorithmStatus.RuntimeError, _collapseMessage);
                leanEngineSystemHandlers.Notify.SetAuthentication(job);
                leanEngineSystemHandlers.Notify.Send(new RuntimeErrorPacket(job.UserId, job.AlgorithmId, _collapseMessage));
                leanEngineSystemHandlers.JobQueue.AcknowledgeJob(job);
                return;
            }

            try
            {
                var algorithmManager = new AlgorithmManager(liveMode, job);

                leanEngineSystemHandlers.LeanManager.Initialize(leanEngineSystemHandlers, leanEngineAlgorithmHandlers, job, algorithmManager);

                var engine = new Engine.Engine(leanEngineSystemHandlers, leanEngineAlgorithmHandlers, liveMode);
                engine.Run(job, algorithmManager, assemblyPath, WorkerThread.Instance);
            }
            finally
            {
                //Delete the message from the job queue:
                leanEngineSystemHandlers.JobQueue.AcknowledgeJob(job);
                Log.Trace("Engine.Main(): Packet removed from queue: " + job.AlgorithmId);

                // clean up resources
                leanEngineSystemHandlers.Dispose();
                leanEngineAlgorithmHandlers.Dispose();
                Log.LogHandler.Dispose();

                Log.Trace("Program.Main(): Exiting Lean...");

                Environment.Exit(0);
            }
        }
    }
}