using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO.Abstractions;
using System.Threading.Tasks;
using BO.AppServer.Metadata.Enums;
using BO.ProcessServer.Business.Enums;
using BO.ProcessServer.Business.StatisticCounters;
using BO.ProcessServer.Business.Workers.Contexts;
using BO.ProcessServer.Options;
using Connector.PS;
using Quadarax.Foundation.Core.IO.MimeTypes;
using Quadarax.Foundation.Core.Logging;
using Quadarax.Foundation.Core.Thread;

namespace BO.ProcessServer.Business.Workers
{
    internal class SingleDocumentCalculationWorker : ContinousWorker
    {
        #region *** Constants ***
        private const string CS_WK_NAME = "Document";
        #endregion
        #region *** Private fields ***
        private IFileSystem _fileSystem;
        #endregion

        #region *** Properties ***
        public string ShellCommand { get; set; }
        public ServerProcessStateEnum Status { get; set; }
        public DateTime Started { get; set; }
        public DateTime Finished { get; set; }
        #endregion

        #region *** Constructors ***
        public SingleDocumentCalculationWorker(IConnectionPS connection, IFileSystem fileSystem, long documentId, IList<string> files, Configuration configuration, Statistics statistics, Pool pool,
            ILogger logger) : base($"{CS_WK_NAME}#{documentId:D8}", new CalculationCtx(connection, documentId, files, configuration, statistics, pool),
            logger)
        {
            Status = ServerProcessStateEnum.Pending;
            _fileSystem = fileSystem ?? throw new ArgumentNullException(nameof(fileSystem));
        }
        #endregion

        #region *** Iteration ***
        protected override async Task Do(IWorkerContext context)
        {
            var ctx = (CalculationCtx)context;

            Status = ServerProcessStateEnum.Running;
            Started = DateTime.Now;

            // get document metadata
            var document = await ctx.Connection.GetDocumentInfoAsync(ctx.DocumentId);
            
            // find document proper scenario
            var scenarioMan = new Scenarios.Scenarios(ctx.Configuration, GetLogger());
            var scenario = scenarioMan.FindScenario(document);
            if (scenario == null)
            {
                // scenario doesn't exists for document -> change status to pending and move files to Failed branch.
                await ctx.Connection.SetDocumentStateAsync(ctx.DocumentId, DocumentStatusEnum.Pending);
                ctx.Pool.MoveDocumentFiles(Pool.PoolTypeEnum.Working, Pool.PoolTypeEnum.Fail, ctx.DocumentId);
                Status = ServerProcessStateEnum.FailInternal;
            }
            else
            {
                // scenario exists
                var processInfo = new ProcessStartInfo();
                processInfo.FileName = scenario.ShellCommand;
                processInfo.WindowStyle = scenario.RunWindowsStyle;
                processInfo.WorkingDirectory = ctx.Configuration.System.ScenarioPathBase;
                processInfo.Arguments = TranslateArguments(scenario.ShellCommandArguments, ctx.InputFiles,
                    document.PresetProcessProfile, document.PresetQuality, document.PresetWatermark,
                    document.PresetTest);
                processInfo.RedirectStandardOutput = true;
                processInfo.RedirectStandardError = true;
                ShellCommand = processInfo.FileName + " " + processInfo.Arguments;

                using (ctx.Process = Process.Start(processInfo))
                {
                    var errors = await ctx.Process.StandardError.ReadToEndAsync();
                    var outputs = await ctx.Process.StandardOutput.ReadToEndAsync();
                    Log(LogSeverityEnum.Info,
                        $"Starting process '{Name}.{ctx.Process?.ProcessName}' [Id:{ctx.Process?.Id}]: {ShellCommand}");
                    if (ctx.Process != null)
                    {
                        ctx.Process.WaitForExit();
                        if (!string.IsNullOrEmpty(errors))
                            Log(LogSeverityEnum.Error, errors);
                        if (!string.IsNullOrEmpty(outputs))
                            Log(LogSeverityEnum.Info, outputs);

                        Log(LogSeverityEnum.Info,
                            $"End process '{Name}.{ctx.Process?.ProcessName}' [Id:{ctx.Process?.Id}]: Exit code {ctx.Process.ExitCode}");

                        if (ctx.Process.ExitCode == scenario.ExitCodeSucc)
                        {
                            Status = ServerProcessStateEnum.Done;

                        }
                        else if (ctx.Process.ExitCode == scenario.ExitCodeFail)
                        {
                            Status = ServerProcessStateEnum.FailExit;
                        }
                        else
                        {
                            Log(LogSeverityEnum.Warn,
                                $"Process '{Name}.{ctx.Process?.ProcessName}' has unhandled exitcode {ctx.Process.ExitCode}! Goes to fail.");
                            Status = ServerProcessStateEnum.FailInternal;
                        }
                    }
                    else
                    {
                        Status = ServerProcessStateEnum.FailInternal;
                    }
                }
            }
            Finished = DateTime.Now;

            if (Status == ServerProcessStateEnum.Done)
            {
                var files = ctx.Pool.GetDocumentFiles(Pool.PoolTypeEnum.Working, document.Id, Constants.CS_POOL_OUTFILE_EXT);
                foreach (var file in files)
                {
                    await using (var fs = await ctx.Pool.PopDocumentAsync(file))
                    {
                        await ctx.Connection.SetDocumentContentAsync(document.Id,
                            _fileSystem.Path.GetFileNameWithoutExtension(file),
                            MimeTypeUtil.GetMimeType(_fileSystem.Path.GetExtension(file)), false, fs);
                        Log(LogSeverityEnum.Debug, $"Process '{Name}.{ctx.Process?.ProcessName}' file '{file}' uploaded.");
                    }
                }
                await ctx.Connection.SetDocumentStateAsync(document.Id, DocumentStatusEnum.DoneOk);
                ctx.Pool.MoveDocumentFiles(Pool.PoolTypeEnum.Working, Pool.PoolTypeEnum.Done, document.Id);
            }
            else if (Status == ServerProcessStateEnum.FailInternal || Status == ServerProcessStateEnum.FailExit ||
                     Status == ServerProcessStateEnum.FailTimeout)
            {
                ctx.Pool.MoveDocumentFiles(Pool.PoolTypeEnum.Working, Pool.PoolTypeEnum.Fail, document.Id);
            }
            Log(LogSeverityEnum.Info, $"Process '{Name}.{ctx.Process?.ProcessName}' resolution state is '{Status}'.");
        }

        #endregion


        #region *** Overrides ***
        protected override void OnBeforeStart()
        {
            Status = ServerProcessStateEnum.Running;
            Started = DateTime.Now;
            base.OnBeforeStart();
        }

        protected override void OnTimeout(IWorkerContext context)
        {
            var ctx = (CalculationCtx)context;
            ctx.Process.Dispose();
            ctx.Process = null;
            Finished = DateTime.Now;
            Status = ServerProcessStateEnum.FailTimeout;
        }
        #endregion

        #region *** Private Operations ***
        private string TranslateArguments(string arguments,IEnumerable<string> files, string profile, int quality, bool isWatermark,bool isTest)
        {
            var result = arguments.Replace(Constants.CS_TAG_INPUT_FILES, string.Join(Constants.CS_TAG_INPUT_FILES_SEP, files),StringComparison.OrdinalIgnoreCase);
            result = result.Replace(Constants.CS_TAG_P_PROFILE, profile, StringComparison.OrdinalIgnoreCase);
            result = result.Replace(Constants.CS_TAG_P_TEST, isTest.ToString(), StringComparison.OrdinalIgnoreCase);
            result = result.Replace(Constants.CS_TAG_P_WATERMARK, isWatermark.ToString(), StringComparison.OrdinalIgnoreCase);
            result = result.Replace(Constants.CS_TAG_P_QUALITY, quality.ToString(), StringComparison.OrdinalIgnoreCase);
            result = result.Replace(Constants.CS_TAG_P_OUT_EXT, Constants.CS_POOL_OUTFILE_EXT, StringComparison.OrdinalIgnoreCase);
            return result;
        }
        #endregion
    }
}