using Hcs.WebApp.Data.Hcs;
using Hcs.WebApp.Data.Hcs.CampaignArgs;
using Hcs.WebApp.Services;
using Microsoft.EntityFrameworkCore;

namespace Hcs.WebApp.BackgroundServices.CampaignManagers
{
    public class ParseHousesDataManager_15_7_0_1(
        IServiceScopeFactory scopeFactory,
        OperationExecutionState operationExecutionState,
        ResultGetState resultGetState,
        DataParsingState dataParsingState,
        Campaign campaign) : ManagerBase(scopeFactory, operationExecutionState, resultGetState, dataParsingState, campaign)
    {
        private enum Step
        {
            Start = 0,
            ParseWait = 1,
            End = 2
        }

        private FileToParseService? fileToParseService;

        protected override int StepCount => Enum.GetValues(typeof(Step)).Length;

        protected FileToParseService FileToParseService => fileToParseService ??= scope.ServiceProvider.GetRequiredService<FileToParseService>();

        public override async Task ProcessAsync()
        {
            switch ((Step)campaign.Step)
            {
                case Step.Start:
                    await DoStartStepAsync();
                    break;

                case Step.ParseWait:
                    await DoParseWaitStepAsync();
                    break;
            }
        }
        
        private async Task DoStartStepAsync()
        {
            DateTime startedAt = default;
            IEnumerable<Operation>? operations = null;

            using var context = HeadquartersService.GetNewContext();
            var executionStrategy = context.Database.CreateExecutionStrategy();
            await executionStrategy.ExecuteAsync(async () =>
            {
                using var transaction = await context.Database.BeginTransactionAsync();
                try
                {
                    startedAt = DateTime.UtcNow;
                    await HeadquartersService.SetCampaignStartedAsync(context, campaign.Id, startedAt);

                    await ProgressStepAsync(context, (int)Step.ParseWait);

                    var args = campaign.DeserializeArgs() as CampaignParseArgs;
                    operations = await HeadquartersService.InitiateOperationsAsync(context, 1, campaign.Id, Operation.OperationType.ParseHousesData_15_7_0_1);
                    await FileToParseService.SetOperationToFileToParseAsync(context, args!.fileToParseId, operations.First());
                    
                    await transaction.CommitAsync();
                }
                catch
                {
                    transaction?.Rollback();

                    throw;
                }
            });

            if (operations != null)
            {
                dataParsingState.EnqueueOperation(operations.First());
            }

            State = IManager.ManagerState.Started;

            InvokeOnCampaignStarted(startedAt);
        }

        private async Task DoParseWaitStepAsync()
        {
            if (dataParsingState.HasCampaignOperation(campaign.Id)) return;

            DateTime endedAt = default;

            using var context = HeadquartersService.GetNewContext();
            var executionStrategy = context.Database.CreateExecutionStrategy();
            await executionStrategy.ExecuteAsync(async () =>
            {
                using var transaction = await context.Database.BeginTransactionAsync();
                try
                {
                    await ProgressStepAsync(context, (int)Step.End);

                    endedAt = DateTime.UtcNow;
                    await HeadquartersService.SetCampaignEndedAsync(context, campaign.Id, endedAt);

                    await transaction.CommitAsync();
                }
                catch
                {
                    transaction?.Rollback();

                    throw;
                }
            });

            State = IManager.ManagerState.Ended;

            InvokeOnCampaignEnded(endedAt, string.Empty);
        }
    }
}