using System;
using System.Threading;
using System.Threading.Tasks;
using LavishVMAPI;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using MRBot.PassiveTasks;
using StackExchange.Profiling;

namespace MRBot.Services;

internal sealed class PassiveTaskManager : BackgroundService
{
    private const uint PulseRate = 10;
    private readonly ILogger<PassiveTaskManager> _logger;
    private readonly IPassiveTaskList _passiveTaskList;
    private readonly MiniProfiler _profiler;
    private DateTime _lastLogTime = DateTime.MinValue;
    private uint _pulseCount;

    public PassiveTaskManager(IPassiveTaskList passiveTaskList, ILogger<PassiveTaskManager> logger,
        MiniProfiler profiler)
    {
        _passiveTaskList = passiveTaskList;
        _logger = logger;
        _profiler = profiler;
    }

    private bool ShouldPulse
    {
        get
        {
            if (_pulseCount >= PulseRate)
            {
                _pulseCount = 0;
                return true;
            }

            _pulseCount++;
            return false;
        }
    }

    public override Task StartAsync(CancellationToken cancellationToken)
    {
        _logger.LogInformation("Starting passive task manager");
        return base.StartAsync(cancellationToken);
    }

    public override Task StopAsync(CancellationToken cancellationToken)
    {
        _logger.LogInformation("Stopping passive task manager");
        return base.StopAsync(cancellationToken);
    }

    private Task ServiceLoopAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            if (!ShouldPulse) continue;
            // using (_profiler.Step("PassiveTaskManager.ServiceLoopAsync"))
            {
                foreach (var task in _passiveTaskList)
                {
                    if (stoppingToken.IsCancellationRequested) return Task.FromCanceled(stoppingToken);
                    _logger.LogInformation($"Pulsing task {task.Type}");
                    // using (_profiler.Step($"FrameLock.{task.Type}"))
                    using (new FrameLock(true))
                    {
                        task.Execute();
                    }
                }
            }

            Thread.Sleep(500);
        }

        return Task.CompletedTask;
    }

    protected override Task ExecuteAsync(CancellationToken stoppingToken)
    {
        return Task.Factory.StartNew(async () => { await ServiceLoopAsync(stoppingToken); }, stoppingToken,
            TaskCreationOptions.LongRunning, TaskScheduler.Default);
    }

    public override void Dispose()
    {
        _logger.LogInformation("Disposing passive task manager");
        base.Dispose();
    }
}