using System;
using System.Linq;
using System.Threading.Tasks;
using Content.Server.Atmos;
using Content.Server.Body.Components;
using Content.Server.Body.Systems;
using Content.Shared.Atmos;
using Content.Shared.Body.Components;
using NUnit.Framework;
using Robust.Server.Maps;
using Robust.Shared.GameObjects;
using Robust.Shared.IoC;
using Robust.Shared.Map;
using Robust.Shared.Maths;

namespace Content.IntegrationTests.Tests.Body
{
    [TestFixture]
    [TestOf(typeof(LungSystem))]
    public class LungTest : ContentIntegrationTest
    {
        private const string Prototypes = @"
- type: entity
  name: HumanBodyAndBloodstreamDummy
  id: HumanBodyAndBloodstreamDummy
  components:
  - type: Bloodstream
    max_volume: 100
  - type: SolutionContainerManager
  - type: Body
    template: HumanoidTemplate
    preset: HumanPreset
    centerSlot: torso
  - type: ThermalRegulator
    metabolismHeat: 5000
    radiatedHeat: 400
    implicitHeatRegulation: 5000
    sweatHeatRegulation: 5000
    shiveringHeatRegulation: 5000
    normalBodyTemperature: 310.15
    thermalRegulationTemperatureThreshold: 25
  - type: Respirator
    needsGases:
      Oxygen: 0.00060763888
    producesGases:
      Oxygen: 0.00045572916
      CarbonDioxide: 0.00015190972
";

        [Test]
        public async Task AirConsistencyTest()
        {
            var options = new ServerContentIntegrationOption{ExtraPrototypes = Prototypes};
            var server = StartServer(options);

            server.Assert(() =>
            {
                var mapManager = IoCManager.Resolve<IMapManager>();

                var mapId = mapManager.CreateMap();

                var entityManager = IoCManager.Resolve<IEntityManager>();

                var human = entityManager.SpawnEntity("HumanBodyAndBloodstreamDummy", new MapCoordinates(Vector2.Zero, mapId));

                var bodySys = EntitySystem.Get<BodySystem>();
                var lungSys = EntitySystem.Get<LungSystem>();

                Assert.That(IoCManager.Resolve<IEntityManager>().TryGetComponent(human, out SharedBodyComponent body));

                var lungs = bodySys.GetComponentsOnMechanisms<LungComponent>(human, body).ToArray();
                Assert.That(lungs.Count, Is.EqualTo(1));
                Assert.That(IoCManager.Resolve<IEntityManager>().TryGetComponent(human, out BloodstreamComponent bloodstream));

                var gas = new GasMixture(1);

                var originalOxygen = 2;
                var originalNitrogen = 8;
                var breathedPercentage = Atmospherics.BreathVolume / gas.Volume;

                gas.AdjustMoles(Gas.Oxygen, originalOxygen);
                gas.AdjustMoles(Gas.Nitrogen, originalNitrogen);

                var (lung, _) = lungs[0];
                lungSys.TakeGasFrom(((IComponent) lung).Owner, 1, gas, lung);

                var lungOxygen = originalOxygen * breathedPercentage;
                var lungNitrogen = originalNitrogen * breathedPercentage;

                Assert.That(bloodstream.Air.GetMoles(Gas.Oxygen), Is.EqualTo(lungOxygen));
                Assert.That(bloodstream.Air.GetMoles(Gas.Nitrogen), Is.EqualTo(lungNitrogen));

                var mixtureOxygen = originalOxygen - lungOxygen;
                var mixtureNitrogen = originalNitrogen - lungNitrogen;

                Assert.That(gas.GetMoles(Gas.Oxygen), Is.EqualTo(mixtureOxygen));
                Assert.That(gas.GetMoles(Gas.Nitrogen), Is.EqualTo(mixtureNitrogen));

                var lungOxygenBeforeExhale = lung.Air.GetMoles(Gas.Oxygen);
                var lungNitrogenBeforeExhale = lung.Air.GetMoles(Gas.Nitrogen);

                // Empty after it transfer to the bloodstream
                Assert.Zero(lungOxygenBeforeExhale);
                Assert.Zero(lungNitrogenBeforeExhale);

                lungSys.PushGasTo(((IComponent) lung).Owner, gas, lung);

                var lungOxygenAfterExhale = lung.Air.GetMoles(Gas.Oxygen);
                var exhaledOxygen = Math.Abs(lungOxygenBeforeExhale - lungOxygenAfterExhale);

                // Not completely empty
                Assert.Positive(lung.Air.Moles.Sum());

                // Retains needed gas
                Assert.Positive(bloodstream.Air.GetMoles(Gas.Oxygen));

                // Expels toxins
                Assert.Zero(bloodstream.Air.GetMoles(Gas.Nitrogen));

                mixtureOxygen += exhaledOxygen;

                var finalTotalOxygen = gas.GetMoles(Gas.Oxygen) +
                                         bloodstream.Air.GetMoles(Gas.Oxygen) +
                                         lung.Air.GetMoles(Gas.Oxygen);

                // No ticks were run, metabolism doesn't run and so no oxygen is used up
                Assert.That(finalTotalOxygen, Is.EqualTo(originalOxygen));
                Assert.That(gas.GetMoles(Gas.Oxygen), Is.EqualTo(mixtureOxygen).Within(0.000001f));

                var finalTotalNitrogen = gas.GetMoles(Gas.Nitrogen) +
                                         bloodstream.Air.GetMoles(Gas.Nitrogen) +
                                         lung.Air.GetMoles(Gas.Nitrogen);

                // Nitrogen stays constant
                Assert.That(finalTotalNitrogen, Is.EqualTo(originalNitrogen).Within(0.000001f));
            });

            await server.WaitIdleAsync();
        }

        [Test]
        public async Task NoSuffocationTest()
        {
            var options = new ServerContentIntegrationOption{ExtraPrototypes = Prototypes};
            var server = StartServer(options);

            await server.WaitIdleAsync();

            var mapLoader = server.ResolveDependency<IMapLoader>();
            var mapManager = server.ResolveDependency<IMapManager>();
            var entityManager = server.ResolveDependency<IEntityManager>();

            MapId mapId;
            IMapGrid grid = null;
            RespiratorComponent respirator = null;
            EntityUid human = default;

            var testMapName = "Maps/Test/Breathing/3by3-20oxy-80nit.yml";

            await server.WaitPost(() =>
            {
                mapId = mapManager.CreateMap();
                grid = mapLoader.LoadBlueprint(mapId, testMapName);
            });

            Assert.NotNull(grid, $"Test blueprint {testMapName} not found.");

            await server.WaitAssertion(() =>
            {
                var center = new Vector2(0.5f, -1.5f);
                var coordinates = new EntityCoordinates(grid.GridEntityId, center);
                human = entityManager.SpawnEntity("HumanBodyAndBloodstreamDummy", coordinates);

                Assert.True(IoCManager.Resolve<IEntityManager>().HasComponent<SharedBodyComponent>(human));
                Assert.True(IoCManager.Resolve<IEntityManager>().TryGetComponent(human, out respirator));
                Assert.False(respirator.Suffocating);
            });

            var increment = 10;


            for (var tick = 0; tick < 600; tick += increment)
            {
                await server.WaitRunTicks(increment);
                await server.WaitAssertion(() =>
                {
                    Assert.False(respirator.Suffocating, $"Entity {IoCManager.Resolve<IEntityManager>().GetComponent<MetaDataComponent>(human).EntityName} is suffocating on tick {tick}");
                });
            }

            await server.WaitIdleAsync();
        }
    }
}