tbd-station-14/Content.Server/Chemistry/EntitySystems/SolutionInjectOnCollideSystem.cs

using Content.Server.Body.Components;
using Content.Server.Chemistry.Components;
using Content.Server.Chemistry.Components.SolutionManager;
using JetBrains.Annotations;
using Robust.Shared.GameObjects;
using Robust.Shared.IoC;
using Robust.Shared.Physics.Dynamics;

namespace Content.Server.Chemistry.EntitySystems
{
    [UsedImplicitly]
    internal sealed class SolutionInjectOnCollideSystem : EntitySystem
    {
        [Dependency] private readonly SolutionContainerSystem _solutionsSystem = default!;
        public override void Initialize()
        {
            base.Initialize();
            SubscribeLocalEvent<SolutionInjectOnCollideComponent, ComponentInit>(HandleInit);
            SubscribeLocalEvent<SolutionInjectOnCollideComponent, StartCollideEvent>(HandleInjection);
        }

        private void HandleInit(EntityUid uid, SolutionInjectOnCollideComponent component, ComponentInit args)
        {
            component.Owner
                .EnsureComponentWarn<SolutionContainerManagerComponent>($"{nameof(SolutionInjectOnCollideComponent)} requires a SolutionContainerManager on {component.Owner}!");
        }

        private void HandleInjection(EntityUid uid, SolutionInjectOnCollideComponent component, StartCollideEvent args)
        {
            if (!args.OtherFixture.Body.Owner.TryGetComponent<BloodstreamComponent>(out var bloodstream) ||
                !_solutionsSystem.TryGetInjectableSolution(component.Owner.Uid, out var solution)) return;

            var solRemoved = solution.SplitSolution(component.TransferAmount);
            var solRemovedVol = solRemoved.TotalVolume;

            var solToInject = solRemoved.SplitSolution(solRemovedVol * component.TransferEfficiency);

            bloodstream.TryTransferSolution(solToInject);
        }
    }
}