#nullable enable
using System.Diagnostics.CodeAnalysis;
using Content.Shared.Chemistry;
using Robust.Server.Interfaces.GameObjects;
using Robust.Shared.Interfaces.GameObjects;
using Robust.Shared.Interfaces.Map;
using Robust.Shared.IoC;
using Robust.Shared.Map;

namespace Content.Server.GameObjects.Components.Fluids
{
    public static class SpillExtensions
    {
        /// <summary>
        ///     Spills the specified solution at the entity's location if possible.
        /// </summary>
        /// <param name="entity">
        ///     The entity to use as a location to spill the solution at.
        /// </param>
        /// <param name="solution">Initial solution for the prototype.</param>
        /// <param name="prototype">The prototype to use.</param>
        /// <param name="sound">Play the spill sound.</param>
        /// <returns>The puddle if one was created, null otherwise.</returns>
        public static PuddleComponent? SpillAt(this Solution solution, IEntity entity, string prototype, bool sound = true)
        {
            var coordinates = entity.Transform.Coordinates;
            return solution.SpillAt(coordinates, prototype, sound);
        }

        /// <summary>
        ///     Spills the specified solution at the entity's location if possible.
        /// </summary>
        /// <param name="entity">
        ///     The entity to use as a location to spill the solution at.
        /// </param>
        /// <param name="solution">Initial solution for the prototype.</param>
        /// <param name="prototype">The prototype to use.</param>
        /// <param name="puddle">The puddle if one was created, null otherwise.</param>
        /// <param name="sound">Play the spill sound.</param>
        /// <returns>True if a puddle was created, false otherwise.</returns>
        public static bool TrySpillAt(this Solution solution, IEntity entity, string prototype, [NotNullWhen(true)] out PuddleComponent? puddle, bool sound = true)
        {
            puddle = solution.SpillAt(entity, prototype, sound);
            return puddle != null;
        }

        /// <summary>
        ///     Spills solution at the specified grid coordinates.
        /// </summary>
        /// <param name="solution">Initial solution for the prototype.</param>
        /// <param name="coordinates">The coordinates to spill the solution at.</param>
        /// <param name="prototype">The prototype to use.</param>
        /// <param name="sound">Whether or not to play the spill sound.</param>
        /// <returns>The puddle if one was created, null otherwise.</returns>
        public static PuddleComponent? SpillAt(this Solution solution, EntityCoordinates coordinates, string prototype, bool sound = true)
        {
            if (solution.TotalVolume == 0)
            {
                return null;
            }

            var mapManager = IoCManager.Resolve<IMapManager>();
            var entityManager = IoCManager.Resolve<IEntityManager>();
            var serverEntityManager = IoCManager.Resolve<IServerEntityManager>();

            var gridId = coordinates.GetGridId(entityManager);
            var mapGrid = mapManager.GetGrid(gridId);

            // If space return early, let that spill go out into the void
            var tileRef = mapGrid.GetTileRef(coordinates);
            if (tileRef.Tile.IsEmpty)
            {
                return null;
            }

            // Get normalized co-ordinate for spill location and spill it in the centre
            // TODO: Does SnapGrid or something else already do this?
            var spillTileMapGrid = mapManager.GetGrid(gridId);
            var spillTileRef = spillTileMapGrid.GetTileRef(coordinates).GridIndices;
            var spillGridCoords = spillTileMapGrid.GridTileToLocal(spillTileRef);

            var spilt = false;

            foreach (var spillEntity in entityManager.GetEntitiesAt(spillTileMapGrid.ParentMapId, spillGridCoords.Position))
            {
                if (!spillEntity.TryGetComponent(out PuddleComponent? puddleComponent))
                {
                    continue;
                }

                if (!puddleComponent.TryAddSolution(solution, sound))
                {
                    continue;
                }

                spilt = true;
                break;
            }

            // Did we add to an existing puddle
            if (spilt)
            {
                return null;
            }

            var puddle = serverEntityManager.SpawnEntity(prototype, spillGridCoords);
            var newPuddleComponent = puddle.GetComponent<PuddleComponent>();

            newPuddleComponent.TryAddSolution(solution, sound);

            return newPuddleComponent;
        }

        /// <summary>
        ///     Spills the specified solution at the entity's location if possible.
        /// </summary>
        /// <param name="coordinates">The coordinates to spill the solution at.</param>
        /// <param name="solution">Initial solution for the prototype.</param>
        /// <param name="prototype">The prototype to use.</param>
        /// <param name="puddle">The puddle if one was created, null otherwise.</param>
        /// <param name="sound">Play the spill sound.</param>
        /// <returns>True if a puddle was created, false otherwise.</returns>
        public static bool TrySpillAt(this Solution solution, EntityCoordinates coordinates, string prototype, [NotNullWhen(true)] out PuddleComponent? puddle, bool sound = true)
        {
            puddle = solution.SpillAt(coordinates, prototype, sound);
            return puddle != null;
        }
    }
}