using System.Reflection;

using Gamecraft.Blocks.BlockGroups;
using HarmonyLib;
using RobocraftX.Blocks;
using RobocraftX.Common;
using RobocraftX.GroupTags;
using RobocraftX.StateSync;
using Svelto.ECS;
using Svelto.ECS.Native;
using Techblox.Blocks.Connections;
using Unity.Collections;
using Unity.Jobs;
using Allocator = Unity.Collections.Allocator;

using TechbloxModdingAPI.Engines;
using TechbloxModdingAPI.Utility;

namespace TechbloxModdingAPI.Blocks.Engines
{
    public class RemovalEngine : IApiEngine, IDeterministicTimeStopped
    {
        private static IEntityFunctions _entityFunctions;
        private static MachineGraphConnectionEntityFactory _connectionFactory;
        private NativeHashSet<ulong> removedConnections = new(2000, Allocator.Persistent);

        public bool RemoveBlock(EGID target)
        {
            if (!entitiesDB.Exists<MachineGraphConnectionsEntityStruct>(target))
                return false;
            using var connStructMapper =
                entitiesDB.QueryNativeMappedEntities<MachineGraphConnectionsEntityStruct>(GroupTag<BLOCK_TAG>.Groups,
                    Svelto.Common.Allocator.Temp);
            if (entitiesDB.TryQueryNativeMappedEntities<MachineConnectionComponent>(
                    ConnectionsExclusiveGroups.MACHINE_CONNECTION_GROUP, out var mapper))
            {
                BlockGroupUtility.RemoveBlockConnections(target, removedConnections, _connectionFactory,
                    connStructMapper, mapper, entitiesDB.GetEntityReferenceMap(), _entityFunctions);
            }

            _entityFunctions.RemoveEntity<BlockEntityDescriptor>(target);
            return true;
        }

        public void Ready()
        {
        }

        public EntitiesDB entitiesDB { get; set; }

        public void Dispose()
        {
            removedConnections.Dispose();
        }

        public string Name => "TechbloxModdingAPIRemovalGameEngine";
        public string name => Name;

		public bool isRemovable => false;

		[HarmonyPatch]
        class FactoryObtainerPatch
        {
            static void Postfix(IEntityFunctions entityFunctions,
                MachineGraphConnectionEntityFactory machineGraphConnectionEntityFactory)
            {
                _entityFunctions = entityFunctions;
                _connectionFactory = machineGraphConnectionEntityFactory;
                Logging.MetaDebugLog("Requirements injected.");
            }

            static MethodBase TargetMethod(Harmony instance)
            {
                return AccessTools.TypeByName("RobocraftX.CR.MachineEditing.RemoveBlockEngine").GetConstructors()[0];
            }
        }

        public JobHandle DeterministicStep(in float deltaTime, JobHandle inputDeps)
        {
            removedConnections.Clear();
            return default;
        }
    }
}