using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using RobocraftX;
using RobocraftX.Blocks;
using RobocraftX.Blocks.Ghost;
using RobocraftX.Common;
using RobocraftX.Multiplayer;
using RobocraftX.SimulationModeState;
using RobocraftX.UECS;
using Unity.Entities;
using Svelto.Context;
using Svelto.ECS;
using Svelto.ECS.EntityStructs;
using Unity.Transforms;
using Unity.Mathematics;
using UnityEngine;

using GamecraftModdingAPI.Utility;

namespace GamecraftModdingAPI.Blocks
{
    /// <summary>
    /// Engine which executes block movement actions
    /// </summary>
    public class MovementEngine : IApiEngine
    {
        public string Name { get; } = "GamecraftModdingAPIMovementGameEngine";

        public IEntitiesDB entitiesDB { set; private get; }

        public bool IsInGame = false;

        public void Dispose()
        {
            IsInGame = false;
        }

        public void Ready()
        {
            IsInGame = true;
        }

        // implementations for Movement static class

        public float3 MoveBlock(uint blockID, float3 vector)
        {
            ref PositionEntityStruct posStruct = ref this.entitiesDB.QueryEntity<PositionEntityStruct>(blockID, CommonExclusiveGroups.OWNED_BLOCKS_GROUP);
            ref GridRotationStruct gridStruct = ref this.entitiesDB.QueryEntity<GridRotationStruct>(blockID, CommonExclusiveGroups.OWNED_BLOCKS_GROUP);
            ref LocalTransformEntityStruct transStruct = ref this.entitiesDB.QueryEntity<LocalTransformEntityStruct>(blockID, CommonExclusiveGroups.OWNED_BLOCKS_GROUP);
            ref UECSPhysicsEntityStruct phyStruct = ref this.entitiesDB.QueryEntity<UECSPhysicsEntityStruct>(blockID, CommonExclusiveGroups.OWNED_BLOCKS_GROUP);
            // main (persistent) position
            posStruct.position += vector;
            // placement grid  position
            gridStruct.position += vector;
            // rendered position
            transStruct.position += vector;
            // collision position
            FullGameFields._physicsWorld.EntityManager.SetComponentData(phyStruct.uecsEntity, new Translation
            {
                Value = posStruct.position
            });
            return posStruct.position;
        }

        public float3 MoveConnectedBlocks(uint blockID, float3 vector)
        {
            Stack<uint> cubeStack = new Stack<uint>();
            Gamecraft.DataStructures.FasterList<uint> cubesToMove = new Gamecraft.DataStructures.FasterList<uint>();
            ConnectedCubesUtility.TreeTraversal.GetConnectedCubes(entitiesDB, blockID, cubeStack, cubesToMove, (in GridConnectionsEntityStruct g) => { return false; });
            for (int i = 0; i < cubesToMove.Count; i++)
            {
                MoveBlock(cubesToMove[i], vector);
                entitiesDB.QueryEntity<GridConnectionsEntityStruct>(cubesToMove[i], CommonExclusiveGroups.OWNED_BLOCKS_GROUP).isProcessed = false;
            }
            return this.entitiesDB.QueryEntity<PositionEntityStruct>(blockID, CommonExclusiveGroups.OWNED_BLOCKS_GROUP).position;
        }

        public bool IsBuildMode()
        {
            return GamecraftModdingAPI.Utility.GameState.IsBuildMode();
        }
    }
}