using System.Collections.Generic;
using System.Linq;
using Global.Patches;
using Global.Shared.API;
using Global.Shared.Events;
using Global.Shared.OcTree.Data;
using Global.Shared.Plugin;
using Sandbox.Game.Entities;
using VRage.Game.Components;
using VRage.Game.Entity;
using VRage.Game.ModAPI;

namespace Global.Shared.OcTree
{
    public class OcTreeHandler
    {
        public GenericOcTree<GridData> GridTree { get; private set; }

        public GenericOcTree<ControllableEntityData> CharacterTree { get; private set; }

        internal void Init()
        {
            var cfg = GlobalInstance.Config;
            var offset = cfg.CenterPosition;
            var x = cfg.Size;
            var y = cfg.Size;
            var z = cfg.Size;
            GridTree = new GenericOcTree<GridData>(offset.X - x, offset.Y - y, offset.Z - z, x * 2, y * 2, z * 2,
                cfg.Capacity, cfg.MaxDepth);
            CharacterTree =
                new GenericOcTree<ControllableEntityData>(offset.X - x, offset.Y - y, offset.Z - z, x * 2, y * 2, z * 2,
                    cfg.Capacity, cfg.MaxDepth);

            BlockEvents.OnPlayerControlAcquired += AddControllableEntity;
            BlockEvents.OnPlayerControlReleased += RemoveControllableEntity;
        }

        public IGridData AddGrid(MyCubeGrid grid)
        {
            var bigOwner = grid.BigOwners.Count == 0 ? "No Owner!" : grid.BigOwners.First().ToString();
            // check if grid is new subgrid
            if (MyMechanicalConnectionBlockBasePatch.IsCreatingSubPart)
            {
                GlobalInstance.Log.Trace(
                    $"Grid is subgrid, ignoring {grid.DisplayName} {grid.PositionComp.GetPosition()} {bigOwner}");
                return null;
            }

            if (!GridTree.Contains(grid.EntityId))
            {
                var grids = grid.GetGridGroup(GridLinkTypeEnum.Mechanical).GetGrids(new List<IMyCubeGrid>());
                var largestGrid = grid;
                if (grids.Count > 1)
                    foreach (var g in grids.Cast<MyCubeGrid>())
                        if (g.BlocksCount > largestGrid.BlocksCount)
                            largestGrid = g;

                grid = largestGrid;
                //GlobalInstance.Log.Info(
                //$"Adding grid to OcTree: {grid.EntityId} {grid.DisplayName} {grid.PositionComp.GetPosition()}");

                var data = new GridData(grid);
                grid.PositionComp.OnPositionChanged += Grid_OnPositionChanged;
                grid.OnMarkForClose += RemoveGrid;
                grid.OnTeleported += Grid_OnChanged;
                GridTree.Insert(data);
                grid.OnConnectionChanged += Grid_OnConnectionChanged;

                GridEvents.GridCreated?.Invoke(grid);
                return data;
            }

            GlobalInstance.Log.Debug(
                $"Attempted to add grid to OcTree that already exists, {grid.DisplayName} {grid.PositionComp.GetPosition()} {bigOwner}");

            var existing = GridTree[grid.EntityId];

            if (existing != null) return existing;

            GridTree.Remove(grid.EntityId);
            return AddGrid(grid);
        }

        public void AddControllableEntity(IMyControllableEntity entity)
        {
            if (entity.ControllerInfo?.Controller?.Player == null && !(entity is IMyCharacter))
                //GlobalInstance.Log.Info($"Entity is not controlled {entity.Entity.EntityId} {entity.Entity.DisplayName}");
                return;
            //GlobalInstance.Log.Debug($"AddControllableEntity {entity.Entity.EntityId} {entity.Entity.DisplayName}");
            entity.Entity.OnMarkForClose += RemoveControllableEntity;

            var data = new ControllableEntityData(entity);

            if (!CharacterTree.Contains(entity.Entity.EntityId)) CharacterTree.Insert(data);
        }

        public void RemoveControllableEntity(IMyControllableEntity entity)
        {
            RemoveControllableEntity((MyEntity)entity);
        }

        public void RemoveControllableEntity(MyEntity entity)
        {
            //GlobalInstance.Log.Debug("RemoveControllableEntity");
            CharacterTree.Remove(entity.EntityId);
        }

        private void Grid_OnConnectionChanged(MyCubeGrid arg1, GridLinkTypeEnum arg2)
        {
            if (arg2 != GridLinkTypeEnum.Mechanical) return;

            GridTree.Update(arg1.EntityId);
        }

        internal void RemoveGrid(MyEntity grid)
        {
            GlobalInstance.Log.Debug($"Removing grid from OcTree: {grid.EntityId} {grid.DisplayName}");
            GridEvents.GridRemoved?.Invoke(grid as MyCubeGrid);

            grid.PositionComp.OnPositionChanged -= Grid_OnPositionChanged;
            grid.OnMarkForClose -= RemoveGrid;
            grid.OnTeleported -= Grid_OnChanged;

            GridTree.Remove(grid.EntityId);
        }

        private void Grid_OnChanged(MyEntity obj)
        {
            GridTree.Update(obj.EntityId);
        }

        private void Grid_OnPositionChanged(MyPositionComponentBase obj)
        {
            if (!(obj.Entity is MyCubeGrid grid)) return;
            if (grid.Closed || grid.MarkedForClose) return;

            GridTree.Update(grid.EntityId);
        }
    }
}