using System;
using System.Collections.Generic;

using DataLoader;
using Gamecraft.Blocks.BlockGroups;
using Svelto.ECS;
using Svelto.ECS.EntityStructs;
using RobocraftX.Common;
using RobocraftX.Blocks;
using Unity.Mathematics;
using RobocraftX.PilotSeat;
using RobocraftX.Rendering;
using Techblox.BlockLabelsServer;
using TechbloxModdingAPI.Blocks;
using TechbloxModdingAPI.Blocks.Engines;
using TechbloxModdingAPI.Client.App;
using TechbloxModdingAPI.Common;
using TechbloxModdingAPI.Common.Engines;
using TechbloxModdingAPI.Common.Traits;
using TechbloxModdingAPI.Tests;
using TechbloxModdingAPI.Utility;
using Unity.Transforms;
using UnityEngine;

namespace TechbloxModdingAPI
{
	/// <summary>
	/// A single (perhaps scaled) block. Properties may return default values if the block is removed and then setting them is ignored.
	/// For specific block type operations, use the specialised block classes in the TechbloxModdingAPI.Blocks namespace.
	/// </summary>
	public class Block : EcsObjectBase<BlockEntityDescriptor>, IHasPhysics, IEquatable<Block>, IEquatable<EGID>
	{
		protected static readonly PlacementEngine PlacementEngine = new();
		protected static readonly RemovalEngine RemovalEngine = new();
		protected static readonly SignalEngine SignalEngine = new();
		protected static readonly BlockEventsEngine BlockEventsEngine = new();
		protected static readonly ScalingEngine ScalingEngine = new();
		protected static readonly BlockCloneEngine BlockCloneEngine = new();

		protected internal static readonly BlockEngine BlockEngine = new();

		/// <summary>
		/// Place a new block at the given position. If scaled, position means the center of the block. The default block size is 0.2 in terms of position.
		/// Place blocks next to each other to connect them.
		/// The placed block will be a complete block with a placement grid and collision which will be saved along with the game.
		/// </summary>
		/// <param name="block">The block's type</param>
		/// <param name="position">The block's position - default block size is 0.2</param>
		/// <param name="autoWire">Whether the block should be auto-wired (if functional)</param>
		/// <param name="player">The player who placed the block</param>
		/// <returns>The placed block or null if failed</returns>
		public static Block PlaceNew(BlockIDs block, float3 position, bool autoWire = false, Player player = null)
		{
			if (PlacementEngine.IsInGame && GameClient.IsBuildMode)
			{
				var initializer = PlacementEngine.PlaceBlock(block, position, player, autoWire);
				var bl = New(initializer);
				Placed += bl.OnPlacedInit;
				return bl;
			}

			return null;
		}

		/// <summary>
		/// Returns the most recently placed block.
		/// </summary>
		/// <returns>The block object or null if doesn't exist</returns>
		public static Block GetLastPlacedBlock()
		{
			uint lastBlockID = CommonExclusiveGroups.blockIDGeneratorClient.Peek() - 1;
			EGID? egid = BlockEngine.FindBlockEGID(lastBlockID);
			return egid.HasValue ? New(egid.Value) : null;
		}

		/*public static Block CreateGhostBlock()
		{
			return BlockGroup._engine.BuildGhostChild();
		}*/

		/// <summary>
		/// An event that fires each time a block is placed.
		/// </summary>
		public static event EventHandler<BlockPlacedRemovedEventArgs> Placed
		{ //TODO: Rename and add instance version in 3.0
			add => BlockEventsEngine.Placed += value;
			remove => BlockEventsEngine.Placed -= value;
		}

		/// <summary>
		/// An event that fires each time a block is removed.
		/// </summary>
		public static event EventHandler<BlockPlacedRemovedEventArgs> Removed
		{
			add => BlockEventsEngine.Removed += value;
			remove => BlockEventsEngine.Removed -= value;
		}

		private static readonly Dictionary<ExclusiveBuildGroup, (Func<EGID, Block> Constructor, Type Type)> GroupToConstructor =
			new()
			{
				{CommonExclusiveGroups.DAMPEDSPRING_BLOCK_GROUP, (id => new DampedSpring(id), typeof(DampedSpring))},
				{CommonExclusiveGroups.ENGINE_BLOCK_BUILD_GROUP, (id => new Engine(id), typeof(Engine))},
				{CommonExclusiveGroups.LOGIC_BLOCK_GROUP, (id => new LogicGate(id), typeof(LogicGate))},
				{CommonExclusiveGroups.PISTON_BLOCK_GROUP, (id => new Piston(id), typeof(Piston))},
				{CommonExclusiveGroups.SERVO_BLOCK_GROUP, (id => new Servo(id), typeof(Servo))},
				{CommonExclusiveGroups.WHEELRIG_BLOCK_BUILD_GROUP, (id => new WheelRig(id), typeof(WheelRig))}
			};

		static Block()
		{
			foreach (var group in SeatGroups.SEATS_BLOCK_GROUPS) // Adds driver and passenger seats, occupied and unoccupied
				GroupToConstructor.Add(group, (id => new Seat(id), typeof(Seat)));
		}

		/// <summary>
		/// Returns a correctly typed instance of this block. The instances are shared for a specific block.
		/// If an instance is no longer referenced a new instance is returned.
		/// </summary>
		/// <param name="egid">The EGID of the block</param>
		/// <param name="signaling">Whether the block is definitely a signaling block</param>
		/// <returns></returns>
		internal static Block New(EGID egid, bool signaling = false)
		{
			return New(egid, default, signaling);
		}

		private static Block New(EcsInitData initData, bool signaling = false)
		{
			return New(initData.EGID, initData, signaling);
		}

		private static Block New(EGID egid, EcsInitData initData, bool signaling)
		{
			if (egid == default) return null;
			Func<EGID, Block> constructor;
			Type type = null;
			if (GroupToConstructor.TryGetValue(egid.groupID, out var value))
				(constructor, type) = value;
			else
				constructor = signaling ? e => new SignalingBlock(e) : e => new Block(e);

			return initData != default
				? GetInstanceNew(initData, constructor, type)
				: GetInstanceExisting(egid, constructor, type);
		}

		public Block(EGID id) : base(id)
		{
			Type expectedType;
			if (GroupToConstructor.ContainsKey(id.groupID) &&
			    !GetType().IsAssignableFrom(expectedType = GroupToConstructor[id.groupID].Type))
				throw new BlockSpecializationException($"Incorrect block type! Expected: {expectedType} Actual: {GetType()}");
		}

		/// <summary>
		/// This overload searches for the correct group the block is in.
		/// It will throw an exception if the block doesn't exist.
		/// Use the EGID constructor where possible or subclasses of Block as those specify the group.
		/// </summary>
		public Block(uint id) : this(BlockEngine.FindBlockEGID(id)
		                             ?? throw new BlockTypeException(
			                             "Could not find the appropriate group for the block." +
			                             " The block probably doesn't exist or hasn't been submitted."))
		{
		}

		private EGID copiedFrom;

		/// <summary>
		/// The block's current position or zero if the block no longer exists.
		/// A block is 0.2 wide by default in terms of position.
		/// </summary>
		public float3 Position
		{
			get => GetComponent<PositionEntityStruct>().position;
			set
			{
				// main (persistent) position
				GetComponent<PositionEntityStruct>().position = value;
				// placement grid position
				GetComponent<GridRotationStruct>().position = value;
				// rendered position
				GetComponent<LocalTransformEntityStruct>().position = value;
				this.UpdatePhysicsUECSComponent(new Translation { Value = value });

				GetComponent<GridConnectionsEntityStruct>().areConnectionsAssigned = false;
				if (blockGroup != null)
					blockGroup.PosAndRotCalculated = false;
				BlockEngine.UpdateDisplayData(Id);
			}
		}

		/// <summary>
		/// The block's current rotation in degrees or zero if the block doesn't exist.
		/// </summary>
		public float3 Rotation
		{
			get => ((Quaternion)GetComponent<RotationEntityStruct>().rotation).eulerAngles;
			set
			{
				// main (persistent) rotation
				Quaternion newRotation = GetComponent<RotationEntityStruct>().rotation;
				newRotation.eulerAngles = value;
				GetComponent<RotationEntityStruct>().rotation = newRotation;
				// placement grid rotation
				GetComponent<GridRotationStruct>().rotation = newRotation;
				// rendered rotation
				GetComponent<LocalTransformEntityStruct>().rotation = newRotation;
				this.UpdatePhysicsUECSComponent(new Rotation { Value = newRotation });

				// They are assigned during machine processing anyway
				GetComponent<GridConnectionsEntityStruct>().areConnectionsAssigned = false;
				if (blockGroup != null)
					blockGroup.PosAndRotCalculated = false;
				BlockEngine.UpdateDisplayData(Id);
			}
		}

		/// <summary>
		/// The block's non-uniform scale or zero if the block's invalid. Independent of the uniform scaling.
		/// The default scale of 1 means 0.2 in terms of position.
		/// </summary>
		public float3 Scale
		{
			get => GetComponent<ScalingEntityStruct>().scale;
			set
			{
				int uscale = UniformScale;
				if (value.x < 4e-5) value.x = uscale;
				if (value.y < 4e-5) value.y = uscale;
				if (value.z < 4e-5) value.z = uscale;
				GetComponent<ScalingEntityStruct>().scale = value;
				GetComponent<GridConnectionsEntityStruct>().areConnectionsAssigned = false;
				//BlockEngine.GetBlockInfo<GridScaleStruct>(this).gridScale = value - (int3) value + 1;
				if (!Exists) return; //UpdateCollision needs the block to exist
				ScalingEngine.UpdateCollision(Id);
				BlockEngine.UpdateDisplayData(Id);
			}
		}

		/// <summary>
		/// The block's uniform scale or zero if the block's invalid. Also sets the non-uniform scale.
		/// The default scale of 1 means 0.2 in terms of position.
		/// </summary>
		public int UniformScale
		{
			get => GetComponent<UniformBlockScaleEntityStruct>().scaleFactor;
			set
			{
				//It appears that only the non-uniform scale has any visible effect so we'll set that as well
				if (value < 1) value = 1;
				GetComponent<UniformBlockScaleEntityStruct>().scaleFactor = value;
				Scale = new float3(value, value, value);
			}
		}

		/**
		 * Whether the block is flipped.
		 */
		public bool Flipped
		{
			get => GetComponent<ScalingEntityStruct>().scale.x < 0;
			set
			{
				ref var st = ref GetComponent<ScalingEntityStruct>();
				st.scale.x = math.abs(st.scale.x) * (value ? -1 : 1);
				BlockEngine.UpdateDisplayedPrefab(this, (byte) Material, value);
			}
		}

		/// <summary>
		/// The block's type (ID). Returns BlockIDs.Invalid if the block doesn't exist anymore.
		/// </summary>
		public BlockIDs Type
		{
			get
			{
				var opt = GetComponentOptional<DBEntityStruct>();
				return opt ? (BlockIDs) opt.Get().DBID : BlockIDs.Invalid;
			}
		}

		/// <summary>
		/// The block's color. Returns BlockColors.Default if the block no longer exists.
		/// </summary>
		public BlockColor Color
		{
			get
			{
				var opt = GetComponentOptional<ColourParameterEntityStruct>();
				return new BlockColor(opt ? opt.Get().indexInPalette : byte.MaxValue);
			}
			set
			{
				 // TODO: Expose CubeListData in the API
				if (value.Color == BlockColors.Default)
					value = new BlockColor(FullGameFields._dataDb.TryGetValue((int) Type, out CubeListData cld)
						? cld.DefaultColour
						: throw new BlockTypeException("Unknown block type! Could not set default color."));
				ref var color = ref GetComponent<ColourParameterEntityStruct>();
				color.indexInPalette = value.Index;
				color.hasNetworkChange = true;
				color.paletteColour = BlockEngine.ConvertBlockColor(color.indexInPalette); //Setting to 255 results in black
				BlockEngine.UpdateBlockColor(Id);
			}
		}

		/// <summary>
		/// The block's exact color. Gets reset to the palette color (Color property) after reentering the game.
		/// </summary>
		public float4 CustomColor
		{
			get => GetComponent<ColourParameterEntityStruct>().paletteColour;
			set
			{
				ref var color = ref GetComponent<ColourParameterEntityStruct>();
				color.paletteColour = value;
				color.hasNetworkChange = true;
			}
		}

		/**
		 * The block's material.
		 */
		public BlockMaterial Material
		{
			get
			{
				var opt = GetComponentOptional<CubeMaterialStruct>();
				return opt ? (BlockMaterial) opt.Get().materialId : BlockMaterial.Default;
			}
			set
			{
				byte val = (byte) value;
				if (value == BlockMaterial.Default)
					val = FullGameFields._dataDb.TryGetValue((int) Type, out CubeListData cld)
						? cld.DefaultMaterialID
						: throw new BlockTypeException("Unknown block type! Could not set default material.");
				if (!FullGameFields._dataDb.ContainsKey<MaterialPropertiesData>(val))
					throw new BlockException($"Block material {value} does not exist!");
				ref var comp = ref GetComponent<CubeMaterialStruct>();
				if (comp.materialId == val)
					return;
				comp.materialId = val;
				BlockEngine.UpdateDisplayedPrefab(this, val, Flipped); //The default causes the screen to go black
			}
		}

		/// <summary>
		/// The text displayed on the block if applicable, or null.
		/// Setting it is temporary to the session, it won't be saved.
		/// </summary>
		[TestValue(null)]
		public string Label
		{
			get
			{
				var opt = GetComponentOptional<LabelResourceIDComponent>();
				return opt ? FullGameFields._managers.blockLabelResourceManager.GetText(opt.Get().instanceID) : null;
			}
			set
			{
				var opt = GetComponentOptional<LabelResourceIDComponent>();
				if (opt) FullGameFields._managers.blockLabelResourceManager.SetText(opt.Get().instanceID, value);
			}
		}

		private BlockGroup blockGroup;
		/// <summary>
		/// Returns the block group this block is a part of. Block groups can also be placed using blueprints.
		/// Returns null if not part of a group, although all blocks should have their own by default.<br />
		/// Setting the group after the block has been initialized will not update everything properly,
		/// so you can only set this property on blocks newly placed by your code.<br />
		/// To set it for existing blocks, you can use the Copy() method and set the property on the resulting block
		/// (and remove this block).
		/// </summary>
		public BlockGroup BlockGroup
		{
			get
			{
				if (blockGroup != null) return blockGroup;
				if (!GameClient.IsBuildMode) return null; // Breaks in simulation
				var bgec = GetComponent<BlockGroupEntityComponent>();
				return blockGroup = bgec.currentBlockGroup == -1
					? null
					: GetInstanceExisting(new EGID((uint)bgec.currentBlockGroup, BlockGroupExclusiveGroups.BlockGroupEntityGroup),
						egid => new BlockGroup((int)egid.entityID, this));
			}
			set
			{
				if (Exists)
				{
					Logging.LogWarning("Attempted to set group of existing block. This is not supported."
					                   + " Copy the block and set the group of the resulting block.");
					return;
				}
				blockGroup?.RemoveInternal(this);
				if (!InitData.Valid)
					return;
				GetComponent<BlockGroupEntityComponent>().currentBlockGroup = (int?) value?.Id.entityID ?? -1;
				value?.AddInternal(this);
				blockGroup = value;
			}
		}

		/// <summary>
		/// Whether the block should be static in simulation. If set, it cannot be moved. The effect is temporary, it will not be saved with the block.
		/// </summary>
		public bool Static
		{
			get => GetComponent<BlockStaticComponent>().isStatic;
			set => GetComponent<BlockStaticComponent>().isStatic = value;
		}

		/// <summary>
		/// The mass of the block.
		/// </summary>
		public float Mass
		{
			get => GetComponent<MassStruct>().mass;
		}

		/// <summary>
		/// Block complexity used for build rules. Determines the 'cost' of the block.
		/// </summary>
		public BlockComplexity Complexity
		{
			get => new(GetComponent<BlockComplexityComponent>());
			set => GetComponent<BlockComplexityComponent>() = value;
		}

		/// <summary>
		/// Returns an array of blocks that are connected to this one. Returns an empty array if the block doesn't exist.
		/// </summary>
		public Block[] GetConnectedCubes() => BlockEngine.GetConnectedBlocks(Id);

		/// <summary>
		/// Removes this block.
		/// </summary>
		/// <returns>True if the block exists and could be removed.</returns>
		public bool Remove() => RemovalEngine.RemoveBlock(Id);

		/// <summary>
		/// Returns the rigid body of the chunk of blocks this one belongs to during simulation.
		/// Can be used to apply forces or move the block around while the simulation is running.
		/// </summary>
		/// <returns>The SimBody of the chunk or null if the block doesn't exist or not in simulation mode.</returns>
		public SimBody GetSimBody()
		{
			var st = GetComponent<GridConnectionsEntityStruct>();
			/*return st.machineRigidBodyId != uint.MaxValue
				? new SimBody(st.machineRigidBodyId, st.clusterId) - TODO:
				: null;*/
			return null;
		}

		/// <summary>
		/// Creates a copy of the block in the game with the same properties, stats and wires.
		/// </summary>
		/// <returns></returns>
		public Block Copy()
		{
			var block = PlaceNew(Type, Position);
			block.Rotation = Rotation;
			block.Color = Color;
			block.Material = Material;
			block.UniformScale = UniformScale;
			block.Scale = Scale;
			block.copiedFrom = Id;
			return block;
		}

		private void OnPlacedInit(object sender, BlockPlacedRemovedEventArgs e)
		{ //Member method instead of lambda to avoid constantly creating delegates
			if (e.ID != Id) return;
			Placed -= OnPlacedInit; //And we can reference it
			if (copiedFrom != default)
				BlockCloneEngine.CopyBlockStats(copiedFrom, Id);
		}

		public override string ToString()
		{
			return $"{nameof(Id)}: {Id}, {nameof(Position)}: {Position}, {nameof(Type)}: {Type}, {nameof(Color)}: {Color}, {nameof(Exists)}: {Exists}";
		}

		public bool Equals(Block other)
		{
			if (ReferenceEquals(null, other)) return false;
			if (ReferenceEquals(this, other)) return true;
			return Id.Equals(other.Id);
		}
		
		public bool Equals(EGID other)
		{
			return Id.Equals(other);
		}

		public override bool Equals(object obj)
		{
			if (ReferenceEquals(null, obj)) return false;
			if (ReferenceEquals(this, obj)) return true;
			if (obj.GetType() != this.GetType()) return false;
			return Equals((Block) obj);
		}

		public override int GetHashCode()
		{
			return Id.GetHashCode();
		}

		public static void Init()
		{
			EngineManager.AddEngine(PlacementEngine, ApiEngineType.Build);
			EngineManager.AddEngine(RemovalEngine, ApiEngineType.Build);
			EngineManager.AddEngine(BlockEngine, ApiEngineType.Build, ApiEngineType.PlayServer, ApiEngineType.PlayClient);
			EngineManager.AddEngine(BlockEventsEngine, ApiEngineType.Build);
			EngineManager.AddEngine(ScalingEngine, ApiEngineType.Build);
			EngineManager.AddEngine(SignalEngine, ApiEngineType.Build);
			EngineManager.AddEngine(BlockCloneEngine, ApiEngineType.Build);
			Wire.signalEngine = SignalEngine; // requires same functionality, no need to duplicate the engine
		}
	}
}