using Photon.Deterministic;
using System;

namespace Quantum
{
	public static unsafe partial class HFSMManager
	{
		public static unsafe partial class ThreadSafe
		{
			// ========== PUBLIC METHODS ==================================================================================

			/// <summary>
			/// Initializes the HFSM, making the current state to be equals the initial state
			/// </summary>
			public static unsafe void Init(FrameThreadSafe frame, EntityRef entity, HFSMRoot root)
			{
				if (frame.TryGetPointer(entity, out HFSMAgent* agent))
				{
					HFSMData* hfsmData = &agent->Data;
					Init(frame, hfsmData, entity, root);
				}
				else
				{
					Log.Error("[Bot SDK] Tried to initialize an entity which has no HfsmAgent component");
				}
			}

			/// <summary>
			/// Initializes the HFSM, making the current state to be equals the initial state
			/// </summary>
			public static unsafe void Init(FrameThreadSafe frame, HFSMData* hfsm, EntityRef entity, HFSMRoot root)
			{
				hfsm->Root = root;
				if (hfsm->Root.Equals(default) == false)
				{
					HFSMState initialState = frame.FindAsset<HFSMState>(root.InitialState.Id);
					ChangeState(initialState, frame, hfsm, entity, "");
				}
			}

			/// <summary>
			/// Update the state of the HFSM.
			/// </summary>
			/// <param name="deltaTime">Usually the current deltaTime so the HFSM accumulates the time stood on the current state</param>
			public static void Update(FrameThreadSafe frame, FP deltaTime, EntityRef entity)
			{
				if (frame.TryGetPointer(entity, out HFSMAgent* agent))
				{
					HFSMData* hfsmData = &agent->Data;
					Update(frame, deltaTime, hfsmData, entity);
				}
				else
				{
					Log.Error("[Bot SDK] Tried to update an entity which has no HFSMAgent component");
				}
			}

			/// <summary>
			/// Update the state of the HFSM.
			/// </summary>
			/// <param name="deltaTime">Usually the current deltaTime so the HFSM accumulates the time stood on the current state</param>
			public static void Update(FrameThreadSafe frame, FP deltaTime, HFSMData* hfsmData, EntityRef entity)
			{
				HFSMState currentState = frame.FindAsset<HFSMState>(hfsmData->CurrentState.Id);
				currentState.UpdateState(frame, deltaTime, hfsmData, entity);
			}

			/// <summary>
			/// Triggers an event if the target HFSM listens to it
			/// </summary>
			public static unsafe void TriggerEvent(FrameThreadSafe frame, EntityRef entity, string eventName)
			{
				if (frame.TryGetPointer(entity, out HFSMAgent* agent))
				{
					HFSMData* hfsmData = &agent->Data;
					TriggerEvent(frame, hfsmData, entity, eventName);
				}
				else
				{
					Log.Error("[Bot SDK] Tried to trigger an event to an entity which has no HFSMAgent component");
				}
			}

			/// <summary>
			/// Triggers an event if the target HFSM listens to it
			/// </summary>
			public static unsafe void TriggerEvent(FrameThreadSafe frame, HFSMData* hfsmData, EntityRef entity, string eventName)
			{
				Int32 eventInt = 0;

				HFSMRoot hfsmRoot = frame.FindAsset<HFSMRoot>(hfsmData->Root.Id);
				if (hfsmRoot.RegisteredEvents.TryGetValue(eventName, out eventInt))
				{
					if (hfsmData->CurrentState.Equals(default) == false)
					{
						HFSMState currentState = frame.FindAsset<HFSMState>(hfsmData->CurrentState.Id);
						currentState.Event(frame, hfsmData, entity, eventInt);
					}
				}
			}

			/// <summary>
			/// Triggers an event if the target HFSM listens to it
			/// </summary>
			public static unsafe void TriggerEventNumber(FrameThreadSafe frame, HFSMData* hfsmData, EntityRef entity, Int32 eventInt)
			{
				if (hfsmData->CurrentState.Equals(default) == false)
				{
					HFSMState currentState = frame.FindAsset<HFSMState>(hfsmData->CurrentState.Id);
					currentState.Event(frame, hfsmData, entity, eventInt);
				}
			}

			// ========== INTERNAL METHODS ================================================================================

			/// <summary>
			/// Executes the On Exit actions for the current state, then changes the current state
			/// </summary>
			internal static void ChangeState(HFSMState nextState, FrameThreadSafe frame, HFSMData* hfsmData, EntityRef entity, string transitionId)
			{
				Assert.Check(nextState != null, "Tried to change HFSM to a null state");

				HFSMState currentState = frame.FindAsset<HFSMState>(hfsmData->CurrentState.Id);
				currentState?.ExitState(nextState, frame, hfsmData, entity);
				hfsmData->CurrentState = nextState;

				if (frame.IsVerified == true && entity != default(EntityRef))
				{
					StateChanged?.Invoke(entity, hfsmData->CurrentState.Id.Value, transitionId);
				}

				nextState.EnterState(frame, hfsmData, entity);
			}
		}
	}
}