using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.InputSystem;

namespace Syntriax.Modules.Movement.VariableMovement
{
    public class VariableMovementController : MonoBehaviour, IVariableMovementController
    {
        public UnityEvent<IVariableMovement> OnVariableMovementChanged { get; protected set; } = null;
        public IInputActionCollection InputActionCollection { get; set; } = null;
        private IVariableMovement _activeVariableMovement = null;
        public IVariableMovement ActiveVariableMovement
        {
            get => _activeVariableMovement;
            protected set
            {
                _activeVariableMovement = value;
                OnVariableMovementChanged.Invoke(value);

                if (movementController != null)
                    SetMultiplierToActiveMovement(movementController.ActiveMovement);
            }
        }

        protected bool isSet = false;
        protected IMovementController movementController = null;
        protected IVariableMovement defaultVariableMovement = null;
        protected List<IVariableMovementWithState> variableMovementsWithState = null;
        protected VMCollection collection;

        protected virtual void Awake()
        {
            OnVariableMovementChanged = new UnityEvent<IVariableMovement>();
            defaultVariableMovement = new VariableMovement();
            variableMovementsWithState = new List<IVariableMovementWithState>(16);
        }

        protected virtual void Start()
        {
            movementController = GetComponent<IMovementController>();
            movementController.OnMovementChanged.AddListener(SetMultiplierToActiveMovement);
        }

        protected void SetMultiplierToActiveMovement(IMovement currentMovement)
        {
            if (!isSet)
                return;

            currentMovement.MovementMultiplier = ActiveVariableMovement.Asset.Multiplier;

        }

        public void LoadVariableMovementCollection(VMCollection collection)
        {
            if (InputActionCollection == null)
                throw new System.NullReferenceException("InputActionCollection must be set on the VariableMovementController to load a collection!");

            this.collection = collection;
            isSet = true;

            UnsubscribeFromMovements();

            variableMovementsWithState.Clear();
            foreach (VMAsset asset in collection.VMAssets)
                variableMovementsWithState.Add(new VariableMovementWithState(asset, InputActionCollection));
            defaultVariableMovement.Asset = collection.DefaultAsset;

            SubscribeToMovements();
            UpdateActiveVariableMovement();
        }

        protected virtual void SubscribeToMovements()
        {
            foreach (IVariableMovementWithState variableMovementWithState in variableMovementsWithState)
                variableMovementWithState.OnToggleStateChanged.AddListener(VariableMovementStateListener);
        }

        protected virtual void UnsubscribeFromMovements()
        {
            foreach (IVariableMovementWithState variableMovementWithState in variableMovementsWithState)
                variableMovementWithState.OnToggleStateChanged.RemoveListener(VariableMovementStateListener);
        }

        private void VariableMovementStateListener(bool arg0) => UpdateActiveVariableMovement();
        protected virtual void UpdateActiveVariableMovement()
        {
            foreach (IVariableMovementWithState variableMovementWithState in variableMovementsWithState)
                if (variableMovementWithState.Enabled)
                {
                    ActiveVariableMovement = variableMovementWithState;
                    return;
                }

            ActiveVariableMovement = defaultVariableMovement;
        }
    }
}