using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace MoreMountains.Tools
{
    /// <summary>
    /// A class used to receive level values from a MMRadioBroadcaster, and apply it to (almost) any value on any object
    /// </summary>
    [MMRequiresConstantRepaint]
    public class MMRadioReceiver : MMMonoBehaviour
    {
        [Header("Target")]
        /// the receiver to write the level to
        public MMPropertyReceiver Receiver;

        [Header("Channel")]
        /// whether or not this receiver should listen to the channel
        public bool CanListen = true;
        /// the Channel to listen to (has to match the one on the MMRadioBroadcaster you're listening to)
        [MMCondition("CanListen", true)]
        public int Channel = 0;

        [Header("Modifiers")]
        /// whether or not to randomize the received level, this will generate at awake a random level multiplier, to apply to the level
        public bool RandomizeLevel = false;
        /// if random, the min bound of the random multiplier
        [MMCondition("RandomizeLevel", true)]
        public float MinRandomLevelMultiplier = 0f;
        /// if random, the max bound of the random multiplier
        [MMCondition("RandomizeLevel", true)]
        public float MaxRandomLevelMultiplier = 1f;

        protected bool _listeningToEvents = false;
        protected float _randomLevelMultiplier = 1f;
        protected float _lastLevel;

        /// <summary>
        /// On Awake, starts listening and generates a random level multiplier if needed
        /// </summary>
        protected virtual void Awake()
        {
            Receiver.Initialization(this.gameObject);

            if (!_listeningToEvents && CanListen)
            {
                StartListening();
            }

            if (RandomizeLevel)
            {
                _randomLevelMultiplier = Random.Range(MinRandomLevelMultiplier, MaxRandomLevelMultiplier);
            }
        }

        /// <summary>
        /// Sets the level on the receiver
        /// </summary>
        /// <param name="newLevel"></param>
        public virtual void SetLevel(float newLevel)
        {
            Receiver.SetLevel(newLevel);
        }

        /// <summary>
        /// When getting a radio level event, we make sure it's the right channel, and apply it if needed
        /// </summary>
        /// <param name="channel"></param>
        /// <param name="level"></param>
        protected virtual void OnRadioLevelEvent(int channel, float level)
        {
            if (channel != Channel)
            {
                return;
            }
            if (RandomizeLevel)
            {
                level *= _randomLevelMultiplier;
            }
            SetLevel(level);
        }

        /// <summary>
        /// Stops listening to events on destroy
        /// </summary>
        protected virtual void OnDestroy()
        {
            _listeningToEvents = false;
            StopListening();
        }

        /// <summary>
        /// Starts listening for events
        /// </summary>
        public virtual void StartListening()
        {
            _listeningToEvents = true;
            MMRadioLevelEvent.Register(OnRadioLevelEvent);
        }

        /// <summary>
        /// Stops listening for events
        /// </summary>
        public virtual void StopListening()
        {
            _listeningToEvents = false;
            MMRadioLevelEvent.Unregister(OnRadioLevelEvent);
        }
    }
}