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

public abstract class AbstractCharacter : MonoBehaviour
{
    //
    // Core components of a character
    //
    protected Mover _mover;
    protected AbstractShooter _shooter;
    
    // 
    // Characteristics and status of a character
    //
    // Speed in m/s
    [SerializeField] protected float _maxSpeed = 10;
    public float MaxSpeed
    {
        get { return _maxSpeed; }
        set { _maxSpeed = value; }
    }

    [SerializeField] protected int _maxHealth = 1;
    public int MaxHealth => _maxHealth;
    public int CurrentHealth { get; set; }
    
    [SerializeField] protected float _maxEnergy = 100;
    public float MaxEnergy => _maxEnergy;
    public float CurrentEnergy { get; set; }
    // Energy gained back per second
    [SerializeField] private float _energyRegen = 20;
    public float EnergyRegen
    {
        get { return _energyRegen; }
        set { _energyRegen = value; }
    }

    protected bool _isShooting;
    // True if the energy went down to zero
    protected bool _isDepleted;
    
    // Start is called before the first frame update
    void Start()
    {
        CurrentHealth = MaxHealth;
        CurrentEnergy = MaxEnergy;

        _mover = GetComponentInParent<Mover>();
        _shooter = GetComponentInParent<AbstractShooter>();

        if (_mover == null)
        {
            throw new MissingComponentException("No Mover !");
        }

        if (_shooter == null)
        {
            throw new MissingComponentException("No Shooter !");
        }
    }

    // Manages the energy of the character
    void Update()
    {
        if (!_isShooting && CurrentEnergy < MaxEnergy)
        {
            var regen = _isDepleted ? EnergyRegen * 0.75f : EnergyRegen;
            CurrentEnergy += regen * Time.deltaTime;
        }

        if (CurrentEnergy > MaxEnergy)
        {
            CurrentEnergy = MaxEnergy;
            if (_isDepleted)
            {
                _isDepleted = false;
            }
        }
        if (CurrentEnergy <= 0)
        {
            CurrentEnergy = 0;
            _isDepleted = true;
        }

        // The InputManager is executed before and updates it to true if needed
        _isShooting = false;
        
        // FIXME : Debug drawing to show energy level
        Debug.DrawLine(new Vector3(-5,4), new Vector3(-5 + 10 * CurrentEnergy/MaxEnergy,4),Color.blue);
    }

    public abstract void Move(Vector2 movementDirection);
    public abstract void Shoot();

    private void OnCollisionEnter2D(Collision2D other)
    {
        Bullet bullet = other.gameObject.GetComponent<Bullet>();
        if (bullet == null)
        {
            return;
        }
        Hurt(bullet.Damage);
    }
    
    public void Hurt(int damage)
    {
        CurrentHealth -= damage;
        if (CurrentHealth <= 0)
        {
            Death();
        }
    }
    // Handles the death of the character, should be overriden
    protected abstract void Death();
}