using Chickensoft.Collections;
using Godot;
using System;
using Zennysoft.Ma.Adapter;

namespace Zennysoft.Game.Ma;

public class ExperiencePointsComponent : IExperiencePointsComponent
{
  public IAutoProp<int> CurrentExp => _currentExp;

  public IAutoProp<int> ExpToNextLevel => _expToNextLevel;

  public IAutoProp<double> ExpGainRate => _expGainRate;

  public IAutoProp<int> Level => _level;

  private readonly AutoProp<int> _currentExp;

  private readonly AutoProp<int> _expToNextLevel;

  private readonly AutoProp<double> _expGainRate;

  private readonly AutoProp<int> _level;

  public event Action PlayerLevelUp;

  public event Action PlayerLevelDown;

  public ExperiencePointsComponent()
  {
    var firstLevelExpRequirement = ExpToNextLevelCalculation(1);
    _expToNextLevel = new AutoProp<int>(firstLevelExpRequirement);
    _currentExp = new AutoProp<int>(0);
    _expGainRate = new AutoProp<double>(1);
    _level = new AutoProp<int>(1);
  }

  public void Reset()
  {
    _currentExp.OnNext(0);
    _expGainRate.OnNext(1);
    _level.OnNext(1);
    var firstLevelExpRequirement = ExpToNextLevelCalculation(1);
    _expToNextLevel.OnNext(firstLevelExpRequirement);
  }

  public void Gain(int baseExpGain)
  {
    var modifiedExpGain = baseExpGain * _expGainRate.Value;
    _currentExp.OnNext(Mathf.RoundToInt(modifiedExpGain + _currentExp.Value));
    while (_currentExp.Value >= _expToNextLevel.Value)
      LevelUp();
  }

  public void GainUnmodified(int flatRateExp)
  {
    var newCurrentExpTotal = flatRateExp + _currentExp.Value;
    _currentExp.OnNext(newCurrentExpTotal);
    while (_currentExp.Value >= _expToNextLevel.Value)
      LevelUp();
  }

  public void ModifyExpGainRate(double newRate) => _expGainRate.OnNext(newRate);

  public void LevelUp()
  {
    SfxDatabase.Instance.Play(SoundEffect.LevelUp);
    _level.OnNext(_level.Value + 1);
    var expToNextLevel = ExpToNextLevelCalculation(_level.Value);
    _currentExp.OnNext(_currentExp.Value - _expToNextLevel.Value);
    _expToNextLevel.OnNext(expToNextLevel);
    PlayerLevelUp?.Invoke();
  }

  public void LevelDown()
  {
    SfxDatabase.Instance.Play(SoundEffect.DecreaseStat);
    _currentExp.OnNext(0);

    if (_level.Value == 1)
      return;

    var newLevel = Mathf.Max(_level.Value - 1, 1);
    _level.OnNext(newLevel);
    var expToNextLevel = ExpToNextLevelCalculation(newLevel);
    _expToNextLevel.OnNext(expToNextLevel);
    PlayerLevelDown.Invoke();
  }

  private int ExpToNextLevelCalculation(int nextLevel)
  {
    return (int)(6.5 * nextLevel + 4.5 * Math.Pow(nextLevel, 2) + Math.Pow(nextLevel, 3));
  }
}