using System;
using System.Collections;
using System.Collections.Generic;
using Unity.VisualScripting;
using UnityEngine;
using UnityEngine.Serialization;
using Utility;

public class MusicManager : MonoBehaviourSingleton<MusicManager>
{
    [SerializeField]
    private List<AudioClip> _ambientMusic;
    [FormerlySerializedAs("_showDownMusic")] [SerializeField]
    private AudioClip _winningMusic;
    [SerializeField]
    private AudioClip _losingMusic;

    [SerializeField, ShowOnly]
    private float _musicTimer = 5f;
    private float _musicCheckInterval = 30f;
    private AudioSource _audioSource;
    private AudioClip _currentlyPlaying;
    private float _defaultVolume;
    private ShowDown _showDown = ShowDown.NotYet;
    private bool _doneFading = false;
    private bool _showDownIsPlaying = false;
    
    private enum ShowDown
    {
        NotYet,
        AlmostFinished,
        TimesRunningOut
    }

    // Start is called before the first frame update
    void Start()
    {
        _audioSource = GetComponent<AudioSource>();
        _defaultVolume = _audioSource.volume;
    }

    // Update is called once per frame
    void Update()
    {
        CheckForFinalMusic();

        if (_showDown == ShowDown.NotYet)
        {
            _musicTimer -= Time.deltaTime;
            
            if (_musicTimer <= 0)
            {
                _musicTimer = _musicCheckInterval;
                if (!_audioSource.isPlaying)
                {
                    PlayNewMusic();
                }
            }
        }
    }

    private void FadeOutMusic()
    {
        _audioSource.volume -= _audioSource.volume * Time.deltaTime;
        _audioSource.volume = _audioSource.volume <= 0.05f ? 0.0f : _audioSource.volume;
        _doneFading = _audioSource.volume <= 0.05f;
    }

    private void CheckForFinalMusic()
    {
        ShowDown oldShowDown = _showDown;
        
        if (TimeManager.Instance.RealLifeSecondsUntilDeadline < 100)
        {
            _showDown = ShowDown.TimesRunningOut;
        }
        else if (GameManager.Instance.GameProgress > 0.85)
        {
            _showDown = ShowDown.AlmostFinished;
        }
        else 
        {
            _showDown = ShowDown.NotYet;
        }

        if (!GameManager.Instance.IsStarted)
        {
            _showDown = ShowDown.NotYet;
        }
        
        if (oldShowDown != _showDown)
        {
            switch (_showDown)
            {
                case ShowDown.NotYet:
                    FadeToClip(_ambientMusic.GetRandomElement());
                    break;
                case ShowDown.AlmostFinished:
                    FadeToClip(_winningMusic);
                    break;
                case ShowDown.TimesRunningOut:
                    FadeToClip(_losingMusic);
                    break;
            }
        }
    }

    private void FadeToClip(AudioClip audioClip)
    {
        StartCoroutine(FadeToClipRoutine(audioClip));
    }

    [SerializeField]
    private float _fadeDuration = 1.0f;
    
    private IEnumerator FadeToClipRoutine(AudioClip audioClip)
    {
        float currentTime = 0;
        float start = _audioSource.volume;
        while (currentTime < _fadeDuration)
        {
            currentTime += Time.deltaTime;
            _audioSource.volume = Mathf.Lerp(start, 0.0f, currentTime / _fadeDuration);
            yield return null;
        }
        
        _audioSource.Stop();
        _audioSource.volume = _defaultVolume;
        _audioSource.clip = audioClip;
        _audioSource.loop = true;
        _audioSource.Play();
    }
    
    private void PlayNewMusic()
    {
        if (_currentlyPlaying == null)
        {
            _audioSource.clip = _ambientMusic.GetRandomElement();
            _audioSource.Play();
        }
        else
        {
            _ambientMusic.Remove(_currentlyPlaying);
            AudioClip newMusic = _ambientMusic.GetRandomElement();
            _ambientMusic.Add(_currentlyPlaying);
            _audioSource.clip = newMusic;
            _audioSource.Play();
        }
    }
}