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

public class MusicManager : MonoBehaviourSingleton<MusicManager>
{
    [SerializeField]
    private List<AudioClip> _ambientMusic;
    [SerializeField]
    private AudioClip _showDownMusic;

    [SerializeField, ShowOnly]
    private float _musicTimer = 5f;
    private float _musicCheckInterval = 30f;
    private AudioSource _audioSource;
    private AudioClip _currentlyPlaying;
    private float _defaultVolume;
    private bool _showDownTime = false;
    private bool _doneFading = false;
    private bool _showDownIsPlaying = false;

    // 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 (!_showDownTime)
        {
            _musicTimer -= Time.deltaTime;

            if (_musicTimer <= 0)
            {
                _musicTimer = _musicCheckInterval;
                if (!_audioSource.isPlaying)
                {
                    PlayNewMusic();
                }
            }
        }
        else
        {
            if (_doneFading)
            {
                if (!_showDownIsPlaying)
                    PlayShowDownMusic();
            }
            else
            {
                FadeOutMusic();
            }
        }
    }

    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()
    {
        float timeLeft = (float)GameManager.Instance.ExpectedRemainingGameDuration;
        _showDownTime = timeLeft < 0.9 * _showDownMusic.length;
    }

    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();
        }
    }

    private void PlayShowDownMusic()
    {
        _showDownIsPlaying = true;
        _audioSource.Stop();
        _audioSource.volume = _defaultVolume;
        _audioSource.clip = _showDownMusic;
        _audioSource.loop = true;
        _audioSource.Play();
    }
}