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

public class AudioPlayer : MonoBehaviour
{
    // =========================================================================

    // Background Themes
    public AudioSource BackgroundThemeBotanicalRoom;
    public AudioSource BackgroundThemeMachineRoom;
    public AudioSource BackgroundThemeCryoRoom;
    public AudioSource BackgroundThemeKitchenRoom;
    public AudioSource BackgroundThemeControlRoom;

    private AudioSource CurrentBackgroundTheme;

    // Sound Fx
    public AudioSource FxClick1;
    public AudioSource FxClick2;
    public AudioSource FxClick3;
    public AudioSource FxClick4;
    public AudioSource FxExplosion;
    public AudioSource FxData;
    public AudioSource FxSuitNoise;
    public AudioSource FxSquelch1;
    public AudioSource FxSquelch2;
    public AudioSource FxLaser1;
    public AudioSource FxLaser2;

    // Parameters for fading between background themes
    public float FadeSpeed = 0.025f;
    public float FadeDelay = 0.01f;
    public float Volume = 1f;

    // =========================================================================

    // Singleton
    public static AudioPlayer Instance = null;

    private void Awake()
    {
        if (Instance == null)
        {
            Instance = this;
        }
        else if (Instance != this)
        {
            Destroy(gameObject);
        }
        DontDestroyOnLoad(gameObject);
    }

    // =========================================================================

	// Public API

	public void PlayFxClick1() { PlayFx(FxClick1); }
    public void PlayFxClick2() { PlayFx(FxClick2); }
    public void PlayFxClick3() { PlayFx(FxClick3); }
    public void PlayFxClick4() { PlayFx(FxClick4); }
    public void PlayFxExplosion() { PlayFx(FxExplosion); }
    public void PlayFxData() { PlayFx(FxData); }
    public void PlayFxSuitNoise() { PlayFx(FxSuitNoise); }
    public void PlayFxSquelch1() { PlayFx(FxSquelch1); }
    public void PlayFxSquelch2() { PlayFx(FxSquelch2); }
    public void PlayFxLaser1() { PlayFx(FxLaser1); }
    public void PlayFxLaser2() { PlayFx(FxLaser2); }

    public void PlayBackgroundThemeBotanicalRoom() 
    {
        PlayBackgroundTheme(BackgroundThemeBotanicalRoom);
    }

    public void PlayBackgroundThemeMachineRoom() 
    {
        PlayBackgroundTheme(BackgroundThemeMachineRoom);
    }

    public void PlayBackgroundThemeCryoRoom()
    {
        PlayBackgroundTheme(BackgroundThemeCryoRoom);
    }

    public void PlayBackgroundThemeKitchenRoom() 
    {
        PlayBackgroundTheme(BackgroundThemeKitchenRoom);    
    }

    public void PlayBackgroundThemeControlRoom()
    {
        PlayBackgroundTheme(BackgroundThemeControlRoom);
    }

	// =========================================================================

    // Internal control

    private void PlayFx(AudioSource fx)
    {
        if (fx.isPlaying) 
        {
            fx.Stop();
            fx.time = 0;   
        }
        fx.Play();
    }

    private void PlayBackgroundTheme(AudioSource backgroundTheme)
    {
        StartCoroutine(
            FadeNextBackgroundTheme(
                CurrentBackgroundTheme, 
                backgroundTheme, 
                FadeSpeed, 
                FadeDelay,
                Volume
            )
        );
        CurrentBackgroundTheme = backgroundTheme;
    }

	// Background theme fade in/ fade out

	static IEnumerator FadeNextBackgroundTheme(
        AudioSource current, 
        AudioSource next,
        float fadeSpeed,
        float fadeDelay,
        float volume
    ) 
    {
        // Fade out current clip, if neccessary
        if (current != null)
        {
            while (current.volume > 0)
            {
                current.volume -= fadeSpeed * volume;
                yield return new WaitForSeconds(fadeDelay);
            }
            current.Stop();    
        }

        // Fade in next clip
        next.loop = true;
        next.volume = 0;
        next.Play();
        while (next.volume < volume)
        {
            next.volume += fadeSpeed * volume;
            yield return new WaitForSeconds(fadeDelay);
        }
    }

}