InterstitialAdUnit

using System;
using GoogleMobileAds.Api;
using UniRx;
using UnityEngine;

[CreateAssetMenu(menuName = "Mobile Ads/Interstitial", fileName = "InterstitialAdUnit", order = 0)]
public class InterstitialAdUnit : GoogleAdUnit
{
    private InterstitialAd _interstitial;
    public Subject<Unit> OnLoaded { get; } = new Subject<Unit>();
    public Subject<Unit> OnShowed { get; } = new Subject<Unit>();
    public Subject<Unit> OnClosed { get; } = new Subject<Unit>();

    public override void Load()
    {
        // Initialize an InterstitialAd.
        _interstitial = new InterstitialAd(AdUnitID);
        _interstitial.OnAdLoaded += InterstitialOnOnAdLoaded;
        _interstitial.OnAdOpening += InterstitialOnOnAdOpening;
        _interstitial.OnAdClosed += InterstitialOnOnAdClosed;
        // Create an empty ad request.
        var request = new AdRequest.Builder()
                .AddExtra("npa", GoogleAds.NonPersonalizedAds.ToString())
                .Build();
        // Load the interstitial with the request.
        _interstitial.LoadAd(request);
#if UNITY_EDITOR
        OnLoaded.OnNext(Unit.Default);
#endif
    }

    private void InterstitialOnOnAdClosed(object sender, EventArgs e)
    {
        if (sender is InterstitialAd interstitialAd)
            interstitialAd.OnAdOpening -= InterstitialOnOnAdOpening;

        GoogleAdsHandler.MainThread.Post(_ => OnClosed.OnNext(Unit.Default), null);
    }

    private void InterstitialOnOnAdOpening(object sender, EventArgs e)
    {
        if (sender is InterstitialAd interstitialAd)
            interstitialAd.OnAdOpening -= InterstitialOnOnAdOpening;

        GoogleAdsHandler.MainThread.Post(_ => OnShowed.OnNext(Unit.Default), null);
    }

    private void InterstitialOnOnAdLoaded(object sender, EventArgs e)
    {
        if (sender is InterstitialAd interstitialAd)
            interstitialAd.OnAdLoaded -= InterstitialOnOnAdLoaded;

        Debug.Log("GoogleAdsHandler.MainThread = " + GoogleAdsHandler.MainThread);

        GoogleAdsHandler.MainThread.Post(_ => OnLoaded.OnNext(Unit.Default), null);
    }

    public override void Show()
    {
        _interstitial.Show();
#if UNITY_EDITOR
        OnShowed.OnNext(Unit.Default);
#endif
    }

    public override void ShowOnLoaded(Action<bool> onLoadedStatus)
    {
        if (_interstitial != null && _interstitial.IsLoaded())
        {
            onLoadedStatus?.Invoke(true);
            Show();
        }
        else
        {
            onLoadedStatus?.Invoke(false);
            OnLoaded.Take(1).Subscribe(_ =>
            {
                Show();
                onLoadedStatus?.Invoke(true);
            });
            Load();
        }
    }
}