BuyButton

using System;
using AnimalsSimulator.Project;
using TMPro;
using UniRx;
using UnityEngine;
using UnityEngine.UI;
using Zenject;

namespace AnimalsSimulator.Common.UI
{
    [RequireComponent(typeof(Button))]
    public class BuyButton : MonoBehaviour
    {
        [SerializeField] private TextMeshProUGUI _priceText;
        [SerializeField] private Button _button;

        [Inject] private PurchaseService _purchaseService;

        private CompositeDisposable _disposable;

        private void OnValidate() => _button ??= GetComponent<Button>();

        public IObservable<Unit> BindOnClick(IReadOnlyReactiveProperty<int> price)
        {
            _disposable?.Dispose();
            _disposable = new CompositeDisposable();

            price.Subscribe(SetPrice)
                .AddTo(_disposable);

            var reactiveCommand = price.Select(_purchaseService.CanBuy)
                .Merge(_purchaseService.Money.Select(CanBuy))
                .ToReactiveCommand();

            reactiveCommand.BindToOnClick(_button, _ => _purchaseService.Purchase(price.Value))
                .AddTo(_disposable);

            return reactiveCommand;

            bool CanBuy(int money) =>
                price.Value <= money;
        }

        private void SetPrice(int price)
        {
            var text = price.ToString();

            _priceText.SetText(text);
        }
    }
}