using System;
using UnityEngine;
using UnityEngine.UI;

namespace Runtime
{
    public class CarouselImage : MonoBehaviour
    {
        public CarouselImageItem pfb;
        Sprite[] sprites;
        CarouselImageItem[] buttons;
        int currentIndex;

        readonly Vector2 leftPos = new Vector2(-165, 0);
        readonly Vector2 centerPos = new Vector2(0, 0);
        readonly Vector2 rightPos = new Vector2(165, 0);

        Vector3 bigSize = Vector3.one;
        Vector3 smallSize = new Vector3(0.7f, 0.7f, 0.7f);
        
        public Action<int> ClickAction;

        public void Init(Sprite[] sprites, int index)
        {
            buttons = new CarouselImageItem[sprites.Length];
            this.sprites = sprites;
            this.currentIndex = index;
            for (var i = 0; i < this.sprites.Length; i++)
            {
                var sprite = this.sprites[i];
                var o = GameObject.Instantiate(pfb, this.transform);
                o.GetComponent<Image>().sprite = sprite;

                buttons[i] = o;
                int themId = i;
                o.Button.onClick.AddListener(() => { Carousel(themId); });
            }

            ResetAll(index);
        }

        public void ResetAll(int centerIndex)
        {
            currentIndex = centerIndex;
            foreach (CarouselImageItem button in buttons)
            {
                button.Hide();
            }

            if (centerIndex - 1 >= 0)
                buttons[centerIndex - 1].AppearAtPos(leftPos, smallSize);
            buttons[centerIndex].AppearAtPos(centerPos, bigSize);
            if (centerIndex + 1 < buttons.Length)
                buttons[centerIndex + 1].AppearAtPos(rightPos, smallSize);
        }

        void Carousel(int i)
        {
            if (currentIndex == i)
                return;
            ClickAction?.Invoke(i);

            if (i < currentIndex)
            {
                if (currentIndex - 1 >= 0)
                    buttons[currentIndex - 1].MoveToPos(centerPos, bigSize);
                buttons[currentIndex].MoveToPos(rightPos, smallSize);
                if (currentIndex + 1 < buttons.Length)
                    buttons[currentIndex + 1].Disappear();
                if (currentIndex - 2 >= 0)
                    buttons[currentIndex - 2].AppearAtPos(leftPos, smallSize);
                Debug.Log("click to left");
            }
            else
            {
                if (currentIndex - 1 >= 0)
                    buttons[currentIndex - 1].Disappear();
                buttons[currentIndex].MoveToPos(leftPos, smallSize);
                if (currentIndex + 1 < buttons.Length)
                    buttons[currentIndex + 1].MoveToPos(centerPos, bigSize);
                if (currentIndex + 2 < buttons.Length)
                    buttons[currentIndex + 2].AppearAtPos(rightPos, smallSize);
                Debug.Log("click to right");
            }

            currentIndex = i;
        }
    }
}