using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems; // Wajib ada
using System.Collections;

public class MenuSlider : MonoBehaviour
{
    [Header("Hubungkan UI di Sini")]
    public ScrollRect scrollRect;       // Tarik Object Card_Window
    public RectTransform contentHolder; // Tarik Object Content_Holder

    [Header("Setting")]
    public float snapSpeed = 10f; // Kecepatan geser kartu

    // Variabel internal (Jangan diubah manual)
    private float[] cardPositions; 
    private int currentIndex = 0;
    private float targetX = 0;
    private bool isInitialized = false;

    void Start()
    {
        // Delay sebentar biar Layout Group selesai menghitung ukuran
        Invoke("InitializePositions", 0.1f);
    }

    // Hitung posisi koordinat setiap kartu
    void InitializePositions()
    {
        int childCount = contentHolder.childCount;
        cardPositions = new float[childCount];

        // Ambil lebar kartu pertama + spasi
        float cardWidth = contentHolder.GetChild(0).GetComponent<RectTransform>().rect.width;
        float spacing = contentHolder.GetComponent<HorizontalLayoutGroup>().spacing;
        float step = cardWidth + spacing;

        for (int i = 0; i < childCount; i++)
        {
            // Posisi X selalu minus karena geser ke kiri
            cardPositions[i] = -(i * step);
        }

        isInitialized = true;
    }

    void Update()
    {
        if (!isInitialized) return;

        // Logika Geser Halus (Lerp)
        Vector2 currentPos = contentHolder.anchoredPosition;
        float newX = Mathf.Lerp(currentPos.x, targetX, Time.deltaTime * snapSpeed);
        contentHolder.anchoredPosition = new Vector2(newX, currentPos.y);
    }

    // --- FUNGSI TOMBOL NEXT ---
    public void NextCard()
    {
        // 1. Bunyi SFX
        if (Audio.instance != null) Audio.instance.PlayButtonSound();

        // 2. Animasi Tombol
        GameObject tombol = EventSystem.current.currentSelectedGameObject;
        
        if (tombol != null)
        {
            StartCoroutine(AnimasiDanPindah(tombol.transform, true)); 
        }
        else
        {
            MoveLogic(true); 
        }
    }

    // --- FUNGSI TOMBOL PREV ---
    public void PrevCard()
    {
        // 1. Bunyi SFX
        if (Audio.instance != null) Audio.instance.PlayButtonSound();

        // 2. Animasi Tombol
        GameObject tombol = EventSystem.current.currentSelectedGameObject;

        if (tombol != null)
        {
            StartCoroutine(AnimasiDanPindah(tombol.transform, false)); 
        }
        else
        {
            MoveLogic(false);
        }
    }

    // Animasi Tombol Next/Prev (Squash -> Pindah Logic -> Stretch)
    IEnumerator AnimasiDanPindah(Transform tombol, bool isNext)
    {
        float timer = 0;
        float durasi = 0.1f; 

        // FASE 1: SQUASH (Ditekan)
        while (timer < durasi)
        {
            timer += Time.deltaTime;
            float t = timer / durasi;
            float scaleX = Mathf.Lerp(1f, 1.2f, t);
            float scaleY = Mathf.Lerp(1f, 0.8f, t);
            tombol.localScale = new Vector3(scaleX, scaleY, 1f);
            yield return null;
        }

        // -- PINDAHKAN KARTU SEKARANG (Biar responsif) --
        MoveLogic(isNext); 
        timer = 0;

        // FASE 2: STRETCH (Membal Balik)
        while (timer < durasi)
        {
            timer += Time.deltaTime;
            float t = timer / durasi;
            float scaleX = Mathf.Lerp(1.2f, 1f, t); // Balik ke 1
            float scaleY = Mathf.Lerp(0.8f, 1f, t); // Balik ke 1
            tombol.localScale = new Vector3(scaleX, scaleY, 1f);
            yield return null;
        }

        // Pastikan normal
        tombol.localScale = Vector3.one; 
    }

    // Logika Matematika Geser Index
    void MoveLogic(bool isNext)
    {
        if (isNext)
        {
            if (currentIndex < cardPositions.Length - 1)
            {
                currentIndex++;
                targetX = cardPositions[currentIndex];
            }
        }
        else
        {
            if (currentIndex > 0)
            {
                currentIndex--;
                targetX = cardPositions[currentIndex];
            }
        }
    }
}