using UnityEngine;
using UnityEngine.UI;

/// <summary>
/// Deteksi kecerahan kamera secara real-time.
/// Tampilkan/sembunyikan button senter otomatis berdasarkan brightness.
/// </summary>
public class LightDetector : MonoBehaviour
{
    [Header("UI")]
    public GameObject flashlightButton; // drag button senter ke sini

    [Header("Pengaturan")]
    [Range(0f, 1f)]
    public float threshold = 0.15f; // di bawah nilai ini = gelap, button muncul
    public float checkInterval = 0.5f; // cek setiap berapa detik

    private WebCamTexture webCamTexture;
    private float timer = 0f;

    void Start()
    {
        // Sembunyikan button saat awal
        if (flashlightButton != null)
            flashlightButton.SetActive(false);

        // Gunakan kamera belakang
        WebCamDevice[] devices = WebCamTexture.devices;
        string backCamName = "";
        foreach (var d in devices)
        {
            if (!d.isFrontFacing)
            {
                backCamName = d.name;
                break;
            }
        }

        webCamTexture = new WebCamTexture(backCamName, 64, 64, 15); // resolusi kecil = ringan
        webCamTexture.Play();
    }

    void Update()
    {
        if (webCamTexture == null || !webCamTexture.isPlaying) return;

        timer += Time.deltaTime;
        if (timer < checkInterval) return;
        timer = 0f;

        float brightness = GetAverageBrightness();
        bool isDark = brightness < threshold;

        if (flashlightButton != null)
            flashlightButton.SetActive(isDark);
    }

    float GetAverageBrightness()
    {
        Color32[] pixels = webCamTexture.GetPixels32();
        if (pixels == null || pixels.Length == 0) return 1f;

        float total = 0f;
        int step = Mathf.Max(1, pixels.Length / 256); // sample sebagian pixel saja biar ringan

        int count = 0;
        for (int i = 0; i < pixels.Length; i += step)
        {
            Color32 c = pixels[i];
            // luminance sederhana
            total += (c.r * 0.299f + c.g * 0.587f + c.b * 0.114f) / 255f;
            count++;
        }

        return count > 0 ? total / count : 1f;
    }

    void OnDestroy()
    {
        if (webCamTexture != null && webCamTexture.isPlaying)
            webCamTexture.Stop();
    }
}