using UnityEngine;
using System;
using System.IO;

/// <summary>
/// 스크린샷 캡처 관리 (RGB + 알파채널)
/// </summary>
[Serializable]
public class ScreenshotManager
{
    [Tooltip("스크린샷 해상도 (기본: 4K)")]
    public int screenshotWidth = 3840;

    [Tooltip("스크린샷 해상도 (기본: 4K)")]
    public int screenshotHeight = 2160;

    [Tooltip("스크린샷 저장 경로 (비어있으면 바탕화면)")]
    public string screenshotSavePath = "";

    [Tooltip("파일명 앞에 붙을 접두사")]
    public string screenshotFilePrefix = "Screenshot";

    [Tooltip("알파 채널 추출용 셰이더")]
    public Shader alphaShader;

    [Tooltip("NiloToon Prepass 버퍼 텍스처 이름")]
    public string niloToonPrepassBufferName = "_NiloToonPrepassBufferTex";

    [Tooltip("촬영할 카메라 (비어있으면 메인 카메라 사용)")]
    public Camera screenshotCamera;

    [Tooltip("알파 채널 블러 반경 (0 = 블러 없음, 1.0 = 약한 블러)")]
    [Range(0f, 3f)]
    public float alphaBlurRadius = 1.0f;

    [NonSerialized]
    private Material alphaMaterial;

    private Action<string> log;
    private Action<string> logError;

    public void Initialize(Action<string> log, Action<string> logError)
    {
        this.log = log;
        this.logError = logError;

        if (screenshotCamera == null)
        {
            screenshotCamera = Camera.main;
        }

        if (alphaShader == null)
        {
            alphaShader = Shader.Find("Hidden/AlphaFromNiloToon");
            if (alphaShader == null)
            {
                logError?.Invoke("알파 셰이더를 찾을 수 없습니다: Hidden/AlphaFromNiloToon");
            }
        }

        if (string.IsNullOrEmpty(screenshotSavePath))
        {
            screenshotSavePath = Path.Combine(Application.dataPath, "..", "Screenshots");
        }

        if (!Directory.Exists(screenshotSavePath))
        {
            Directory.CreateDirectory(screenshotSavePath);
            log?.Invoke($"Screenshots 폴더 생성됨: {screenshotSavePath}");
        }
    }

    public void CaptureScreenshot()
    {
        if (screenshotCamera == null)
        {
            logError?.Invoke("촬영할 카메라가 설정되지 않았습니다!");
            return;
        }

        string fileName = GenerateFileName("png");
        string fullPath = Path.Combine(screenshotSavePath, fileName);

        try
        {
            RenderTexture rt = new RenderTexture(screenshotWidth, screenshotHeight, 24);
            RenderTexture currentRT = screenshotCamera.targetTexture;

            screenshotCamera.targetTexture = rt;
            screenshotCamera.Render();

            RenderTexture.active = rt;
            Texture2D screenshot = new Texture2D(screenshotWidth, screenshotHeight, TextureFormat.RGB24, false);
            screenshot.ReadPixels(new Rect(0, 0, screenshotWidth, screenshotHeight), 0, 0);
            screenshot.Apply();

            byte[] bytes = screenshot.EncodeToPNG();
            File.WriteAllBytes(fullPath, bytes);

            screenshotCamera.targetTexture = currentRT;
            RenderTexture.active = null;
            rt.Release();
            UnityEngine.Object.Destroy(rt);
            UnityEngine.Object.Destroy(screenshot);

            log?.Invoke($"스크린샷 저장 완료: {fullPath}");
        }
        catch (Exception e)
        {
            logError?.Invoke($"스크린샷 촬영 실패: {e.Message}");
        }
    }

    public void CaptureAlphaScreenshot()
    {
        if (screenshotCamera == null)
        {
            logError?.Invoke("촬영할 카메라가 설정되지 않았습니다!");
            return;
        }

        if (alphaShader == null)
        {
            logError?.Invoke("알파 셰이더가 설정되지 않았습니다!");
            return;
        }

        string fileName = GenerateFileName("png", "_Alpha");
        string fullPath = Path.Combine(screenshotSavePath, fileName);

        try
        {
            RenderTexture rt = new RenderTexture(screenshotWidth, screenshotHeight, 24);
            RenderTexture currentRT = screenshotCamera.targetTexture;

            screenshotCamera.targetTexture = rt;
            screenshotCamera.Render();

            Texture niloToonPrepassBuffer = Shader.GetGlobalTexture(niloToonPrepassBufferName);

            if (niloToonPrepassBuffer == null)
            {
                logError?.Invoke($"NiloToon Prepass 버퍼를 찾을 수 없습니다: {niloToonPrepassBufferName}");
                screenshotCamera.targetTexture = currentRT;
                UnityEngine.Object.Destroy(rt);
                return;
            }

            if (alphaMaterial == null)
            {
                alphaMaterial = new Material(alphaShader);
            }

            RenderTexture alphaRT = new RenderTexture(screenshotWidth, screenshotHeight, 0, RenderTextureFormat.ARGB32);
            alphaMaterial.SetTexture("_MainTex", rt);
            alphaMaterial.SetTexture("_AlphaTex", niloToonPrepassBuffer);
            alphaMaterial.SetFloat("_BlurRadius", alphaBlurRadius);

            Graphics.Blit(rt, alphaRT, alphaMaterial);

            RenderTexture.active = alphaRT;
            Texture2D screenshot = new Texture2D(screenshotWidth, screenshotHeight, TextureFormat.RGBA32, false);
            screenshot.ReadPixels(new Rect(0, 0, screenshotWidth, screenshotHeight), 0, 0);
            screenshot.Apply();

            byte[] bytes = screenshot.EncodeToPNG();
            File.WriteAllBytes(fullPath, bytes);

            screenshotCamera.targetTexture = currentRT;
            RenderTexture.active = null;
            rt.Release();
            UnityEngine.Object.Destroy(rt);
            alphaRT.Release();
            UnityEngine.Object.Destroy(alphaRT);
            UnityEngine.Object.Destroy(screenshot);

            log?.Invoke($"알파 스크린샷 저장 완료: {fullPath}");
        }
        catch (Exception e)
        {
            logError?.Invoke($"알파 스크린샷 촬영 실패: {e.Message}");
        }
    }

    public void OpenScreenshotFolder()
    {
        if (Directory.Exists(screenshotSavePath))
        {
            System.Diagnostics.Process.Start(screenshotSavePath);
            log?.Invoke($"저장 폴더 열기: {screenshotSavePath}");
        }
        else
        {
            logError?.Invoke($"저장 폴더가 존재하지 않습니다: {screenshotSavePath}");
        }
    }

    private string GenerateFileName(string extension, string suffix = "")
    {
        string timestamp = DateTime.Now.ToString("yyyyMMdd_HHmmss");
        return $"{screenshotFilePrefix}{suffix}_{timestamp}.{extension}";
    }

    public void Cleanup()
    {
        if (alphaMaterial != null)
        {
            UnityEngine.Object.Destroy(alphaMaterial);
        }
    }
}