using UnityEngine;
using System;
using System.IO;
using System.Windows.Forms; // 모니터 식별 및 스크린 정보
using System.Drawing;       // Bitmap 관련
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using TMPro;
using Unity.VisualScripting;
using Application = UnityEngine.Application;
using Screen = System.Windows.Forms.Screen;
using Graphics = System.Drawing.Graphics;

public class TakeScreen : MonoBehaviour
{
    // 캡처할 모니터 인덱스 (2 = 첫번째 모니터)
    public int selectMonitorIndex = 2;
    public int takeNumber;
    int monitorIndex = 0;
    
    MONITORINFO selectMonitor;
    int selectWidth;
    int selectHeight;
    
    [SerializeField] 
    TMP_InputField inputPrefix;
    
    [SerializeField] 
    TMP_InputField inputResult;
        
    [SerializeField] 
    DirectorySelect directorySelector;
    
    // WinAPI 구조체
    [StructLayout(LayoutKind.Sequential)]
    public struct RECT
    {
        public int left, top, right, bottom;
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    public struct MONITORINFO
    {
        public int cbSize;
        public RECT rcMonitor;
        public RECT rcWork;
        public int dwFlags;

        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
        public string szDevice;
        
    }
    
    // WinAPI 델리게이트
    private delegate bool MonitorEnumProc(IntPtr hMonitor, IntPtr hdcMonitor, ref RECT lprcMonitor, IntPtr dwData);
    
    // WinAPI 함수
    [DllImport("user32.dll")]
    private static extern bool EnumDisplayMonitors(IntPtr hdc, IntPtr lprcClip, MonitorEnumProc lpfnEnum, IntPtr dwData);
    
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    private static extern bool GetMonitorInfo(IntPtr hMonitor, ref MONITORINFO lpmi);
    
    [DllImport("user32.dll")]
    private static extern IntPtr GetDC(IntPtr hWnd);
    
    [DllImport("gdi32.dll")]
    private static extern IntPtr CreateCompatibleDC(IntPtr hdc);
    
    [DllImport("gdi32.dll")]
    private static extern IntPtr CreateCompatibleBitmap(IntPtr hdc, int width, int height);
    
    [DllImport("gdi32.dll")]
    private static extern IntPtr SelectObject(IntPtr hdc, IntPtr hgdiobj);

    [DllImport("gdi32.dll")]
    private static extern bool BitBlt(IntPtr hdcDest, int nXDest, int nYDest, int nWidth, int nHeight, 
                                      IntPtr hdcSrc, int nXSrc, int nYSrc, CopyPixelOperation dwRop);
    
    [DllImport("gdi32.dll")]
    private static extern bool DeleteObject(IntPtr hObject);
    
    [DllImport("gdi32.dll")]
    private static extern bool DeleteDC(IntPtr hdc);
    
    [DllImport("user32.dll")]
    private static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);
    
    
    private void Start()
    {
        Debug.Log("=== 모든 모니터 정보 ===");
        EnumDisplayMonitors(IntPtr.Zero, IntPtr.Zero, MonitorCallback, IntPtr.Zero);
    }

    private bool MonitorCallback(IntPtr hMonitor, IntPtr hdcMonitor, ref RECT lprcMonitor, IntPtr dwData)
    {
        MONITORINFO mi = new MONITORINFO();
        mi.cbSize = Marshal.SizeOf(typeof(MONITORINFO));
        monitorIndex++;
        
        if (GetMonitorInfo(hMonitor, ref mi) && monitorIndex == selectMonitorIndex)
        {
            int width = mi.rcMonitor.right - mi.rcMonitor.left;
            int height = mi.rcMonitor.bottom - mi.rcMonitor.top;
            bool isPrimary = (mi.dwFlags & 1) != 0;
            
            Debug.Log(
                $"{mi.szDevice} 모니터 \n" + 
                $" - 해상도 : {width} x {height}\n" +
                $" - 위치 : x = {mi.rcMonitor.left}, y = {mi.rcMonitor.top}\n" +
                $" - 주 모니터 여부 : {isPrimary}\n"
            );

            selectMonitor = mi;
            selectWidth = width;
            selectHeight = height;
        }

        return true;    // 계속 나머지 모니터 순회
    }

    public void Take()
    {
        string fileName = $"{inputPrefix.text}_{string.Format("{0:D2}", takeNumber)}.png";
        string savePath = Path.Combine(directorySelector.selectedFolderPath, fileName);
        
        Shot(selectMonitor.rcMonitor.left, selectMonitor.rcMonitor.top, selectWidth, selectHeight, savePath);
    }
    
    void Shot(int x, int y, int width, int height, string savePath)
    {
        IntPtr desktopDC = GetDC(IntPtr.Zero);
        IntPtr memoryDC = CreateCompatibleDC(desktopDC);
        IntPtr bitmap =  CreateCompatibleBitmap(desktopDC, width, height);
        IntPtr oldBitmap = SelectObject(memoryDC, bitmap);
        
        BitBlt(memoryDC, 0, 0, width, height, desktopDC, x, y, CopyPixelOperation.SourceCopy | CopyPixelOperation.CaptureBlt);

        using (Bitmap bmp = Image.FromHbitmap(bitmap))
        {
            bmp.Save(savePath, ImageFormat.Png);
        }
        
        // 정리
        SelectObject(memoryDC, oldBitmap);
        DeleteObject(bitmap);
        DeleteDC(memoryDC);
        ReleaseDC(desktopDC, memoryDC);

        inputResult.text = savePath;
    }
}