using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace winampsongDB {
    public partial class Form1 : Form {
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        private static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, int wParam, int lParam);

        [DllImport("user32.dll", SetLastError = true)]
        static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        [DllImport("user32.dll", SetLastError = true)]
        static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);

        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
        static extern uint RegisterWindowMessage(string lpString);

        [DllImport("kernel32.dll")]
        public static extern IntPtr OpenProcess(int dwDesiredAccess, bool bInheritHandle, uint dwProcessId);

        [DllImport("kernel32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool CloseHandle(IntPtr hObject);

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern bool ReadProcessMemory(
          IntPtr hProcess,
          IntPtr lpBaseAddress,
          [Out] byte[] lpBuffer,
          int dwSize,
          out int lpNumberOfBytesRead
        );

        private static string ReadWinampString(IntPtr hwnd, IntPtr location) {
            uint pid;
            IntPtr process;

            GetWindowThreadProcessId(hwnd, out pid);
            if (pid == 0)
                return string.Empty;

            if ((process = OpenProcess(0x0008 | 0x0010, false, pid)) == IntPtr.Zero)
                return string.Empty;

            int bytesRead;
            byte[] buffer = new byte[1024];

            try {
                if (!ReadProcessMemory(process, location, buffer, buffer.Length, out bytesRead))
                    return string.Empty;
            } finally {
                CloseHandle(process);
            }

            string str = Encoding.GetEncoding(1252 /* windows-1252 - windows extended ASCII */).GetString(buffer);
            return str.Contains("\0") ? str.Substring(0,str.IndexOf('\0')) : str;
        }

        uint WinampSongChangeMsg = 0xFFFFFFF;

        string title, file;

        public Form1() {
            WinampSongChangeMsg = RegisterWindowMessage("WinampSongChange");

            InitializeComponent();
        }

        public void UpdateSong() {
            IntPtr hwnd;
            if ((hwnd = GetWinampHandle()) == null)
                return;

            int plPos = (int)SendMessage(hwnd, 0x0400 /* WM_USER/WM_WA_IPC */, 0, 125 /*IPC_GETLISTPOS*/);

            IntPtr strPtr = SendMessage(hwnd, 0x0400 /* WM_USER/WM_WA_IPC */, plPos, 211 /*IPC_GETPLAYLISTFILE*/);
            file = ReadWinampString(hwnd, strPtr);

            strPtr = SendMessage(hwnd, 0x0400 /* WM_USER/WM_WA_IPC */, plPos, 212 /*IPC_GETPLAYLISTTITLE*/);
            title = ReadWinampString(hwnd, strPtr);

            songTitle.Text = title;
            UpdateDisp();
        }

        private static IntPtr GetWinampHandle() {
            return FindWindow("Winamp v1.x", null);
        }

        protected override void WndProc(ref Message m) {
            if (m.Msg == WinampSongChangeMsg) // songchanged
                UpdateSong();

            base.WndProc(ref m);
        }
    }
}