using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using RomCheater.Logging;
using System.Runtime.InteropServices;
using System.Diagnostics;

namespace Sojaner.MemoryScanner
{
    public class PEReader
    {
        public PEReader(FileInfo fi) : this(fi.FullName) { }
        public PEReader(string filename) { this.Read(filename); }

        #region marshalling
        private void Read(string filename)
        {
            logger.Debug.WriteLine("Reading Exe: {0}", filename);

            using (FileStream fs = new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read))
            {
                byte[] data = new byte[] { };
                GCHandle pinnedPacket = new GCHandle();
                int size = 0;
                BinaryReader br = new BinaryReader(fs);

                #region IMAGE_DOS_HEADER
                size = Marshal.SizeOf(typeof(IMAGE_DOS_HEADER));
                data = br.ReadBytes(size);
                pinnedPacket = GCHandle.Alloc(data, GCHandleType.Pinned);
                IMAGE_DOS_HEADER IMAGE_DOS_HEADER = (IMAGE_DOS_HEADER)Marshal.PtrToStructure(pinnedPacket.AddrOfPinnedObject(), typeof(IMAGE_DOS_HEADER));
                pinnedPacket.Free();
                #endregion

                // skip the old dos stub
                br.BaseStream.Seek(IMAGE_DOS_HEADER.e_lfanew, SeekOrigin.Begin);

                #region IMAGE_NT_HEADERS
                size = Marshal.SizeOf(typeof(IMAGE_NT_HEADERS));
                data = br.ReadBytes(size);
                pinnedPacket = GCHandle.Alloc(data, GCHandleType.Pinned);
                IMAGE_NT_HEADERS IMAGE_NT_HEADERS = (IMAGE_NT_HEADERS)Marshal.PtrToStructure(pinnedPacket.AddrOfPinnedObject(), typeof(IMAGE_NT_HEADERS));
                pinnedPacket.Free();
                #endregion

                br.Close();
            }

 
        }
        #endregion

        #region header support
        #region IMAGE_DATA_DIRECTORY
        [StructLayout(LayoutKind.Sequential)]
        public struct IMAGE_DATA_DIRECTORY
        {
            public UInt32 VirtualAddress;
            public UInt32 Size;
        }
        #endregion
        #region IMAGE_FILE_HEADER
        [StructLayout(LayoutKind.Sequential)]
        public struct IMAGE_FILE_HEADER
        {
            public UInt16 Machine;
            public UInt16 NumberOfSections;
            public UInt32 TimeDateStamp;
            public UInt32 PointerToSymbolTable;
            public UInt32 NumberOfSymbols;
            public UInt16 SizeOfOptionalHeader;
            public UInt16 Characteristics;
        }
        #endregion
        #region IMAGE_DOS_HEADER
        [StructLayout(LayoutKind.Sequential)]
        public struct IMAGE_DOS_HEADER
        {
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
            public char[] e_magic;       // Magic number
            public UInt16 e_cblp;    // Bytes on last page of file
            public UInt16 e_cp;      // Pages in file
            public UInt16 e_crlc;    // Relocations
            public UInt16 e_cparhdr;     // Size of header in paragraphs
            public UInt16 e_minalloc;    // Minimum extra paragraphs needed
            public UInt16 e_maxalloc;    // Maximum extra paragraphs needed
            public UInt16 e_ss;      // Initial (relative) SS value
            public UInt16 e_sp;      // Initial SP value
            public UInt16 e_csum;    // Checksum
            public UInt16 e_ip;      // Initial IP value
            public UInt16 e_cs;      // Initial (relative) CS value
            public UInt16 e_lfarlc;      // File address of relocation table
            public UInt16 e_ovno;    // Overlay number
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
            public UInt16[] e_res1;    // Reserved words
            public UInt16 e_oemid;       // OEM identifier (for e_oeminfo)
            public UInt16 e_oeminfo;     // OEM information; e_oemid specific
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 10)]
            public UInt16[] e_res2;    // Reserved words
            public Int32 e_lfanew;      // File address of new exe header
            private string _e_magic
            {
                get { return new string(e_magic); }
            }
            public bool isValid
            {
                get { return _e_magic == "MZ"; }
            }
        }
        #endregion
        #region IMAGE_NT_HEADERS
        [StructLayout(LayoutKind.Explicit)]
        public struct IMAGE_NT_HEADERS
        {
            [FieldOffset(0)]
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
            public char[] Signature;

            [FieldOffset(4)]
            public IMAGE_FILE_HEADER FileHeader;

            [FieldOffset(24)]
            public IMAGE_OPTIONAL_HEADER OptionalHeader;

            private string _Signature
            {
                get { return new string(Signature); }
            }

            public bool isValid
            {
                get { return _Signature == "PE\0\0" && (OptionalHeader.Magic == MagicType.IMAGE_NT_OPTIONAL_HDR32_MAGIC || OptionalHeader.Magic == MagicType.IMAGE_NT_OPTIONAL_HDR64_MAGIC); }
            }
        }
        #endregion
        #region MachineType
        public enum MachineType : ushort
        {
            Native = 0,
            I386 = 0x014c,
            Itanium = 0x0200,
            x64 = 0x8664
        }
        #endregion
        #region MagicType
        public enum MagicType : ushort
        {
            IMAGE_NT_OPTIONAL_HDR32_MAGIC = 0x10b,
            IMAGE_NT_OPTIONAL_HDR64_MAGIC = 0x20b
        }
        #endregion
        #region SubSystemType
        public enum SubSystemType : ushort
        {
            IMAGE_SUBSYSTEM_UNKNOWN = 0,
            IMAGE_SUBSYSTEM_NATIVE = 1,
            IMAGE_SUBSYSTEM_WINDOWS_GUI = 2,
            IMAGE_SUBSYSTEM_WINDOWS_CUI = 3,
            IMAGE_SUBSYSTEM_POSIX_CUI = 7,
            IMAGE_SUBSYSTEM_WINDOWS_CE_GUI = 9,
            IMAGE_SUBSYSTEM_EFI_APPLICATION = 10,
            IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER = 11,
            IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER = 12,
            IMAGE_SUBSYSTEM_EFI_ROM = 13,
            IMAGE_SUBSYSTEM_XBOX = 14

        }
        #endregion
        #region DllCharacteristicsType
        public enum DllCharacteristicsType : ushort
        {
            RES_0 = 0x0001,
            RES_1 = 0x0002,
            RES_2 = 0x0004,
            RES_3 = 0x0008,
            IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE = 0x0040,
            IMAGE_DLL_CHARACTERISTICS_FORCE_INTEGRITY = 0x0080,
            IMAGE_DLL_CHARACTERISTICS_NX_COMPAT = 0x0100,
            IMAGE_DLLCHARACTERISTICS_NO_ISOLATION = 0x0200,
            IMAGE_DLLCHARACTERISTICS_NO_SEH = 0x0400,
            IMAGE_DLLCHARACTERISTICS_NO_BIND = 0x0800,
            RES_4 = 0x1000,
            IMAGE_DLLCHARACTERISTICS_WDM_DRIVER = 0x2000,
            IMAGE_DLLCHARACTERISTICS_TERMINAL_SERVER_AWARE = 0x8000
        }
        #endregion
        #region IMAGE_OPTIONAL_HEADER
        [StructLayout(LayoutKind.Explicit)]
        public struct IMAGE_OPTIONAL_HEADER
        {
            [FieldOffset(0)]
            public MagicType Magic;

            [FieldOffset(2)]
            public byte MajorLinkerVersion;

            [FieldOffset(3)]
            public byte MinorLinkerVersion;

            [FieldOffset(4)]
            public uint SizeOfCode;

            [FieldOffset(8)]
            public uint SizeOfInitializedData;

            [FieldOffset(12)]
            public uint SizeOfUninitializedData;

            [FieldOffset(16)]
            public uint AddressOfEntryPoint;

            [FieldOffset(20)]
            public uint BaseOfCode;

            // PE32 contains this additional field
            [FieldOffset(24)]
            public uint BaseOfData;

            [FieldOffset(28)]
            public uint ImageBase;

            [FieldOffset(32)]
            public uint SectionAlignment;

            [FieldOffset(36)]
            public uint FileAlignment;

            [FieldOffset(40)]
            public ushort MajorOperatingSystemVersion;

            [FieldOffset(42)]
            public ushort MinorOperatingSystemVersion;

            [FieldOffset(44)]
            public ushort MajorImageVersion;

            [FieldOffset(46)]
            public ushort MinorImageVersion;

            [FieldOffset(48)]
            public ushort MajorSubsystemVersion;

            [FieldOffset(50)]
            public ushort MinorSubsystemVersion;

            [FieldOffset(52)]
            public uint Win32VersionValue;

            [FieldOffset(56)]
            public uint SizeOfImage;

            [FieldOffset(60)]
            public uint SizeOfHeaders;

            [FieldOffset(64)]
            public uint CheckSum;

            [FieldOffset(68)]
            public SubSystemType Subsystem;

            [FieldOffset(70)]
            public DllCharacteristicsType DllCharacteristics;

            [FieldOffset(72)]
            public uint SizeOfStackReserve;

            [FieldOffset(76)]
            public uint SizeOfStackCommit;

            [FieldOffset(80)]
            public uint SizeOfHeapReserve;

            [FieldOffset(84)]
            public uint SizeOfHeapCommit;

            [FieldOffset(88)]
            public uint LoaderFlags;

            [FieldOffset(92)]
            public uint NumberOfRvaAndSizes;

            [FieldOffset(96)]
            public IMAGE_DATA_DIRECTORY ExportTable;

            [FieldOffset(104)]
            public IMAGE_DATA_DIRECTORY ImportTable;

            [FieldOffset(112)]
            public IMAGE_DATA_DIRECTORY ResourceTable;

            [FieldOffset(120)]
            public IMAGE_DATA_DIRECTORY ExceptionTable;

            [FieldOffset(128)]
            public IMAGE_DATA_DIRECTORY CertificateTable;

            [FieldOffset(136)]
            public IMAGE_DATA_DIRECTORY BaseRelocationTable;

            [FieldOffset(144)]
            public IMAGE_DATA_DIRECTORY Debug;

            [FieldOffset(152)]
            public IMAGE_DATA_DIRECTORY Architecture;

            [FieldOffset(160)]
            public IMAGE_DATA_DIRECTORY GlobalPtr;

            [FieldOffset(168)]
            public IMAGE_DATA_DIRECTORY TLSTable;

            [FieldOffset(176)]
            public IMAGE_DATA_DIRECTORY LoadConfigTable;

            [FieldOffset(184)]
            public IMAGE_DATA_DIRECTORY BoundImport;

            [FieldOffset(192)]
            public IMAGE_DATA_DIRECTORY IAT;

            [FieldOffset(200)]
            public IMAGE_DATA_DIRECTORY DelayImportDescriptor;

            [FieldOffset(208)]
            public IMAGE_DATA_DIRECTORY CLRRuntimeHeader;

            [FieldOffset(216)]
            public IMAGE_DATA_DIRECTORY Reserved;
        }
        #endregion
        #region IMAGE_EXPORT_DIRECTORY
        [StructLayout(LayoutKind.Sequential)]
        public struct IMAGE_EXPORT_DIRECTORY
        {
            public UInt32 Characteristics;
            public UInt32 TimeDateStamp;
            public UInt16 MajorVersion;
            public UInt16 MinorVersion;
            public UInt32 Name;
            public UInt32 Base;
            public UInt32 NumberOfFunctions;
            public UInt32 NumberOfNames;
            public UInt32 AddressOfFunctions;     // RVA from base of image
            public UInt32 AddressOfNames;     // RVA from base of image
            public UInt32 AddressOfNameOrdinals;  // RVA from base of image
        }
        #endregion
        #endregion
    }
}