using System.Runtime.InteropServices;

namespace SabreTools.Data.Models.COFF
{
    /// <summary>
    /// At the beginning of an object file, or immediately after the signature
    /// of an image file, is a standard COFF file header in the following format.
    /// Note that the Windows loader limits the number of sections to 96.
    /// </summary>
    /// <see href="https://learn.microsoft.com/en-us/windows/win32/debug/pe-format"/>
    [StructLayout(LayoutKind.Sequential)]
    public sealed class FileHeader
    {
        /// <summary>
        /// The number that identifies the type of target machine.
        /// </summary>
        [MarshalAs(UnmanagedType.U2)]
        public MachineType Machine;

        /// <summary>
        /// The number of sections. This indicates the size of the section table,
        /// which immediately follows the headers.
        /// </summary>
        public ushort NumberOfSections;

        /// <summary>
        /// The low 32 bits of the number of seconds since 00:00 January 1, 1970
        /// (a C run-time time_t value), which indicates when the file was created.
        /// </summary>
        public uint TimeDateStamp;

        /// <summary>
        /// The file offset of the COFF symbol table, or zero if no COFF symbol table
        /// is present. This value should be zero for an image because COFF debugging
        /// information is deprecated.
        /// </summary>
        public uint PointerToSymbolTable;

        /// <summary>
        /// The number of entries in the symbol table. This data can be used to locate
        /// the string table, which immediately follows the symbol table. This value
        /// should be zero for an image because COFF debugging information is deprecated.
        /// </summary>
        public uint NumberOfSymbols;

        /// <summary>
        /// The size of the optional header, which is required for executable files but
        /// not for object files. This value should be zero for an object file.
        /// </summary>
        public ushort SizeOfOptionalHeader;

        /// <summary>
        /// The flags that indicate the attributes of the file.
        /// </summary>
        [MarshalAs(UnmanagedType.U2)]
        public Characteristics Characteristics;
    }
}
