#pragma once
#include <luna/LinkedList.h>
#include <luna/TarStream.h>
#include <luna/Types.h>

#define ELFMAG "\177ELF"
#define SELFMAG 4
#define EI_CLASS 4    /* File class byte index */
#define ELFCLASS64 2  /* 64-bit objects */
#define EI_DATA 5     /* Data encoding byte index */
#define ELFDATA2LSB 1 /* 2's complement, little endian */
#define ET_EXEC 2     /* Executable file */
#define PT_LOAD 1     /* Loadable program segment */
#ifdef ARCH_X86_64
#define EM_MACH 62 /* AMD x86-64 architecture */
#else
#error "Unknown architecture."
#endif

typedef struct
{
    u8 e_ident[16];  /* Magic number and other info */
    u16 e_type;      /* Object file type */
    u16 e_machine;   /* Architecture */
    u32 e_version;   /* Object file version */
    u64 e_entry;     /* Entry point virtual address */
    u64 e_phoff;     /* Program header table file offset */
    u64 e_shoff;     /* Section header table file offset */
    u32 e_flags;     /* Processor-specific flags */
    u16 e_ehsize;    /* ELF header size in bytes */
    u16 e_phentsize; /* Program header table entry size */
    u16 e_phnum;     /* Program header table entry count */
    u16 e_shentsize; /* Section header table entry size */
    u16 e_shnum;     /* Section header table entry count */
    u16 e_shstrndx;  /* Section header string table index */
} Elf64_Ehdr;

typedef struct
{
    u32 p_type;   /* Segment type */
    u32 p_flags;  /* Segment flags */
    u64 p_offset; /* Segment file offset */
    u64 p_vaddr;  /* Segment virtual address */
    u64 p_paddr;  /* Segment physical address */
    u64 p_filesz; /* Segment size in file */
    u64 p_memsz;  /* Segment size in memory */
    u64 p_align;  /* Segment alignment */
} Elf64_Phdr;

struct ELFData
{
    u64 entry;
};

namespace ELFLoader
{
    Result<ELFData> load(const TarStream::Entry& elf_entry, const TarStream& stream);
};