#include "arch/kernel/main.hpp"

#include "arch/boot/multiboot.hpp"
#include "arch/boot/pointers.hpp"
#include "arch/video/vga/text.hpp"

namespace teachos::arch::kernel
{
  auto print_memory_map(memory_map_info * mminfo) -> void
  {
    using namespace video::vga;

    uint32_t const entry_size = mminfo->entry_size;
    uint32_t const entry_version = mminfo->entry_version;
    text::write("Entry Size: ", text::common_attributes::green_on_black);
    text::write_number(entry_size, text::common_attributes::green_on_black);
    text::write("Version: ", text::common_attributes::green_on_black);
    text::write_number(entry_version, text::common_attributes::green_on_black);

    uint32_t const remaining_size = mminfo->tag.size - (4 * sizeof(uint32_t));
    uint32_t const entry_amount = remaining_size / entry_size;

    auto begin = &mminfo->entries;
    auto end = begin + entry_amount;
    for (auto entry = begin; entry != end; ++entry)
    {
      text::write("Base Address: ", text::common_attributes::green_on_black);
      text::write_number(entry->base_addr, text::common_attributes::green_on_black);
      text::write("Length: ", text::common_attributes::green_on_black);
      text::write_number(entry->length, text::common_attributes::green_on_black);
      text::write("Type: ", text::common_attributes::green_on_black);
      text::write_number(entry->type, text::common_attributes::green_on_black);
      text::write("Reserved: ", text::common_attributes::green_on_black);
      text::write_number(entry->reserved, text::common_attributes::green_on_black);
    }
  }

  auto print_elf_sections(elf_symbols_section * symbol) -> void
  {
    using namespace video::vga;

    uint16_t const num = symbol->num;
    text::write("Number of entries: ", text::common_attributes::green_on_black);
    text::write_number(num, text::common_attributes::green_on_black);
    uint16_t const entsize = symbol->entsize;
    text::write("Entry Size: ", text::common_attributes::green_on_black);
    text::write_number(entsize, text::common_attributes::green_on_black);
    uint16_t const shndx = symbol->shndx;
    text::write("Section index: ", text::common_attributes::green_on_black);
    text::write_number(shndx, text::common_attributes::green_on_black);

    auto begin = &symbol->sections;
    auto end = begin + num;
    for (auto section = begin; section != end; ++section)
    {
      uint32_t const sh_name = section->sh_name;
      text::write("Section name: ", text::common_attributes::green_on_black);
      text::write_number(sh_name, text::common_attributes::green_on_black);
      uint32_t const sh_type = section->sh_type;
      text::write("Section type: ", text::common_attributes::green_on_black);
      text::write_number(sh_type, text::common_attributes::green_on_black);
      uint64_t const sh_flags = section->sh_flags;
      text::write("Section flags: ", text::common_attributes::green_on_black);
      text::write_number(sh_flags, text::common_attributes::green_on_black);
      uint64_t const sh_addr = section->sh_addr;
      text::write("Section name: ", text::common_attributes::green_on_black);
      text::write_number(sh_addr, text::common_attributes::green_on_black);
      uint64_t const sh_offset = section->sh_offset;
      text::write("Section name: ", text::common_attributes::green_on_black);
      text::write_number(sh_offset, text::common_attributes::green_on_black);
      uint64_t const sh_size = section->sh_size;
      text::write("Section name: ", text::common_attributes::green_on_black);
      text::write_number(sh_size, text::common_attributes::green_on_black);
      uint32_t const sh_link = section->sh_link;
      text::write("Section name: ", text::common_attributes::green_on_black);
      text::write_number(sh_link, text::common_attributes::green_on_black);
      uint32_t const sh_info = section->sh_info;
      text::write("Section name: ", text::common_attributes::green_on_black);
      text::write_number(sh_info, text::common_attributes::green_on_black);
      uint64_t const sh_addralign = section->sh_addralign;
      text::write("Section name: ", text::common_attributes::green_on_black);
      text::write_number(sh_addralign, text::common_attributes::green_on_black);
      uint64_t const sh_entsize = section->sh_entsize;
      text::write("Section name: ", text::common_attributes::green_on_black);
      text::write_number(sh_entsize, text::common_attributes::green_on_black);
    }
  }

  auto main() -> void
  {
    using namespace video::vga;

    text::clear();
    text::cursor(false);
    text::write("TeachOS is starting up...", text::common_attributes::green_on_black);

    auto mip = arch::boot::multiboot_information_pointer;

    // Address of the first multiboot tag
    auto multiboot_tag = (struct multiboot_tag *)((uint8_t *)mip + 8);

    /*
     * Loop over the multiboot2 tags to access the information needed.
     * Tags are defined in the header.
     */
    for (auto tag = multiboot_tag; tag->type != MULTIBOOT_TAG_TYPE_END;
         tag = (struct multiboot_tag *)((uint8_t *)tag + ((tag->size + 7) & ~7)))
    {
      switch (tag->type)
      {
        case MULTIBOOT_TAG_TYPE_ELF_SECTIONS:
          print_elf_sections((struct elf_symbols_section *)tag);
          break;
        case MULTIBOOT_TAG_TYPE_MMAP:
          print_memory_map((struct memory_map_info *)tag);
          break;
      }
    }
  }
}  // namespace teachos::arch::kernel