#include "arch/kernel/main.hpp"

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

namespace teachos::arch::kernel
{
  auto print_mem_info(arch::memory::MemoryInfo * mem_info) -> void
  {
    using namespace video::vga;

    auto mem_lower = mem_info->mem_lower;
    text::write("Lower memory (kB): ", text::common_attributes::green_on_black);
    text::write_number(mem_lower, text::common_attributes::green_on_black);

    auto mem_upper = mem_info->mem_upper;
    text::write("Upper memory (kB): ", text::common_attributes::green_on_black);
    text::write_number(mem_upper, text::common_attributes::green_on_black);
  }

  auto print_memory_map(arch::memory::MemoryMap * mminfo) -> void
  {
    using namespace video::vga;

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

    uint32_t const entry_version = mminfo->entry_version;
    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(static_cast<std::underlying_type<arch::memory::MemoryAreaType>::type>(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(arch::memory::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 address: ", 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 offset: ", 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 size: ", 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 link: ", 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 info: ", 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 address align: ", 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 entry size: ", 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);

    arch::memory::MultibootInfo * multiboot_information_pointer =
        (arch::memory::MultibootInfo *)arch::boot::multiboot_information_pointer;
    auto multiboot_tag = &(multiboot_information_pointer->tags);

    text::write("Multiboot Start: ", text::common_attributes::green_on_black);
    text::write_number(arch::boot::multiboot_information_pointer, text::common_attributes::green_on_black);
    text::write("Multiboot End: ", text::common_attributes::green_on_black);
    text::write_number(arch::boot::multiboot_information_pointer + multiboot_information_pointer->total_size,
                       text::common_attributes::green_on_black);

    /*
     * Loop over the multiboot2 tags to access the information needed.
     * Tags are defined in the header file and are padded so that each
     * Tag starts at an 8-bytes aligned adress.
     *
     * The increment part aligns the size to an 8-byte address.
     */
    for (auto tag = multiboot_tag; tag->type != arch::memory::MultibootTagType::END;
         tag = (arch::memory::MultibootTag *)(((uint8_t *)tag) + ((tag->size + 7) & ~7)))
    {
      switch (tag->type)
      {
        case arch::memory::MultibootTagType::BASIC_MEMORY_INFO:
          print_mem_info((arch::memory::MemoryInfo *)tag);
          break;
        case arch::memory::MultibootTagType::ELF_SECTIONS:
          print_elf_sections((arch::memory::elf_symbols_section *)tag);
          break;
        case arch::memory::MultibootTagType::MEMORY_MAP:
          print_memory_map((arch::memory::MemoryMap *)tag);
          break;
        default:
          // All other cases are not important and can be ignored
          break;
      }
    }
  }
}  // namespace teachos::arch::kernel