#include "x86_64/memory/scoped_mapping.hpp"

#include "kapi/memory.hpp"
#include "kapi/system.hpp"

#include "x86_64/memory/mmu.hpp"
#include "x86_64/memory/page_table.hpp"
#include "x86_64/memory/paging_root.hpp"

#include <cstddef>
#include <utility>

namespace teachos::memory::x86_64
{

  scoped_mapping::scoped_mapping(scoped_mapping && other) noexcept
      : m_page{std::exchange(other.m_page, page{})}
      , m_mapper{std::exchange(other.m_mapper, nullptr)}
      , m_mapped{std::exchange(other.m_mapped, false)}
  {}

  scoped_mapping::scoped_mapping(page page, page_mapper & mapper)
      : m_page{page}
      , m_mapper{&mapper}
      , m_mapped{false}
  {
    if (paging_root::get()->translate(page))
    {
      system::panic("[MEM] Tried to map a page that is already mapped!");
    }
  }

  scoped_mapping::~scoped_mapping() noexcept
  {
    if (m_mapped)
    {
      unmap();
      x86_64::tlb_flush(m_page.start_address());
    }
  }

  auto scoped_mapping::operator=(scoped_mapping && other) noexcept -> scoped_mapping &
  {
    swap(*this, other);
    return *this;
  }

  auto scoped_mapping::map(frame frame, page_table::entry::flags flags) -> std::byte *
  {
    auto result = m_mapper->map(m_page, frame, to_mapper_flags(flags));
    m_mapped = true;
    return result;
  }

  auto scoped_mapping::unmap() -> void
  {
    m_mapper->unmap(m_page);
    m_mapped = false;
  }

  auto swap(scoped_mapping & lhs, scoped_mapping & rhs) -> void
  {
    using std::swap;
    swap(lhs.m_page, rhs.m_page);
    swap(lhs.m_mapper, rhs.m_mapper);
    swap(lhs.m_mapped, rhs.m_mapped);
  }

}  // namespace teachos::memory::x86_64