#include "devices/storage/RAMDisk/RAMDiskDevice.hpp"

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

#include "devices/BlockDevice.hpp"

#include <kstd/cstring>

#include <cstddef>

namespace devices::storage::ram_disk
{
  namespace
  {
    constexpr size_t RAM_DISK_BLOCK_SIZE = 512uz;  // TODO BA-FS26 really correct / good??
  }  // namespace

  ram_disk_device::ram_disk_device()  // TODO BA-FS26 remove when kstd::vector is available
      : block_device(0, 0, RAM_DISK_BLOCK_SIZE)
  {}

  ram_disk_device::ram_disk_device(kapi::boot_modules::boot_module const & module, size_t major, size_t minor)
      : block_device(major, minor, RAM_DISK_BLOCK_SIZE)
      , m_boot_module(module)
  {}

  auto ram_disk_device::read_block(size_t block_index, void * buffer) const -> void
  {
    if (buffer == nullptr)
    {
      kapi::system::panic("[RAM DISK DEVICE] read_block called with null buffer.");
    }

    auto const info = calculate_transfer(block_index);

    if (info.to_transfer > 0)
    {
      auto const src = static_cast<std::byte const *>(m_boot_module.start_address) + info.offset;
      kstd::libc::memcpy(buffer, src, info.to_transfer);
    }

    if (info.remainder > 0)
    {
      kstd::libc::memset(static_cast<std::byte *>(buffer) + info.to_transfer, 0, info.remainder);
    }
  }

  auto ram_disk_device::write_block(size_t block_index, void const * buffer) -> void
  {
    if (buffer == nullptr)
    {
      kapi::system::panic("[RAM DISK DEVICE] write_block called with null buffer.");
    }

    auto const info = calculate_transfer(block_index);

    if (info.to_transfer > 0)
    {
      auto const dest = static_cast<std::byte *>(m_boot_module.start_address) + info.offset;
      kstd::libc::memcpy(dest, buffer, info.to_transfer);
    }
  }

  auto ram_disk_device::size() const -> size_t
  {
    return m_boot_module.size;
  }
}  // namespace devices::storage::ram_disk