#include <kernel/devices/storage/management.hpp>

#include <kernel/devices/storage/controller.hpp>
#include <kernel/devices/storage/ram_disk/controller.hpp>

#include <kapi/boot_modules.hpp>
#include <kapi/devices/device.hpp>
#include <kapi/system.hpp>

#include <kstd/memory>
#include <kstd/vector>

#include <algorithm>
#include <cstddef>
#include <optional>
#include <ranges>

namespace
{
  constexpr size_t static minors_per_device = 16;
  constexpr size_t static start_major = 1;
  constinit size_t static next_free_major = start_major;

  constinit auto static storage_management = std::optional<kernel::devices::storage::management>{};
}  // namespace

namespace kernel::devices::storage
{
  auto management::init() -> void
  {
    if (storage_management)
    {
      kapi::system::panic("[DEVICES] Storage management has already been initialized.");
    }
    storage_management.emplace(management{});

    auto ram_disk_controller = kstd::make_shared<ram_disk::controller>(&kapi::boot_modules::get_boot_module_registry());
    storage_management->add_controller(ram_disk_controller);

    std::ranges::for_each(storage_management->m_controllers, [](auto controller) { controller->probe(); });
  }

  auto management::get() -> management &
  {
    if (!storage_management)
    {
      kapi::system::panic("[DEVICES] Storage management has not been initialized.");
    }

    return *storage_management;
  }

  auto management::add_controller(kstd::shared_ptr<controller> const & controller) -> void
  {
    controller->set_ids(next_free_major++, minors_per_device);
    m_controllers.push_back(controller);
  }

  auto management::all_controllers() const -> kstd::vector<kstd::shared_ptr<controller>> const &
  {
    return m_controllers;
  }

  auto management::device_by_major_minor(size_t major, size_t minor) -> kstd::shared_ptr<kapi::devices::device>
  {
    auto found = std::ranges::find_if(m_controllers, [=](auto const & controller) {
      if (controller != nullptr && controller->major() == major)
      {
        return controller->device_by_minor(minor) != nullptr;
      }
      return false;
    });

    if (found != std::ranges::cend(m_controllers))
    {
      return found->get()->device_by_minor(minor);
    }

    return nullptr;
  }

  auto management::determine_boot_device() -> kstd::shared_ptr<kapi::devices::device>
  {
    return device_by_major_minor(start_major, 0);
  }
}  // namespace kernel::devices::storage

namespace kernel::tests::devices::storage::management
{
  auto deinit() -> void
  {
    storage_management.reset();
    next_free_major = start_major;
  }
}  // namespace kernel::tests::devices::storage::management