#include <kapi/devices/power.hpp>

#include <kapi/devices.hpp>

#include <kstd/memory.hpp>
#include <kstd/print.hpp>
#include <kstd/result.hpp>
#include <kstd/vector.hpp>

#include <ranges>

namespace kapi::devices
{

  namespace
  {
    auto resume_subtree(device & node) -> void;

    // NOLINTNEXTLINE(misc-no-recursion)
    auto suspend_subtree(device & node) -> kstd::result<void>
    {
      auto suspended_children = kstd::vector<kstd::shared_ptr<device>>{};

      if (auto as_bus = node.facet<bus>())
      {
        for (auto const & child : as_bus->children())
        {
          auto result = suspend_subtree(*child);
          if (!result)
          {
            for (auto const & already_suspended : std::views::reverse(suspended_children))
            {
              resume_subtree(*already_suspended);
            }

            return result;
          }

          suspended_children.push_back(child);
        }
      }

      if (auto driver = node.bound_driver())
      {
        auto result = driver->suspend(node);
        if (!result)
        {
          for (auto const & already_suspended : std::views::reverse(suspended_children))
          {
            resume_subtree(*already_suspended);
          }

          return result;
        }
      }

      return kstd::success();
    }

    // NOLINTNEXTLINE(misc-no-recursion)
    auto resume_subtree(device & node) -> void
    {
      if (auto driver = node.bound_driver())
      {
        auto result = driver->resume(node);
        if (!result)
        {
          kstd::println(kstd::print_sink::stderr, "[OS:PM] failed to resume device '{}': {}", node.name(),
                        result.error().message());
        }
      }

      if (auto as_bus = node.facet<bus>())
      {
        for (auto const & child : as_bus->children())
        {
          resume_subtree(*child);
        }
      }
    }
  }  // namespace

  auto suspend_tree(bus & root) -> kstd::result<void>
  {
    return suspend_subtree(root);
  }

  auto resume_tree(bus & root) -> void
  {
    resume_subtree(root);
  }

}  // namespace kapi::devices