#include "kapi/interrupts.hpp"

#include <kstd/flat_map>
#include <kstd/print>
#include <kstd/vector>

#include <algorithm>
#include <cstdint>

namespace kapi::interrupts
{

  namespace
  {
    auto constinit handlers = kstd::flat_map<std::uint32_t, kstd::vector<handler *>>{};
  }  // namespace

  auto register_handler(std::uint32_t irq_number, handler & handler) -> void
  {
    if (handlers.contains(irq_number))
    {
      auto & handler_list = handlers.at(irq_number);
      handler_list.push_back(&handler);
    }
    else
    {
      handlers.emplace(irq_number, kstd::vector{&handler});
    }
  }

  auto unregister_handler(std::uint32_t irq_number, handler & handler) -> void
  {
    auto & handler_list = handlers.at(irq_number);
    auto [first, last] = std::ranges::remove(handler_list, &handler);
    handler_list.erase(first, last);
  }

  auto dispatch(std::uint32_t irq_number) -> status
  {
    if (!handlers.contains(irq_number))
    {
      kstd::println(kstd::print_sink::stderr, "[OS:interrupts] No handler for IRQ{}", irq_number);
      return status::unhandled;
    }

    auto & handler_list = handlers.at(irq_number);

    if (handler_list.empty())
    {
      kstd::println(kstd::print_sink::stderr, "[OS:interrupts] No handler for IRQ{}", irq_number);
      return status::unhandled;
    }

    for (auto handler : handler_list)
    {
      if (handler && handler->handle_interrupt(irq_number) == status::handled)
      {
        return status::handled;
      }
    }

    return status::unhandled;
  }

}  // namespace kapi::interrupts