#ifndef THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_COLLECTOR_GPIO_COLLECTOR_H_
#define THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_COLLECTOR_GPIO_COLLECTOR_H_

#include <memory>
#include <string>
#include <utility>
#include <vector>

#include "absl/container/flat_hash_map.h"
#include "absl/status/status.h"
#include "absl/status/statusor.h"
#include "absl/strings/string_view.h"
#include "thread/thread.h"
#include "time/clock.h"
#include "nlohmann/json.hpp"
#include "tlbmc/collector/collector.h"
#include "gpio_config.pb.h"
#include "tlbmc/hal/gpio/gpio.h"
#include "tlbmc/hal/gpio/gpio_monitor.h"
#include "tlbmc/scheduler/scheduler.h"

namespace milotic_tlbmc {

struct GpioThreadManager {
  explicit GpioThreadManager(ecclesia::Clock* clock)
      : task_scheduler(std::make_unique<TaskScheduler>(clock)) {}

  ~GpioThreadManager();

  std::vector<std::unique_ptr<ecclesia::ThreadInterface>> threads;
  std::vector<std::shared_ptr<boost::asio::io_context>> io_contexts;
  std::vector<
      boost::asio::executor_work_guard<boost::asio::io_context::executor_type>>
      work_guards;
  std::unique_ptr<TaskScheduler> task_scheduler;
};

class GpioCollector : public Collector {
 public:
  // Parameters for creating a GPIO collector.
  struct Params {
    // Using a thread factory to allow us to switch to fibers in future when it
    // gets open sourced.
    ecclesia::ThreadFactoryInterface* thread_factory =
        ecclesia::GetDefaultThreadFactory();
    ecclesia::Clock* clock = ecclesia::Clock::RealClock();
    GpioConfigs gpio_configs;
  };

  static absl::StatusOr<std::unique_ptr<GpioCollector>> Create(
      const Params& params);

  nlohmann::json ToJson() const override;

  nlohmann::json GetSchedulerStats() const override {
    return thread_manager_->task_scheduler->ToJson();
  }

  absl::Status SetGpio(absl::string_view gpio_name, bool value);

 protected:
  // Protected constructor to allow mocking.
  GpioCollector() = default;

 private:
  GpioCollector(
      std::unique_ptr<GpioThreadManager>&& thread_manager,
      absl::flat_hash_map<std::string, std::unique_ptr<Gpio>>&& input_gpios,
      absl::flat_hash_map<std::string, std::unique_ptr<Gpio>>&& output_gpios,
      absl::flat_hash_map<std::string, std::unique_ptr<GpioMonitor>>&&
          gpio_monitors)
      : thread_manager_(std::move(thread_manager)),
        input_gpios_(std::move(input_gpios)),
        output_gpios_(std::move(output_gpios)),
        gpio_monitors_(std::move(gpio_monitors)) {}

  std::unique_ptr<GpioThreadManager> thread_manager_;
  absl::flat_hash_map<std::string, std::unique_ptr<Gpio>> input_gpios_;
  absl::flat_hash_map<std::string, std::unique_ptr<Gpio>> output_gpios_;
  absl::flat_hash_map<std::string, std::unique_ptr<GpioMonitor>> gpio_monitors_;
};

class EmptyGpioCollector final : public GpioCollector {
 public:
  static std::unique_ptr<EmptyGpioCollector> Create();

  nlohmann::json GetSchedulerStats() const override;

  nlohmann::json ToJson() const override;
};

}  // namespace milotic_tlbmc

#endif  // THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_COLLECTOR_GPIO_COLLECTOR_H_