#pragma once

#include "boottime_api/boottime_api.h"

#include <boost/asio/steady_timer.hpp>
#include <sdbusplus/asio/connection.hpp>
#include <sdbusplus/asio/object_server.hpp>
#include <sdbusplus/bus.hpp>
#include <sdbusplus/bus/match.hpp>

#include <functional>
#include <optional>
#include <vector>

namespace boot_time_monitor
{
/**
 * @brief Contains functionality related to interacting with systemd for boot
 * time information.
 */
namespace systemd
{

namespace btm = boot_time_monitor;

/**
 * @brief Handles monitoring of systemd boot timestamps for BMC nodes.
 *
 * This class periodically queries systemd's D-Bus interface
 * (`org.freedesktop.systemd1.Manager`) to retrieve various monotonic
 * timestamps related to the boot process (Firmware, Loader, Kernel, InitRD,
 * Userspace, Finish). It waits until the `FinishTimestampMonotonic` is
 * available, indicating the userspace boot is complete. Once available, it
 * calculates the duration of each stage and records these durations using the
 * provided `IApi` instance, specifically targeting nodes tagged with
 * `kBootTimeTagBMC`.
 */
class Handler
{
  public:
    /**
     * @brief Constructs the systemd Handler.
     *
     * Initializes the handler and starts a timer (`m_bmc_finish_timer`) to
     * periodically check for systemd boot completion.
     *
     * @param conn Shared pointer to the sdbusplus ASIO connection.
     * @param api Shared pointer to the central boot time monitoring API.
     */
    Handler(std::shared_ptr<sdbusplus::asio::connection> conn,
            std::shared_ptr<btm::api::IBoottimeApi> api,
            btm::NodeConfig bmcNode);

  private:
    /** @brief Interval for polling systemd properties until boot is finished.
     */
    const std::chrono::seconds kCheckBmcFinishInterval =
        std::chrono::seconds(10);
    /**
     * @brief Timer callback function to check systemd boot timestamps.
     *
     * Queries systemd D-Bus properties for boot timestamps. If the finish
     * timestamp is available, calculates stage durations and records them via
     * `mApi`. Otherwise, reschedules the timer.
     *
     * @param ec Boost error code from the timer operation.
     * @param conn Shared pointer to the sdbusplus ASIO connection.
     */
    void UpdateBmcCheckpoints(const boost::system::error_code& ec);

    /**
     * @brief Queries a specific timestamp property from systemd via D-Bus.
     *
     * @param[in] propertyName The name of the systemd property to query.
     *
     * @return A `std::optional<uint64_t>` containing the timestamp on success,
     * or an empty optional on failure.
     */
    std::optional<uint64_t>
        QuerySystemdTimestamp(std::string_view propertyName);

    /**
     * @brief Reschedules the timer to continue polling systemd.
     *
     * This helper function resets the polling timer to fire again after the
     * predefined interval, triggering another call to UpdateBmcCheckpoints.
     */
    void RestartPolling();

#ifdef NPCM7XX_OR_NEWER
    /**
     * The below 2 functions are to support the (Firmware + Loader) time
     * logging for NPCM7XX or newer Nuvoton BMCs.
     */

    /**
     * @brief Read 4 byte value from given memory address.
     *
     * @param target Memory address to read from.
     * @return The value from the memory address. Return nullopt if failed.
     */
    std::optional<uint32_t> readMem4Bytes(uint32_t target);
    /**
     * @brief Get system uptime from /proc/uptime.
     *
     * @return System uptime in milliseconds. Return nullopt if failed.
     */
    std::optional<int64_t> getUpTimeInMs();
#endif

    /** @brief Shared pointer to the central boot time monitoring API. */
    std::shared_ptr<btm::api::IBoottimeApi> mApi;
    /** @brief ASIO timer used to periodically check for systemd boot
     * completion. */
    boost::asio::steady_timer mBMCFinishTimer;
    /** @brief Shared pointer to the sdbusplus D-Bus connection. */
    std::shared_ptr<sdbusplus::asio::connection> mDbusConn;
    /** @brief Configuration for the node being monitored. */
    btm::NodeConfig mNode;
};
} // namespace systemd
} // namespace boot_time_monitor