#define NUNAVUT_ASSERT assert
#include "cyphal_hardware_interface/cyphal_system.hpp"

#include <chrono>
#include <cmath>
#include <cstddef>
#include <hardware_interface/hardware_info.hpp>
#include <limits>
#include <memory>
#include <set>
#include <sstream>
#include <string>
#include <vector>

#include <thread>

#include "socketcan.h"

// #include "serial.hpp"

#include "hardware_interface/types/hardware_interface_type_values.hpp"
#include "rclcpp/rclcpp.hpp"

// #include "cyphal.hpp"
#include <chrono>
#include <iostream>
#include <thread>
#include <cstdint>

#define NUNAVUT_ASSERT assert

extern "C" {
#include "canard.h"
#include <uavcan/_register/Access_1_0.h>
#include <uavcan/_register/List_1_0.h>
#include <uavcan/node/Heartbeat_1_0.h>
#include <uavcan/node/port/List_0_1.h>
}

namespace cyphal_hardware_interface {

uint64_t getMonotonicMicroseconds() {
  auto now = std::chrono::steady_clock::now();
  auto micros = std::chrono::duration_cast<std::chrono::microseconds>(
                    now.time_since_epoch())
                    .count();
  return static_cast<uint64_t>(micros);
}

cyphalSystemHardware::~cyphalSystemHardware() {
  if (can_socket >= 0) {
    RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"),
                "Closing socket of interface '%s'", can_if_.c_str());
    // close(serial_port_handle);
  }
}

void cyphalSystemHardware::send(
                 const CanardMicrosecond tx_deadline_usec,
                 const CanardTransferMetadata *const metadata,
                 const size_t payload_size,
                 const void *const payload_data,
                 const CanardMicrosecond now_usec)
{
        const struct CanardPayload payload = {.size = payload_size, .data = payload_data};
        (void)canardTxPush(&canard_tx_queues[0],
                           &canard,
                           tx_deadline_usec,
                           metadata,
                           payload,
                           now_usec, NULL);
    
}

void cyphalSystemHardware::read_list(
                 ) {
  uavcan_register_List_Request_1_0 msg = {0};
  msg.index = 0;
const CanardMicrosecond now_usec = getMonotonicMicroseconds();
  uint8_t serialized
      [uavcan_register_List_Request_1_0_SERIALIZATION_BUFFER_SIZE_BYTES_];
  size_t serialized_size = sizeof(serialized);
  const int8_t err = uavcan_register_List_Request_1_0_serialize_(
      &msg, &serialized[0], &serialized_size);
  assert(err >= 0);
  assert(err >= 0);
  if (err >= 0) {
    const CanardTransferMetadata transfer = {
        .priority = CanardPriorityNominal,
        .transfer_kind = CanardTransferKindRequest,
        .port_id = uavcan_register_List_1_0_FIXED_PORT_ID_,
        .remote_node_id = 125,
        .transfer_id =
            (CanardTransferID)(next_transfer_id++),
    };
    send(now_usec +
             1e9, // Set transmission deadline 1 second, optimal for heartbeat.
         &transfer, serialized_size, &serialized[0], now_usec);
  }
}

/**
 * @brief Static method to call read_thread via std::thread
 * @param context pointer to this
 */
void cyphalSystemHardware::read_thread_static(void *context) {
  static_cast<cyphalSystemHardware *>(context)->read_thread();
}

hardware_interface::CallbackReturn
cyphalSystemHardware::on_init(const hardware_interface::HardwareInfo &info) {
  if (hardware_interface::SystemInterface::on_init(info) !=
      hardware_interface::CallbackReturn::SUCCESS) {
    return hardware_interface::CallbackReturn::ERROR;
  }

  can_if_ = default_if_;

  if (info_.hardware_parameters.count("can_if") > 0) {
    can_if_ = info_.hardware_parameters.at("can_if");
  } else {
    RCLCPP_WARN(rclcpp::get_logger("cyphalSystemHardware"),
                "No can interface specified in urdf, using default value");
  }
  RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"), "If set as %s",
              can_if_.c_str());

  std::vector<hardware_interface::ComponentInfo> components;
  components.insert(components.begin(), info_.joints.begin(),
                    info_.joints.end());
  components.insert(components.begin(), info_.sensors.begin(),
                    info_.sensors.end());
  components.insert(components.begin(), info_.gpios.begin(), info_.gpios.end());

  for (const hardware_interface::ComponentInfo &joint : components) {
    for (const auto &i : joint.command_interfaces) {
      RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"), "%s: %s: %d",
                  joint.name.c_str(), i.name.c_str(), (int)i.parameters.size());
    }
    for (const auto &i : joint.state_interfaces) {
      RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"), "%s: %s: %d",
                  joint.name.c_str(), i.name.c_str(), (int)i.parameters.size());
    }
    // std::string param_name = "command:" + i.name;
    // if (joint.parameters.count(param_name) <= 0) {
    //   RCLCPP_FATAL(
    //       rclcpp::get_logger("cyphalSystemHardware"),
    //       "command interface '%s' of joint/gpio '%s' has no parameter "
    //       "'command:%s'.",
    //       i.name.c_str(), joint.name.c_str(), i.name.c_str());
    //   return hardware_interface::CallbackReturn::ERROR;
    // }
    // auto interface_name = joint.parameters.at(param_name);
    /*if (interfaces_map.count(interface_name) > 0) {
      RCLCPP_FATAL(rclcpp::get_logger("cyphalSystemHardware"),
                   "Sync Interface '%s' used twice. FATAL ERROR.",
                   interface_name.c_str());
      return hardware_interface::CallbackReturn::ERROR;
    }
    interfaces_map[interface_name] = {
        std::numeric_limits<double>::quiet_NaN(),
        (joint.parameters.count("factor") > 0)
            ? std::stod(joint.parameters.at("factor"))
            : 1.0,
        joint.name, true, i.name};*/
  }
  /*
  for (const auto &i : joint.state_interfaces) {
    std::string param_name = "state:" + i.name;
    if (joint.parameters.count(param_name) <= 0) {
      RCLCPP_FATAL(
          rclcpp::get_logger("cyphalSystemHardware"),
          "state interface '%s' of joint/sensor/gpio '%s' has no parameter "
          "'state:%s'.",
          i.name.c_str(), joint.name.c_str(), i.name.c_str());
      return hardware_interface::CallbackReturn::ERROR;
    }
    auto interface_name = joint.parameters.at(param_name);
    if (interfaces_map.count(interface_name) > 0) {
      RCLCPP_FATAL(rclcpp::get_logger("cyphalSystemHardware"),
                   "Sync Interface '%s' used twice. FATAL ERROR.",
                   interface_name.c_str());
      return hardware_interface::CallbackReturn::ERROR;
    }
    interfaces_map[interface_name] = {
        std::numeric_limits<double>::quiet_NaN(),
        (joint.parameters.count("factor") > 0)
            ? std::stod(joint.parameters.at("factor"))
            : 1.0,
        joint.name, false, i.name};
  }
}
// for (const auto &[key, value] : interfaces_map) {
// RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"),
//             "Interface %s added (factor: %f).", key.c_str(), value.factor);
// }*/

  canard_memory.deallocate = canardDeallocate;
  canard_memory.allocate = canardAllocate;

  // The libcanard instance requires the allocator for managing protocol states.
  canard = canardInit(canard_memory);

  //canard_tx_queues[0] = canardTxInit(100, CANARD_MTU_CAN_CLASSIC, canard_memory);
  canard.node_id = 100;

  static struct CanardRxSubscription rx;
  int8_t res = //
      canardRxSubscribe(&canard, CanardTransferKindMessage,
                        uavcan_node_Heartbeat_1_0_FIXED_PORT_ID_,
                        uavcan_node_Heartbeat_1_0_EXTENT_BYTES_,
                        CANARD_DEFAULT_TRANSFER_ID_TIMEOUT_USEC, &rx);
  if (res < 0) {
    return hardware_interface::CallbackReturn::ERROR;
  }

  //res = //
  //    canardRxSubscribe(&canard, CanardTransferKindResponse,
  //                      uavcan_register_List_1_0_FIXED_PORT_ID_,
  //                      uavcan_register_List_Request_1_0_EXTENT_BYTES_,
  //                      CANARD_DEFAULT_TRANSFER_ID_TIMEOUT_USEC, &rx);
  //if (res < 0) {
  //  return hardware_interface::CallbackReturn::ERROR;
  //}

  return hardware_interface::CallbackReturn::SUCCESS;
} // namespace cyphal_hardware_interface

hardware_interface::CallbackReturn cyphalSystemHardware::on_configure(
    const rclcpp_lifecycle::State & /*previous_state*/) {

  can_socket = socketcanOpen(can_if_.c_str(), 8); /* MTU == 8 -> classic CAN */
  if (can_socket < 0) {
    RCLCPP_FATAL(rclcpp::get_logger("cyphalSystemHardware"),
                 "Could not open socket for can interface '%s'",
                 can_if_.c_str());
    return hardware_interface::CallbackReturn::FAILURE;
  }

  RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"),
              "Opened socketcan socket for '%s'", can_if_.c_str());

  //read_list();
  read_thread_handle = std::thread([this]() { read_thread_static(this); });
  return hardware_interface::CallbackReturn::SUCCESS;
}

hardware_interface::CallbackReturn cyphalSystemHardware::on_activate(
    const rclcpp_lifecycle::State & /*previous_state*/) {
  // BEGIN: This part here is for exemplary purposes - Please do not copy to
  // your production code
  RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"), "Activating");

  RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"),
              "Successfully activated!");

  return hardware_interface::CallbackReturn::SUCCESS;
}

static void
processReceivedTransfer(const struct CanardRxTransfer *const transfer,
                        const CanardMicrosecond now_usec) {
  if (transfer->metadata.transfer_kind == CanardTransferKindResponse) {
    if (transfer->metadata.port_id == uavcan_register_List_1_0_FIXED_PORT_ID_) {

      uavcan_register_List_Response_1_0 resp = {0};
      size_t size = transfer->payload.size;

      if (uavcan_register_List_Response_1_0_deserialize_(
              &resp, (uint8_t *)transfer->payload.data, &size) >= 0) {
        RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"),
                    "uavcan_register_List_1_0_FIXED_PORT_ID_");
      }
    }
    RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"),
                "CanardTransferKindResponse %d",
                transfer->metadata.remote_node_id);
  } else if (transfer->metadata.transfer_kind == CanardTransferKindMessage) {
    if (transfer->metadata.port_id ==
        uavcan_node_Heartbeat_1_0_FIXED_PORT_ID_) {
      uavcan_node_Heartbeat_1_0 msg;
      size_t size = transfer->payload.size;
      if (uavcan_node_Heartbeat_1_0_deserialize_(
              &msg, (uint8_t *)transfer->payload.data, &size) >= 0) {

        RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"), "Heartbeat %d",
                    transfer->metadata.remote_node_id);
      }
    }
    RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"),
                "transfer->metadata.port_id == %d",
                (int)transfer->metadata.port_id);
    // if(transfer->metadata.port_id == 103)
    //  // Publish the servo status -- this is a low-rate message with
    //  low-severity diagnostics.
    //     reg_udral_service_actuator_common_Status_0_1 msg = {0};
    //     // TODO: POPULATE THE MESSAGE: temperature, errors, etc.
    //     msg.motor_temperature.kelvin = state->servo.motor_temperature;
    //     msg.controller_temperature.kelvin =
    //     state->servo.controller_temperature; uint8_t
    //     serialized[reg_udral_service_actuator_common_Status_0_1_SERIALIZATION_BUFFER_SIZE_BYTES_];
    //     size_t serialized_size = sizeof(serialized);
    //     const int8_t err =
    //         reg_udral_service_actuator_common_Status_0_1_serialize_(&msg,
    //         &serialized[0], &serialized_size);
    //     assert(err >= 0);
    //     if (err >= 0)
    //     {
    //         const CanardTransferMetadata transfer = {
    //             .priority = CanardPriorityNominal,
    //             .transfer_kind = CanardTransferKindMessage,
    //             .port_id = state->port_id.pub.servo_status,
    //             .remote_node_id = CANARD_NODE_ID_UNSET,
    //             .transfer_id = (CanardTransferID)servo_transfer_id,
    //         };
    //         send(state, now_usec + MEGA, &transfer, serialized_size,
    //         &serialized[0], now_usec);
    //     }
  }
}

void cyphalSystemHardware::write_can() {
  // Transmit pending frames from the prioritized TX queues managed by
  // libcanard.
  const CanardMicrosecond now_usec = getMonotonicMicroseconds();
  struct CanardTxQueue *const que = &canard_tx_queues[0];
  struct CanardTxQueueItem *tqi =
      canardTxPeek(que); // Find the highest-priority frame.
  while (tqi != NULL) {
    // Attempt transmission only if the frame is not yet timed out while waiting
    // in the TX queue. Otherwise just drop it and move on to the next one.
    if ((tqi->tx_deadline_usec == 0) || (tqi->tx_deadline_usec > now_usec)) {
      const struct CanardFrame canard_frame = {
          .extended_can_id = tqi->frame.extended_can_id,
          .payload = {.size = tqi->frame.payload.size,
                      .data = tqi->frame.payload.data}};
      // const int16_t result = socketcanPush(sock[ifidx], &canard_frame, 0); //
      // Non-blocking write attempt.
      const int16_t result = socketcanPush(can_socket,
          &canard_frame, 0); // Non-blocking write attempt.
                             // digitalWrite(38, 0); /*enable*/delay(1000);
                             // digitalWrite(38, 1); /*disable*/delay(1000);

      // const int16_t result = 0;
      if (result == 0) {
        break; // The queue is full, we will try again on the next iteration.
      }
      if (result < 0) {
        return; // SocketCAN interface failure (link down?)
        //return -result; // SocketCAN interface failure (link down?)
      }
    }

    struct CanardTxQueueItem *const mut_tqi = canardTxPop(que, tqi);
    canardTxFree(que, &canard, mut_tqi);

    tqi = canardTxPeek(que);
  }
}

void cyphalSystemHardware::read_thread() {
  while (true) {

    struct CanardFrame frame;
    CanardMicrosecond out_timestamp_usec;
    CanardMicrosecond timeout_usec = 0;
    bool loopback = false;

    uint8_t payload_buffer[CANARD_MTU_CAN_CLASSIC];
    int ret = socketcanPop(can_socket, &frame, &out_timestamp_usec,
                           sizeof(payload_buffer), payload_buffer, timeout_usec,
                           &loopback);

    if(loopback || ret == 0) {
      continue;
    }

    if (ret < 0) {
      RCLCPP_FATAL(rclcpp::get_logger("cyphalSystemHardware"),
                   "socketcanPop error (ret=%d)", ret);
      return;
    }
    // RCLCPP_INFO(
    //     rclcpp::get_logger("cyphalSystemHardware"),
    //     "ok %d %dms %d: %02X %02X %02X %02X %02X %02X %02X %02X", ret,
    //     (int)out_timestamp_usec / 1000, (int)frame.payload.size,
    //     frame.payload.size <= 0 ? 0 : (int)((uint8_t
    //     *)frame.payload.data)[0], frame.payload.size <= 1 ? 0 :
    //     (int)((uint8_t *)frame.payload.data)[1], frame.payload.size <= 2 ? 0
    //     : (int)((uint8_t *)frame.payload.data)[2], frame.payload.size <= 3 ?
    //     0 : (int)((uint8_t *)frame.payload.data)[3], frame.payload.size <= 4
    //     ? 0 : (int)((uint8_t *)frame.payload.data)[4], frame.payload.size <=
    //     5 ? 0 : (int)((uint8_t *)frame.payload.data)[5], frame.payload.size
    //     <= 6 ? 0 : (int)((uint8_t *)frame.payload.data)[6],
    //     frame.payload.size <= 7 ? 0 : (int)((uint8_t
    //     *)frame.payload.data)[7]);

    // The SocketCAN adapter uses the wall clock for timestamping, but we need
    // monotonic. Wall clock can only be used for time synchronization.
    const CanardMicrosecond timestamp_usec = getMonotonicMicroseconds();
    struct CanardRxTransfer transfer;
    memset(&transfer, 0, sizeof transfer);
    const int ifidx = 0; /* interface id */
    const int8_t canard_result = canardRxAccept(&canard, out_timestamp_usec,
                                                &frame, ifidx, &transfer, NULL);
    if (canard_result > 0) {
      processReceivedTransfer(&transfer, timestamp_usec);
      canard.memory.deallocate(canard.memory.user_reference,
                               transfer.payload.allocated_size,
                               transfer.payload.data);
    } else if (canard_result == -CANARD_ERROR_OUT_OF_MEMORY) {
      (void)0; // The frame did not complete a transfer so there is nothing to
               // do.
      // OOM should never occur if the heap is sized correctly. You can track
      // OOM errors via heap API.
      RCLCPP_FATAL(rclcpp::get_logger("cyphalSystemHardware"), "OOM!");
      return;
    } else if (canard_result == 0) {
      (void)0; // The frame did not complete a transfer so there is nothing to
               // do.
      using namespace std::chrono_literals;
      std::this_thread::sleep_for(10us);
      continue;
    } else {
      assert(false); // No other error can possibly occur at runtime.
      // return hardware_interface::return_type::ERROR;
      return;
    }
  }
}

hardware_interface::CallbackReturn cyphalSystemHardware::on_deactivate(
    const rclcpp_lifecycle::State & /*previous_state*/) {
  // BEGIN: This part here is for exemplary purposes - Please do not copy to
  // your production code
  RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"), "Deactivating");

  /*  for (auto i = 0; i < hw_stop_sec_; i++) {
      rclcpp::sleep_for(std::chrono::seconds(1));
      RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"),
                  "%.1f seconds left...", hw_stop_sec_ - i);
    }
    // END: This part here is for exemplary purposes - Please do not copy to
    your
    // production code

    RCLCPP_INFO(rclcpp::get_logger("cyphalSystemHardware"),
                "Successfully deactivated!");
  */
  return hardware_interface::CallbackReturn::SUCCESS;
}
hardware_interface::return_type
cyphalSystemHardware::read(const rclcpp::Time & /*time*/,
                           const rclcpp::Duration & /*period*/) {

  // if (!sync)
  //   return hardware_interface::return_type::ERROR;

  return hardware_interface::return_type::OK;
}

hardware_interface::return_type
cyphal_hardware_interface ::cyphalSystemHardware::write(
    const rclcpp::Time & /*time*/, const rclcpp::Duration & /*period*/) {

  return hardware_interface::return_type::OK;
}

} // namespace cyphal_hardware_interface

#include "pluginlib/class_list_macros.hpp"
PLUGINLIB_EXPORT_CLASS(cyphal_hardware_interface::cyphalSystemHardware,
                       hardware_interface::SystemInterface)