#include <Components/Ble/BleController.h>
#include <SystemTask/SystemTask.h>
#include <cstring>
#include "DfuService.h"

using namespace Pinetime::Controllers;

constexpr ble_uuid128_t DfuService::serviceUuid;
constexpr ble_uuid128_t DfuService::controlPointCharacteristicUuid;
constexpr ble_uuid128_t DfuService::revisionCharacteristicUuid;
constexpr ble_uuid128_t DfuService::packetCharacteristicUuid;

int DfuServiceCallback(uint16_t conn_handle, uint16_t attr_handle,
                       struct ble_gatt_access_ctxt *ctxt, void *arg) {
  auto dfuService = static_cast<DfuService *>(arg);
  return dfuService->OnServiceData(conn_handle, attr_handle, ctxt);
}

void NotificationTimerCallback( TimerHandle_t xTimer ) {
  auto dfuService = static_cast<DfuService *>(pvTimerGetTimerID( xTimer ));
  dfuService->OnNotificationTimer();
}

DfuService::DfuService(Pinetime::System::SystemTask &systemTask, Pinetime::Controllers::Ble &bleController,
                       Pinetime::Drivers::SpiNorFlash &spiNorFlash) :
        systemTask{systemTask},
        bleController{bleController},
        spiNorFlash{spiNorFlash},
        characteristicDefinition{
                {
                        .uuid = (ble_uuid_t *) &packetCharacteristicUuid,
                        .access_cb = DfuServiceCallback,
                        .arg = this,
                        .flags = BLE_GATT_CHR_F_WRITE_NO_RSP,
                        .val_handle = nullptr,
                },
                {
                        .uuid = (ble_uuid_t *) &controlPointCharacteristicUuid,
                        .access_cb = DfuServiceCallback,
                        .arg = this,
                        .flags = BLE_GATT_CHR_F_WRITE | BLE_GATT_CHR_F_NOTIFY,
                        .val_handle = nullptr,
                },
                {
                        .uuid = (ble_uuid_t *) &revisionCharacteristicUuid,
                        .access_cb = DfuServiceCallback,
                        .arg = this,
                        .flags = BLE_GATT_CHR_F_READ,
                        .val_handle = &revision,

                },
                {
                        0
                }

        },
        serviceDefinition{
                {
                        /* Device Information Service */
                        .type = BLE_GATT_SVC_TYPE_PRIMARY,
                        .uuid = (ble_uuid_t *) &serviceUuid,
                        .characteristics = characteristicDefinition
                },
                {
                        0
                },
        } {
  notificationTimer = xTimerCreate ("notificationTimer", 1000, pdFALSE, this, NotificationTimerCallback);
}

void DfuService::Init() {
  ble_gatts_count_cfg(serviceDefinition);
  ble_gatts_add_svcs(serviceDefinition);
}

int DfuService::OnServiceData(uint16_t connectionHandle, uint16_t attributeHandle, ble_gatt_access_ctxt *context) {

  ble_gatts_find_chr((ble_uuid_t *) &serviceUuid, (ble_uuid_t *) &packetCharacteristicUuid, nullptr,
                     &packetCharacteristicHandle);
  ble_gatts_find_chr((ble_uuid_t *) &serviceUuid, (ble_uuid_t *) &controlPointCharacteristicUuid, nullptr,
                     &controlPointCharacteristicHandle);
  ble_gatts_find_chr((ble_uuid_t *) &serviceUuid, (ble_uuid_t *) &revisionCharacteristicUuid, nullptr,
                     &revisionCharacteristicHandle);

  if (attributeHandle == packetCharacteristicHandle) {
    if (context->op == BLE_GATT_ACCESS_OP_WRITE_CHR)
      return WritePacketHandler(connectionHandle, context->om);
    else return 0;
  } else if (attributeHandle == controlPointCharacteristicHandle) {
    if (context->op == BLE_GATT_ACCESS_OP_WRITE_CHR)
      return ControlPointHandler(connectionHandle, context->om);
    else return 0;
  } else if (attributeHandle == revisionCharacteristicHandle) {
    if (context->op == BLE_GATT_ACCESS_OP_READ_CHR)
      return SendDfuRevision(context->om);
    else return 0;
  } else {
    NRF_LOG_INFO("[DFU] Unknown Characteristic : %d", attributeHandle);
    return 0;
  }
}

int DfuService::SendDfuRevision(os_mbuf *om) const {
  int res = os_mbuf_append(om, &revision, sizeof(revision));
  return (res == 0) ? 0 : BLE_ATT_ERR_INSUFFICIENT_RES;
}

int DfuService::WritePacketHandler(uint16_t connectionHandle, os_mbuf *om) {
  switch (state) {
    case States::Start: {
      softdeviceSize = om->om_data[0] + (om->om_data[1] << 8) + (om->om_data[2] << 16) + (om->om_data[3] << 24);
      bootloaderSize = om->om_data[4] + (om->om_data[5] << 8) + (om->om_data[6] << 16) + (om->om_data[7] << 24);
      applicationSize = om->om_data[8] + (om->om_data[9] << 8) + (om->om_data[10] << 16) + (om->om_data[11] << 24);
      bleController.FirmwareUpdateTotalBytes(applicationSize);
      NRF_LOG_INFO("[DFU] -> Start data received : SD size : %d, BT size : %d, app size : %d", softdeviceSize,
                   bootloaderSize, applicationSize);

      for (int erased = 0; erased < maxImageSize; erased += 0x1000) {
#if 1
        spiNorFlash.SectorErase(writeOffset + erased);
#endif
      }

      uint8_t data[]{16, 1, 1};
      SendNotification(connectionHandle, data, 3);
      state = States::Init;
    }
      return 0;
    case States::Init: {
      uint16_t deviceType = om->om_data[0] + (om->om_data[1] << 8);
      uint16_t deviceRevision = om->om_data[2] + (om->om_data[3] << 8);
      uint32_t applicationVersion =
              om->om_data[4] + (om->om_data[5] << 8) + (om->om_data[6] << 16) + (om->om_data[7] << 24);
      uint16_t softdeviceArrayLength = om->om_data[8] + (om->om_data[9] << 8);
      uint16_t sd[softdeviceArrayLength];
      for (int i = 0; i < softdeviceArrayLength; i++) {
        sd[i] = om->om_data[10 + (i * 2)] + (om->om_data[10 + (i * 2) + 1] << 8);
      }
      expectedCrc =
              om->om_data[10 + (softdeviceArrayLength * 2)] + (om->om_data[10 + (softdeviceArrayLength * 2) + 1] << 8);

      NRF_LOG_INFO(
              "[DFU] -> Init data received : deviceType = %d, deviceRevision = %d, applicationVersion = %d, nb SD = %d, First SD = %d, CRC = %u",
              deviceType, deviceRevision, applicationVersion, softdeviceArrayLength, sd[0], expectedCrc);

      return 0;
    }

    case States::Data: {
      nbPacketReceived++;
      auto offset = ((nbPacketReceived - 1) % nbPacketsToNotify) * 20;
      std::memcpy(tempBuffer + offset, om->om_data, om->om_len);
      if (firstCrc) {
        tempCrc = ComputeCrc(om->om_data, om->om_len, NULL);
        firstCrc = false;
      } else
        tempCrc = ComputeCrc(om->om_data, om->om_len, &tempCrc);

      if (nbPacketReceived > 0 && (nbPacketReceived % nbPacketsToNotify) == 0) {
#if 1
        spiNorFlash.Write(writeOffset + ((nbPacketReceived - nbPacketsToNotify) * 20), tempBuffer, 200);
#endif
      }


      bytesReceived += om->om_len;
      bleController.FirmwareUpdateCurrentBytes(bytesReceived);
      //NRF_LOG_INFO("[DFU] -> Bytes received : %d in %d packets", bytesReceived, nbPacketReceived);



      if ((nbPacketReceived % nbPacketsToNotify) == 0 && bytesReceived != applicationSize) {
        uint8_t data[5]{static_cast<uint8_t>(Opcodes::PacketReceiptNotification),
                        (uint8_t) (bytesReceived & 0x000000FFu), (uint8_t) (bytesReceived >> 8u),
                        (uint8_t) (bytesReceived >> 16u), (uint8_t) (bytesReceived >> 24u)};
        NRF_LOG_INFO("[DFU] -> Send packet notification: %d bytes received", bytesReceived);
        SendNotification(connectionHandle, data, 5);
      }
      if (bytesReceived == applicationSize) {
        if ((nbPacketReceived % nbPacketsToNotify) != 0) {
          auto remaningPacket = nbPacketReceived % nbPacketsToNotify;
          uint32_t spiOffset = writeOffset + ((nbPacketReceived - remaningPacket) * 20);

          spiNorFlash.Write(writeOffset + ((nbPacketReceived - remaningPacket) * 20), tempBuffer, remaningPacket * 20);
        }

        if (applicationSize < maxImageSize)
          WriteMagicNumber();

        uint8_t data[3]{static_cast<uint8_t>(Opcodes::Response),
                        static_cast<uint8_t>(Opcodes::ReceiveFirmwareImage),
                        static_cast<uint8_t>(ErrorCodes::NoError)};
        NRF_LOG_INFO("[DFU] -> Send packet notification : all bytes received! CRC = %u -- %d", tempCrc, connectionHandle);
        SendNotification(connectionHandle, data, 3);
        state = States::Validate;
      }
    }
      return 0;
    default:
      // Invalid state
      return 0;
  }
  return 0;
}

int DfuService::ControlPointHandler(uint16_t connectionHandle, os_mbuf *om) {
  auto opcode = static_cast<Opcodes>(om->om_data[0]);
  NRF_LOG_INFO("[DFU] -> ControlPointHandler");

  switch (opcode) {
    case Opcodes::StartDFU: {
      if (state != States::Idle && state != States::Start) {
        NRF_LOG_INFO("[DFU] -> Start DFU requested, but we are not in Idle state");
        return 0;
      }
      if (state == States::Start) {
        NRF_LOG_INFO("[DFU] -> Start DFU requested, but we are already in Start state");
        return 0;
      }
      auto imageType = static_cast<ImageTypes>(om->om_data[1]);
      if (imageType == ImageTypes::Application) {
        NRF_LOG_INFO("[DFU] -> Start DFU, mode = Application");
        state = States::Start;
        bleController.StartFirmwareUpdate();
        bleController.State(Pinetime::Controllers::Ble::FirmwareUpdateStates::Running);
        bleController.FirmwareUpdateTotalBytes(0xffffffffu);
        bleController.FirmwareUpdateCurrentBytes(0);
        systemTask.PushMessage(Pinetime::System::SystemTask::Messages::BleFirmwareUpdateStarted);
        return 0;
      } else {
        NRF_LOG_INFO("[DFU] -> Start DFU, mode %d not supported!", imageType);
        return 0;
      }
    }
      break;
    case Opcodes::InitDFUParameters: {
      if (state != States::Init) {
        NRF_LOG_INFO("[DFU] -> Init DFU requested, but we are not in Init state");
        return 0;
      }
      bool isInitComplete = (om->om_data[1] != 0);
      NRF_LOG_INFO("[DFU] -> Init DFU parameters %s", isInitComplete ? " complete" : " not complete");

      if (isInitComplete) {
        notificationBuffer[0] = static_cast<uint8_t>(Opcodes::Response);
        notificationBuffer[1] = static_cast<uint8_t>(Opcodes::InitDFUParameters);
        notificationBuffer[2] =  (isInitComplete ? uint8_t{1} : uint8_t{0});
        notificationSize = 3;
        notificatonConnectionHandle = connectionHandle;
        xTimerStart(notificationTimer, 0);
        return 0;
      }
    }
      return 0;
    case Opcodes::PacketReceiptNotificationRequest:
      nbPacketsToNotify = om->om_data[1];
      NRF_LOG_INFO("[DFU] -> Receive Packet Notification Request, nb packet = %d", nbPacketsToNotify);
      return 0;
    case Opcodes::ReceiveFirmwareImage:
      if (state != States::Init) {
        NRF_LOG_INFO("[DFU] -> Receive firmware image requested, but we are not in Start Init");
        return 0;
      }
      NRF_LOG_INFO("[DFU] -> Starting receive firmware");
      state = States::Data;
      return 0;
    case Opcodes::ValidateFirmware: {
      if (state != States::Validate) {
        NRF_LOG_INFO("[DFU] -> Validate firmware image requested, but we are not in Data state");
        return 0;
      }

      NRF_LOG_INFO("[DFU] -> Validate firmware image requested -- %d", connectionHandle);

      if(Validate()){
        state = States::Validated;

        notificationBuffer[0] = static_cast<uint8_t>(Opcodes::Response);
        notificationBuffer[1] = static_cast<uint8_t>(Opcodes::ValidateFirmware);
        notificationBuffer[2] =  static_cast<uint8_t>(ErrorCodes::NoError);
        notificationSize = 3;
        notificatonConnectionHandle = connectionHandle;
        xTimerStart(notificationTimer, 0);

      } else {
        notificationBuffer[0] = static_cast<uint8_t>(Opcodes::Response);
        notificationBuffer[1] = static_cast<uint8_t>(Opcodes::ValidateFirmware);
        notificationBuffer[2] =  static_cast<uint8_t>(ErrorCodes::CrcError);
        notificationSize = 3;
        notificatonConnectionHandle = connectionHandle;
        xTimerStart(notificationTimer, 0);
      }

      return 0;
    }
    case Opcodes::ActivateImageAndReset:
      if (state != States::Validated) {
        NRF_LOG_INFO("[DFU] -> Activate image and reset requested, but we are not in Validated state");
        return 0;
      }
      NRF_LOG_INFO("[DFU] -> Activate image and reset!");
      bleController.StopFirmwareUpdate();
      systemTask.PushMessage(Pinetime::System::SystemTask::Messages::BleFirmwareUpdateFinished);
      return 0;
    default:
      return 0;
  }
}

void DfuService::SendNotification(uint16_t connectionHandle, const uint8_t *data, const size_t size) {
  auto *om = ble_hs_mbuf_from_flat(data, size);
  auto ret = ble_gattc_notify_custom(connectionHandle, controlPointCharacteristicHandle, om);
  ASSERT(ret == 0);
}

uint16_t DfuService::ComputeCrc(uint8_t const *p_data, uint32_t size, uint16_t const *p_crc) {
  uint16_t crc = (p_crc == NULL) ? 0xFFFF : *p_crc;

  for (uint32_t i = 0; i < size; i++) {
    crc = (uint8_t) (crc >> 8) | (crc << 8);
    crc ^= p_data[i];
    crc ^= (uint8_t) (crc & 0xFF) >> 4;
    crc ^= (crc << 8) << 4;
    crc ^= ((crc & 0xFF) << 4) << 1;
  }

  return crc;
}

bool DfuService::Validate() {
  uint32_t chunkSize = 200;
  int currentOffset = 0;
  uint16_t crc = 0;

  bool first = true;
  while (currentOffset < applicationSize) {
    uint32_t readSize = (applicationSize - currentOffset) > chunkSize ? chunkSize : (applicationSize - currentOffset);

    spiNorFlash.Read(writeOffset + currentOffset, tempBuffer, readSize);
    if (first) {
      crc = ComputeCrc(tempBuffer, readSize, NULL);
      first = false;
    } else
      crc = ComputeCrc(tempBuffer, readSize, &crc);
    currentOffset += readSize;
  }

  NRF_LOG_INFO("Expected CRC : %u - Processed CRC : %u", expectedCrc, crc);
  bool crcOk = (crc == expectedCrc);
  if (crcOk) {
    bleController.State(Pinetime::Controllers::Ble::FirmwareUpdateStates::Validated);
    NRF_LOG_INFO("Image OK");
  } else {
    bleController.State(Pinetime::Controllers::Ble::FirmwareUpdateStates::Error);
    NRF_LOG_INFO("Image Error : bad CRC");
  }
  return crcOk;
}

void DfuService::WriteMagicNumber() {
  uint32_t magic[4] = {
          0xf395c277,
          0x7fefd260,
          0x0f505235,
          0x8079b62c,
  };

  uint32_t offset = writeOffset + (maxImageSize - (4 * sizeof(uint32_t)));
  spiNorFlash.Write(offset, reinterpret_cast<uint8_t *>(magic), 4 * sizeof(uint32_t));
}

void DfuService::OnNotificationTimer() {
  if(notificationSize > 0) {
    SendNotification(notificatonConnectionHandle, notificationBuffer, notificationSize);
    notificationSize = 0;
  }
}