/*
 * meterBusClient.cpp
 *
 *  Created on: 08.03.2014
 *      Author: wn
 */



#include "meterBusClient.h"



String MeterBusClientConfig::exec(String params) {
  String res = "done";

  int space = params.indexOf(' ');
  String p1 = "";
  char pb1[128];
  if (space != -1) {
    params.toCharArray(pb1, 128, space+1);
  }

  if (params.startsWith("a ") && (space != -1)) {
    unsigned int a = atoi(pb1);
    m_meterBusClient->setAddress(a);
  } else {
    res = "subcommand not found";
  }
  return res;
}





MeterBusClient::MeterBusClient() : m_meterBusClientConfig(this), m_address(0) {

}



void MeterBusClient::begin(CmdServer *cmdServer) {
  m_meterBusClientConfig.registerYourself(cmdServer);


  Serial3.begin(1200);


  setAddress(Config::getUChar(Config::METERBUSCLIENT_ADDRESS));

}

void MeterBusClient::setAddress(unsigned char a) {
  Config::setUChar(Config::METERBUSCLIENT_ADDRESS, a);
  m_address = a;
}

unsigned char MeterBusClient::getAddress() {
  return m_address;
}



/*
 * Single Character: E5h
 *
 * Short Frame:
 *   Start      10h
 *   C-Field
 *   A-Field
 *   Check-Sum
 *   Stop       16h
 *
 * Control Frame:
 *   Start      68h
 *   Length     = 3
 *   Length
 *   Start      68h
 *   C-Field
 *   A-Field
 *   CI-Field
 *   Check-Sum
 *   Stop       16h
 *
 * Long Frame:
 *   Start      68h
 *   Length
 *   Length
 *   Start      68h
 *   C-Field
 *   A-Field
 *   CI-Field
 *   User-Data
 *   Check-Sum
 *   Stop       16h
 *
 * Frames:
 *   SND_NKE
 *     Short Frame, C: 40h
 *
 *   REQ_UD2
 *     Short Frame, C: 5Bh
 */


bool isChecksumValid(MeterBusFrame frame) {
  unsigned char ctrlsum = frame.aField + frame.cField + frame.ciField;
  for (int i = 0; i < (frame.length - 3); i++) {
    ctrlsum += frame.userData[i];
  }
  return (ctrlsum == frame.checksum);
}

void MeterBusClient::handleFrame() {
  if (m_frame.aField != getAddress()) {
    Serial.print(getResource(MBC_NOT_FOR_ME_KEY)); Serial.print((int)m_frame.aField, 16); Serial.println();
  } else if (! isChecksumValid(m_frame)) {
    Serial.println(getResource(MBC_INVALID_CHECKSUM_KEY));
  } else {
    // handle the frame
    Serial.print("s: "); Serial.println(m_frame.startDelimiter, 16);
    Serial.print("l: "); Serial.println(m_frame.length, 16);
    Serial.print("c: "); Serial.println(m_frame.cField, 16);
    Serial.print("a: "); Serial.println(m_frame.ciField, 16);
  }
}


typedef enum {
  STATE_START, STATE_IDLE, STATE_SHORT_FRAME, STATE_LONG_CTRL_FRAME, STATE_HANDLE, STATE_INVALID, STATE_FOREIGN, STATE_DONE
} e_meterBusClientState;

typedef enum {
  SUBSTATE_LENGTH, SUBSTATE_LENGTH_REPEAT, SUBSTATE_START_REPEAT, SUBSTATE_C_FIELD, SUBSTATE_A_FIELD, SUBSTATE_CI_FIELD,
  SUBSTATE_USERDATA, SUBSTATE_CHECKSUM, SUBSTATE_STOP
} e_meterBusClientSubState;


void MeterBusClient::exec() {
  static e_meterBusClientState state = STATE_IDLE;
  static e_meterBusClientSubState subState = SUBSTATE_LENGTH;
  bool done = false;

  int chi = Serial3.read();
  char ch = (char) chi;

  switch (state) {
  case STATE_START:
    m_frame.startDelimiter = 0;
    m_frame.length = 0;
    m_frame.cField = 0;
    m_frame.aField = 0;
    m_frame.ciField = 0;
    memset(m_frame.userData, 0, sizeof(m_frame.userData));
    m_frame.valid = false;
    state = STATE_IDLE;
    break;

  case STATE_IDLE:
    if (chi != -1) {
      if (ch == 0x10) {
        Serial.println("switching to short frame, c field");
        m_frame.startDelimiter = 0x10;
        state = STATE_SHORT_FRAME;
        subState = SUBSTATE_C_FIELD;
      } else if (ch == 0x68)  {
        Serial.println("switching to long frame, length");
        m_frame.startDelimiter = 0x68;
        state = STATE_LONG_CTRL_FRAME;
        subState = SUBSTATE_LENGTH;
      } else {
        Serial.println("switching to invalid");
        state = STATE_INVALID;
      }
    }
    break;

  case STATE_SHORT_FRAME:
    if (chi != -1) {
      if (subState == SUBSTATE_C_FIELD) {
        m_frame.cField = ch;
        subState = SUBSTATE_A_FIELD;
      } else if (subState == SUBSTATE_A_FIELD) {
        m_frame.aField = ch;
        subState  = SUBSTATE_CHECKSUM;
      } else if (subState == SUBSTATE_STOP) {
        if (ch == 0x16) {
          m_frame.valid = true;
          state = STATE_HANDLE;
        } else {
          state = STATE_INVALID;
        }
      }
    }
    break;

  case STATE_LONG_CTRL_FRAME:
    if (chi != -1) {
      if (subState == SUBSTATE_LENGTH) {
        m_frame.length = ch;
        if (m_frame.length < 3) {
          state = STATE_INVALID;
        } else {
          subState = SUBSTATE_LENGTH_REPEAT;
        }
      } else if (subState == SUBSTATE_LENGTH_REPEAT) {
        if (ch == m_frame.length) {
          subState = SUBSTATE_START_REPEAT;
        } else {
          state = STATE_INVALID;
        }
      } else if (subState == SUBSTATE_START_REPEAT) {
        if (ch == 0x68) {
          subState = SUBSTATE_C_FIELD;
        } else {
          state = STATE_INVALID;
        }
      } else if (subState == SUBSTATE_C_FIELD) {
        m_frame.cField = ch;
        subState = SUBSTATE_A_FIELD;
      } else if (subState == SUBSTATE_A_FIELD) {
        m_frame.aField = ch;
        subState = SUBSTATE_CI_FIELD;
      } else if (subState == SUBSTATE_CI_FIELD) {
        m_frame.ciField = ch;
        if (m_frame.length == 3) {
          subState = SUBSTATE_CHECKSUM;
        } else {
          subState = SUBSTATE_USERDATA;
        }
      } else if (subState == SUBSTATE_USERDATA) {
        // count and collect
        // then: subState = SUBSTATE_CHECKSUM
      } else if (subState == SUBSTATE_CHECKSUM) {
        m_frame.checksum = ch;
        subState = SUBSTATE_STOP;
      } else if (subState == SUBSTATE_STOP) {
        if (ch == 0x16) {
          m_frame.valid = true;
          state = STATE_HANDLE;
        } else {
          state = STATE_INVALID;
        }
      }
    }
    break;

  case STATE_INVALID:
    Serial.println(getResource(MBC_INVALID_FRAME_KEY));
    state = STATE_START;
    break;

  case STATE_HANDLE:
    Serial.println("handle frame");
    if (m_frame.valid) {
      handleFrame();
    } else {
      Serial.println(getResource(MBC_NO_VALID_FRAME_KEY));
    }
    state = STATE_DONE;
    break;

  case STATE_FOREIGN:
    // not for me message
    state = STATE_START;
    break;

  case STATE_DONE:
    // may be another useful message
    state = STATE_START;
    break;
  }
}