//
// BitBank Capactive Touch Sensor Library
// Written by Larry Bank
//
// Copyright 2023 BitBank Software, Inc. All Rights Reserved.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//    http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ===========================================================================

#include "bb_captouch.h"

void BBCapTouch::reset(int iRST) {
  pinMode(iRST, OUTPUT);
  digitalWrite(iRST, LOW);
  delay(100);
  digitalWrite(iRST, HIGH);
  delay(100);
} /* reset() */

//
// Initialize the library
// It only needs to initialize the I2C interface; the chip is ready // ESPEasy: I2C is already ready
//
int BBCapTouch::init(int iSDA, int iSCL, int iRST, int iINT, uint32_t u32Speed) {
  if (_iType != CT_TYPE_UNKNOWN) { return CT_SUCCESS; } // Already set, exit

  //  Wire.begin(iSDA, iSCL); // this is specific to ESP32 MCUs // ESPEasy doesn't allow this
  //  Wire.setClock(u32Speed);
  #ifdef ESP32
  unsigned long orgTimeout = Wire.getTimeout();
  Wire.setTimeout(100);
  #endif // ifdef ESP32

  _iType = CT_TYPE_UNKNOWN;

  if (I2CTest(AXS15231_ADDR)) {
    _iType = CT_TYPE_AXS15231;
    _iAddr = AXS15231_ADDR;

    if (iRST != -1) {
      reset(iRST);
    }
  } // AXS15231
  else if (I2CTest(CST226_ADDR)) { // CST226
    _iType = CT_TYPE_CST226;
    _iAddr = CST226_ADDR;

    if (iINT != -1) {
      pinMode(iINT, INPUT);
    }

    if (iRST != -1) {
      reset(iRST);
    }
  } // CST226

  if (I2CTest(GT911_ADDR1) || I2CTest(GT911_ADDR2)) { // GT911
    _iType = CT_TYPE_GT911;
  }

  if (_iType == CT_TYPE_GT911) { // reset the sensor to start it
    if ((-1 != iRST) && (-1 != iINT)) {
      pinMode(iRST, OUTPUT);
      pinMode(iINT, OUTPUT);
      digitalWrite(iINT, LOW);
      digitalWrite(iRST, LOW);
      delay(5);
      digitalWrite(iINT, LOW);  // set I2C addr to ADDR1
      delay(1);
      digitalWrite(iRST, HIGH); // when it comes out of reset, it samples INT
      delay(10);
      digitalWrite(iINT, LOW);
      delay(50);
      pinMode(iINT, INPUT);
    }

    // double check the I2C addr in case it changed
    if (I2CTest(GT911_ADDR1)) {
      _iAddr = GT911_ADDR1;
    } else if (I2CTest(GT911_ADDR2)) {
      _iAddr = GT911_ADDR2;
    }
  } // GT911
  else if (I2CTest(FT6X36_ADDR)) { // FT62x6
    // Check Vendor ID and get Chip ID
    uint8_t ucTemp[1]{};
    I2CReadRegister(FT6X36_ADDR, TOUCH_REG_VENDID, ucTemp, 1); // Check the Vendor ID reg

    if (ucTemp[0] != FT62XX_VENDID) {
      return CT_ERROR;
    }
    I2CReadRegister(FT6X36_ADDR, TOUCH_REG_CHIPID, ucTemp, 1); // read the Chip ID reg
    _id = ucTemp[0];                                           // Chip ID only read to be used for FT5316

    _iType = CT_TYPE_FT6X36;
    _iAddr = FT6X36_ADDR;

    if (iRST != -1) {
      reset(iRST);
    }

    if (_thresh > -1) {
      uint8_t ucsetThresh[2] = { 0x80, (uint8_t)_thresh }; // 0x80 = FT62XX_REG_THRESHOLD
      I2CWrite(_iAddr, (uint8_t *)ucsetThresh, 2);
    }
  } // FT62x6
  else if (I2CTest(CST820_ADDR)) { // CST820
    _iType = CT_TYPE_CST820;
    _iAddr = CST820_ADDR;

    if (iRST != -1) {
      reset(iRST);
    }
  } // CST820
  else if (I2CTest(CHSC5816_ADDR)) { // CHSC5816
    _iType = CT_TYPE_CHSC5816;
    _iAddr = CHSC5816_ADDR;

    if (iRST != -1) {
      reset(iRST);
    }
  } // CHSC5816
  #ifdef ESP32
  Wire.setTimeout(orgTimeout); // ESPEasy: Restore original I2C timeout
  #endif // ifdef ESP32

  if (CT_TYPE_UNKNOWN == _iType) {
    return CT_ERROR; // no device found
  }
  return CT_SUCCESS;
} /* init() */

//
// Test if an I2C device is monitoring an address
// return true if it responds, false if no response
//
bool BBCapTouch::I2CTest(uint8_t u8Addr) {
  // Check if a device acknowledges the address.
  Wire.beginTransmission(u8Addr);
  return Wire.endTransmission(true) == 0;
} /* I2CTest() */

//
// Write I2C data
// quits if a NACK is received and returns 0
// otherwise returns the number of bytes written
//
int BBCapTouch::I2CWrite(uint8_t u8Addr, uint8_t *pData, int iLen) {
  int rc = 0;

  Wire.beginTransmission(u8Addr);
  Wire.write(pData, (uint8_t)iLen);
  rc = !Wire.endTransmission();
  return rc;
} /* I2CWrite() */

//
// Read N bytes starting at a specific 16-bit I2C register
//
int BBCapTouch::I2CReadRegister16(uint8_t u8Addr, uint16_t u16Register, uint8_t *pData, int iLen) {
  int i = 0;

  Wire.beginTransmission(u8Addr);
  Wire.write((uint8_t)(u16Register >> 8)); // high byte
  Wire.write((uint8_t)u16Register);        // low byte
  Wire.endTransmission();
  Wire.requestFrom(u8Addr, (uint8_t)iLen);

  while (Wire.available() && i < iLen) {
    pData[i++] = Wire.read();
  }
  return i;
} /* I2CReadRegister16() */

//
// Read N bytes starting at a specific I2C internal register
// returns 1 for success, 0 for error
//
int BBCapTouch::I2CReadRegister(uint8_t u8Addr, uint8_t u8Register, uint8_t *pData, int iLen) {
  int i = 0;

  Wire.beginTransmission(u8Addr);
  Wire.write(u8Register);
  Wire.endTransmission();
  Wire.requestFrom(u8Addr, (uint8_t)iLen);

  // i = Wire.readBytes(pData, iLen);
  while (Wire.available() && i < iLen) {
    pData[i++] = Wire.read();
  }
  return i;
} /* I2CReadRegister() */

//
// Read N bytes
//
int BBCapTouch::I2CRead(uint8_t u8Addr, uint8_t *pData, int iLen) {
  int i = 0;

  Wire.requestFrom(u8Addr, (uint8_t)iLen);

  while (Wire.available() && i < iLen) {
    pData[i++] = Wire.read();
  }
  return i;
} /* I2CRead() */

//
// Private function to rotate touch samples if the user
// specified a new display orientation
//
void BBCapTouch::fixSamples(TOUCHINFO *pTI) {
  int i, x, y;

  for (i = 0; i < pTI->count; ++i) {
    switch (_iOrientation) {
      case 90:
        x         = pTI->y[i];
        y         = _iWidth - 1 - pTI->x[i];
        pTI->x[i] = x;
        pTI->y[i] = y;
        break;
      case 180:
        pTI->x[i] = _iWidth - 1 - pTI->x[i];
        pTI->y[i] = _iHeight - 1 - pTI->y[i];
        break;
      case 270:
        x         = _iHeight - 1 - pTI->y[i];
        y         = pTI->x[i];
        pTI->x[i] = x;
        pTI->y[i] = y;
        break;
      default: // do nothing
        break;
    }
  }
} /* fixSamples() */

//
// Read the touch points
// returns 0 (none), 1 if touch points are available
// The point count and info is returned in the TOUCHINFO structure
//
int BBCapTouch::getSamples(TOUCHINFO *pTI) {
  uint8_t c, *s, ucTemp[32];
  int     i, j, rc;

  if (!pTI) {
    return 0;
  }
  pTI->count = 0;

  if (_iType == CT_TYPE_AXS15231) { // AXS15231
    uint8_t ucReadCMD[8] = { 0xb5, 0xab, 0xa5, 0x5a, 0, 0, 0, 0x8 };
    I2CWrite(_iAddr, (uint8_t *)ucReadCMD, 8);
    I2CRead(_iAddr, ucTemp, 14);    // read up to 2 touch points
    c = ucTemp[1];                  // number of touch points

    if ((c == 0) || (c > 2) || (ucTemp[0] != 0)) { return 0; }
    pTI->count = c;
    j          = 0; // buffer offset

    for (i = 0; i < c; i++) {
      pTI->x[i]    = ((ucTemp[j + 2] & 0xf) << 8) + ucTemp[j + 3];
      pTI->y[i]    = ((ucTemp[j + 4] & 0xf) << 8) + ucTemp[j + 5];
      pTI->area[i] = 1;
      j           += 6;
    }

    if (_iOrientation != 0) { fixSamples(pTI); }
    return c > 0;
  }                                             // AXS15231

  if (_iType == CT_TYPE_CST226) {               // CST226
    i = I2CReadRegister(_iAddr, 0, ucTemp, 28); // read the whole block of regs

    if ((ucTemp[0] == 0x83) && (ucTemp[1] == 0x17) && (ucTemp[5] == 0x80)) {
      // home button pressed
      return 0;
    }

    if (ucTemp[6] != 0xab) { return 0; }

    if (ucTemp[0] == 0xab) { return 0; }

    if (ucTemp[5] == 0x80) { return 0; }
    c = ucTemp[5] & 0x7f;

    if ((c > 5) || (c == 0)) {     // invalid point count
      ucTemp[0] = 0;
      ucTemp[1] = 0xab;
      I2CWrite(_iAddr, ucTemp, 2); // reset
      return 0;
    }

    pTI->count = c;
    j          = 0;

    for (i = 0; i < c; i++) {
      pTI->x[i]        = (uint16_t)((ucTemp[j + 1] << 4) | ((ucTemp[j + 3] >> 4) & 0xf));
      pTI->y[i]        = (uint16_t)((ucTemp[j + 2] << 4) | (ucTemp[j + 3] & 0xf));
      pTI->pressure[i] = ucTemp[j + 4];
      j                = (i == 0) ? (j + 7) : (j + 5);
    }

    if (_iOrientation != 0) { fixSamples(pTI); }
    return c > 0;
  } // CST226

  if (_iType == CT_TYPE_CST820) {                              // CST820
    I2CReadRegister(_iAddr, CST820_TOUCH_REGS + 1, ucTemp, 1); // read touch count

    if ((ucTemp[0] < 1) || (ucTemp[0] > 5)) { // something went wrong
      return 0;
    }

    pTI->count = ucTemp[0];
    I2CReadRegister(_iAddr, CST820_TOUCH_REGS + 2, ucTemp, pTI->count * 6);
    s = ucTemp;

    for (i = 0; i < pTI->count; i++) {
      pTI->x[i]    = ((s[0] & 0xf) << 8) | s[1];
      pTI->y[i]    = ((s[2] & 0xf) << 8) | s[3];
      pTI->area[i] = 1; // no data available
      s           += 6;
    }

    if (_iOrientation != 0) { fixSamples(pTI); }
    return 1;
  } // CST820

  if (_iType == CT_TYPE_FT6X36) { // FT62x6
    if (_id == FT5316_CHIPID) {
      I2CReadRegister(_iAddr, TOUCH_REG_MODE, ucTemp, 1); // Handle specific issue

      if (ucTemp[0]) {
        // wrong mode
        ucTemp[0] = TOUCH_REG_MODE;
        ucTemp[1] = 0;
        I2CWrite(_iAddr, ucTemp, 2);
      }
    }
    rc = I2CReadRegister(_iAddr, TOUCH_REG_STATUS, ucTemp, 1);         // read touch status

    if (rc == 0) {                                                     // something went wrong
      return 0;
    }
    i = ucTemp[0];                                                     // number of touch points available

    if (i > 0) {                                                       // get data, max. 2 points
      rc = I2CReadRegister(_iAddr, TOUCH_REG_XH, ucTemp, 6 * i);       // read X+Y position(s)

      if (((ucTemp[0] & 0x40) == 0) && ((ucTemp[2] & 0xf0) != 0xf0)) { // finger is down
        pTI->x[0] = ((ucTemp[0] & 0xf) << 8) | ucTemp[1];
        pTI->y[0] = ((ucTemp[2] & 0xf) << 8) | ucTemp[3];

        // get touch pressure and area
        pTI->pressure[0] = ucTemp[4];
        pTI->area[0]     = ucTemp[5];
        pTI->count++;
      }

      if (i > 1) {                                                       // get second point
        if (((ucTemp[6] & 0x40) == 0) && ((ucTemp[8] & 0xf0) != 0xf0)) { // finger is down
          pTI->x[1] = ((ucTemp[6] & 0xf) << 8) | ucTemp[7];
          pTI->y[1] = ((ucTemp[8] & 0xf) << 8) | ucTemp[9];

          // get touch pressure and area
          pTI->pressure[1] = ucTemp[10];
          pTI->area[1]     = ucTemp[11];
          pTI->count++;
        }
      }
    } // if touch points available

    if (_iOrientation != 0) { fixSamples(pTI); }
    return i > 0;
  } // FT62x6
  else if (_iType == CT_TYPE_GT911) {                       // GT911
    I2CReadRegister16(_iAddr, GT911_POINT_INFO, ucTemp, 1); // get number of touch points
    i = ucTemp[0] & 0xf;                                    // number of touches

    if ((i <= 5) && ucTemp[0] & 0x80) { // if buffer status is good + >= 1 touch points
      ucTemp[0] = (uint8_t)(GT911_POINT_INFO >> 8);
      ucTemp[1] = (uint8_t)GT911_POINT_INFO;
      ucTemp[2] = 0;                    // clear touch info for next time
      I2CWrite(_iAddr, ucTemp, 3);

      pTI->count = i;

      for (int j = 0; j < i; j++) { // read each touch point block
        I2CReadRegister16(_iAddr, GT911_POINT_1 + (j * 8), ucTemp, 7);
        pTI->x[j]        = ucTemp[1] + (ucTemp[2] << 8);
        pTI->y[j]        = ucTemp[3] + (ucTemp[4] << 8);
        pTI->area[j]     = ucTemp[5] + (ucTemp[6] << 8);
        pTI->pressure[j] = 0;
      }

      if (i && (_iOrientation != 0)) { fixSamples(pTI); }
      return i > 0;
    }
  } // GT911
  else if (_iType == CT_TYPE_CHSC5816) { // CHSC5816
    __CHSC5816_PointReg touch;

    // CHSC5816_REG_POINT
    uint8_t write_buffer[] = { 0x20, 0x00, 0x00, 0x2c };
    I2CWrite(_iAddr, write_buffer, 4);
    I2CRead(_iAddr, touch.data, 8);

    if ((touch.rp.status == 0xFF) && (touch.rp.fingerNumber == 0)) {
      return 0;
    }
    pTI->x[0] = static_cast<uint16_t>(touch.rp.x_h4 << 8) | touch.rp.x_l8;
    pTI->y[0] = static_cast<uint16_t>(touch.rp.y_h4 << 8) | touch.rp.y_l8;

    if (_iOrientation != 0) { fixSamples(pTI); }

    return 1;
  } // CHSC5816
  return 0;
}   /* getSamples() */

int BBCapTouch::setOrientation(int iOrientation, int iWidth, int iHeight) {
  if ((iOrientation != 0) && (iOrientation != 90) && (iOrientation != 180) && (iOrientation != 270)) {
    return CT_ERROR;
  }
  _iOrientation = iOrientation;
  _iWidth       = iWidth;
  _iHeight      = iHeight;
  return CT_SUCCESS;
} /* setOrientation() */

void BBCapTouch::sensorType(int iType) {
  _iType = iType;
}

void BBCapTouch::setI2CAddress(int i2caddr) {
  _iAddr = i2caddr;
}

/**
 * Threashold is used _during_ init() so should be set before init() is called.
 */
void BBCapTouch::setThreshold(int thresh) {
  _thresh = thresh;
}