/*
  xsns_56_rtc_chips.ino - RTC chip support for Tasmota

  SPDX-FileCopyrightText: 2022 Theo Arends

  SPDX-License-Identifier: GPL-3.0-only
*/

#ifdef USE_I2C
#ifdef USE_RTC_CHIPS
/*********************************************************************************************\
 * RTC chip support
\*********************************************************************************************/

#define XDRV_56             56

#ifdef USE_GPS                     // GPS driver has it's own NTP server
#undef RTC_NTP_SERVER              // Disable NTP server (+0k8 code)
#endif

struct {
  uint32_t (* ReadTime)(void);
  void (* SetTime)(uint32_t);
  int32_t (* MemRead)(uint8_t *, uint32_t);
  int32_t (* MemWrite)(uint8_t *, uint32_t);
  bool detected;
  int8_t mem_size = -1;
  uint8_t address;
  uint8_t bus;
  char name[10];
} RtcChip;

/*********************************************************************************************\
 * DS1307 and DS3231
 *
 * I2C Address: 0x68
\*********************************************************************************************/
#ifdef USE_DS3231

#define XI2C_26             26      // See I2CDEVICES.md

#define DS3231_ADDRESS      0x68    // DS3231 I2C Address

// DS3231 Register Addresses
#define DS3231_SECONDS      0x00
#define DS3231_MINUTES      0x01
#define DS3231_HOURS        0x02
#define DS3231_DAY          0x03
#define DS3231_DATE         0x04
#define DS3231_MONTH        0x05
#define DS3231_YEAR         0x06
#define DS3231_CONTROL      0x0E
#define DS3231_STATUS       0x0F

// Control register bits
#define DS3231_OSF          7
#define DS3231_EOSC         7
#define DS3231_BBSQW        6
#define DS3231_CONV         5
#define DS3231_RS2          4
#define DS3231_RS1          3
#define DS3231_INTCN        2

//Other
#define DS3231_HR1224       6       // Hours register 12 or 24 hour mode (24 hour mode==0)
#define DS3231_CENTURY      7       // Century bit in Month register
#define DS3231_DYDT         6       // Day/Date flag bit in alarm Day/Date registers

/*-------------------------------------------------------------------------------------------*\
 * Read time from DS3231 and return the epoch time (second since 1-1-1970 00:00)
\*-------------------------------------------------------------------------------------------*/
uint32_t DS3231ReadTime(void) {
  TIME_T tm;
  tm.second = Bcd2Dec(I2cRead8(RtcChip.address, DS3231_SECONDS));
  tm.minute = Bcd2Dec(I2cRead8(RtcChip.address, DS3231_MINUTES));
  tm.hour = Bcd2Dec(I2cRead8(RtcChip.address, DS3231_HOURS) & ~_BV(DS3231_HR1224));    // Assumes 24hr clock
  tm.day_of_week = I2cRead8(RtcChip.address, DS3231_DAY);
  tm.day_of_month = Bcd2Dec(I2cRead8(RtcChip.address, DS3231_DATE));
  tm.month = Bcd2Dec(I2cRead8(RtcChip.address, DS3231_MONTH) & ~_BV(DS3231_CENTURY));  // Don't use the Century bit
  tm.year = Bcd2Dec(I2cRead8(RtcChip.address, DS3231_YEAR));
  return MakeTime(tm);
}

/*-------------------------------------------------------------------------------------------*\
 * Get time as TIME_T and set the DS3231 time to this value
\*-------------------------------------------------------------------------------------------*/
void DS3231SetTime(uint32_t epoch_time) {
  TIME_T tm;
  BreakTime(epoch_time, tm);
  I2cWrite8(RtcChip.address, DS3231_SECONDS, Dec2Bcd(tm.second));
  I2cWrite8(RtcChip.address, DS3231_MINUTES, Dec2Bcd(tm.minute));
  I2cWrite8(RtcChip.address, DS3231_HOURS, Dec2Bcd(tm.hour));
  I2cWrite8(RtcChip.address, DS3231_DAY, tm.day_of_week);
  I2cWrite8(RtcChip.address, DS3231_DATE, Dec2Bcd(tm.day_of_month));
  I2cWrite8(RtcChip.address, DS3231_MONTH, Dec2Bcd(tm.month));
  I2cWrite8(RtcChip.address, DS3231_YEAR, Dec2Bcd(tm.year));
  I2cWrite8(RtcChip.address, DS3231_STATUS, I2cRead8(RtcChip.address, DS3231_STATUS) & ~_BV(DS3231_OSF));  // Clear the Oscillator Stop Flag
}

/*-------------------------------------------------------------------------------------------*\
 * Detection
\*-------------------------------------------------------------------------------------------*/
void DS3231Detected(void) {
  if (!RtcChip.detected && I2cEnabled(XI2C_26)) {
    RtcChip.address = DS3231_ADDRESS;
    if (I2cSetDevice(RtcChip.address)) {
      if (I2cValidRead(RtcChip.address, DS3231_STATUS, 1)) {
        RtcChip.detected = 1;
        strcpy_P(RtcChip.name, PSTR("DS3231"));
        RtcChip.ReadTime = &DS3231ReadTime;
        RtcChip.SetTime = &DS3231SetTime;
        RtcChip.mem_size = -1;
      }
    }
  }
}
#endif  // USE_DS3231

/*********************************************************************************************\
 * BM8563 - Real Time Clock
 *
 * I2C Address: 0x51 (Fixed in library as BM8563_ADRESS)
\*********************************************************************************************/
#ifdef USE_BM8563

#define XI2C_59             59       // See I2CDEVICES.md

#include "BM8563.h"

struct {
  BM8563 Rtc;
  bool rtc_ready = false;
  bool ntp_time_ok = false;
} bm8563_driver;

uint32_t BM8563GetUtc(void) {
  RTC_TimeTypeDef RTCtime;
  // 1. read has errors ???
  bm8563_driver.Rtc.GetTime(&RTCtime);
//   core2_globs.Rtc.GetTime(&RTCtime);
  RTC_DateTypeDef RTCdate;
  bm8563_driver.Rtc.GetDate(&RTCdate);
  TIME_T tm;
  tm.second =  RTCtime.Seconds;
  tm.minute = RTCtime.Minutes;
  tm.hour = RTCtime.Hours;
  tm.day_of_week = RTCdate.WeekDay;
  tm.day_of_month = RTCdate.Date;
  tm.month = RTCdate.Month;
  tm.year = RTCdate.Year - 1970;
  return MakeTime(tm);
}

void BM8563SetUtc(uint32_t epoch_time) {
  TIME_T tm;
  BreakTime(epoch_time, tm);
  RTC_TimeTypeDef RTCtime;
  RTCtime.Hours = tm.hour;
  RTCtime.Minutes = tm.minute;
  RTCtime.Seconds = tm.second;
  bm8563_driver.Rtc.SetTime(&RTCtime);
  RTC_DateTypeDef RTCdate;
  RTCdate.WeekDay = tm.day_of_week;
  RTCdate.Month = tm.month;
  RTCdate.Date = tm.day_of_month;
  RTCdate.Year = tm.year + 1970;
  bm8563_driver.Rtc.SetDate(&RTCdate);
}

/*-------------------------------------------------------------------------------------------*\
 * Detection
\*-------------------------------------------------------------------------------------------*/
void BM8563Detected(void) {
  if (!RtcChip.detected && I2cEnabled(XI2C_59)) {
    RtcChip.address = BM8563_ADRESS;
    if (I2cSetDevice(RtcChip.address, 0)) {
      RtcChip.detected = 1;
    }
#ifdef ESP32
    else if (I2cSetDevice(RtcChip.address, 1)) {
      RtcChip.detected = 1;
      RtcChip.bus = 1;
      bm8563_driver.Rtc.setBus(1);                            // switch to bus 1
    }
#endif
    if (RtcChip.detected) {
      bm8563_driver.Rtc.begin();
      strcpy_P(RtcChip.name, PSTR("BM8563"));
      RtcChip.ReadTime = &BM8563GetUtc;
      RtcChip.SetTime = &BM8563SetUtc;
      RtcChip.mem_size = -1;
    }
  }
}
#endif  // USE_BM8563


/*********************************************************************************************\
 * PCF85363 support
 *
 * I2C Address: 0x51
\*********************************************************************************************/
#ifdef USE_PCF85363

#define XI2C_66             66      // See I2CDEVICES.md

#define PCF85363_ADDRESS    0x51    // PCF85363 I2C Address

/*-------------------------------------------------------------------------------------------*\
 * Read time and return the epoch time (second since 1-1-1970 00:00)
\*-------------------------------------------------------------------------------------------*/
uint32_t Pcf85363ReadTime(void) {
  Wire.beginTransmission(RtcChip.address);
  Wire.write(0x00);
  Wire.endTransmission();

  uint8_t buffer[8];
  Wire.requestFrom(RtcChip.address, (uint8_t)8);
  for (uint32_t i = 0; i < 8; i++) { buffer[i] = Wire.read(); }
  Wire.endTransmission();

  TIME_T tm;
  tm.second = Bcd2Dec(buffer[1] & 0x7F);
  tm.minute = Bcd2Dec(buffer[2] & 0x7F);
  tm.hour = Bcd2Dec(buffer[3]);
  tm.day_of_month = Bcd2Dec(buffer[4]);
  tm.day_of_week = buffer[5];
  tm.month = Bcd2Dec(buffer[6]);
  tm.year = 30 + Bcd2Dec(buffer[7]);  // Offset from 1970. So 2022 - 1970 = 52
  return MakeTime(tm);
}

/*-------------------------------------------------------------------------------------------*\
 * Get time as TIME_T and set time to this value
\*-------------------------------------------------------------------------------------------*/
void Pcf85363SetTime(uint32_t epoch_time) {
  TIME_T tm;
  BreakTime(epoch_time, tm);

  uint8_t buffer[8];
  buffer[0] = 0x00;                  // 100th_seconds (not used)
  buffer[1] = Dec2Bcd(tm.second);
  buffer[2] = Dec2Bcd(tm.minute);
  buffer[3] = Dec2Bcd(tm.hour);
  buffer[4] = Dec2Bcd(tm.day_of_month);
  buffer[5] = tm.day_of_week;
  buffer[6] = Dec2Bcd(tm.month);
  buffer[7] = Dec2Bcd(tm.year -30);  // Offset from 1970
/*
  // Handbook page 13
  Wire.beginTransmission(RtcChip.address);
  Wire.write(0x2E);
  Wire.write(0x01);                  // Set stop
  Wire.write(0xA4);                  // Clear prescaler
  for (uint32_t i = 0; i < 8; i++) { Wire.write(buffer[i]); }
  Wire.endTransmission();
  Wire.beginTransmission(RtcChip.address);
  Wire.write(0x2E);
  Wire.write(0x00);                  // Set start
  Wire.endTransmission();
*/
  Wire.beginTransmission(RtcChip.address);
  Wire.write(0x00);
  for (uint32_t i = 0; i < 8; i++) { Wire.write(buffer[i]); }
  Wire.endTransmission();
}

/*-------------------------------------------------------------------------------------------*\
 * Dump all registers
\*-------------------------------------------------------------------------------------------*/
/*
void Pcf85363Dump(void) {
  uint8_t buffer[64];

  // 0x00 to 0x2F
  Wire.beginTransmission(RtcChip.address);
  Wire.write(0x00);
  Wire.endTransmission();
  Wire.requestFrom(RtcChip.address, (uint8_t)48);
  for (uint32_t i = 0; i < 48; i++) {
    buffer[i] = Wire.read();
  }
  Wire.endTransmission();
  AddLog(LOG_LEVEL_DEBUG, PSTR("P85: Read 0x00: %48_H"), buffer);

  // 0x40 to 0x7F
  Wire.beginTransmission(RtcChip.address);
  Wire.write(0x40);
  Wire.endTransmission();
  Wire.requestFrom(RtcChip.address, (uint8_t)64);
  for (uint32_t i = 0; i < 64; i++) {
    buffer[i] = Wire.read();
  }
  Wire.endTransmission();
  AddLog(LOG_LEVEL_DEBUG, PSTR("P85: Read 0x40: %64_H"), buffer);
}
*/

/*-------------------------------------------------------------------------------------------*\
 * Memory block functions
\*-------------------------------------------------------------------------------------------*/
int32_t Pcf8563MemRead(uint8_t *buffer, uint32_t size) {
  return I2cReadBuffer(RtcChip.address, 0x40, buffer, size);
}

int32_t Pcf8563MemWrite(uint8_t *buffer, uint32_t size) {
  return I2cWriteBuffer(RtcChip.address, 0x40, (uint8_t *)buffer, size);
}

/*-------------------------------------------------------------------------------------------*\
 * Detection
\*-------------------------------------------------------------------------------------------*/
void Pcf85363Detected(void) {
  if (!RtcChip.detected && I2cEnabled(XI2C_66)) {
    RtcChip.address = PCF85363_ADDRESS;
    if (I2cSetDevice(RtcChip.address)) {
      RtcChip.detected = 1;
      strcpy_P(RtcChip.name, PSTR("PCF85363"));
      RtcChip.ReadTime = &Pcf85363ReadTime;
      RtcChip.SetTime = &Pcf85363SetTime;
      RtcChip.mem_size = 64;
      RtcChip.MemRead = &Pcf8563MemRead;
      RtcChip.MemWrite = &Pcf8563MemWrite;
    }
  }
}
#endif // USE_PCF85363

/*********************************************************************************************\
 * RTC Detect and time set
\*********************************************************************************************/

void RtcChipDetect(void) {
  RtcChip.detected = 0;
  RtcChip.bus = 0;

#ifdef USE_DS3231
  DS3231Detected();
#endif  // USE_DS3231
#ifdef USE_BM8563
  BM8563Detected();
#endif  // USE_BM8563
#ifdef USE_PCF85363
  Pcf85363Detected();
#endif // USE_PCF85363

  if (!RtcChip.detected) { return; }

  I2cSetActiveFound(RtcChip.address, RtcChip.name, RtcChip.bus);

  if (Rtc.utc_time < START_VALID_TIME) {                          // Not sync with NTP/GPS (time not valid), so read time
    uint32_t time = RtcChip.ReadTime();                           // Read UTC TIME
    if (time > START_VALID_TIME) {
      Rtc.utc_time = time;
      RtcSync(RtcChip.name);
    }
  }
}

void RtcChipTimeSynced(void) {
  if ((Rtc.utc_time > START_VALID_TIME) &&                        // Valid UTC time
      (abs((int32_t)(Rtc.utc_time - RtcChip.ReadTime())) > 2)) {  // Time has drifted from RTC more than 2 seconds
    RtcChip.SetTime(Rtc.utc_time);                                // Update time
    AddLog(LOG_LEVEL_DEBUG, PSTR("RTC: %s re-synced (" D_UTC_TIME ") %s"), RtcChip.name, GetDateAndTime(DT_UTC).c_str());
  }
}

int32_t RtcChipMemSize(void) {
  return RtcChip.mem_size;                                        // Not supported or max size
}

int32_t RtcChipMemRead(uint8_t *buffer, uint32_t size) {
  if (size <= RtcChip.mem_size) {
    return RtcChip.MemRead(buffer, size);
  }
  return -1;                                                      // Not supported or too large
}

int32_t RtcChipMemWrite(uint8_t *buffer, uint32_t size) {
  if (size <= RtcChip.mem_size) {
    return RtcChip.MemWrite(buffer, size);
  }
  return -1;                                                      // Not supported or too large
}

/*********************************************************************************************\
 * NTP server functions
\*********************************************************************************************/
#ifdef RTC_NTP_SERVER

#include "NTPServer.h"
#include "NTPPacket.h"

#define NTP_MILLIS_OFFSET   50

const char kRtcChipCommands[] PROGMEM = "Rtc|"  // Prefix
  D_CMND_NTPSERVER;

void (* const RtcChipCommand[])(void) PROGMEM = {
  &CmndRtcNtpServer };

NtpServer RtcChipTimeServer(PortUdp);

void RtcChipEverySecond(void) {
  static bool ntp_server_started = false;

  if (Settings->sbflag1.local_ntp_server && (Rtc.utc_time > START_VALID_TIME)) {
    if (!ntp_server_started) {
      if (RtcChipTimeServer.beginListening()) {
        ntp_server_started = true;
        AddLog(LOG_LEVEL_DEBUG, PSTR("RTC: NTP server started"));
      }
    } else {
      RtcChipTimeServer.processOneRequest(Rtc.utc_time, NTP_MILLIS_OFFSET);
    }
  }
}

void CmndRtcNtpServer(void) {
  // RtcChipNtpServer 0 or 1
  if (XdrvMailbox.payload >= 0) {
    Settings->sbflag1.local_ntp_server = 0;
    if ((XdrvMailbox.payload &1) && RtcChipTimeServer.beginListening()) {
      Settings->sbflag1.local_ntp_server = 1;
    }
  }
  ResponseCmndStateText(Settings->sbflag1.local_ntp_server);
}
#endif  // RTC_NTP_SERVER

/*********************************************************************************************\
 * Interface
\*********************************************************************************************/

bool Xdrv56(uint8_t function) {
  bool result = false;

#ifdef RTC_NTP_SERVER
  switch (function) {
    case FUNC_EVERY_SECOND:
      RtcChipEverySecond();
      break;
    case FUNC_COMMAND:
      result = DecodeCommand(kRtcChipCommands, RtcChipCommand);
      break;
  }
#endif  // RTC_NTP_SERVER

  if (FUNC_MODULE_INIT == function) {
    RtcChipDetect();
  }
  else if (RtcChip.detected) {
    switch (function) {
      case FUNC_TIME_SYNCED:
        RtcChipTimeSynced();
        break;
    }
  }

  return result;
}

#endif  // USE_RTC_CHIPS
#endif  // USE_I2C