/**
 * My Nixie Clock IN-12
 * Vladimir N. Shilov <shilow@ukr.net>
 * 2019.01.18
 */
/* Compiler libs */
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/sleep.h>
#include <avr/eeprom.h>
#include <avr/pgmspace.h>

/* Project libs */
#include "i2c.h"
#include "ds3231.h"
#include "rtos.h"
#include "event-system.h"
#include "common.h"
#include "main.h"

/* Defines */
/* Timer2 settings */
#define TIMER2_HZ         400
#define TIMER2_PRESCALER  1024
#define TIMER2_CS         (1<<CS22 | 1<<CS21 | 1<<CS20)
#define TIMER2_CNT        (0x100 - (F_CPU / TIMER2_PRESCALER / TIMER2_HZ))

/* Display timeout, sec */
#define DISP_WDT_TIME   10

#ifdef USE_UART
/* USART */
#define BAUD            19200UL
#define BAUD_PRESCALE   (uint8_t)((F_CPU / BAUD / 16UL) - 1)
#define CHAR_NEWLINE    '\n'
#define CHAR_RETURN     '\r'
#define RETURN_NEWLINE  "\r\n"
#endif // USE_UART

#ifdef USE_BRIGHT_CONTROL
/* Lamp brightness */
#define BRIGHT_IDX_MAX    4
#define FULL_BRIGHT_ON    0x06
#define FULL_BRIGHT_OFF   0x22
static const uint8_t PROGMEM brightConv[BRIGHT_IDX_MAX+1] = {
  218, 225, 230, 240, 255
};
#endif // USE_BRIGHT_CONTROL

#ifdef USE_DHT
// timeout in timer tiks, step 4 mks
#define DHT_TIMEOUT       1500
#define DHT_TOUT1         55
static struct {
  uint8_t Humidity;
  uint16_t Temperature;
} dhtData;
#endif // USE_DHT


/* Variables */
static volatile uint8_t Digit[4] = {1, 2, 3, 4};
static rtc_t RTC, setRTC;
static volatile struct {
  uint8_t RTC_Int:  1;
  uint8_t saveCal:  1;
  uint8_t blinkC:   1;
  uint8_t blink0:   1;
  uint8_t blink1:   1;
  uint8_t blink2:   1;
  uint8_t blink3:   1;
  uint8_t saveEEP:  1;
} Flag;
static btn_t Button[BTN_NUM] = {
  {0, evBTN1Pressed, evBTN1Holded, BUTTON1_PIN},
  {0, evBTN2Pressed, evBTN2Pressed, BUTTON2_PIN},
  {0, evBTN3Pressed, evBTN3Pressed, BUTTON3_PIN}
};
static volatile uint8_t DISP_WDT = 0;
static EEMEM uint8_t EEP_BrightIdx;
static uint8_t brightIdx;
static EEMEM uint8_t EEP_SummerTime;

/* Function prototypes */
static void Board_Init(void);
static void dotOn(void);
static void btnProcess(void);
static void valIncrease(uint8_t * val, uint8_t max);
static void valDecrease(uint8_t * val, uint8_t max);
static void blink(void);
static void setSummerWinterTime(void);
#ifdef USE_DHT
static void dhtStart(void);
static void dhtProcess(void);
static void dhtEnd(void);
static void dhtTimeout(void);
static void dhtNoAck(void);
#endif // USE_DHT
#ifdef USE_UART
void usart_putc (char send);
void usart_puts (const char *send);
#endif // USE_UART

void main(void) {
  /**
   * Локальные переменные
   */
  uint8_t event = 0;
  Flag.RTC_Int = 0;
  Flag.saveCal = 0;
  Flag.blink0 = 0;
  Flag.blink1 = 0;
  Flag.blink2 = 0;
  Flag.blink3 = 0;
  Flag.blinkC = 0;
  Flag.saveEEP = 0;

#ifdef USE_BRIGHT_CONTROL
  brightIdx = eeprom_read_byte(&EEP_BrightIdx);
  if (brightIdx > BRIGHT_IDX_MAX) {
    brightIdx = BRIGHT_IDX_MAX;
  }
#endif // USE_BRIGHT_CONTROL

  /**
   * Инициализация, настройка...
   */
  Board_Init();

  /* Initialize Scheduler */
  RTOS_Init();
  tdelay_ms(1000); // warm up

  /* Initialize I2C Bus and RTC */
  I2C_Init();
  RTC_Init();
  RTC_ReadAll(&RTC);

  /* Initialize Event State Machine */
  ES_Init(stShowTime);

  showTime();

  RTOS_SetTask(btnProcess, 3, BTN_SCAN_PERIOD);
#ifdef USE_DHT
  RTOS_SetTask(dhtStart, 2000, 15000);
#endif // USE_DHT

  /** main loop */
  do {
    /* new second interrupt from RTC */
    if (Flag.RTC_Int != 0) {
      Flag.RTC_Int = 0;
      ES_PlaceEvent(evNewSecond);

      RTC_ReadTime(&RTC);
      if (RTC.Sec == 0 && RTC.Min == 0) {
        // begin of new hour
        if (RTC.Hr == 0) {
          RTC_ReadCalendar(&RTC);
          ES_PlaceEvent(evRefreshCal);
        }
#ifdef USE_BRIGHT_CONTROL
        if (RTC.Hr >= FULL_BRIGHT_ON && RTC.Hr < FULL_BRIGHT_OFF) {
          OCR2 = pgm_read_byte(&brightConv[BRIGHT_IDX_MAX]);
        } else {
          OCR2 = pgm_read_byte(&brightConv[brightIdx]);
        }
#endif // USE_BRIGHT_CONTROL

        setSummerWinterTime();
      } // begin new hour

      if (DISP_WDT != 0) {
        DISP_WDT --;
        if (DISP_WDT == 0) {
          ES_PlaceEvent(evDisplayWDT);

          if (Flag.saveCal != 0) {
            Flag.saveCal = 0;
            RTC_WriteCalendar(&RTC);
          }

          if (Flag.saveEEP != 0) {
            Flag.saveEEP = 0;
            eeprom_update_byte(&EEP_BrightIdx, brightIdx);
          }
        }
      }
    } // End of New Second

    event = ES_GetEvent();
    if (event) {
      ES_Dispatch(event);
    }

    // крутим диспетчер
    RTOS_DispatchTask();

    // делать нечего -- спим, ждём прерывание
    set_sleep_mode(SLEEP_MODE_IDLE);
    sleep_mode();

  } while(1);
}

/**
 *  П о д п р о г р а м м ы
 */

/**
 * @brief Initialize peripheral
 */
static void Board_Init(void) {
  /* power off Analog Comparator */
  ACSR = ACD;

  /* GPIO */
  PORTB = BUTTON_PINS; // enable pull-up
  DDRC = DIGIT_PINS; // as output
  DDRD = (DOT_PIN | ANOD_PINS); // as output

#ifdef USE_DHT
  /* Timer1, IC negative edge, CTC mode, 64 prescaler, 4 mks one tick */
  TCCR1B = ((0<<ICES1) | (1<<CS11) | (1<<CS10));
#endif // USE_DHT

  /* Timer2 - refresh Nixie values */
  TCCR2 = TIMER2_CS;
  TCNT2 = TIMER2_CNT;
  TIMSK = _BV(TOIE2);

#ifdef USE_BRIGHT_CONTROL
  OCR2 = pgm_read_byte(&brightConv[BRIGHT_IDX_MAX]);
  TIMSK |= _BV(OCIE2);
#endif // USE_BRIGHT_CONTROL

  /* Interrupt from RTC */
  MCUCR = _BV(ISC11); // falling edge
  GICR = _BV(INT1);

#ifdef USE_UART
  /* USART */
  // Turn on USART hardware (no RX, TX)
  UCSRB |= (0 << RXEN) | (1 << TXEN);
  // 8 bit char sizes
  UCSRC |= (1 << UCSZ0) | (1 << UCSZ1);
  // Set baud rate
  UBRRH = (BAUD_PRESCALE >> 8);
  UBRRL = BAUD_PRESCALE;
#endif // USE_UART

  /* Enable Interrupts */
  sei();
}

/**
 * @brief Correct current time for Sun or Winter
 */
static void setSummerWinterTime(void) {
  uint8_t sunTime = eeprom_read_byte(&EEP_SummerTime);

  /* Переход на летнее время */
  if ((RTC.Mon == 3) && (RTC.WD == 7) && (RTC.Hr == 3) && (sunTime != 0)) {
    if ((RTC.Day + 7) > 31) {
      RTC.Hr = 4;
      RTC_WriteHHMM(&RTC);
      sunTime = 0;
    }
  }

  /* Переход на зимнее время */
  if ((RTC.Mon == 10) && (RTC.WD == 7) && (RTC.Hr == 4) && (sunTime == 0)) {
    if ((RTC.Day + 7) > 31) {
      RTC.Hr = 3;
      RTC_WriteHHMM(&RTC);
      sunTime = 1;
    }
  }

  eeprom_update_byte(&EEP_SummerTime, sunTime);
}

static void dotOn(void) {
  PORTD |= DOT_PIN;
}

void dotOff(void) {
  PORTD &= ~(DOT_PIN);
}

void dotOnPersistent(void) {
  RTOS_DeleteTask(dotOff);
  PORTD |= DOT_PIN;
}

#ifdef USE_DHT
static void dhtStart(void) {
  RTOS_SetTask(dhtProcess, 2, 0);
  DHT_PIN_LOW;
}

static void dhtProcess(void) {
  uint8_t cnt1, cnt2, buf;
  uint16_t tcnt_old, hmdt, tmprtr;

  DHT_PIN_INPUT;
  TCNT1 = 0;

  // ждём первого "0"
  while(bit_is_set(PINB, PB0) && TCNT1<DHT_TOUT1);
  if (TCNT1 >= DHT_TOUT1) {
    RTOS_SetTask(dhtNoAck, 0, 0);
    return;
  }
  // white for end of preamble
  while(bit_is_clear(PINB, PB0));
  while(bit_is_set(PINB, PB0) && TCNT1<DHT_TIMEOUT);
  if (TCNT1 >= DHT_TIMEOUT) {
    RTOS_SetTask(dhtTimeout, 0, 0);
  }
  hmdt = 0; tmprtr = 0;
  for (cnt1=0; cnt1<32; cnt1+=8) { // 0 8 16 24 32
    buf = 0;
    for (cnt2=0; cnt2<8; cnt2++) {
      buf <<= 1;
      // "0", начало периода
      while(bit_is_clear(PINB, PB0)); // ждём начало импульса
      tcnt_old = TCNT1; // начало импульса
      while(bit_is_set(PINB, PB0) && TCNT1<DHT_TIMEOUT); // ждём конец импульса
      if ((TCNT1 - tcnt_old) > 10) {
        buf |= 1;
      }
    }
    switch (cnt1) {
    case 0:
      hmdt = buf << 8;
      break;
    case 8:
      hmdt |= buf;
      break;
    case 16:
      tmprtr = buf << 8;
      break;
    case 24:
      tmprtr |= buf;
      break;
    }
  }
  if (TCNT1 >= DHT_TIMEOUT) {
    RTOS_SetTask(dhtTimeout, 0, 0);
    return;
  }

  dhtData.Humidity = (uint8_t)((hmdt + 5) / 10);
  dhtData.Temperature = tmprtr;

  RTOS_SetTask(dhtEnd, 0, 0);
}

static void dhtEnd(void) {
#ifdef USE_UART
  char buffer[6];

  usart_puts("Humidity: ");
  itoa(dhtData.Humidity, buffer, 10);
  usart_puts(buffer);
  usart_puts(" %\t\t");

  usart_puts("Temperature: ");
  itoa(dhtData.Temperature/10, buffer, 10);
  usart_puts(buffer);
  usart_putc('.');
  itoa(dhtData.Temperature%10, buffer, 10);
  usart_puts(buffer);
  usart_puts("oC\r\n");
#endif // USE_UART
}

static void dhtNoAck(void) {
#ifdef USE_UART
  usart_puts("DHT22 no ACK occurred.\r\n");
#endif // USE_UART
}

static void dhtTimeout(void) {
#ifdef USE_UART
  usart_puts("DHT22 Timeout occurred.\r\n");
#endif // USE_UART
}

void showTemperature(void) {
  dotOn();
  uint8_t a = dhtData.Temperature / 10;
  uint8_t b = dhtData.Temperature % 10;
  Digit[0] = a / 10;
  Digit[1] = a % 10;
  Digit[2] = b;
  Digit[3] = DIGIT_BLANK;
}

void showHumidity(void) {
  dotOff();
  Digit[0] = DIGIT_BLANK;
  Digit[1] = DIGIT_BLANK;
  Digit[2] = dhtData.Humidity / 10;
  Digit[3] = dhtData.Humidity % 10;}
#endif // USE_DHT

/**
  * @brief  Обработка кнопок.
  * @param  : None
  * @retval : None
  */
static void btnProcess(void) {
  uint8_t i;
  for (i=0; i<BTN_NUM; i++) {
    if (Button[i].pin != 0) {
      // button pressed
      if (BUTTON_STATE(Button[i].pin) == 0) {
        Button[i].time ++;
        if (Button[i].time >= BTN_TIME_HOLDED) {
          Button[i].time -= BTN_TIME_REPEATED;
          if (Button[i].holded == Button[i].pressed) {
            // if pressed and holded - same function, then button pressed auto repeat
            ES_PlaceEvent(Button[i].pressed);
          }
        }
      } else {
        // button released
        if (Button[i].time >= (BTN_TIME_HOLDED - BTN_TIME_REPEATED)) {
          ES_PlaceEvent(Button[i].holded); // process long press
        } else if (Button[i].time >= BTN_TIME_PRESSED) {
          ES_PlaceEvent(Button[i].pressed); // process short press
        }
        Button[i].time = 0;
        RTOS_SetTask(btnProcess, BTN_TIME_PAUSE, BTN_SCAN_PERIOD);
      }
    } /* end (pin == 0) */
  } /* end FOR */
}

void showTime(void) {
  switch(RTC.Sec) {
#ifdef USE_DHT
  case 0x20:
  case 0x50:
    showTemperature();
    break;

  case 0x22:
  case 0x52:
    showHumidity();
    break;
#endif // USE_DHT

  case 0x27:
  case 0x28:
  case 0x29:
  case 0x57:
  case 0x58:
  case 0x59:
    dotOn();
    showMMSS();
    break;

  default:
    dotOn();
    RTOS_SetTask(dotOff, 500, 0);

    if (RTC.Hr > 0x09) {
      Digit[0] = RTC.Hr >> 4;
    } else {
      Digit[0] = DIGIT_BLANK;
    }
    Digit[1] = RTC.Hr & 0x0F;
    Digit[2] = RTC.Min >> 4;
    Digit[3] = RTC.Min & 0x0F;
  }

}

void showMMSS(void) {
  Digit[0] = RTC.Min >> 4;
  Digit[1] = RTC.Min & 0x0F;
  Digit[2] = RTC.Sec >> 4;
  Digit[3] = RTC.Sec & 0x0F;
}

void showWDay(void) {
  DISP_WDT = DISP_WDT_TIME;
  Digit[0] = DIGIT_BLANK;
  Digit[1] = DIGIT_BLANK;
  Digit[2] = RTC.WD & 0x0F;
  Digit[3] = DIGIT_BLANK;
}

void showMDay(void) {
  DISP_WDT = DISP_WDT_TIME;
  Digit[0] = RTC.Day >> 4;
  Digit[1] = RTC.Day & 0x0F;
  Digit[2] = DIGIT_BLANK;
  Digit[3] = DIGIT_BLANK;
}

void showMonth(void) {
  DISP_WDT = DISP_WDT_TIME;
  Digit[0] = DIGIT_BLANK;
  Digit[1] = DIGIT_BLANK;
  Digit[2] = RTC.Mon >> 4;
  Digit[3] = RTC.Mon & 0x0F;
}

void showYear(void) {
  DISP_WDT = DISP_WDT_TIME;
  Digit[0] = 0x02;
  Digit[1] = 0x00;
  Digit[2] = RTC.Year >> 4;
  Digit[3] = RTC.Year & 0x0F;
}

void incWDay(void) {
  if (RTC.WD < 7) {
    RTC.WD ++;
  } else {
    RTC.WD = 1;
  }
  Flag.saveCal = 1;
}

void decWDay(void) {
  if (RTC.WD > 1) {
    RTC.WD --;
  } else {
    RTC.WD = 7;
  }
  Flag.saveCal = 1;
}

void incMDay(void) {
  valIncrease(&RTC.Day, 31);
  Flag.saveCal = 1;
}

void decMDay(void) {
  valDecrease(&RTC.Day, 31);
  Flag.saveCal = 1;
}

void incMonth(void) {
  valIncrease(&RTC.Mon, 12);
  if (RTC.Mon == 0) {
    RTC.Mon = 1;
  }
  Flag.saveCal = 1;
}

void decMonth(void) {
  valDecrease(&RTC.Mon, 12);
  if (RTC.Mon == 0) {
    RTC.Mon = 0x12;
  }
  Flag.saveCal = 1;
}

void incYear(void) {
  valIncrease(&RTC.Year, 99);
  Flag.saveCal = 1;
}

void decYear(void) {
  valDecrease(&RTC.Year, 99);
  Flag.saveCal = 1;
}

#ifdef USE_BRIGHT_CONTROL
void showBright(void) {
  DISP_WDT = DISP_WDT_TIME;
  Digit[0] = DIGIT_BLANK;
  Digit[1] = DIGIT_BLANK;
  Digit[2] = brightIdx;
  Digit[3] = DIGIT_BLANK;
}

void incBright(void) {
  if (brightIdx < BRIGHT_IDX_MAX) {
    brightIdx ++;
    OCR2 = pgm_read_byte(&brightConv[brightIdx]);
    Flag.saveEEP = 1;
  }
}

void decBright(void) {
  if (brightIdx > 0 ) {
    brightIdx --;
    OCR2 = pgm_read_byte(&brightConv[brightIdx]);
    Flag.saveEEP = 1;
  }
}
#endif // USE_BRIGHT_CONTROL

static void blink(void) {
  static uint8_t s = 0;
  switch (s) {
  case 0:
    Flag.blinkC = 0;
    RTOS_SetTask(blink, 750, 0);
    s = 1;
    break;

  case 1:
    Flag.blinkC = 1;
    RTOS_SetTask(blink, 250, 0);
    s = 0;
    break;

  default:
    s = 0;
  }
}

void setTimeShow(void) {
  dotOn();
  RTOS_SetTask(dotOff, 500, 0);

  Digit[0] = setRTC.Hr >> 4;
  Digit[1] = setRTC.Hr & 0x0F;
  Digit[2] = setRTC.Min >> 4;
  Digit[3] = setRTC.Min & 0x0F;
}

void setTimeBegin(void) {
  RTC_ReadTime(&setRTC);
  RTOS_SetTask(btnProcess, 500, BTN_SCAN_PERIOD);
}

void setHHBegin(void) {
  Flag.blink0 = 1;
  Flag.blink1 = 1;
  Flag.blink2 = 0;
  Flag.blink3 = 0;
  RTOS_SetTask(blink, 0, 0);
  setTimeShow();
}

void setHHInc(void) {
  valIncrease(&setRTC.Hr, 23);
}

void setHHDec(void) {
  valDecrease(&setRTC.Hr, 23);
}

void setMMBegin(void) {
  Flag.blink0 = 0;
  Flag.blink1 = 0;
  Flag.blink2 = 1;
  Flag.blink3 = 1;
  RTOS_SetTask(blink, 0, 0);
  setTimeShow();
}

void setMMInc(void) {
  valIncrease(&setRTC.Min, 59);
}

void setMMDec(void) {
  valDecrease(&setRTC.Min, 59);
}

void setTimeEnd(void) {
  RTOS_SetTask(btnProcess, 500, BTN_SCAN_PERIOD);

  setRTC.Sec = 0;
  RTC_WriteTime(&setRTC);

  RTOS_DeleteTask(blink);
  Flag.blink0 = 0;
  Flag.blink1 = 0;
  Flag.blink2 = 0;
  Flag.blink3 = 0;
  Flag.blinkC = 0;

  RTC_ReadTime(&RTC);
}

/**
  * @brief  Increase BCD value.
  * @param  : val, max
  * @retval : None
  */
static void valIncrease(uint8_t * val, uint8_t max) {
  uint8_t bin = 10 * (*val >> 4) + (*val & 0x0f);
  if (bin < max) {
    bin ++;
  } else {
    bin = 0;
  }
  *val = ((bin / 10 ) << 4) | (bin % 10);
}

/**
  * @brief  Decrease BCD value.
  * @param  : value, max
  * @retval : None
  */
static void valDecrease(uint8_t * val, uint8_t max) {
  uint8_t bin = 10 * (*val >> 4) + (*val & 0x0f);
  if (bin > 0) {
    bin --;
  } else {
    bin = max;
  }
  *val = ((bin / 10 ) << 4) | (bin % 10);
}

#ifdef USE_UART
void usart_putc (char send) {
    // Do nothing for a bit if there is already
    // data waiting in the hardware to be sent
    while ((UCSRA & (1 << UDRE)) == 0) {};
    UDR = send;
}

void usart_puts (const char *send) {
    // Cycle through each character individually
    while (*send) {
        usart_putc(*send++);
    }
}
#endif // USE_UART

/**
 *  П р е р ы в а н и я
 */

/**
 * @brief RTC one seconds interrupt
 */
ISR (INT1_vect) {
  Flag.RTC_Int = 1;
}

/**
 * @brief Refresh Nixie output
 * @note  Digit[] must be in range 0x00 - 0x0F
 */
#pragma GCC optimize ("O3")
ISR(TIMER2_OVF_vect) {
  static uint8_t idx = 0;

  // reload timer
  TCNT2 = TIMER2_CNT;

  // read current register value and clean bits
  uint8_t pd = PORTD & ~ANOD_PINS;
  uint8_t pc = PORTC & ~DIGIT_PINS;

#ifndef USE_BRIGHT_CONTROL
  // power off lamps
  PORTD = pd;
  PORTC = pc;
#endif

  switch (idx) {
  case 0:
    // output lamp value
    PORTC = pc | Digit[0];
    // power on lamp
    if (Digit[0] != DIGIT_BLANK) {
      if (Flag.blink0 == 0 || Flag.blinkC == 0) {
        PORTD = pd | ANOD1;
      }
    }
    idx = 1;
    break;

  case 1:
    PORTC = pc | Digit[1];
    if (Digit[1] != DIGIT_BLANK) {
      if (Flag.blink1 == 0 || Flag.blinkC == 0) {
        PORTD = pd | ANOD2;
      }
    }
    idx = 2;
    break;

  case 2:
    PORTC = pc | Digit[2];
    if (Digit[2] != DIGIT_BLANK) {
      if (Flag.blink2 == 0 || Flag.blinkC == 0) {
        PORTD = pd | ANOD3;
      }
    }
    idx = 3;
    break;

  case 3:
    PORTC = pc | Digit[3];
    if (Digit[3] != DIGIT_BLANK) {
      if (Flag.blink3 == 0 || Flag.blinkC == 0) {
        PORTD = pd | ANOD4;
      }
    }
    idx = 0;
    break;

  default:
    idx = 0;
    break;
  }
}

#ifdef USE_BRIGHT_CONTROL
/**
 * @brief Power Off Nixie output
 * @note  For Brightnes dimming
 */
#pragma GCC optimize ("O3")
ISR(TIMER2_COMP_vect) {
  // power off lamps
  PORTD &= ~ANOD_PINS;
  PORTC &= ~DIGIT_PINS;
}
#endif // USE_BRIGHT_CONTROL

/**
 * @brief заглушка для неиспользуемых прерываний
 */
ISR(__vector_default,ISR_NAKED) {
  reti();
}