#include "SoftI2C.h"

SoftI2C::SoftI2C(uint8_t sda, uint8_t scl, uint32_t freq) {
  sda_pin = sda;
  scl_pin = scl;
  delay_us = 1000000 / (2 * freq); // نیم پریود
}

void SoftI2C::begin() {
  pinMode(sda_pin, INPUT_PULLUP);
  pinMode(scl_pin, INPUT_PULLUP);
  delay(10);
}

void SoftI2C::end() {
  stop_condition();
  pinMode(sda_pin, INPUT);
  pinMode(scl_pin, INPUT);
}

void SoftI2C::start_condition() {
  pinMode(sda_pin, OUTPUT);
  sda_high();
  scl_high();
  i2c_delay();
  sda_low();
  i2c_delay();
  scl_low();
  i2c_delay();
}

void SoftI2C::stop_condition() {
  pinMode(sda_pin, OUTPUT);
  sda_low();
  i2c_delay();
  scl_high();
  i2c_delay();
  sda_high();
  i2c_delay();
  pinMode(sda_pin, INPUT_PULLUP);
  pinMode(scl_pin, INPUT_PULLUP);
}

bool SoftI2C::write_byte(uint8_t data) {
  pinMode(sda_pin, OUTPUT);
  
  for(int i = 7; i >= 0; i--) {
    if(data & (1 << i)) {
      sda_high();
    } else {
      sda_low();
    }
    i2c_delay();
    scl_high();
    i2c_delay();
    scl_low();
    i2c_delay();
  }
  
  // خواندن ACK
  pinMode(sda_pin, INPUT_PULLUP);
  i2c_delay();
  scl_high();
  i2c_delay();
  bool ack = !read_sda();
  scl_low();
  i2c_delay();
  
  return ack;
}

uint8_t SoftI2C::read_byte(bool ack) {
  pinMode(sda_pin, INPUT_PULLUP);
  uint8_t data = 0;
  
  for(int i = 7; i >= 0; i--) {
    scl_high();
    i2c_delay();
    if(read_sda()) {
      data |= (1 << i);
    }
    scl_low();
    i2c_delay();
  }
  
  // ارسال ACK/NACK
  pinMode(sda_pin, OUTPUT);
  if(ack) {
    sda_low();
  } else {
    sda_high();
  }
  i2c_delay();
  scl_high();
  i2c_delay();
  scl_low();
  i2c_delay();
  
  return data;
}

bool SoftI2C::begin_transmission(uint8_t addr) {
  start_condition();
  return write_byte(addr << 1); // آدرس + بیت write
}

bool SoftI2C::write(uint8_t data) {
  return write_byte(data);
}

bool SoftI2C::end_transmission() {
  stop_condition();
  return true;
}

uint8_t SoftI2C::request_from(uint8_t addr, uint8_t count) {
  start_condition();
  if(!write_byte((addr << 1) | 1)) { // آدرس + بیت read
    return 0;
  }
  return count;
}

uint8_t SoftI2C::read() {
  return read_byte(true);
}

bool SoftI2C::available() {
  return true;
}