#include <stdint.h>
#include "os_type.h"
#include "osapi.h"
#include "user_interface.h"
#include "gpio.h"
#include "onewire.h"

sint8 ICACHE_FLASH_ATTR init(oneWire_t *owDev) {
  uint32_t time;
  // reset the ow line, check for presence?
  time = system_get_time() + 500;
  gpio_output_set(0, BIT4, BIT4, 0); // pull GPIO4 low
  while(system_get_time() < time); // delay 500uS
  gpio_output_set(0, 0, 0, BIT4); // let go of GPIO4
  time = system_get_time() + 60;
  while(system_get_time() < time);
  uint8_t presence = (uint8_t)(gpio_input_get() >> 4) & 0x1;
  if(presence) {
    return 1;
  } else {
    return -1;
  }
}

void ICACHE_FLASH_ATTR transact(oneWire_t *owDev, ds18b20_cmds cmd) {
  uint32_t time;
  uint8_t sendBit;
  uint8_t inBit = 0x00;
  uint8_t inByte = 0x00;
  if((cmd == SKIP_ROM) | (cmd == CONVERT_T)) {
    for(uint8_t i = 7; i >= 0; i--) {
      sendBit = (cmd >> i) & 0x1;
      if(sendBit == 1) {
	time = system_get_time() + 10;
	gpio_output_set(0, BIT4, BIT4, 0); // pull low
	while(system_get_time() < time);
	gpio_output_set(0, 0, 0, BIT4); // let go
      } else {
	time = system_get_time() + 100;
	gpio_output_set(0, BIT4, BIT4, 0); //pull low
	while(system_get_time() < time);
	gpio_output_set(0, 0, 0, BIT4);
      }
    }
  } else if(cmd == SCRATCH_READ) {
    for(uint8_t i = 7; i >= 0; i--) {
      sendBit = (cmd >> i) & 0x1;
      if(sendBit == 1) {
	time = system_get_time() + 10;
	gpio_output_set(0, BIT4, BIT4, 0); // pull low
	while(system_get_time() < time);
	gpio_output_set(0, 0, 0, BIT4); // let go
      } else {
	time = system_get_time() + 100;
	gpio_output_set(0, BIT4, BIT4, 0); //pull low
	while(system_get_time() < time);
	gpio_output_set(0, 0, 0, BIT4);
      }
    }
    // now read the scratchpad
    for(uint8_t i = 0; i < 2; i++) {
      for(uint8_t j = 0; j < 8; j++) {
	time = system_get_time() + 8;
	gpio_output_set(0, BIT4, BIT4, 0);
	while(system_get_time() < time);
	gpio_output_set(0, 0, 0, BIT4);
	inBit = (uint8_t)(gpio_input_get() >> 4) & 0x01;
	inByte |= inBit << j;
      }
      owDev->scratchpad[i] = inByte;
    }
  }
}