#include <OneWire.h>
#include <DallasTemperature.h>
#include <ESP8266WiFi.h>
#include <ModbusIP_ESP8266.h>
#include "config.h"
#include "LittleFS.h"

#define RELAY_PIN D2
#define TEMP_SENSOR_PIN D5
// network
// After how much time without connection we will 
// reboot (in millis)
#define NON_CONNECTED_REBOOT_TIMEOUT 60000 
#define RECONNECT_TIMEOUT 10000

IPAddress my_ip(MY_IP);
IPAddress gateway(MY_GW);
IPAddress subnet(MY_NET);

// modbus consts and works
#define TCP_PORT 15000
#define POLL_INTERVAL 10000
#define T_UPDATE_INTERVAL 2000

#define MODE_AUTO 0
#define MODE_MANUAL 1

#define REGISTER_ON_TEMP 0
#define REGISTER_OFF_TEMP 1
#define REGISTER_MODE 2
#define REGISTER_CUR_TEMP 3
#define REGISTER_CUR_STATE 4
#define REGISTER_SECONDARY_TEMP 5

ModbusIP mb;
OneWire oneWire(TEMP_SENSOR_PIN);
DallasTemperature sensor(&oneWire);

char id[64];

long last_poll;
long last_update;

int t_on = 100;
int t_off = 1000;
int cur_mode = MODE_AUTO;
int cur_t = 0;
int cur_state = 0;

bool TryLoad(char *filename)
{
  File f = LittleFS.open(filename, "r");
	if (!f) return false;
	String s = f.readStringUntil('\n');
	t_on = atoi(s.c_str());
  s = f.readStringUntil('\n');
	t_off = atoi(s.c_str());
  f.close();
  if (t_on == 0) return false;
	return true;
}

void LoadState()
{
  if (TryLoad("/settings.txt")) return;
  TryLoad("/settings.txt.bak");
}

void SaveTo(char *filename)
{
  File f = LittleFS.open(filename, "w");
	if (!f) return;
	f.println(t_on);
  f.println(t_off);
	f.close();
}

void SaveState()
{
  SaveTo("/settings.txt");
	SaveTo("/settings.txt.bak");
}


void setup() 
{
	if (!LittleFS.begin())
	{
		Serial.println("Unable to mount the filesystem");
		ESP.restart();
	}
	LoadState();
	pinMode(RELAY_PIN, OUTPUT);
  pinMode(TEMP_SENSOR_PIN, INPUT);
	Serial.begin(115200);
	Serial.println("Initialised...");

	WiFi.mode(WIFI_STA);
	WiFi.config(my_ip, gateway, subnet);
	WiFi.setAutoReconnect(true);
	WiFi.begin(WIFI_NAME, WIFI_PASS);
	Serial.print("Connecting");
	delay(500);
	Serial.println();

	uint8_t macAddr[6];
	WiFi.macAddress(macAddr);
	sprintf(id, "%02x:%02x:%02x:%02x:%02x:%02x", macAddr[0], macAddr[1], macAddr[2], macAddr[3], macAddr[4], macAddr[5]);
	Serial.printf("mac address: %s\n", id);
	last_poll = millis();
	
	mb.server(15000);
	mb.addHreg(REGISTER_ON_TEMP, t_on);
	mb.addHreg(REGISTER_OFF_TEMP, t_off);
	mb.addHreg(REGISTER_MODE, cur_mode);
	mb.addHreg(REGISTER_CUR_TEMP, cur_t);
	mb.addHreg(REGISTER_CUR_STATE, cur_state);
	mb.addHreg(REGISTER_SECONDARY_TEMP, cur_t);
  //
  sensor.begin();
  sensor.setResolution(12);
  sensor.requestTemperatures();
}

void UpdateCurrent()
{
	cur_t = int(sensor.getTempCByIndex(0) * 100);
	last_update = millis();
}

unsigned long last_connected = 0;
unsigned long last_connecting = 0;

void loop() 
{
	unsigned long current = millis();
	int u = 0;
	if (current < last_update || current - last_update >= T_UPDATE_INTERVAL)
	{
		UpdateCurrent();
		u = 1;
	}
	mb.task();
	t_on = mb.Hreg(REGISTER_ON_TEMP);
	t_off = mb.Hreg(REGISTER_OFF_TEMP);
	cur_mode = mb.Hreg(REGISTER_MODE);
	if (cur_mode == 0)
	{
		if (cur_t < t_on) cur_state = 1;
		else if (cur_t > t_off) cur_state = 0;
		mb.Hreg(REGISTER_CUR_STATE, cur_state);
	}
	else
	{
		cur_state = mb.Hreg(REGISTER_CUR_STATE);
	}
	digitalWrite(RELAY_PIN, cur_state);
	if (u) 
	{
    SaveState();
		Serial.println("Cur state");
		Serial.println(cur_state);
    Serial.println(cur_t);
	}
	mb.Hreg(REGISTER_ON_TEMP, t_on);
	mb.Hreg(REGISTER_OFF_TEMP, t_off);
	mb.Hreg(REGISTER_MODE, cur_mode);
	mb.Hreg(REGISTER_CUR_TEMP, cur_t);
	mb.Hreg(REGISTER_SECONDARY_TEMP, cur_t);
	if (WiFi.status() != WL_CONNECTED)
	{
		if (current < last_connecting || current - last_connecting > RECONNECT_TIMEOUT)
	  {   
        WiFi.reconnect();
        last_connecting = current;
    }
	}
	else
	{
		last_connected = current;
	}
	if (current < last_connected || current - last_connected > NON_CONNECTED_REBOOT_TIMEOUT)
	{
    SaveState();
		ESP.restart();
	}
}