#include <DHT.h>
#include <EEPROM.h>
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <Wire.h>

#define DHTPIN 2     // D4 what digital pin we're connected to
#define DHTTYPE DHT11   // DHT 11

bool debug = false;

// DHT humidity sensor
DHT dht(DHTPIN, DHTTYPE);

//Wifi stuff
const char* ssid     = "";
const char* password = "";
WiFiClient espClient;

//mqtt stuff
const char* mqtt_user = "";
const char* mqtt_pass = "";
const char* clientId = "";
const char* MQTTtopic = "";
IPAddress server(192, 168, 1 ,42);
PubSubClient client(server, 1883, espClient);

//MPU-6050 stuff
const int MPU_addr=0x68;  // I2C address of the MPU-6050
int16_t AcX,AcY,AcZ,Tmp,GyX,GyY,GyZ;
// Vars for an average of the gyro readings.
const int numReadings = 6;
const int threshold = 20000;              // Shakiness at which we consider the washing machine to be running
unsigned int readIndex = 0;              // the index of the current reading
unsigned long shakiness = 0;             // Commulative fluctuation in XYZ acc

void setup_wifi() {

  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  randomSeed(micros());

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    // Attempt to connect
    if (client.connect(clientId, mqtt_user, mqtt_pass)) {
      Serial.println("connected");
      // Once connected, publish an announcement...
      // client.publish(MQTTTopic, "Starting...");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void setup_gyro(){
  Wire.begin();
  Wire.beginTransmission(MPU_addr);
  Wire.write(0x6B);  // PWR_MGMT_1 register
  Wire.write(0);     // set to zero (wakes up the MPU-6050)
  Wire.endTransmission(true);
}


void setup() {
  Serial.begin(115200);
  dht.begin();
  setup_wifi();
  setup_gyro();
  client.setServer(server, 1883);
}


void read_gyro(){
    /*
    We consider the washing machine to be shaking, when there's much fluctuation in the X, Y, Z readings.
    */
    int16_t Old_AcX,Old_AcY,Old_AcZ;
    shakiness = 0;
    readIndex = 0;
    for (readIndex; readIndex < numReadings; readIndex++) {
        Old_AcX = AcX; Old_AcY = AcY; Old_AcZ = AcZ;
        Wire.beginTransmission(MPU_addr);
        Wire.write(0x3B);  // starting with register 0x3B (ACCEL_XOUT_H)
        Wire.endTransmission(false);
        Wire.requestFrom(MPU_addr,14,true);  // request a total of 14 registers
        AcX=Wire.read()<<8|Wire.read();  // 0x3B (ACCEL_XOUT_H) & 0x3C (ACCEL_XOUT_L)
        AcY=Wire.read()<<8|Wire.read();  // 0x3D (ACCEL_YOUT_H) & 0x3E (ACCEL_YOUT_L)
        AcZ=Wire.read()<<8|Wire.read();  // 0x3F (ACCEL_ZOUT_H) & 0x40 (ACCEL_ZOUT_L)
        Tmp=Wire.read()<<8|Wire.read();  // 0x41 (TEMP_OUT_H) & 0x42 (TEMP_OUT_L)
        Tmp=(Tmp/340.00+36.53);
        // add the reading to the total:
        if (readIndex > 0) {
            shakiness = shakiness + abs(AcX - Old_AcX) + abs(AcY - Old_AcY) + abs(AcZ - Old_AcZ);
        }
        delay(333);
        }
    // calculate the average:
    Serial.print("AcX: "); Serial.print(AcX); Serial.print(" AcY: "); Serial.print(AcY);Serial.print(" AcZ: "); Serial.println(AcZ);
    Serial.print("shakiness: "); Serial.println(shakiness);
}

void loop() {
  delay(2000);
  read_gyro();

  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();

  // Check if any reads failed and exit early (to try again).
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Compute heat index in Celsius (isFahreheit = false)
  float hic = dht.computeHeatIndex(t, h, false);

  // battery connected wiyth 100kOHM resistor to A0
  pinMode(A0, INPUT);
  unsigned int raw = analogRead(A0);
  float volt = raw * 4.2 / 1023.0;


  bool running = false;
  if (shakiness > threshold) {
      running = true;
  }


  // reserve 1 byte of eeprom
  EEPROM.begin(2);
  byte romstore[2];
  romstore[0] = EEPROM.read(0);
  romstore[1] = EEPROM.read(1);

  // 123 in [0] is a marker to detect first use
  if (romstore[0] != 123) {
     romstore[0] = 123;
     // romstore[1] is a marker of how many cycles ago we were running.
     // Only 1-10 is of real interest...
     romstore[1] = 254;
  }

  // Only report that whe are running when we measure running for the second time.
  bool report_running = false;
  if (running and romstore[1] == 0) {
    report_running = true;
  }

  if (running) {
     romstore[1] = 0;
  } else if (romstore[1] < 254) {
    romstore[1]++;
  }
  //  system_rtc_mem_write(64, rtcStore, 2);
  EEPROM.write(0, romstore[0]);
  EEPROM.write(1, romstore[1]);
  EEPROM.end();


 // ------------------------ Send message

  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  String payload = "{\"Humidity\":" + String(h) +
                    ",\"Temp\":" + String(t) +
                    ",\"GyroTemp\":" + String(Tmp) +
                    ",\"Hic\":" + String(hic) +
                    ",\"Volt\":" + String(volt) +
                    ",\"Shakiness\":" + String(shakiness) +
                    //",\"AcX\":" + String(AcX) +
                    //",\"AcY\":" + String(AcY) +
                    //",\"AcZ\":" + String(AcZ) +
                    ",\"running\":" + String(report_running) +
                    "}";

  delay(2000);

  Serial.println(payload);
  int succ = false;
  int attempts = 10;
  while (succ == false && attempts-- > 0) {
    succ = client.publish(MQTTtopic, payload.c_str());
    Serial.print('Sending: ');
    Serial.println(succ);
    delay(500);
  }


  // we're checking if the machine starts again every minute for ten minutus
  // after the last detection of movement.
  if (debug != true) {
    if (romstore[1] < 10) {
      ESP.deepSleep(60e6);
    }
    // sleep 10 minutes.
    ESP.deepSleep(600e6);
  }
}