// Standard ESP8266 libs from project folder
#include <ESP8266mDNS.h>
#include <ESP8266HTTPUpdateServer.h>
#include <ESP8266WiFi.h>
#include <DNSServer.h>
#include <ESP8266WebServer.h>
#include <ESP8266HTTPClient.h>

#include <WiFiClient.h>  // WiFiClient
#include <WiFiManager.h> // WiFiManager from bib manager

// Project includes
#include "constants.h"
#include "config.h"
#include "config_user.h"

//*************************************************************************//
// check if some settings are correct

#ifdef HTTP_CALL_ON_WINDSPEED_EXCEED
#if (HTTP_CALL_ON_WINDSPEED_INTERVAL_S < WIND_SENSOR_MEAS_TIME_S)
#error "HTTP_CALL_ON_WINDSPEED_INTERVAL_S < WIND_SENSOR_MEAS_TIME_S"
#endif
#endif

//*************************************************************************//
// constant variables

const uint8_t VALUES = 8; // see constants.h file - count of number of SENSOR_ defines
float currentSensorData[VALUES] = { nanf("no value"), nanf("no value"), nanf("no value"),
                                    nanf("no value"), nanf("no value"), nanf("no value"),
                                    nanf("no value"), nanf("no value") };
float (*sensors[VALUES])() = {};

uint8_t sensor_value[] = { SENSOR_TEMPERATURE,
                           SENSOR_HUMIDITY,
                           SENSOR_LIGHT,
                           SENSOR_WINDSPEED,
                           SENSOR_PRESSURE,
                           SENSOR_BAT_VOLTAGE,
                           SENSOR_ESAVEMODE,
                           SENSOR_BATCHARGESTATE };

uint32_t update_sensor_cnt           = 0;
uint32_t update_webserver_cnt        = 0;
uint32_t update_windspeed_exceed_cnt = 0;
uint32_t wifi_check_interval_counter = 0;

const String wifiName = "oko-weather-" + DEVICE_NAME;

WiFiManager wifiManager;

uint8_t fsm_state = FSM_STATE_WU;

uint8_t sensor_cnt = 0;

boolean validData = false;

//*************************************************************************//

void debug(String x)
{
#ifdef DEBUG
  Serial.println(x);
#endif

#ifdef USE_LOGGER
  logdata(String(millis()) + ":" + x);
#endif
}

//*************************************************************************//

void setup()
{

#if defined(DEBUG) || defined(SERIAL_FEATURE)
  Serial.begin(115200);
#endif

  // Pin settings
  pinMode(BAT_CHARGED_PIN,        INPUT);
  pinMode(BAT_CHARGING_PIN,       INPUT);
  pinMode(STATUS_LED_PIN,        OUTPUT);
  pinMode(ANEMOMETER_PIN,  INPUT_PULLUP);
  pinMode(A0,                     INPUT);

  digitalWrite(STATUS_LED_PIN, LOW);

#ifndef BAT_PINS_D34
  debug("D5 D6 used as battery pins");
#else
  debug("D3 D4 used as battery pins");
#endif

#ifdef BATTERY_POWERED
  criticalBatCheck();
#endif

  wifiConnect();
  debug("Connected!");

#ifdef INFLUXDB_FEATURE
  influxdb_begin();
#endif

  initSensors();

#ifdef WEBUPDATER_FEATURE
#ifndef BATTERY_POWERED
  setupWebUpdater(DEVICE_NAME, WiFi.localIP().toString());
#endif
#endif

  //It's magic! leave in
  delay(100);

#ifdef BATTERY_POWERED
  debug("battery powered");
  _loop();

  digitalWrite(STATUS_LED_PIN, LOW);

  criticalBatCheck();

  WiFi.mode(WIFI_OFF);
  WiFi.forceSleepBegin();

  debug("deep sleep");

  // the ESP.deepSleep requires microseconds as input, after the
  // sleep the system will run into the setup routine
  ESP.deepSleep(POWERSAVING_SLEEP_S * 1000000, WAKE_RF_DEFAULT);
  delay(100);
#endif

#ifdef ENABLE_WATCHDOG
  // Enable the internal watchdog
  ESP.wdtEnable(WATCHDOG_TIMEOUT_MS);
#endif

}

//*************************************************************************//

void initSensors()
{
  // Initialize and configure the sensors
#ifdef SENSOR_APDS9930
  if (sensor_apds9930_begin()) {
    sensors[SENSOR_LIGHT] = &apds9930_light;
  }
#endif

#ifdef SENSOR_APDS9960
  if (sensor_apds9960_begin()) {
    sensors[SENSOR_LIGHT] = &apds9960_light;
  }
#endif

#ifdef SENSOR_BME280
  //Temperature + pressure
  if (sensor_bme280_begin(BME_ADDRESS)) {
    sensors[SENSOR_TEMPERATURE] = &bme280_temperature;
    sensors[SENSOR_HUMIDITY]    = &bme280_humidity;
    sensors[SENSOR_PRESSURE]    = &bme280_pressure;
  }
#endif

#ifdef SENSOR_WIND
  sensors[SENSOR_WINDSPEED] = &wind_speed;
#endif

#ifdef SENSOR_BATTERY
  sensors[SENSOR_BAT_VOLTAGE]    = &battery_voltage;
  sensors[SENSOR_BATCHARGESTATE] = &battery_charging;
  sensors[SENSOR_ESAVEMODE]      = &isEnergySavingMode;
#endif
}

//*************************************************************************//

void wifiConnectionCheck()
{

  if ((wifi_check_interval_counter + WIFI_CHECK_INTERVAL_MS) > millis())
  {
    // if check interval is not exceeded abort check
    return;
  }

  wifi_check_interval_counter = millis();

  if (WiFi.status() == WL_CONNECTED)
  {
    // if we are connected
    return;
  }

  debug("no connection or time to check " + String(WiFi.status() == WL_CONNECTED));

  wifiConnect();

}

void wifiConnect()
{

  // Establish WiFi connection if not already applied

  wifiManager.setMinimumSignalQuality(WIFI_MINIMUM_SIGNAL_QUALITY);
  // the time in seconds to wait for the known wifi connection
  wifiManager.setConnectTimeout(WIFI_AUTOCONNECT_TIMEOUT_S);
  // the time in seconds to wait for the user to configure the device
  wifiManager.setTimeout(WIFI_CONFIG_PORTAL_TIMEOUT_S);

  while (!wifiManager.autoConnect(wifiName.c_str(), "DEADBEEF"))
  {

#ifdef SLEEP_IF_NO_WLAN_CONNECTION
    // If autoconnect to WLAN failed and no client connected, go to deep sleep
    ESP.deepSleep(POWERSAVING_SLEEP_S * 1000000, WAKE_RF_DEFAULT);
    delay(100);
#endif

#ifndef SLEEP_IF_NO_WLAN_CONNECTION
    // sleep a few seconds and go on trying to connect
    debug("WiFi connection failed, try again in 5 seconds...");
    delay(5000);
#endif

  }

}

//*************************************************************************//

#ifdef BATTERY_POWERED
void criticalBatCheck()
{
  float volt = battery_voltage();
  if (volt <= BAT_EMERGENCY_DEEPSLEEP_VOLTAGE)
  {
    debug("Bat Voltage: " + String(volt) + " V");
    debug("Low battery, going into deep sleep.");
    // Casting to an unsigned int, so it fits into the integer range
    ESP.deepSleep(1U * EMERGENCY_SLEEP_S * 1000000); // battery low, shutting down
    delay(100);
  }
}
#endif

//*************************************************************************//

void loop()
{

#ifdef ENABLE_WATCHDOG
  ESP.wdtFeed();
#endif

#ifdef BATTERY_POWERED
  delay(50);
  return;
#endif

  // call sub loop function
  _loop();

  // Needed to give WIFI time to function properly
  delay(DELAY_LOOP_MS);

}

//*************************************************************************//

void _loop()
{

  switch (fsm_state)
  {

    case FSM_STATE_WU:
      //debug("web updater call if required");
#ifdef WEBUPDATER_FEATURE
      if ((update_webserver_cnt + (UPDATE_WEBSERVER_INTVERVAL_S * 1000)) <= millis())
      {
        //debug("web updater call");
        update_webserver_cnt = millis();
        doWebUpdater();
      }
#endif
      fsm_state = FSM_STATE_WSE;
      break;

    case FSM_STATE_WSE:
      debug("wind speed exceeded check if required");
#ifdef HTTP_CALL_ON_WINDSPEED_EXCEED
      if ((update_windspeed_exceed_cnt + (HTTP_CALL_ON_WINDSPEED_INTERVAL_S * 1000)) <= millis())
      {
        debug("reading wind sensor exceed");

        update_windspeed_exceed_cnt = millis();

        readWindSpeedExceed();
      }
#endif
      fsm_state = FSM_STATE_RS;
      break;

    case FSM_STATE_RS:
      //debug("reset time check if required");
#ifdef RESET_ESP_TIME_INTERVAL
      // if millis() reached interval restart ESP
      if (RESET_ESP_TIME_INTERVAL_MS <= millis())
      {
        debug("resetting firmware intentionally");
        // Push reset button after flashing once or do a manual power cycle to get the functionality working.
        ESP.restart();
      }
#endif
      fsm_state = FSM_STATE_WC;
      break;

    case FSM_STATE_WC:
      wifiConnectionCheck();
      fsm_state = FSM_STATE_WS;
      break;

    case FSM_STATE_WS:
      //debug("disable measure of wind speed if required");
#ifdef defined(BATTERY_POWERED) && defined(SENSOR_WIND)
      if (energySavingMode() == 1) {
        // Disable expensive tasks
        sensors[SENSOR_WINDSPEED] = 0;
        //debug("read of wind sensor because of low battery disabled");
      } else {
        sensors[SENSOR_WINDSPEED] = &wind_speed;
        //debug("read of wind sensor because of high battery enabled");
      }
#endif
      sensor_cnt = 0;
      fsm_state = FSM_STATE_US;
      break;

    case FSM_STATE_US:
      //debug("read sensor data check");
      if ((update_sensor_cnt + (UPDATE_SENSOR_INTERVAL_S * 1000)) <= millis())
      {
        debug("read sensor data " + String(sensor_cnt));
        if (sensors[sensor_cnt])
        {
          debug("sensors[sensor_value[" + String(sensor_cnt) + " ]]=" + String((int)sensors[sensor_value[sensor_cnt]]) + ":" + String(sensor_value[sensor_cnt]));
          currentSensorData[sensor_cnt] = sensors[sensor_value[sensor_cnt]]();
          //currentSensorData[sensor_cnt] = sensor_cnt;

        } else {

          debug("sensors[sensor_value[" + String(sensor_cnt) + "]]=nan");
          currentSensorData[sensor_cnt] = nan("no value");
        }
  
        if (sensor_cnt < VALUES)
        {
          sensor_cnt++;
          fsm_state = FSM_STATE_US; // jump to same state again, more sensors to read
        } else {
          update_sensor_cnt = millis();
          sensor_cnt = 0;
          fsm_state = FSM_STATE_SC; // next state
        }
      } else {
        debug("skip read sensor data");
        fsm_state = FSM_STATE_WU; // no new data, reset FSM
      }
      break;

    case FSM_STATE_SC:
      debug("log to serial if required");
#ifdef SERIAL_FEATURE
      logToSerial(currentSensorData);
#endif
      fsm_state = FSM_STATE_ID;
      break;

    case FSM_STATE_ID:
      debug("send data to influxdb if required");
#ifdef INFLUXDB_FEATURE
      for (uint8_t i = 0; i < 5 and validData == false; i++)
      {
        if (currentSensorData[i] != 0)
        {
          validData = true;
        }
      }

      if (validData == true)
      {
        // send data only if valid data is available
        pushToInfluxDB(DEVICE_NAME, currentSensorData);
      }
#endif
      fsm_state = FSM_STATE_SD;
      break;

    case FSM_STATE_SD:
      debug("set sensor data in webupdater if required");
#ifdef WEBUPDATER_FEATURE
      setSensorData(currentSensorData);
#endif
      fsm_state = FSM_STATE_WU;
      break;

    default:
      fsm_state = FSM_STATE_WU;
      break;

  } // close of switch

  //delay(100); // TODO warum hier ein delay?

  //debug("FSM state = " + String(fsm_state));
  /*if (fsm_state == FSM_STATE_WU)
  {
    debug("----------");
  }*/
}

//*************************************************************************//

void readWindSpeedExceed()
{
  if (sensors[SENSOR_WINDSPEED])
  {
    // read from windspeed sensorSTATUS_LED_PIN
    digitalWrite(STATUS_LED_PIN, HIGH);
    currentSensorData[SENSOR_WINDSPEED] = sensors[SENSOR_WINDSPEED]();
    digitalWrite(STATUS_LED_PIN, LOW);

    if (currentSensorData[SENSOR_WINDSPEED] >= HTTP_CALL_ON_WINDSPEED_EXCEED_MPS)
    {
      digitalWrite(STATUS_LED_PIN, HIGH);

      // call the url HTTP_CALL_ON_WINDSPEED_URL
      WiFiClient client;
      HTTPClient http;

      http.begin(client, String(HTTP_CALL_ON_WINDSPEED_URL).c_str());
      // Send HTTP GET request
      int httpResponseCode = http.GET();

      if (httpResponseCode > 0) {
        String response = http.getString();
        debug("http response code: " + String(httpResponseCode) + " = " + response);
        // TODO handle response
      }

      http.end();
      debug("Called windspeed exceed callout");
      digitalWrite(STATUS_LED_PIN, LOW);
    }

#ifdef WEBUPDATER_FEATURE
    setSensorData(currentSensorData);
#endif

  } else {
    currentSensorData[SENSOR_WINDSPEED] = nan("no value");
  }
}

//*************************************************************************//

void logToSerial(float sensorValues[])
{
  Serial.println("");
  Serial.println("Current readings:");
  Serial.println("Temperature: " + String(sensorValues[SENSOR_TEMPERATURE]) + " °C");
  Serial.println("Humidity: " + String(sensorValues[SENSOR_HUMIDITY]) + " %");
  Serial.println("Light: " + String(sensorValues[SENSOR_LIGHT]) + " Lux");
  Serial.println("Windspeed: " + String(sensorValues[SENSOR_WINDSPEED]) + " km/h");
  Serial.println("Pressure: " + String(sensorValues[SENSOR_PRESSURE]) + " hPa");
  Serial.println("Bat Voltage: " + String(sensorValues[SENSOR_BAT_VOLTAGE]) + " V");
  Serial.println("Bat charge state: " + String(sensorValues[SENSOR_BATCHARGESTATE]));
  Serial.println("Energy saving: " + String(sensorValues[SENSOR_ESAVEMODE]));
}

//*************************************************************************//