/*
 * Outside Lighting Controll - ESP8266 Client
 * 
 * copyright: Jannik Beyerstedt | http://jannikbeyerstedt.de | code@jannikbeyerstedt.de
 * license: http://www.gnu.org/licenses/gpl-3.0.txt GPLv3 License
 */

#include <ESP8266WiFi.h>

const char* host = "ursaminor.fra80";
String serviceUri = "/lightscontrol/service.php";
const int httpPort = 80;

const int relaisPin = D2;

bool lightState = false;
unsigned int lightTime = 0;
bool updated = false;

const unsigned int wifiConnectTimeout = 20;     /* num of 500ms intervals */
const unsigned int serverConnectAttempts = 10;  /* max num of attempts */
unsigned int srvConnCnt;

bool wifiConnect(void) {
  unsigned int cycles = 0;
  
  Serial.println("Connecting to WiFi");
  WiFi.mode(WIFI_STA);
  WiFi.begin("WLAN-Bey-IoT", "IoT-Fra80");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");

    cycles++;
    if (cycles > wifiConnectTimeout) {
      return false;
    }
  }
  Serial.print(" ok, IP: ");
  Serial.println(WiFi.localIP());
  return true;
}

void setup() {
  Serial.begin(115200);
  delay(100);

  pinMode(0, OUTPUT);
  pinMode(relaisPin, OUTPUT);
  digitalWrite(relaisPin, HIGH);  /* failsafe */

  while (!wifiConnect()) {
    /* wait 5s and try again */
    delay(5000);
  }

  srvConnCnt = 0;
}

void loop() {
  if (srvConnCnt > serverConnectAttempts) {
    digitalWrite(relaisPin, HIGH);  /* failsafe */
  }
  
  Serial.print("connecting to ");
  Serial.println(host);

  WiFiClient client;
  if (!client.connect(host, httpPort)) {
    Serial.println("ERROR connection failed");
    srvConnCnt++;
    return;
  }
  srvConnCnt = 0;

  // This will send the request to the server
  String httpRequest = "GET " + serviceUri + " HTTP/1.1\r\n" +
                       "Host: " + host + "\r\n" +
                       "Connection: close\r\n\r\n";
  client.print(httpRequest);
  delay(100);


  // Read the lines of the reply from server

  // first expect a HTTP 200 status code
  while (client.available()) {
    String line = client.readStringUntil('\n');
    if (line.indexOf("HTTP") != -1) {
      if (line.indexOf("200") == -1) {
        Serial.println("ERROR: invalid http status code");
      }
      break;
    } else {
      ;
    }
  }

  // then read until the payload is found
  while (client.available()) {
    String line = client.readStringUntil('\n');

    int start = line.indexOf("s=");
    if (start != -1) {
      // parse state information
      String buf;

      buf = line.substring(start + 2, start + 3);
      if (buf.equals("0")) {
        lightState = 0;
      } else {
        lightState = 1;
      }

      start = line.indexOf("t=");
      buf = line.substring(start + 2);
      lightTime = buf.toInt();

      updated = true;
      Serial.println("response parsed");
    } else {
      ;
    }
  }

  // failsafe
  if (!updated) {
    lightState = true;
    lightTime = 1;
    Serial.println("WARN failsafe");
  }

  Serial.print("Lights: ");
  Serial.print(lightState);
  Serial.print("\tTime: ");
  Serial.println(lightTime);

  digitalWrite(relaisPin, lightState);

  // sleep some time according to the recommendation in the answer
  if (lightTime > 15) { // not more than 15 minutes
    lightTime = 15;
  }

  // only deep sleep, if the time is more than 5 minutes
  if (lightTime >= 5 && lightState == false) {
    Serial.print("sleeping with WiFi off: Minutes ");
    Serial.println(lightTime);
    Serial.flush();

    WiFi.mode(WIFI_OFF);
    delay(lightTime * 60 * 1000);
    wifiConnect();
  } else {
    Serial.print("taking a normal sleep: Minutes ");
    if (lightTime < 1) {
      Serial.println("only 10 seconds");
      delay(10 * 1000);
    } else {
      Serial.println(lightTime);
      delay(lightTime * 60 * 1000);
    }
  }

  Serial.println("");
  updated = false;
}