#include <WiFi.h>

RTC_DATA_ATTR int bootCount = 0;

const char *ssid = "SSID";
const char *pass = "PASSWORD";

const gpio_num_t wakeup = GPIO_NUM_33;
const int led = GPIO_NUM_13;
static int onoff = 1; // -1 always on, 0/1 blink

const char *host_name = "192.168.0.40"; //server address
const int  host_port  = 80;

WiFiClient client;

TaskHandle_t thp[1];
void Core0a(void *args) {
  while (1) {
    delay(100);
    if (onoff < 0) digitalWrite(led, HIGH);
    else {
      digitalWrite(led, onoff);
      onoff = 1 - onoff;
    }
  }
}

void setup() {
  Serial.begin(115200);
  delay(1000);

  onoff = 1;
  pinMode(led, OUTPUT);

  xTaskCreatePinnedToCore(Core0a, "Core0a", 4096, NULL, 3, &thp[0], 0); 

  ++bootCount;
  Serial.println("Boot number: " + String(bootCount));

  print_wakeup_reason();

  esp_sleep_enable_ext0_wakeup(wakeup, 1);

  WiFi.begin(ssid, pass);
  Serial.print("WiFi connecting");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected.");
  onoff = -1;

  while (true) {
    if (client.connect(host_name, host_port)) {
      char sendBuffer[128];
      sprintf(sendBuffer, "GET / HTTP/1.1\r\nHost: %s\r\n\r\n", host_name);
      client.print(sendBuffer);
      break;
    } else {
      Serial.println("client.connect error.");
      delay(100);
    }
  }
  while(true) {
    while(client.available()) {
      char c = client.read();
      Serial.print(c);
    }
    if(!client.connected()){
      Serial.println("disconnected");
      client.stop();
      break;
    }
  }

  Serial.println("Go to sleep now");
  esp_deep_sleep_start();
}

void loop() {}

void print_wakeup_reason() {
  esp_sleep_wakeup_cause_t wakeup_reason = esp_sleep_get_wakeup_cause();
  Serial.printf("x%02x: ", wakeup_reason);
  switch (wakeup_reason) {
    case 2: Serial.println("Wakeup caused by external signal using RTC_IO"); break;
    case 3: Serial.println("Wakeup caused by external signal using RTC_CNTL"); break;
    case 4: Serial.println("Wakeup caused by timer"); break;
    case 5: Serial.println("Wakeup caused by touchpad"); break;
    case 6: Serial.println("Wakeup caused by ULP program"); break;
    default: Serial.println("Wakeup was not caused by deep sleep"); break;
  }
}