#define INCLUDE_vTaskSuspend 1

#define LED_COUNT 1
#define LED_PIN 39
#define SDA_PIN 41 // SDA pin, I2C serial data
#define SCL_PIN 40 // SCL pin, I2C serial clock

#include <Arduino.h>
#include <Wire.h> // library requires for IIC communication

#include <U8g2lib.h> // u8g2 library used for drawing on the OLED display
#include <Adafruit_NeoPixel.h>

#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>

// neopixel initialization
Adafruit_NeoPixel pixels(LED_COUNT, LED_PIN, NEO_RGB + NEO_KHZ800);

// display initialization
U8G2_SSD1306_72X40_ER_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE, /*clock*/ SCL_PIN, /*data*/ SDA_PIN); // EastRising 0.42" OLED [full framebuffer, size = 360 bytes]

// image below is generated using the image2cpp website
// 'battery_outline', 70x40px
const unsigned char epd_bitmap_battery_outline [] PROGMEM = {
  0xfc, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01, 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  0xff, 0x03, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x03, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x1e, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3e, 0x03, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3e, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3e,
  0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3e, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x3e, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3e, 0x03, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x3e, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3e, 0x03, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x3e, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3e, 0x03,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3e, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x3e, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3e, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x3e, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1e, 0x03, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06,
  0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x07, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x03, 0xfc,
  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x01
};

hw_timer_t * timer = NULL;
volatile SemaphoreHandle_t timerSemaphore;
portMUX_TYPE timerMux = portMUX_INITIALIZER_UNLOCKED;

HTTPClient http;

void IRAM_ATTR onTimer() {
  // portENTER_CRITICAL_ISR(&timerMux);
  // ...
  // portEXIT_CRITICAL_ISR(&timerMux);

  // Give a semaphore that we can check in the loop
  xSemaphoreGiveFromISR(timerSemaphore, NULL);

  // It is safe to use digitalRead/Write here if you want to toggle an output
}

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

  u8g2.begin();
  u8g2.setDrawColor(1); // set color to white color
  u8g2.setBitmapMode(1); // draw transparent images

  pixels.begin();

  Serial.print("Connecting to WiFi");
  WiFi.begin("Wokwi-GUEST", "", 6);
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
  }
  Serial.println(" Connected!");

  // Create semaphore to inform us when the timer has fired
  timerSemaphore = xSemaphoreCreateBinary();

  // Set timer frequency to 1Mhz
  timer = timerBegin(1000000);

  // Attach onTimer function to our timer.
  timerAttachInterrupt(timer, &onTimer);

  // Set alarm to call onTimer function every second (value in microseconds).
  // Repeat the alarm (third parameter) with unlimited count = 0 (fourth parameter).
  timerAlarm(timer, 5000000, true, 0);
}

void loop(void) {
  if (xSemaphoreTake(timerSemaphore, portMAX_DELAY) == pdTRUE) {
    Serial.println("timer");

    pixels.setPixelColor(0, pixels.Color(0, 150, 0));
    pixels.show();

    u8g2.clearBuffer();	// clear the internal memory

    u8g2.drawXBMP(0, 0, 70, 40, epd_bitmap_battery_outline); // draw the image of the outline of the battery icon

    u8g2.drawPixel(35, 20);

    http.begin("https://httpbin.org/uuid");

    int httpCode = http.GET();
    Serial.print("HTTP Status Code: ");
    Serial.println(httpCode);

    if (httpCode > 0) {
      StaticJsonDocument<768> doc;
      DeserializationError error = deserializeJson(doc, http.getString());

      if (error) {
        Serial.print(F("deserializeJson failed: "));
        Serial.println(error.f_str());
        return;
      }

      String uuid = doc["uuid"].as<String>();

      Serial.println(uuid);

      http.end();
    }

    u8g2.sendBuffer();					// transfer internal memory to the display

    pixels.clear();
  }

  Serial.println("loop");
}