#include <SPI.h> //for IIC -Inter intergrated circuit
#include <Wire.h>
#include <Adafruit_GFX.h> // for graphic
#include <Adafruit_SSD1306.h> //for oled screen

#include "DHT.h"

#define DHTPIN 2     // Digital pin connected to the DHT sensor
#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321


#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
// no need to change, always as default

#define LOGO_HEIGHT   32
#define LOGO_WIDTH    32
// 'DINO', 32x32px
//https://javl.github.io/image2cpp/

int val = 0; //

int cnt = 0;
int prev_val = 0;

bool mode = false;
unsigned long dur_t, start_t;

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  pinMode(3, INPUT_PULLUP);

  Serial.begin(9600);
  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3c, safety precheck
    Serial.println(F("SSD1306 allocation failed"));
    while(true){} // Don't proceed, loop forever
  }
  dht.begin();
  display.clearDisplay();
  delay(300);
}

void loop() {
  while(mode == true){// DYNAMIC DISPLAY
    if(digitalRead(3) == LOW){
      dur_t = counting(3);
      if(dur_t > 100){
        mode = !mode;
        cnt = 1;
        display.clearDisplay();
        break;
      }
    }

    float h = dht.readHumidity();
    float t = dht.readTemperature();

    display.clearDisplay();

    display.setTextSize(1);      // Normal 1:1 pixel scale
    display.setTextColor(SSD1306_WHITE); // Draw white text

    
    display.setCursor(0, 0);     // set position
    display.print("Temp(C): ");

    display.setCursor(70, 0);
    display.print(t);
    display.fillRect(10, 30, 0.5*t + 20 , 10, SSD1306_INVERSE);
    //when temperature = minimum = -40, width = 0
    //when temperature = maximum = 80, width = 60

    display.setCursor(0, 10);     // set position
    display.print("Humid(%): ");

    display.setCursor(70, 10);
    display.print(h);
    display.fillRect(10, 45, 0.6*h , 10, SSD1306_INVERSE);
    //when humidity = minimum = 0, width = 0
    //when humidity = maximum = 100, width = 60.

    display.display();
    delay(1000);
  }

  while(mode == false){//continuous diagram
    if(digitalRead(3) == LOW){
      dur_t = counting(3);
      if(dur_t > 100){
        mode = !mode;
        display.clearDisplay();
        break;
      }
    }

    cnt++;
    if(cnt > 127){
      cnt = 1;
      display.clearDisplay();
    }
    //float h = dht.readHumidity();
    float t = dht.readTemperature();

    t = map(t, -40, 80, 63, 0);
    
    display.drawLine(0, 63, 127, 63, SSD1306_WHITE);// DRAW x axis
    display.drawLine(0, 0, 0, 63, SSD1306_WHITE);// DRAW y axis
    //display.drawPixel(cnt, t, SSD1306_WHITE);
    
    display.drawLine(cnt - 1, prev_val, cnt, t, SSD1306_WHITE);//
    prev_val = t;

    display.display();

    //Serial.println(t);
    delay(1000);
  }
  
}

unsigned long counting(int pin){
  start_t = millis();
  while(digitalRead(pin) == LOW){
    //do nothing
  }
  return millis() - start_t;
}