#include "BluetoothSerial.h"
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_CCS811.h>
#include <Fonts/FreeSans9pt7b.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET     -1
BluetoothSerial SerialBT;
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
Adafruit_BME280 bme;
Adafruit_CCS811 ccs;

#define ICON_WIDTH 8
#define ICON_HEIGHT 16
static const unsigned char PROGMEM temp[] =
{ B00011100, 
  B00100010,
  B00100011,
  B00100010,
  B00101011,
  B00101010,
  B00101011,
  B00101010,
  B00101010,
  B00101010,
  B01001001,
  B01011101,
  B01000001,
  B00111110,
  B00000000,
  B00000000};
  static const unsigned char PROGMEM height[] =
{ B01111110, 
  B01000010,
  B01000010,
  B01111010,
  B01000010,
  B01000010,
  B01111010,
  B01000010,
  B01000010,
  B01111010,
  B01000010,
  B01000010,
  B01111010,
  B01000010,
  B01000010,
  B01111110};
  static const unsigned char PROGMEM humid[] =
{ B00000000, 
  B00011000,
  B00100100,
  B00100100,
  B01000010,
  B01000010,
  B10000001,
  B10000001,
  B10100101,
  B10001001,
  B10010001,
  B10100101,
  B10000001,
  B01000010,
  B00111100,
  B00000000};

void setup() {
  Serial.begin(115200);
  SerialBT.begin("AQM"); //Bluetooth device name
  
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x32
    Serial.println(F("SSD1306 allocation failed"));
    while (1) delay(100);
  }
  display.clearDisplay();              // clear display
  display.setTextSize(1);              // 1:1 pixel scale
  display.setFont(&FreeSans9pt7b);     // set font
  display.setTextColor(SSD1306_WHITE); // draw white text
  display.setCursor(0, 15);            // start at top-left corner
  if (!bme.begin(0x76, &Wire)) {
    Serial.println("Could not find a valid BME280 sensor, check wiring, address, sensor ID!");
    display.write("no BME280 sensor");
    display.display();
    while (1) delay(100);
  }
  if(!ccs.begin()){
    Serial.println("Failed to start CCS sensor! Please check your wiring.");
    display.write("no CCS811 sensor");
    display.display();
    while (1) delay(100);
  }
  ccs.setEnvironmentalData(bme.readHumidity(), bme.readTemperature());
  display.write("waiting for CCS811 sensor");
  Serial.println("Waiting for sensor");
  display.display();
  while(!ccs.available()){
    delay(100);
  }
  // draw initial icons and static info
  display.clearDisplay();
  display.drawBitmap(0, 0, temp, ICON_WIDTH, ICON_HEIGHT, 1);
  display.drawBitmap(60, 0, height, ICON_WIDTH, ICON_HEIGHT, 1);
  display.drawBitmap(0, 16, humid, ICON_WIDTH, ICON_HEIGHT, 1);
  display.drawCircle(48, 5, 2, SSD1306_WHITE);
  display.drawCircle(47, 21, 2, SSD1306_WHITE);
  display.drawCircle(53, 29, 2, SSD1306_WHITE);
  display.drawLine(47,28, 53,22, SSD1306_WHITE);
}

char line[128];       // line buffer
uint16_t eCO2 = 0;    // CO2 value in parts per million
uint16_t TVOCppb = 0; // RVOC in parts per billion

void loop() {
  uint8_t ccRead = ccs.readData(); // read CCS sensor
  if (!ccRead) {
    eCO2 = ccs.geteCO2();
    TVOCppb = ccs.getTVOC();
  }
  float temperature = bme.readTemperature();   // in °C
  float pressure = bme.readPressure() / 100.0; // in hPa / 1 milli Bar
  float humidity = bme.readHumidity();         // in %
  
  // send status to USB serial and bluetooth
  snprintf(line,127, "T: %3.1f°C P: %6.2fhPa H: %4.2f%% eCO2:%i ppm, tvoc:%i ppb\n", temperature, pressure, humidity, eCO2, TVOCppb);
  Serial.print(line);
  SerialBT.print(line);

  // draw to display
  // clear text / draw bar graph area
  display.fillRect(8, 0, 37, 32, SSD1306_BLACK);
  display.fillRect(8+64, 0, 56, 32, SSD1306_BLACK);
  display.fillRect(0, 32, 128, 32, SSD1306_BLACK);
  display.fillRect(64, 32, 64.0 * eCO2 / 8192, 16, SSD1306_WHITE);
  display.fillRect(64, 48, 64.0 * TVOCppb / 1187, 16, SSD1306_WHITE);
  // draw temperature
  display.setCursor(9, 15);
  snprintf(line,127, "%3.1f", temperature);
  display.write(line);
  // draw pressure
  snprintf(line,127, "%6.1f", pressure);
  display.setCursor(73, 15);
  display.write(line);
  // draw humidity
  display.setCursor(9, 31);
  snprintf(line,127, "%3.1f", humidity);
  display.write(line);
  // draw CO2 level
  display.setCursor(9, 46);
  snprintf(line,127, "%04i",eCO2);
  display.write(line);
  // draw TVOC
  display.setCursor(9, 61);
  snprintf(line,127, "%04i",TVOCppb);
  display.write(line);
  // update display
  display.display();
  // zzzZZZZzzz
  delay(10000);
}