// FinalProject.ino
// (C)2026 Dakota Thorpe — AVR-safe edition

#include <SD.h>
#include <SPI.h>
#include <Wire.h>
#include <RTClib.h>
#include <DHT11.h>

// Display lib
#include <Adafruit_SSD1306.h>
#include <LiquidCrystal_I2C.h>

// ================= CONFIG =================

// RTC types
#define RTC_TYPE_DS1307 1
#define RTC_TYPE_DS3231 2

// Display Types
#define DIS_TYPE_SSD1306  1 // Adafruit SSD1306
#define DIS_TYPE_LCD162I  2 // I2C LCD 16x2
#define DIS_TYPE_LCD204I  3 // I2C LCD 20x4
#define DIS_TYPE_NONE     4 // None

// Hardware selections
#define RTC_TYPE RTC_TYPE_DS1307
#define DIS_TYPE DIS_TYPE_SSD1306

// SD
const int sdCS = 10;

// Sensors
const int photo_pin = A0;
DHT11 dht11(2);

// =========== DISPLAY OBJECTS ============

#if DIS_TYPE == DIS_TYPE_SSD1306
  #define SCREEN_WIDTH 128
  #define SCREEN_HEIGHT 64
  Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

#elif DIS_TYPE == DIS_TYPE_LCD162I
  LiquidCrystal_I2C display(0x27, 16, 2);

#elif DIS_TYPE == DIS_TYPE_LCD204I
  LiquidCrystal_I2C display(0x27, 20, 4);
#endif

// =========== DISPLAY HANDLE ============
void InitDisplay() {
  #if DIS_TYPE == DIS_TYPE_SSD1306
    if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
      Serial.println(F("SSD1306 init failed"));
      return;
    }

    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0, 0);
    display.println(F("Logger starting..."));
    display.display();

  #elif DIS_TYPE == DIS_TYPE_LCD162I || DIS_TYPE == DIS_TYPE_LCD204I

    display.init();
    display.backlight();
    display.clear();
    display.setCursor(0, 0);
    display.print(F("Logger starting"));

  #elif DIS_TYPE == DIS_TYPE_NONE
    // No display
  #endif
}

void UpdateDisplay(const DateTime& now, int temp, int hum, int light) {
  #if DIS_TYPE == DIS_TYPE_SSD1306
    display.clearDisplay();
    display.setCursor(0, 0);

    display.print(now.hour()); display.print(':');
    display.print(now.minute()); display.print(':');
    display.println(now.second());

    display.print(F("T: "));
    display.print(temp);
    display.println(F(" C"));

    display.print(F("H: "));
    display.print(hum);
    display.println(F(" %"));

    display.print(F("L: "));
    display.println(light);

    display.display();

  #elif DIS_TYPE == DIS_TYPE_LCD162I

    display.clear();
    display.setCursor(0, 0);
    display.print(now.hour()); display.print(':');
    display.print(now.minute()); display.print(':');
    display.print(now.second());

    display.setCursor(0, 1);
    display.print(F("T:"));
    display.print(temp);
    display.print(F(" H:"));
    display.print(hum);

  #elif DIS_TYPE == DIS_TYPE_LCD204I

    display.clear();
    display.setCursor(0, 0);
    display.print(F("Time "));
    display.print(now.hour()); display.print(':');
    display.print(now.minute()); display.print(':');
    display.print(now.second());

    display.setCursor(0, 1);
    display.print(F("Temp "));
    display.print(temp);
    display.print(F(" C"));

    display.setCursor(0, 2);
    display.print(F("Hum  "));
    display.print(hum);
    display.print(F(" %"));

    display.setCursor(0, 3);
    display.print(F("Light "));
    display.print(light);

  #elif DIS_TYPE == DIS_TYPE_NONE
    // No display
  #endif
}


// ================= RTC =================

#if RTC_TYPE == RTC_TYPE_DS1307
  RTC_DS1307 rtc;
#elif RTC_TYPE == RTC_TYPE_DS3231
  RTC_DS3231 rtc;
#else
  #error "Unknown RTC type"
#endif

// ================= SD =================

File dataFile;

// ================= BUILD TIME PARSER =================

uint8_t monthFromString(const char* m) {
  if (!strcmp(m, "Jan")) return 1;
  if (!strcmp(m, "Feb")) return 2;
  if (!strcmp(m, "Mar")) return 3;
  if (!strcmp(m, "Apr")) return 4;
  if (!strcmp(m, "May")) return 5;
  if (!strcmp(m, "Jun")) return 6;
  if (!strcmp(m, "Jul")) return 7;
  if (!strcmp(m, "Aug")) return 8;
  if (!strcmp(m, "Sep")) return 9;
  if (!strcmp(m, "Oct")) return 10;
  if (!strcmp(m, "Nov")) return 11;
  if (!strcmp(m, "Dec")) return 12;
  return 0;
}

// ================= RTC SETUP =================

void SetRTC2BuildDate() {
  char monthStr[4];
  int day, year;
  int hr, min, sec;

  // "__DATE__" → "Mmm dd yyyy"
  sscanf(__DATE__, "%3s %d %d", monthStr, &day, &year);

  // "__TIME__" → "hh:mm:ss"
  sscanf(__TIME__, "%d:%d:%d", &hr, &min, &sec);

  uint8_t month = monthFromString(monthStr);

  rtc.adjust(DateTime(year, month, day, hr, min, sec));
}

// ================= LOGGING =================

void WriteAllEntries(File& file) {
  DateTime now = rtc.now();

  char date_str[32];
  snprintf(date_str, sizeof(date_str),
           "%04d-%02d-%02dT%02d:%02d:%02d",
           now.year(), now.month(), now.day(),
           now.hour(), now.minute(), now.second());

  int temperature = 0;
  int humidity = 0;
  int light = analogRead(photo_pin);
  
  dht11.readTemperatureHumidity(temperature, humidity);

  file.print(date_str);
  file.print(",");
  file.print(humidity);
  file.print(",");
  file.print(temperature);
  file.print(",");
  file.println(light);
  UpdateDisplay(now, temperature, humidity, light);
  file.flush();
}

// ================= SETUP =================

void setup() {
  Serial.begin(9600);

  pinMode(photo_pin, INPUT);

  Wire.begin();

  // Setup Displays
  InitDisplay();

  if (!rtc.begin()) {
    Serial.println(F("RTC not found!"));
    while (1);
  }

#if RTC_TYPE == RTC_TYPE_DS1307
  if (!rtc.isrunning()) {
    SetRTC2BuildDate();
  }
#else
  SetRTC2BuildDate(); // DS3231 always safe to adjust
#endif

  if (!SD.begin(sdCS)) {
    Serial.println(F("SD init failed"));
    while (1);
  }

  SD.remove("/data.csv");
  dataFile = SD.open("/data.csv", FILE_WRITE);

  dataFile.println(F("date,hum,temp,light"));
}

// ================= LOOP =================

void loop() {
  WriteAllEntries(dataFile);
  delay(1000);
}