#include <Arduino.h>
#include <Wire.h>
#include "RTClib.h"
#include <Adafruit_GFX.h>
#include <Adafruit_SH110X.h>
#include <SD.h>
#include <SPI.h>

// Define for OLED and RTC Modules
#define I2C_SDA 21 //OLED and DS3231: SDA --> GPIO21
#define I2C_SCL 22 //OLED and DS3231: SCL --> GPIO22
#define OLED_I2C_ADDRESS 0x3c //OLED I2C Address
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET -1 // QT-PY / XIAO
Adafruit_SH1106G OLEDdisplay = Adafruit_SH1106G(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

const int CS = 5;

// Config file content
myFile config;
String iniContent = "";

// Variable to keep track of med info
String pills[3];
String when[3];
String notif[3][4];

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

  // SD card initialize
  if (!SD.begin(CS))
  {
    Serial.println(("SD card Initialization falied"));
    return;
  }

  // Read config file
  myFile = SD.open("/config.ini", FILE_READ);
  if (myFile)
  { 
    Serial.println("config.ini is opened");

    // Read all the content in the file and save it to a string
    while (myFile.available()) {
      char c = myFile.read();
      iniContent += c;  // Append each character to the iniContent variable
    }

    // Close the file
    myFile.close();
    Serial.println("File closed.");

    // Output the content stored in the iniContent variable
    Serial.println("File contents:");
    Serial.println(iniContent);
  }
  else
  {
    Serial.println("Error opening config.in");
  }
  Serial.println("Initialization done.");
  Serial.println("*********************************************"); 
}

  // Save medicines information in arrays
  parseIni(iniContent);
  printMedications(); // Print the parsed medications

  // Initialize OLED display
  Serial.println("Start OLED Display...");
  OLEDdisplay.begin(OLED_I2C_ADDRESS, true);
  OLEDdisplay.setContrast(0); // dim display
  OLEDdisplay.display();
  Wire.begin(I2C_SDA, I2C_SCL);
  OLEDdisplay.clearDisplay();
  OLEDdisplay.setTextSize(1);
  OLEDdisplay.setTextColor(SH110X_WHITE);
  OLEDdisplay.setCursor(0, 0);
}

void loop() {
  // Display medicines info looping in order.
  static int currentMed = 0;
  OLEDdisplay.clearDisplay();
  OLEDdisplay.setCursor(0, 0);
  OLEDdisplay.setTextSize(1);
  OLEDdisplay.setTextColor(SH110X_WHITE);

  OLEDdisplay.print("Pill: ");
  OLEDdisplay.println(pills[currentMed]);
  OLEDdisplay.print("Time: ");
  displayTimes(notif[currentMed]);
  OLEDdisplay.print("When: ");
  OLEDdisplay.println(when[currentMed]);

  OLEDdisplay.display();
  delay(5000);
  currentMed = (currentMed + 1) % 3;
}

void displayTimes(String notif[]) {
  int count = 0;
  for (int i = 0; i < 4; i++) {
    if (notif[i].length() > 0) {
      if (count == 2) {
        OLEDdisplay.println();
        OLEDdisplay.print("      ");
      }
      OLEDdisplay.print(notif[i]);
      if (i < 3 && notif[i + 1].length() > 0) {
        OLEDdisplay.print(", ");
      }
      count++;
    }
  }
  OLEDdisplay.println();
}

void parseIni(String ini) {
  String lines[12];
  int lineCount = 0;
  int startIndex = 0;
  int endIndex = ini.indexOf('\n');
  while (endIndex != -1) {
    lines[lineCount++] = ini.substring(startIndex, endIndex);
    startIndex = endIndex + 1;
    endIndex = ini.indexOf('\n', startIndex);
  }
  lines[lineCount++] = ini.substring(startIndex);

  int medIndex = -1;
  for (int i = 0; i < lineCount; i++) {
    if (lines[i].startsWith("[")) {
      medIndex++;
    } else if (lines[i].startsWith("Pill")) {
      pills[medIndex] = getValue(lines[i]);
    } else if (lines[i].startsWith("Notif_time")) {
      fillNotifArray(notif[medIndex], lines[i]);
    } else if (lines[i].startsWith("When")) {
      when[medIndex] = getValue(lines[i]);
    }
  }
}

String getValue(String line) {
  return line.substring(line.indexOf('=') + 2);
}

void fillNotifArray(String notif[], String line) {
  for (int i = 0; i < 4; i++) {
    notif[i] = "";
  }
  int startIndex = line.indexOf('=') + 2;
  int endIndex = line.indexOf(',', startIndex);
  int index = 0;
  while (endIndex != -1 && index < 4) {
    notif[index++] = line.substring(startIndex, endIndex);
    startIndex = endIndex + 2;
    endIndex = line.indexOf(',', startIndex);
  }
  if (startIndex < line.length() && index < 4) {
    notif[index] = line.substring(startIndex);
  }
}

void printMedications() {
  for (int i = 0; i < 3; i++) {
    Serial.print("Medication ");
    Serial.println(i + 1);
    Serial.print("Pill: ");
    Serial.println(pills[i]);
    Serial.print("When: ");
    Serial.println(when[i]);
    Serial.print("Notification Times: ");
    for (int j = 0; j < 4; j++) {
      Serial.print(notif[i][j]);
      if (j < 3) Serial.print(", ");
    }
    Serial.println("\n");
  }
}