#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// ========== Configuration Constants ==========
#define I2C_ADDR    0x27      // I2C address of the LCD (common: 0x27 or 0x3F)
#define LCD_COLS    16        // LCD number of columns
#define LCD_ROWS    2         // LCD number of rows
#define BENCH_LOOPS 5000      // Number of iterations for the benchmark
#define DISPLAY_MS  5000      // How long to show the result on LCD (ms)
#define SERIAL_BAUD 115200    // Serial monitor baud rate

const char* myName = "Shahad";   // Name to display on the first line

// Create LCD object
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLS, LCD_ROWS);

// ========== Function Prototypes ==========
unsigned long runBenchmark(double &result);  // Runs the computation and returns duration

// ========== Setup ==========
void setup() {
  // Initialize Serial communication (for debugging and backup output)
  Serial.begin(SERIAL_BAUD);
  // Wait for serial port to connect (only needed for boards with native USB)
  while (!Serial) { ; }

  // Initialize the LCD
  lcd.init();          // Initialize the LCD hardware
  lcd.backlight();     // Turn on backlight

  // Show a startup message while preparing
  lcd.setCursor(0, 0);
  lcd.print(myName);
  lcd.setCursor(0, 1);
  lcd.print("Preparing...");

  delay(500);  // Brief pause to let the message be seen
}

// ========== Main Loop ==========
void loop() {
  double sum;                     // Will hold the benchmark result
  unsigned long duration;         // Will hold the computation time

  // Run the benchmark and get the duration and sum
  duration = runBenchmark(sum);

  // Output to Serial monitor (useful for logging or if LCD is not available)
  Serial.print("Benchmark result (sum) = ");
  Serial.println(sum, 6);          // Print with 6 decimal places
  Serial.print("Duration (ms) = ");
  Serial.println(duration);

  // Update the LCD with the name and measured time
  lcd.clear();                     // Clear previous content
  lcd.setCursor(0, 0);
  lcd.print(myName);               // First line: name
  lcd.setCursor(0, 1);
  lcd.print("Time: ");
  lcd.print(duration);
  lcd.print(" ms");                // Second line: e.g., "Time: 1234 ms"

  // Wait so the result can be read (adjust DISPLAY_MS as needed)
  delay(DISPLAY_MS);
}

// ========== Benchmark Function ==========

unsigned long runBenchmark(double &result) {
  unsigned long start = millis();   // Record start time

  double sum = 0.0;
  for (int i = 1; i <= BENCH_LOOPS; i++) {
    // Note: On Arduino, double is the same as float (4 bytes).
    // The computation is deliberately heavy to produce a measurable time.
    sum += sqrt((double)i) * sin((double)i);
  }

  unsigned long elapsed = millis() - start;   // Compute elapsed time
  result = sum;                                // Store the sum via reference
  return elapsed;
}