#include <stdio.h>
#include <math.h>
#include <string.h>

int main(){

  // Declare Variables
  float bmi, weight, height, mostellar, duBois, boyd, lifeExpect;
  char gender[15];
  char line[] = "********************************";
  // Display Program Purpose
  printf("%s%s%s\n", line, line, line);
  printf("This program will calculate your BMI, Life Expectancy, and BSA(mulitple methods)\nwith just your weight(kg), height(cm), and gender.\n");
  printf("%s%s%s\n", line, line, line);
  // Read in weight, height, and gender from user
  printf("Please enter your weight(kg): ");
  scanf("%f", &weight);
  printf("Please enter your height(cm): ");
  scanf("%f", &height);

  // Make sure correct values for gender are entered
  while (1) {
    printf("Please enter your gender(male or female): ");
    scanf("%s", gender);
    if (strcmp("male", gender) == 0 || strcmp("female", gender) ==  0) {
      break; 
    } else {
      printf("Bad value: Please enter either male or female all lowercase\n");
    }
  }
  

  // Calculate the BMI
  bmi = 10000 * (weight / pow(height, 2));

  // Calculate the BSA(Mosteller's)
  mostellar = sqrt((height * weight) / 3600);

  // Calculate the BSA(Dubois)
  duBois = (0.20247 * pow((height / 100), 0.725)) * pow(weight, 0.425);

  // Calculate the BSA(boyd)
  boyd = (0.0003207 * pow(height, 0.3)) * pow((1000 * weight), (0.6721 - (0.0188 * log10(weight))));

  // Check if overweight and gender to select correct life expectancy message
  if (strcmp("male", gender)) {
    if (bmi > 25) {
      lifeExpect = 81.4;
    } else {
      lifeExpect = 83.5;
    }
  } else {
    if (bmi > 25) {
      lifeExpect = 77.3;
    } else {
      lifeExpect = 79.4;
    }
  }

  // Display values and output
  printf("For a %s with weight(kg) of %.1fkg and height(cm) of %.1fcm\n", gender, weight, height);
  printf("You have a BMI of %.1f and a life expectancy of %.1f years\n", bmi, lifeExpect);
  printf("You also have a BSA calculated using\n");
  printf("   - Mosteller's:\t%.3f\n", mostellar);
  printf("   - DuBois:\t\t%.3f\n", duBois);
  printf("   - Boyd:\t\t%.3f\n", boyd);

  return 0;
}