////////////////////////////////////////////////////////////////////////////////
// School of Computing, Universiti Teknologi Malaysia
// SCSJ1013- Programming Technique I
// Semester 1, 2018/2019
// Skill-Based Test: Question 2 (65 Marks)
// 14 Dec 2018
//
// Name:
// Matrics No:
// Section: 
//
////////////////////////////////////////////////////////////////////////////////

#include<iostream>
#include<cstdlib>
#include<cstring>
#include<fstream>
#include<iomanip>
#include<limits>

using namespace std;

#define MAXSTREAM numeric_limits<streamsize>::max()

//------------------------------------------------------------------------------------
// Function : readFile  
// Purpose  : To read inputs from a file consisting of the list of patient's name along 
//            with their weights and heights of the patient.
// Parameters:
//           name	   :  the array to hold the list of patient's names read from the file
//           weight    :  the array to hold the list of weights
//           height    :  the array to hold the list of heights
//           count     :  the number of patients read
//------------------------------------------------------------------------------------

// Task 1: Complete the definition of function "readFile"          (10 marks)

void readFile(char name[][20], double weight[], double height[], int &count)
{
	char nm[20];   // patient's name
	double wgt;    // patient's weight
	double hgt;    // patient's height

	ifstream inputFile; 

	//  complete these lines to open the input file, check the input file whether it is exist or not and display the error message (input validation).
	inputFile.open("input.txt") ;
	if (!inputFile)
	{
		cout << "Error !" ;
		exit (0) ;
	 } 





	count = 0;
	while (inputFile.getline (nm, 20, '\t'))
	{

		inputFile >> wgt; 
		inputFile >> hgt; 
		inputFile.ignore(MAXSTREAM, '\n');  //ignore newline

		// complete these lines to store the read data into arrays accordingly and close the open file.

		strcpy(name[count],nm) ;
		weight[count] = wgt ;
		height[count] = hgt ;



		count++;
	}
	
	inputFile.close () ;
	
}

//------------------------------------------------------------------------------------
// Function  : convertMeter
// Purpose   : To convert centimeter to meter
//
// Parameters:
//         	a  - the input array
//			b  - the array that holds the results of meter
//          n  - the size of array 
//
//------------------------------------------------------------------------------------

// Task 2 : Complete the definition of function convertMeter  (5 marks)

void convertMeter(double a[], double b[], int n)
{

	for ( int i = 0 ; i < n ; i++ )
	{
		b[i] = a[i] / 100 ;
	}

}

//------------------------------------------------------------------------------------
// Function  : calculateBMI
// Purpose   : to calculate the elements of arrays x and y correspondingly using BMI formula, and puts the result into another array, z.
//             BMI formula: weight(kg) / (height(m) * height (m))
// Parameters:
//      		x,y  - the input arrays
//              z    - the array that holds the results of the calculation.
//------------------------------------------------------------------------------------
// Task 3 : Complete the defintion of function calculateBMI  (7 marks)

void calculateBMI(const double x[], const double y[], double z[], int n)
{
	for ( int i = 0 ; i < n ; i ++)
	{
		z[i] = x[i] / (y[i] * y[i]) ;
	}
	

}

//------------------------------------------------------------------------------------
// Function  : average
// Purpose   : To calculate the average elements of an array.
//
// Parameters:
//         	a  - the array
//          n  - the size of array 
//
//  Return value:  the average of all the elements of the array
//------------------------------------------------------------------------------------

// Task 4 : Complete the definition of function average  (8 marks)

double average(const double a[], int n)
{
	double sum = 0, ave = 0; 

	for (int i = 0 ; i < n ; i ++ )
	{
		sum += a[i] ;
	}
	
	ave = sum / n ;
	
	return ave ;

}



int main()
{
	char pName[10][20];  	// The list (array) of patient's names
	double pWeight[10]; 	// The list (array) of patient's weights
	double pHeight[10];  	// The list (array) of patient's heights in cm
	double pMeter[10];  	// The list (array) of patient's heights in meter  
	double pBMI[10]; 		// The list of BMI, i.e.,weight / (height x height)
	double aveWgt;    		// Total average weight for all patients
	int n;   				// The number of patients	

	
	
	// Task 5: Using all the functions defined above, write a function call, 
	//(a) to read file from the input file, (b) to convert meter, (c) to calculate BMI and (d) to calculate average of weights. (9 mark)
	readFile(pName,pWeight,pHeight,n) ;
	convertMeter(pHeight,pMeter,n) ;
	calculateBMI(pWeight,pMeter,pBMI,n) ;
	aveWgt = average(pWeight, n) ;
	



	
    // Task 6: Print the list of patient's names along with their weight, height in meter and the calculated BMI to the output file (output.txt). (16 marks)
	// You should open and close the output file, and use proper formatting output.

	cout << "Writing to the output file... " << endl << endl;
	
	ofstream outputFile;
	
	outputFile.open("output.txt") ;
	
	outputFile << left ;
	outputFile << setw(18) << "Name" << setw(18) << "Weight (kg)" << setw(18) << "Height (m)" << setw(18) << "BMI" << endl ;
	outputFile << fixed << setprecision (2) ;

	for ( int i = 0 ; i < n ; i ++ )
	{
		outputFile << setw (18) << pName [i] << setw (18) << pWeight [i] <<  setw(18) << pMeter[i] << setw(18) << pBMI [i];
		outputFile << endl ;
	}
	
	outputFile.close() ;









    // Task 7: Print the number of patients and the average weight of all patients to the program screen. (5 marks).
	
	cout << "Number of patients : " << n << endl  ;
	
	cout << fixed << setprecision (1) << "Average weight :" << aveWgt << endl ;




	return 0;
}