// Zeinalipour-Yazti Demetrios
// csyiazti
// cs10xx -
// Lab Sec#24
// lab9
	/*	Triangle Calculations WITH a highlight on call-by-reference & call-by-value
	 *	This  program finds the missing information of a right triangle many times.	   
	 *	A) Input: length of side X, angle A1
	 *	B) Restrictions: inputs must be positive
	 *	C) Output: side Y, hypotenuse Z, Angle A2.
	 *	D) Pythagorean Theorem.==> 
	 *     Z^2 = X^2 + Y^2
   	 *
	 */
#include <math.h>
#include <fstream>
#include <iostream>

#include <string>
using namespace std;


#define PI 3.14159265


void readData(double &a1, double &x)
{
	
	string filename;

	while (true)
	{ 
      /* get the filename */
	  cout << "Give me the name of the file: " ;
	  cin >> filename;

	  cout << "\nOpening \'" << filename << "\'...";

	  /* open file for input */
	  ifstream infilestream;
	  infilestream.open(filename.c_str(), ios::in);
	
	  if (infilestream) /* overload ! operator*/
	  {
 		cout << "done\n";
		infilestream >> x >> a1;		
		break;
	  }
	  else
	  {
		  cout << "failed\n";
		  cerr << "File could not be opened\n" << endl;	 
		  infilestream.close();		  
	  }
	}
}


void readData2(double *a1, double *x)
{
	
	ifstream infilestream;
	string filename;

	while (true)
	{ 
      /* get the filename */
	  cout << "Give me the name of the file: " ;
	  cin >> filename;
	  
	  cout << "\nOpening " << filename << "...";

	  /* open file for input */
	  ifstream infilestream;
	  infilestream.open(filename.c_str(), ios::in);
	
	  if (infilestream) /* overload ! operator*/
	  {
		cout << "done\n";
 		infilestream >> *x >> *a1;		
		break;
	  }
	  else
	  {
		  cout << "failed\n";
		  cerr << "File could not be opened\n" << endl;	 		  
		  infilestream.close();		 
	  }
	}
}

void calculateAll(double a1, double &a2, double x, double &y, double &z)
{
	a2 =  90 - a1;              /* calculates the other angle  */
	
	y = tan(a1 * PI / 180) * x; /* the length of y */
	
	z = sqrt(x*x + y*y);  /* the length of the hypotenuse with the Pythagorean Theorem. */
}



/* This procedure outputs graphically the triangle.
 */
void printTriangle(const double &a1, const double &a2, const double &x, const double &y, const double &z)
{
	cout << "\n\nPrinting the right triangle" << "\n"
		 << "================================" << "\n\n"
		 << "a1=" << a1 << "\n"
		 << "|\\"									<< '\n' 
		 << "| \\"									<< '\n'
		 << "|  \\"									<< '\n'
		 << "|   \\"								<< '\n'
		 << "|    \\"								<< '\n'
		 << "|     \\"								<< '\n'
		 << "|      \\"								<< '\n'
		 << "|x=" << x << "   \\ " << "z=" << z		<< '\n'
		 << "|        \\"							<< '\n'
		 << "|         \\"							<< '\n'
		 << "|          \\"							<< '\n'
		 << "|           \\"						<< '\n'
		 << "|__90  a2=" << a2 << " \\"				<< '\n'
		 << "|__|__________\\"						<< '\n'
		 << "     y=" << y							<< endl; 
}




void main()
{	
	/* define variables */
	double x;					 /* The length of side x */ 
	double y;		 			 /* The length of side y */
	double z;		 			 /* The length of side z */
	double a1;					 /* The angle a1 	 */
	double a2;					 /* The angle a2 	 */
	
	/* define functions & procedures*/
	/* TWO ways to achieve the same task, reading parameters */
	void readData(double &a1, double &x);
	void readData2(double *a1, double *x);
	
	/* 'a1' and 'x' are passed as const because we don't want to change their value. */
	void calculateAll(const double a1, double &a2, const double x, double &y, double &z);
	
	/* we are passing all parameters by reference in order to avoid unecessary data copying */
	void printTriangle(const double &a1, const double &a2, const double &x, const double &y, const double &z);

	/* print intro */
	cout << "Lab 9 - Right Triangle Calculation with call-by-refernce & call-by-value.\n"
		 << "by Demetris Zeinalipour : cs10 #24.\n\n"
		 << "NOTE:Download \'triangle.txt\' and place it to same directory as this executable!!\n\n";
		 
	
	/* get Values from user  */	
	readData(a1, x);
	//readData2(&a1, &x);
	
	/* Calculating all the missing values */
	calculateAll(a1, a2, x, y, z);
	
	/* Printing out the triangle (graphic) */
	printTriangle(a1, a2, x, y, z);	
		  

}