#include <iostream>             // to use cin and cout
#include <typeinfo>             // to be able to use operator typeid
#include <fstream>
#include <cmath>
#include <iomanip>
#include <string>

// Include here the libraries that your program needs to compile


using  namespace  std;

// Ignore this; it's a little function used for making tests
inline void test(const char* expression, const char* file, int line)
{
    cerr << "test(" << expression << ") failed in file " << file;
    cerr << ", line " << line << "." << endl << endl;
}
// This goes along with the above function...don't worry about it
#define test(EXPRESSION) ((EXPRESSION) ? (void)0 : test(#EXPRESSION, __FILE__, __LINE__))

// Insert here the prototypes of the functions
double round_off(double value, int places);
double square(double x);
double calcLength(double x1, double x2, double y1, double y2);
double semiPerimeter(double ab, double bc, double ca);
double calcArea(double ab, double bc, double ca);
void getPoint(ifstream & iFile, double& q, double& w);
void printDistance(ostream & oFile, double& e, double& r, double& t, double& y, double& z);
int main()
{
    ifstream inFile;
    ofstream outFile;
    double value;
    double num1 = 0., num2 = 0., num3 = 0., num4 = 0., num5 = 0., num6 = 0.;

    inFile.open("inputhw2.txt", ios::in);
    if (!inFile)
    {
        cout << "Input file not found!" << endl;
        system("pause");
        return 1;
    }



    outFile.open("outputhw2.txt", ios::out);
    if (!outFile)
    {
        cout << "Output file not found " << endl;
        system("pause");
        return 1;
    }

    getPoint(inFile, num1, num2);
    getPoint(inFile, num3, num4);
    getPoint(inFile, num5, num6);


    printDistance(outFile, num1, num2, num3, num4, value);
    outFile << calcLength(num2, num4, num1, num3);

    printDistance(outFile, num3, num4, num5, num6, value);
    outFile << calcLength(num3, num5, num4, num6);

    printDistance(outFile, num1, num2, num5, num6, value);
    outFile << calcLength(num1, num5, num2, num6);

    value = calcArea(num1, num2, num3);



    system("pause");

    // Do NOT remove or modify the following statements
    cout << endl << "Testing your solution" << endl << endl;


    test(fabs(round_off(calcLength(1.0, 1.2, 6.0, 6.1), 2) - 7.00) < .001);         // Incorrect calculation of length
    test(fabs(round_off(calcLength(6.0, 6.1, 3.2, 6.5), 2) - 2.83) < .001);         // Incorrect calculation of length
    test(fabs(round_off(calcLength(1.0, 1.2, 3.2, 6.5), 2) - 5.74) < .001);         // Incorrect calculation of length
    test(fabs(calcArea(calcLength(1.0, 1.2, 6.0, 6.1), calcLength(6.0, 6.1, 3.2, 6.5), calcLength(1.0, 1.2, 3.2, 6.5)) - 7.86) < .001);         // Incorrect calculation of area

    test(fabs(round_off(calcLength(1.2, 1.2, 7.6, 4.3), 2) - 7.11) < .001);         // Incorrect calculation of length
    test(fabs(round_off(calcLength(7.6, 4.3, 9.2, 3.4), 2) - 1.84) < .001);         // Incorrect calculation of length
    test(fabs(round_off(calcLength(1.2, 1.2, 9.2, 3.4), 2) - 8.30) < .001);         // Incorrect calculation of length
    test(fabs(calcArea(calcLength(1.2, 1.2, 7.6, 4.3), calcLength(7.6, 4.3, 9.2, 3.4), calcLength(1.2, 1.2, 9.2, 3.4)) - 5.36) < .001);         // Incorrect calculation of area

    test(fabs(round_off(calcLength(1.0, 1.0, 5.0, 5.0), 2) - 5.66) < .001);         // Incorrect calculation of length
    test(fabs(round_off(calcLength(5.0, 5.0, 9.0, 9.0), 2) - 5.66) < .001);         // Incorrect calculation of length
    test(fabs(round_off(calcLength(1.0, 1.0, 9.0, 9.0), 2) - 11.31) < .001);            // Incorrect calculation of length
    test(fabs(calcArea(calcLength(1.0, 1.0, 5.0, 5.0), calcLength(5.0, 5.0, 9.0, 9.0), calcLength(1.0, 1.0, 9.0, 9.0)) - 0.00) < .001);         // Incorrect calculation of area

    system("pause");
    return 0;
}

//********  Function definition  *********
// Read the handout carefully for detailed description of the functions that you have to implement
void getPoint(ifstream & iFile, double& q, double& w)
{
    iFile >> q >> w;
    round_off(q, 1);
    round_off(w, 1);

}

void printDistance(ostream & oFile, double& e, double& r, double& t, double& y, double& z)
{
    oFile << "The distance between " << e << "," << r;


}


double round_off(double value, int places)
{

    return floor((value * pow(10, places)) + .5) / pow(10, places);
}

double square(double x)
{
    return (x * x);
}

double calcLength(double x1, double x2, double y1, double y2)
{
    double r1, r2, sqr1, sqr2, add, result;

    r1 = (x1 - x2);
    r2 = (y1 - y2);
    sqr1 = square(r1);
    sqr2 = square(r2);
    add = (sqr1 + sqr2);
    result = sqrt(add);
    return round_off(result, 10);
}

double semiPerimeter(double ab, double bc, double ca)
{
    double resultsp;
    resultsp = (1 / 2) * (ab + bc + ca);
    round_off(resultsp, 10);
    return resultsp;

}

double calcArea(double ab, double bc, double ca)
{
    double area, l1, l2, l3;
    l1 = semiPerimeter(ab, bc, ca);
    l2 = semiPerimeter(ab, bc, ca);
    l3 = semiPerimeter(ab, bc, ca);
    area = semiPerimeter(ab, bc, ca) * l1 * l2 * l3;

    area = sqrt(area);
    return round_off(area, 2);

}