/* Mission 3 Part 1
 * I.Kaper
 * U2 Reconnaissance
 * Use a pseudorandom number generator to authenticate user
 * Store 2d coordinates of target positions
 * Shuffle travel order randomly
 * Evaluate if outputted flight path is viable under given constraints
 * Display results to user
 *
 */

#include <iostream>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <algorithm>
#include <random>
#include <chrono>

using namespace std;

double distance (double, double, double, double);
double distance_total(double[],double[],int[]);

int main() {
    srand(4); // Set seed value to 4 (the requested seed value)
    int key = rand() % 41; // Generates a random integer between 0 and 40
    // cout << key << endl;
    // The above line was used for testing to determine what pseudorandom number will always be generated
    cout << "Please enter passcode integer to gain access to program" << endl;
    int passcode;
    cin >> passcode;
    string missionName = "Ladybug";
    cout << "Please enter your codename to gain access to program" << endl;
    string codeName;
    cin >> codeName;
    if (passcode != key || missionName != codeName)
    {
        cout << "INCORRECT Credentials!! Program has been terminated" << endl;
        return 0;
    }
    else
    {
        double x_coords[15] = {58,1.25,25,96,22,51,12.8,91,4,63,65.5,12,42,72.7,45};
        double y_coords[15] = {17.19,20,32,48.3,88,26,67,85,64,77,35,80,6.6,99,10.6}; // The above are the given coordinates
        int order[15]={0,1,2,3,4,5,6,7,8,9,10,11,12,13,14}; // This array holds the order in which you will go to each site
                                                             // the hypothetical flight plan
        unsigned seed=chrono::system_clock::now().time_since_epoch().count(); // This creates a unique seed based on system time
        shuffle(&order[0],&order[15],default_random_engine(seed)); // This uses the default random engine and the seed in the previous line
                                                                   // to randomly shuffle the elements in the array order to create
                                                                   // a random flight path

        double totalDistance = distance_total (x_coords,y_coords,order);
        bool enoughGas = (totalDistance < 525);
        cout << "The length of the randomly selected route is " << (int) totalDistance << " miles." << endl; // cast to int for conciseness
        if (enoughGas){
            cout << "The route is short enough to fly without refueling." << endl;
        }
        else{
            cout << "The route is too long to fly without refueling." << endl;
        }

    }


    return 0;
}

double distance(double x1, double y1, double x2, double y2) { // This function uses the Pythagorean theorem to calculate 2d distance

    double ans, x_dist, y_dist;
    x_dist = x2 - x1;
    y_dist = y2 - y1;
    ans = sqrt(pow(x_dist,2)+pow(y_dist,2));
    return ans;

}

double distance_total(double a[], double b[], int c[]) { // This function calculates total flight distance
                                                         // I split it into a subfunction to keep code cleaner
    int foo = 15; // Length of the given array
    double sum;
    for (int i = 0; i < foo-1; i++)
    {   int Index1 = c[i];
        int Index2 = c[i+1];
        double x1 = a[Index1]; double x2 = a[Index2];
        double y1 = b[Index1]; double y2 = b[Index2];
        double z = distance(x1,y1,x2,y2);
        sum += z;
    }
    return sum;

}