#include <GLFW/glfw3.h>
#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <math.h>
#include <stack>
#include <vector>

using namespace std;

static void error_callback(int error, const char* description) {
    fputs(description, stderr);
}

struct Point {
    double x;
    double y;
};

int width = 640;
int height = 480;

vector<Point> points;

void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods );
void mouse_button_callback(GLFWwindow *window, int button, int action, int mods);
void draw_Line();
int main(void) {
    GLFWwindow* window;
    glfwSetErrorCallback(error_callback);
    if (!glfwInit())
        exit(EXIT_FAILURE);
    window = glfwCreateWindow(width, height, "Simple example", NULL, NULL);
    if (!window)
    {
        glfwTerminate();
        exit(EXIT_FAILURE);
    }

    glfwMakeContextCurrent(window);
    glfwSetKeyCallback(window, key_callback);
    glfwSetMouseButtonCallback(window, mouse_button_callback);

    while (!glfwWindowShouldClose(window)) {
        float windowWidth;
        int width, height;
        glfwGetFramebufferSize(window, &width, &height);
        windowWidth = width / (float) height;
        glViewport(0, 0, width, height);
        glClear(GL_COLOR_BUFFER_BIT);

        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(-windowWidth, windowWidth, -1.f, 1.f, 1.f, -1.f);
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        draw_Line();
        glfwSwapBuffers(window);
        glfwPollEvents();
    }
    glfwDestroyWindow(window);
    glfwTerminate();
    exit(EXIT_SUCCESS);
}


void mouse_button_callback (GLFWwindow *window, int button, int action, int mods) {
    if (button == GLFW_MOUSE_BUTTON_LEFT && action == GLFW_PRESS) {
        double x;
        double y;
        glfwGetCursorPos(window, &x, &y);
        points.push_back({x, y});
    }
}


void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods ) {
    if (action == GLFW_PRESS || action == GLFW_REPEAT) {
        switch (key) {
            case GLFW_KEY_ESCAPE:
                glfwSetWindowShouldClose(window, GL_TRUE);
                break;
        }
    }
}

void draw_Line() {
    if (points.size() > 1) {
        for (int i = 0; i < points.size() - 1; i++) {
            Point p1 = points[i];
            Point p2 = points[i + 1];
            p1.x = 2 * (p1.x - width / 2) / width;
            p1.y = 2 * (height / 2 - p1.y) / height;
            p2.x = 2 * (p2.x - width / 2) / width;
            p2.y = 2 * (height / 2 - p2.y) / height;

            cout << p2.x << " " << p2.y << endl;
           cout << p1.x << " " << p1.y << endl;

            glBegin(GL_LINES);
            glColor3b(1, 1, 0);
            glVertex2d(p1.x, p1.y);
            glVertex2d(p2.x, p2.y);
            glEnd();
        }
    }
}