#include <GLFW/glfw3.h>
#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

GLfloat scrW = 500, scrH = 500;

// Y сверху вниз
// X слева направо

struct vertex {
    GLdouble x, y;
};

vector<vertex> mas;

int flag = 0;
int flagCanDraw = 1;



void drawEdges() {
    if (flag) {
        glBegin(GL_LINE_LOOP);
    } else {
        glBegin(GL_LINE_STRIP);
    }
    glColor3f(1, 1, 1);
    for (int i = 0; i < mas.size(); i++) {
    //    glVertex2f(mas[i].x, mas[i].y);
        glRasterPos2d(mas[i].x, mas[i].y);
    }
    glRasterPos2d(mas[0].x, mas[0].y);
}

void keyCallback(GLFWwindow *window, int key, int scancode, int action, int mods) {
    if (action == GLFW_PRESS) {
        switch (key) {
            case GLFW_KEY_1:
                flag = 1;
                flagCanDraw = 0;
                break;
            case GLFW_KEY_C:
                mas.clear();
                flag = 0;
                flagCanDraw = 1;
                break;
        }
    }
}

void mouseCallback(GLFWwindow* window, int button, int action, int mods) {
    if (flagCanDraw) {
        if (button == GLFW_MOUSE_BUTTON_LEFT && action == GLFW_PRESS) {
            GLdouble x, y;
            glfwGetCursorPos(window, &x, &y);
            vertex vertexLeftBut;
            vertexLeftBut.x = x;
            vertexLeftBut.y = y;
            mas.push_back(vertexLeftBut);
        }
    }

}


int main() {
    GLFWwindow *window;


    if (!glfwInit()) {
        return -1;
    }

    window = glfwCreateWindow(scrW, scrH, "Lab4", NULL, NULL);

    glfwSetKeyCallback(window, keyCallback);
    glfwSetMouseButtonCallback(window, mouseCallback);

    glfwSetInputMode(window, GLFW_STICKY_KEYS, 1);

    int screenW, screenH;
    glfwGetFramebufferSize(window, &screenW, &screenH);

    if (!window) {
        glfwTerminate();
        return -1;
    }

    glfwMakeContextCurrent(window);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();


    while (!glfwWindowShouldClose(window)) {

        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glPushMatrix();
        glOrtho(0.0, scrW, scrH, 0.0, -1.0, 1.0);
        glViewport(0, 0, screenW, screenH);

        drawEdges();

        glEnd();
        glPopMatrix();

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glfwTerminate();

    return 0;
}