#include <stdio.h>
#include <stdlib.h>
#include <math.h>

typedef struct tackica{
    float x,y;
    struct tackica *next;
}TACKA;

typedef struct cvor{
    TACKA t;
    struct cvor* next;
}CVOR;

void readDots(CVOR **head);
void showAllDots(CVOR *head);
void dodajTacku(CVOR **head, TACKA tmp);
void uporediTacke(CVOR *head, TACKA tmp);
void obrisiListu(CVOR **head);
float sq(TACKA t);

int main()
{
    CVOR* head;
    head=NULL;
    TACKA tmp;
    int izbor;

    readDots(&head);

    do{
        puts("***************************************************");
        printf("\n\t1. Unos nove tacke.");
        printf("\n\t2. Prikaz svih tacaka.");
        printf("\n\t3. Pronalazenje najblize tacke zadatoj.");
        printf("\n\t4. Brisanje liste.");
        printf("\n\t5. Finito.");
        printf("\n\t >>");
        scanf("%d", &izbor);
        puts("***************************************************");

        switch(izbor){
            case 1:
                printf("X = ");
                scanf("%f", &tmp.x);
                printf("Y = ");
                scanf("%f", &tmp.y);
                dodajTacku(&head, tmp);
                break;
            case 2:
                showAllDots(head);
                break;
            case 3:
                printf("X = ");
                scanf("%f", &tmp.x);
                printf("Y = ");
                scanf("%f", &tmp.y);
                printf("Tacka najbliza zadatoj je tacka :");
                uporediTacke(head, tmp);
                break;
            case 4:
                obrisiListu(&head);
                break;
        }

    }while(izbor!=5);

    obrisiListu(&head);
    showAllDots(head);
    return 0;
}
void readDots(CVOR **head){

    FILE *fp;
    TACKA tmp;

    if((fp=fopen("tacke.txt", "r"))!=NULL){
        while((fscanf(fp,"%f,%f",&tmp.x,&tmp.y))==2){
            CVOR* novi;
            novi = (CVOR*)malloc(sizeof(CVOR));
            novi->t = tmp;
            novi->next = *head;
            *head = novi;
        }
        puts("\nPODACI USPESNO UCITANI!\n");
    }
    else puts("\nGRESKA PRI OTVARANJU DATOTEKE!");
    fclose(fp);
}

void showAllDots(CVOR *head){
    while(head!=NULL){
        printf("TACKA: %.2f, %.2f\n", head->t.x, head->t.y);
        head = head->next;
    }
}

void dodajTacku(CVOR **head, TACKA tmp){
    CVOR* novi;
    novi = (CVOR*)malloc(sizeof(CVOR));
    novi->t = tmp;
    novi->next = *head;
    *head = novi;
}

void uporediTacke(CVOR *head, TACKA tmp){
    float dist1, dist2;
    dist1 = sq(tmp);
    dist2 = sq(head->t);
    float dist = fabs(dist1-dist2);
    TACKA min = head->t;

    while(head!=NULL){
        dist2 = sq(head->t);
        if((fabs(dist1-dist2)) < dist){
            min = head->t;
            dist = (fabs(dist1-dist2));
        }
        head = head->next;
    }
    printf("[%.2f, %.2f]\n", min.x, min.y);
}

void obrisiListu(CVOR **head){
    CVOR *ovajTuSad = *head;
    while(*head){
        ovajTuSad = *head;
        //obrisiListu((*head)->next);
        *head = (*head)->next;
        printf("Deleting... %.2f, %.2f DELETED\n", ovajTuSad->t.x, ovajTuSad->t.y);
        free(ovajTuSad);
    }
    *head = NULL;
}

float sq(TACKA t){
    return sqrt((t.x*t.x)+(t.y*t.y));
}