#include "a_station.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

//vytvorit prazdnu stanicu
struct station* create_station() {
    struct station* station = (struct station*)calloc(1, sizeof(struct station));
    station->tracks = (struct car**)calloc(STATION_SIZE, sizeof(struct car*));
    station->track_count = STATION_SIZE;
    return station;
}

//uvolnit vsetku pamat v tabuľke.
void destroy_station(struct station* station) {
    if (station == NULL) return;

    //prejdi vsetky trate
    for (int i = 0; i < station->track_count; i++) {
        struct car* current = station->tracks[i];
        //prejdi vsetky zaznamy na trati a uvolni ich
        while (current != NULL) {
            struct car* next = current->next;
            free(current);
            current = next;
        }
    }

    //uvolni pole smernikov a stanicu
    free(station->tracks);
    free(station);
}

int select_track(struct station* station, const char* target) {
    unsigned long hash = 5381;
    int c;
    while ((c = *target++))
        hash = ((hash << 5) + hash) + c;
    return (int)(hash % station->track_count);
}

//prida alebo aktualizuje zaznam v stanici
void add_target_capacity(struct station* station, const char* target, int capacity) {
    if (station == NULL || target == NULL) return;

    int track = select_track(station, target);
    struct car* current = station->tracks[track];
    struct car* prev = NULL;

    //prehladavanie spojkoveho zoznamu na trati
    while (current != NULL) {
        if (strcmp(current->value, target) == 0) {
            //zvysit kapacitu ak stanica existuje
            current->capacity += capacity;
            return;
        }
        prev = current;
        current = current->next;
    }

    //novy zaznam ak neexistuje
    struct car* new_car = (struct car*)calloc(1, sizeof(struct car));
    strncpy(new_car->value, target, TARGET_SIZE - 1);
    new_car->value[TARGET_SIZE - 1] = '\0';
    new_car->capacity = capacity;
    new_car->next = NULL;

    if (prev == NULL) {
        station->tracks[track] = new_car;
    } else {
        prev->next = new_car;
    }
}

//vyhladat kapacitu pre zadanu cielovu stanicu
int get_target_capacity(struct station* station, const char* target) {
    if (station == NULL || target == NULL) return 0;

    int track = select_track(station, target);
    struct car* current = station->tracks[track];

    while (current != NULL) {
        if (strcmp(current->value, target) == 0)
            return current->capacity;
        current = current->next;
    }
    return 0; //nenaslo
}

//spocitat pocet roznych cielovych stanic
int count_targets(struct station* station) {
    if (station == NULL) return 0;
    int count = 0;

    for (int i = 0; i < station->track_count; i++) {
        struct car* current = station->tracks[i];
        while (current != NULL) {
            count++;
            current = current->next;
        }
    }

    return count;
}

//spocitat celkovu kapacitu vsetkych zaznamov
int count_capacity(struct station* station) {
    if (station == NULL) return 0;
    int total = 0;

    for (int i = 0; i < station->track_count; i++) {
        struct car* current = station->tracks[i];
        while (current != NULL) {
            total += current->capacity;
            current = current->next;
        }
    }

    return total;
}