lab4

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <locale.h>
#include <limits.h>
#include <conio.h>

int counter = 1;

struct hotel {
    char country[50];
    char city[50];
    char hotel_name[50];
    int hotel_class;
    int day_price;
    int transfer_price;
    int id;
};
typedef struct hotel Hotel;

struct List {
    Hotel hotel;
    struct List *next;
};
typedef struct List *hotel_list;

Hotel input_hotel();

hotel_list add_entry(hotel_list hotels, Hotel hotel);

hotel_list delete_entry(hotel_list);

void edit_entry(hotel_list hotels);

void insert_entry(struct List *cur, Hotel hotel);

hotel_list find_entry(struct List *cur, int id);

void print_entities(hotel_list hotels);

void print_entry(hotel_list hotel);

void delete_list(hotel_list hotels);

void find_cheapest(hotel_list hotels, int hotel_class);

void calculate_trip(hotel_list hotels, int hotel_class);

hotel_list read_file(char *filename, hotel_list hotels);

void save_file(char *filename, hotel_list hotels);

void print_menu();

int main(int argc, char **argv) {
    setlocale(0, "Russian");
    char filename[30], option;
    int search_id, tempint = 0;

    if (argc > 1) strcpy(filename, argv[1]);
    else {
        puts("Initial data filename:");
        gets(filename);
    }
    hotel_list hotels = NULL;
    hotels = read_file(filename, hotels);
    do {
        print_menu();
        option = getchar();
        switch (option) {
            case '1':
                print_entities(hotels);
                break;
            case '2':
                hotels = add_entry(hotels, input_hotel());
                break;
            case '3':
                edit_entry(hotels);
                break;
            case '4':
                hotels = delete_entry(hotels);
                break;
            case '5':
                puts("Position to put into(e.g. 1): ");
                scanf("%d", &search_id);
                if (search_id < 1 || search_id >= counter) {
                    puts("Invalid id");
                    system("pause");
                } else insert_entry(find_entry(hotels, search_id), input_hotel());
                break;
            case '6':
                puts("Hotel class to find cheapest: ");
                scanf("%d", &tempint);
                find_cheapest(hotels, tempint);
                break;
            case '7':
                puts("Hotel class to calculate average: ");
                scanf("%d", &tempint);
                calculate_trip(hotels, tempint);
                break;
            default:
                puts("Invalid option");
        }
    } while (option != '0');
    getchar();
    puts("Enter the filename name to save to:");
    gets(filename);
    save_file(filename, hotels);
    delete_list(hotels);
    return 0;
}

hotel_list find_entry(struct List *cur, int id) {
    for (int i = 0; i < id - 1; i++) cur = cur->next;
    return cur;
}

Hotel input_hotel() {
    Hotel hotel;
    getchar();
    puts("Country:");
    gets(hotel.country);
    puts("City: ");
    gets(hotel.city);
    puts("Hotel name:");
    gets(hotel.hotel_name);
    puts("Hotel class");
    scanf("%d", &hotel.hotel_class);
    puts("Day price");
    scanf("%d", &hotel.day_price);
    puts("Transfer costs:");
    scanf("%d", &hotel.transfer_price);

    hotel.id = counter;
    return hotel;
}

void insert_entry(struct List *cur, Hotel hotel) {
    struct List *temp;
    temp = (struct List *) malloc(sizeof(struct List));
    temp->hotel = hotel;
    temp->next = cur->next;
    cur->next = temp;
}

hotel_list add_entry(hotel_list hotels, Hotel hotel) {
    hotel_list temp;
    if (hotels == NULL) {
        hotels = (hotel_list) malloc(sizeof(struct List));
        temp = hotels;
    } else {
        temp = hotels;
        while (temp->next) temp = temp->next;
        temp->next = (hotel_list) malloc(sizeof(struct List));
        temp = temp->next;
    }
    temp->hotel = hotel;
    temp->next = NULL;
    return hotels;
}


void delete_list(hotel_list hotels) {
    hotel_list temp = hotels;
    while (temp) {
        hotels = temp->next;
        free(temp);
        temp = hotels;
    }
}

hotel_list read_file(char *filename, hotel_list hotels) {
    FILE *fin;
    Hotel hotel;
    if ((fin = fopen(filename, "rb")) == NULL) {
        perror("Can't open this file");
        getch();
        return hotels;
    }
    while (fread(&hotel, sizeof(hotel), 1, fin))
        hotels = add_entry(hotels, hotel);
    fclose(fin);
    return hotels;
}

void save_file(char *filename, hotel_list hotels) {
    FILE *fout;
    if ((fout = fopen(filename, "wb")) == NULL) {
        perror("Can't create the file");
        system("pause");
        return;
    }
    while (hotels) {
        fwrite(&hotels->hotel, sizeof(Hotel), 1, fout);
        hotels = hotels->next;
    }
}

void edit_entry(hotel_list hotels) {
    int n, k = 1;
    char yes;
    system("CLS");
    if (hotels == NULL) {
        puts("No items in the list");
        system("pause");
        return;
    }
    puts("ID to edit:");
    scanf("%d", &n);
    if (n < 1) {
        puts("Error");
        system("pause");
        return;
    }
    while (hotels && k < n) {
        hotels = hotels->next;
        k++;
    }
    if (hotels == NULL) {
        puts("Error");
        system("pause");
        return;
    }
    print_entry(hotels);
    puts("Apply the changes? (y/n)");
    do
        yes = getchar();
    while (yes != 'y' && yes != 'Y' && yes != 'n' && yes != 'N');
    if (yes == 'y' || yes == 'Y')
        hotels->hotel = input_hotel();
}

void print_entities(hotel_list hotels) {

    int b = 1;
    system("CLS");
    if (hotels == NULL) {
        puts("List is empty");
        system("pause");
        return;
    }

    puts("| #  |  Country   |   City     | Hotel name | Hotel class | Day price | Transfer price");
    while (hotels) {
        hotels->hotel.id++;
        printf("| %-2d | %-10s | %-10s | %-10s |      %-6d | %-9d | %-9d \n", b++, hotels->hotel.country,
               hotels->hotel.city, hotels->hotel.hotel_name, hotels->hotel.hotel_class, hotels->hotel.day_price,
               hotels->hotel.transfer_price);
        hotels = hotels->next;
    }
    system("pause");
}

void print_entry(hotel_list entry) {
    printf("Country : %s\nCity : %s\nHotel name : %s\nHotel class : %d\nDay price : %d\nTransfer price : %d\n",
           entry->hotel.country,
           entry->hotel.city, entry->hotel.hotel_name, entry->hotel.hotel_class, entry->hotel.day_price,
           entry->hotel.transfer_price);
}

void find_cheapest(hotel_list hotels, int hotel_class) {
    int min = INT_MAX;
    hotel_list temp;
    while (hotels) {
        hotels->hotel.id++;
        if (hotels->hotel.hotel_class == hotel_class && hotels->hotel.day_price < min) {
            min = hotels->hotel.day_price;
            temp = hotels;
        }
        hotels = hotels->next;
    }
    if (min != INT_MAX) {
        print_entry(temp);
    } else {
        puts("No hotel found");
    }
    system("pause");
}

void calculate_trip(hotel_list hotels, int hotel_class) {
    int counter = 0;
    int cost = 0;
    while (hotels) {
        hotels->hotel.id++;
        if (hotels->hotel.hotel_class == hotel_class) {
            cost += 7 * hotels->hotel.day_price + hotels->hotel.transfer_price;
            counter++;
        }
        hotels = hotels->next;
    }
    cost /= counter;
    printf("Average cost for the %d class is %d", hotel_class, cost);
    system("pause");
}


void print_menu() {
    system("CLS");
    puts("1. Print hotels");
    puts("2. Add hotel");
    puts("3. Edit hotel");
    puts("4. Delete hotel");
    puts("5. Insert hotel");
    puts("6. Find cheapest");
    puts("7. Calculate trip's costs");
    puts("0. Exit");
    puts("Type number to proceed:");
}

hotel_list delete_entry(hotel_list hotels) {
    int n, j = 1;
    char yes;
    hotel_list temp, temp1;
    system("CLS");
    if (hotels == NULL) {
        puts("List is empty");
        system("pause");
        return NULL;
    }
    puts("Number record for delete?");
    scanf("%d", &n);
    if (n < 1) {
        puts("Error");
        system("pause");
        return hotels;
    }
    if (n == 1) {
        print_entry(hotels);
        puts("Delete? (y/n)");
        do
            yes = getchar();
        while (yes != 'y' && yes != 'Y' && yes != 'n' && yes != 'N');
        if (yes == 'y' || yes == 'Y') {
            temp = hotels->next;
            free(hotels);
            return temp;
        } else return hotels;
    }
    if (hotels->next == NULL && n > 1) {
        puts("Error");
        system("pause");
        return hotels;
    }
    temp = hotels;
    temp1 = temp->next;
    while (temp1->next && j < n - 1) {
        temp = temp1;
        temp1 = temp->next;
        j++;
    }
    if (j < n - 1) {
        puts("Error");
        system("pause");
        return hotels;
    }
    print_entry(temp1);
    puts("Delete? (y/n)");
    do
        yes = getchar();
    while (yes != 'y' && yes != 'Y' && yes != 'n' && yes != 'N');
    if (yes == 'y' || yes == 'Y') {
        temp->next = temp1->next;
        free(temp1);
    }
    return hotels;
}