// UchilishtaSvurzanSpisuk.cpp : Defines the entry point for the console application.
//

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

//School Struct
typedef struct {
    char name[50];
    char directorName[30];
    int ID,children;
    int area;
}School;
//Node
typedef struct node {
    School school;
    struct node *next;//Points to the next node
}node;

node *makeSrtLst(node *head, FILE *f,int option = 0) {
    rewind(f);
    node *p, *crnt, *prev;
    do {
        p = (node *)malloc(sizeof(node)); /* if p==0 */
        p->next = NULL;
        if (!fread(&(p->school), sizeof(School), 1, f)) {
            free(p);
            break;
        }
        /* find the correct place – sorted by n */
        if (option != 4) {
            for (prev = NULL, crnt = head;
                crnt && (crnt->school.children > p->school.children);
                prev = crnt, crnt = crnt->next);
        }
        else {
            for (prev = NULL, crnt = head;
                crnt && (crnt->school.area > p->school.area);
                prev = crnt, crnt = crnt->next);
        }
        // put in the list
        if (prev) {
            prev->next = p;
        }
        else {
            head = p;
        }
        p->next = crnt;
        /* or put directly in the head of the list – no sort
        p->next=head;
        head = p;
        */
    } while (1);
    return head;
}

//Print the given node
void prt(node *crnt) {
    while (crnt) {
        printf("Next School Information:\n");
        printf("School Name: %s\n", crnt->school.name);
        printf("School ID: %d\n", crnt->school.ID);
        printf("School Students: %d\n", crnt->school.children);
        printf("School Area: %d\n", crnt->school.area);
        printf("School director's name: %s\n", crnt->school.directorName);
        crnt = crnt->next;
    }
}
//Free Memory
node *free_m(node *crnt) {
    node *next;
    printf("Memory free\n");
    while (crnt) {
        next = crnt->next; free(crnt); crnt = next;
    }
    return NULL;
}
//Validation(If The given ID is uniqe returns 1)
int validateID(node *head, int ID) {
    node *crnt;
    crnt = head;
    while (crnt) {
        if (crnt->school.ID == ID) {
            printf("zashto");
            return 0;
        }
        crnt = crnt->next;
    }
    return 1;
}
//Create a new binary file and save the input information
void saveInfoInFile(FILE *f) {
    School s;
    node *head = NULL;
    do {
        head = makeSrtLst(head, f);
        printf("Next School name (Put '*' To end):");
        scanf(" %49[^\n]", s.name);
        if (!strcmp(s.name, "*")) {
            break;
        }
        printf("%s School ID: ", s.name); fflush(stdin);
        scanf(" %d", &s.ID);
        //Check if the ID is unique
        while (!validateID(head,s.ID)) {
            printf("The ID of the schools should be uniqe\n: ");
            printf("%s School ID: ", s.name); fflush(stdin);
            scanf("%d", &s.ID);
        }
        printf("%d %s Number of students: ", s.ID, s.name); fflush(stdin);
        scanf(" %d", &(s.children));
        //The students must be more than 0
        while (s.children < 0) {
            printf("The children should be >= 0\n: ");
            printf("%s - Number of Students: ", s.name); fflush(stdin);
            scanf(" %d", &s.children);
        }
        printf("%d %s School Area:", s.ID, s.name); fflush(stdin);
        scanf(" %d", &(s.area));
        while (s.area <= 50) {
            printf("The area should be > 50\n: ");
            printf("%s - Area : ", s.name); fflush(stdin);
            scanf(" %d", &s.area);
        }
        printf("%d %s School director's name:", s.ID, s.name); fflush(stdin);
        scanf(" %29[^\n]", s.directorName); fflush(stdin);
        //Write the structure into the file
        fwrite(&s, sizeof(School), 1, f);
        printf("Writing the structure in the file\n");
    } while (1);
    head = free_m(head);
    printf("The file is created\n");
}
//Change School Information
void renewInfoFile(node *crnt,FILE *fp) {
    School s;
    while (crnt) {
        s = crnt->school;
        fwrite(&s, sizeof(School), 1, fp);
        crnt = crnt->next;
    }
}
node *changeSchoolInfo(node *crnt, int ID) {
    node *head = NULL, *prev;
    int choice = 0, tmpID;
    head = crnt;
    prev = crnt;
    while (crnt) {
        if (crnt->school.ID == ID) {
            do {
                printf("School Information:\n");
                printf("School Name: %s\n", crnt->school.name);
                printf("School ID: %d\n", crnt->school.ID);
                printf("School Students: %d\n", crnt->school.children);
                printf("School Area: %d\n", crnt->school.area);
                printf("School director's name: %s\n", crnt->school.directorName);
                printf("1 - Change name\n2 - Change SchoolID\n3 - Change number of students\n4 - Change School area\n5 - Change director's name\n6 - Za izhod\n"); fflush(stdin);
                scanf("%d", &choice);
                switch (choice) {
                case 1:
                    printf("New School Name:"); fflush(stdin);
                    scanf(" %49[^\n]", crnt->school.name);
                    break;
                case 2:
                    printf("New School ID:"); fflush(stdin);
                    scanf(" %d", &tmpID);
                    while ((!validateID(head, tmpID)) ) {
                        if (tmpID == crnt->school.ID) {
                            break;
                        }
                        printf("The ID of the schools should be uniqe\n: "); fflush(stdin);
                        scanf("%d", &tmpID);
                    }
                    crnt->school.ID = tmpID;
                    break;
                case 3:
                    printf("New Number of students:"); fflush(stdin);
                    scanf(" %d", &crnt->school.children);
                    if(crnt->school.children <= 0) {
                        prev->next = crnt->next;
                        return head;
                    }
                    break;
                case 4:
                    printf("New School Area:"); fflush(stdin);
                    scanf(" %d", &crnt->school.area);
                    break;
                case 5:
                    printf("New Director's Name:"); fflush(stdin);
                    scanf(" %29[^\n]", crnt->school.directorName);
                    break;
                default:
                    break;
                }

            } while (choice > 0 && choice < 6);
            break;
        }
        prev = crnt;
        crnt = crnt->next;
    }
    prt(head);
    return head;
}
//Add school to the file
void addSchool() {
    FILE *fp;
    School s;
    fp = fopen("text.dat", "ab+");
    if (!fp) {
        return;
    }
    saveInfoInFile(fp);
    fclose(fp);
}
//Change information about the school
void changeInfo(node *head) {
    FILE *fp;
    School s;
    fp = fopen("text.dat", "wb");
    if (!fp) {
        return;
    }
    int choice = 0, ID = 0, value = 0;
    do {
        printf("School's ID which has to be updated");
        printf("\nVuvedete 0 za izhod: "); fflush(stdin);
        scanf(" %d", &ID);
        if (ID == 0) {
            break;
        }
        printf("\nstigame li do tuk");
        head = changeSchoolInfo(head,ID);
    } while (1);
    renewInfoFile(head,fp);
    fclose(fp);
}
void printMenu() {
    printf("Choose an option between 1 - 4\n");
    printf("1 - Add New School(s)\n");
    printf("2 - Change Information about a school\n");
    printf("3 - Print the List of Schools based on number of students\n");
    printf("4 - Print the List of Schools based on their Area\n");
    printf("5 - Exit\n");
    printf("Option Number: ");
}
int main() {
    FILE *f;
    node *head = NULL;
    int option = 0;
    if (!(f = fopen("text.dat", "rb"))) {
        return 1;
    }
    do {
        printMenu(); fflush(stdin);
        scanf(" %d", &option);
        switch (option) {
        case 1:
            addSchool();
            break;
        case 2:
            head = makeSrtLst(head, f);
            changeInfo(head);
            head = free_m(head);
            break;
        case 3:
            head = makeSrtLst(head, f);
            prt(head);
            head = free_m(head);
            break;
        case 4:
            head = makeSrtLst(head, f, 4);
            prt(head);
            head = free_m(head);
            break;
        default:
            break;
        }
    } while (option > 0 && option < 5);
    fclose(f);
    return 0;
}