#include <iostream>
#include <stdio.h>
#include <conio.h>
#include <windows.h>
#include <stdlib.h>

using namespace std;


struct num{
    bool show_flag;
    char name[20];
    char number[12];
    char surname[20];
    long int index;
} cur_num;

void delNum (FILE *fp, num &cur_num){
cur_num.show_flag = false;
fpos_t cur_pos;
fgetpos(fp, &cur_pos);
fseek(fp,-sizeof(num), SEEK_CUR);
fwrite(&cur_num, sizeof(num), 1, fp);
cout << "Number " << cur_num.number << " of " << cur_num.name << " " << cur_num.surname <<" has been deleted successfully." << endl;
fseek(fp, cur_pos, SEEK_SET);
}


int main(){
char c;
long int ind = 0;
FILE* fp = fopen("D:\\Programming\\number.txt", "r+b");
while (c!=27){
    cout << "1) Enter number." << endl;
    cout << "2) Show all numbers." << endl;
    cout << "3) Delete number by index." << endl;
    cout << "4) Delete number by name." << endl;
    cout << "5) Delete number by surname." << endl;
    cout << "6) Searching by name." << endl;
    cout << "7) Searching by surname." << endl;
    cout << "8) Searching by first letters. (beta)" << endl;
    cout << "Press ESC to quit" << endl;
    c = getch();
    system("cls");
    switch(c){
      case '1': {
                fseek(fp, -sizeof(long int), SEEK_END);
                if (fread(&ind,sizeof(long int), 1, fp))
                cur_num.index = ind + 1; else
                cur_num.index = 1;
                cur_num.show_flag = true;
                cout << "Enter name: ";
                //cin >> cur_num->name;
                scanf("%s",&cur_num.name);
                cout << "Enter surname: ";
                scanf("%s",&cur_num.surname);
                cout << "Enter number: ";
                //cin >> cur_num->number;
                scanf("%s",&cur_num.number);
                fseek(fp, 0, SEEK_END);
                fwrite(&cur_num, sizeof(num), 1, fp);
                } break;
      case '2': {
                fseek(fp, 0, SEEK_SET);
                while (!feof(fp))
                        {
                        if (fread(&cur_num,sizeof(num),1,fp))
                            {
                            cout << "__________________" << endl;
                            cout << "Name: " << cur_num.name << endl;
                            cout << "Surname: " << cur_num.surname << endl;
                            cout << "Number: " << cur_num.number << endl;
                            cout << "Index: " << cur_num.index << endl;
                            cout << "Flag: " << cur_num.show_flag << endl;
                            cout << "__________________" << endl;
                            }
                        }
                } break;
      case '3': {
                cout << "Enter index to delete: ";
                //cin >> &ind;
                scanf("%d",&ind);
                fseek(fp, 0, SEEK_SET);
                while (!feof(fp))
                  if (fread(&cur_num,sizeof(num), 1, fp) && cur_num.show_flag && cur_num.index == ind)
                  delNum(fp,cur_num);
                } break;
      case '4': {
                cout << "Enter name to delete: ";
                char num_name[20];
                //cin >> &num_name;
                scanf("%s",&num_name);
                fseek(fp, 0, SEEK_SET);
                while (!feof(fp))
                  if (fread(&cur_num, sizeof(num), 1, fp) && cur_num.show_flag && strcmp(cur_num.name, num_name) == 0)
                  delNum(fp, cur_num);
                } break;
      case '5': {
                cout << "Enter surname to delete: ";
                char num_surname[30];
                scanf("%s", &num_surname);
                fseek(fp, 0, SEEK_SET);
                while(!feof(fp))
                    if (fread(&cur_num, sizeof(num), 1, fp) && cur_num.show_flag && strcmp(cur_num.surname, num_surname) == 0)
                    delNum(fp, cur_num);
                } break;
      case '6': {
                    cout << "Enter name of human you would like to find: ";
                    char num_name[20];
                    scanf("%s", num_name);
                    fseek(fp, 0, SEEK_SET);
                    while(!feof(fp))
                    if (fread(&cur_num, sizeof(num), 1, fp) && cur_num.show_flag && strcmp(cur_num.name, num_name) == 0){
                        fread(&cur_num,sizeof(num),1,fp);
                        cout << "__________________" << endl;
                        cout << "Name: " << cur_num.name << endl;
                        cout << "Surname: " << cur_num.surname << endl;
                        cout << "Number: " << cur_num.number << endl;
                        cout << "Index: " << cur_num.index << endl;
                        cout << "Flag: " << cur_num.show_flag << endl;
                        cout << "__________________" << endl;
                    }
                } break;
        case '7': {
                    cout << "Enter name of human you would like to find: ";
                    char num_surname[20];
                    scanf("%s", num_surname);
                    fseek(fp, 0, SEEK_SET);
                    while(!feof(fp))
                    if (fread(&cur_num, sizeof(num), 1, fp) && cur_num.show_flag && strcmp(cur_num.surname, num_surname) == 0){
                        fread(&cur_num,sizeof(num),1,fp);
                        cout << "__________________" << endl;
                        cout << "Name: " << cur_num.name << endl;
                        cout << "Surname: " << cur_num.surname << endl;
                        cout << "Number: " << cur_num.number << endl;
                        cout << "Index: " << cur_num.index << endl;
                        cout << "Flag: " << cur_num.show_flag << endl;
                        cout << "__________________" << endl;
                  }
            } break;
         case '8': {
                    cout << "Enter first 3 letters humans surname you would like to find: ";
                    char num_surname[3];
                    char beta_surname[3];
                    scanf("%s", num_surname);
                    fseek(fp, 0, SEEK_SET);
                    for (int i = 0; i < 3; i++){
                        beta_surname[i] = cur_num.surname[i];
                        if (fread(&cur_num, sizeof(num), 1, fp) && cur_num.show_flag && strcmp(beta_surname, num_surname) == 0){
                            fread(&cur_num,sizeof(num),1,fp);
                            cout << "__________________" << endl;
                            cout << "Name: " << cur_num.name << endl;
                            cout << "Surname: " << cur_num.surname << endl;
                            cout << "Number: " << cur_num.number << endl;
                            cout << "Index: " << cur_num.index << endl;
                            cout << "Flag: " << cur_num.show_flag << endl;
                            cout << "__________________" << endl;
                            }
                        }
                } break;
        }
FILE* temp = fopen("D:\\Programming\\temporary.txt", "wb");
fseek(fp, 0, SEEK_SET);
while (!feof(fp))
if (fread(&cur_num, sizeof(num), 1, fp) && cur_num.show_flag == true)
fwrite(&cur_num, sizeof(num), 1, temp);
fclose(fp);
fclose(temp);
remove("D:\\Programming\\number.txt");
rename("D:\\Programming\\temporary.txt", "D:\\Programming\\number.txt");
return 0;
    }
}