#include <iostream>

using namespace std;

enum Gender{MALE=1, FEMALE=2};

struct Date{
    int day;
    int month;
    int year;
    Date(){
        day=1;
        month=1;
        year=1990;
    }
    Date(int day, int month, int year){
        this->day = day;
        this->month=month;
        this->year=year;
    }
};

struct User{
    int u_id;
    string u_name;
    string username;
    string password;
    string email;
    Date birthday;
    Gender gender;
    string phone;
    User(){}
    User(int _u_id, string _u_name, string _username, string _password, string _email, Date _birthday, Gender _gender, string _phone){
        u_id = _u_id;
        u_name = _u_name;
        username = _username;
        password = _password;
        email = _email;
        birthday = _birthday;
        gender = _gender;
        phone = _phone;
    }
};

void printUser(const User& u){
    cout <<"\tUsername: " <<u.username << " - " <<"Email: "<< u.email << endl;
}

void printAllUsers(const User us[], int size){
    for(int i=0; i<size; i++){
        printUser(us[i]);
    }
}

void insert(User us[], int& size, User u){
    us[size++] = u;
}

void deleteUser(User us[], int& size, int u_id){
    int findIndex = -1;
    for(int i=0; i<size; i++){
        if(us[i].u_id==u_id){
            findIndex = i;
            break;
        }
    }
    if(findIndex==-1){
        cout << "Couldn't find your id ";
    }else{
        for(int i=findIndex; i<size-1; i++){
            us[i] = us[i+1];
        }
    }
    size--;
}

User enterInfo(){
    User temp;
    cout<<"Enter your ID: ";
    cin>>temp.u_id;
    cin.ignore();
    cout<<"Enter your name: ";
    getline(cin,temp.u_name);
    cout<<"Enter username: ";
    cin>>temp.username;
    cin.ignore();
    cout<<"Enter password: ";
    cin>>temp.password;
    cin.ignore();
    cout<<"Enter email: ";
    cin>>temp.email;
    cin.ignore();
    cout<<"Enter phone number: ";
    cin>>temp.phone;
    cout<<"Enter birtday (dd/mm/yy): ";
    char c;
    cin>>temp.birthday.day>>c>>temp.birthday.month>>c>>temp.birthday.year;
    cin.ignore();
    int gender;
    cout<<"Enter gender(MALE=1/FEMALE=2): ";
    cin>>gender;
    if(gender==1)
        temp.gender=MALE;
    else
        temp.gender=FEMALE;
    return temp;
}

struct Book{
    int book_id;
    string name;
    int current_u;
    User user[30];
    Book(){};
    Book(int id,string name){
        current_u=0;
        this->name=name;
        book_id=id;
    }
};

bool checkBookValid(int id,const Book book[],int current_book){
    for(int i=0;i<current_book;i++)
        if(book[i].book_id==id){
            return 0;
            cout<<"OK";
        }
    return 1;
}


int main(){
    int current_book=3,id;
    Book book[100];
    book[0]=Book(182852,"Co Gai Den Tu Hom Qua");
    book[1]=Book(257874,"Toi Thay Hoa Vang Tren Co Xanh");
    book[2]=Book(125571,"Mat Biec");
    char respond;
    while(1){
        cout<<"Current book available in the library:"<<endl;
        for(int i=0;i<current_book;i++){
            cout<<"\tID: "<<book[i].book_id<<" - Name: "<<book[i].name<<endl;
        }
        cout<<endl;
        cout<<"'b' to borrow a book"<<endl;
        cout<<"'r' to return a book"<<endl;
        cout<<"'s' to show all user's info borrowed book"<<endl;
        cout<<"'i' to insert new book to library"<<endl;
        cout<<"'q' to quit"<<endl;
        cout<<"\n Enter key: ";
        cin>>respond;
        cout<<endl;
        switch(respond){
            case 'i':{
                int b_id;
                string name;
                do{
                    cout<<"Enter new book ID: ";
                    cin>>b_id;
                }while(!checkBookValid(b_id,book,current_book));
                cout<<"Enter new book name: ";
                cin.ignore();
                getline(cin,name);
                book[current_book].book_id=b_id;
                book[current_book].name=name;
                current_book++;
                break;
            }
            case 'b':  {
                        cout<<"Enter book ID: ";
                        cin>>id;
                        int i=0;
                        for(;book[i].book_id!=id && i<=current_book;i++);
                        if(i==3){
                            cout<<"Couldn't find book ID " <<id<<endl;
                            break;
                        }
                        else
                            cout<<"BOOK NAME: "<<"\t"<<book[i].name<<endl;
                        User temp=enterInfo();
                        insert(book[i].user,book[i].current_u,temp);
                        break;
            }
            case 's':{
                        for(int i=0;i<current_book;i++){
                            cout<<"BOOK: "<<book[i].name<<endl;
                            printAllUsers(book[i].user,book[i].current_u);
                            cout << "---------------------" << endl;
                        }
                        break;
            }
            case 'r':{
                        int b_id,u_id;
                        cout<<"Enter book ID to return :";
                        cin>>b_id;
                        int i=0;
                        for(;book[i].book_id!=id && i<=current_book;i++);
                        if(i==3){
                            cout<<"Couldn't find book ID " <<id<<endl;
                            break;
                        }
                        else{
                            cout<<"BOOK NAME: "<<"\t"<<book[i].name<<endl;
                            cout<<"Enter your user ID: ";
                            cin>>u_id;
                            deleteUser(book[i].user,book[i].current_u,u_id);
                            break;
                        }

            }
            case 'q':
                        return 0;
            default:
                cout<<"Invalid key"<<endl;
        }
    }
    cout<<endl<<endl;
}