phonebook first completion

#include<bits/stdc++.h>
using namespace std;


class phonebook//Base Class
{
public:
    string name;
    string mobile;
    string email;
    virtual  void modifynumber(string nam){};
    virtual void modifyname(string nam){};
    virtual void display(string nam){};
    virtual void add(string name){};
    virtual void delete_number(string name){};
    virtual void clear_all(){};
    virtual void send_messages(string name){};
    virtual void display_sent_messages(string name){};
};
class addnum:public phonebook
{
public:
    void add(string name);
};

//to display or modify existing number
class existnum:public phonebook
{
    void modifynumber(string nam);
    void modifyname(string nam);
    void display(string nam);
};

//to delete a particular number
class deletenum:public phonebook
{
    void delete_number(string name);
};
//to clear the whole phonebook
class clear_phonebook: public phonebook
{
    void clear_all();
};
void addnum:: add(string name)
{
    fstream fin;
    //ofstream out;
    fin.open("file1.csv",ios::in | ios::app);
    //out.open("Edited.csv",ios::out);
    vector<string>row;
    string line,word,temp,num;
    cout<<"Enter the Number"<<endl;
    cin>>num;
    cout<<"Want to add email?"<<endl;
    cout<<"1.Yes"<<"      "<<"2.NO"<<endl;
    int x;
    cin>>x;
    if(x==1)
    {
        cout<<"Enter the email"<<endl;
        string email;
        cin>>email;
        fin<<name<<","<<num<<","<<email<<endl;
    }
    else
    {
        email=" ";
        fin<<name<<","<<num<<","<<email<<endl;
    }
    fin.close();
}

void clear_phonebook::clear_all()
{
    remove("file1.csv");
    return;
}
void existnum::display(string name)
{
    fstream fin;
    fin.open("file1.csv",ios::in);
    vector<string>row;
    string line,word,temp;
    int cnt=0;
    while(getline(fin,line))
    {
        row.clear();
        //getline(fin,line);
        stringstream s(line);
        while(getline(s,word,','))
        {
            row.push_back(word);
        }
        if(name==row[0]){
            cnt=1;
            cout<<row[1]<<endl<<row[2]<<endl;
        }
    }
    fin.close();
    if(cnt==0)
    {
        cout<<"Not found"<<endl;
    }
}
void existnum:: modifyname(string nam)
{
    fstream fin,fout;
    fin.open("file1.csv",ios::in);
    fout.open("file2.csv",ios::out | ios::app);
    vector<string>row;
    string line,word,temp;
    int cnt=0;
    while(getline(fin,line))
    {
        row.clear();
       // getline(fin,line);
        stringstream s(line);
        while(getline(s,word,','))
        {
            row.push_back(word);
        }
        if(nam==row[0]){
            cnt=1;
            cout<<"Enter the Modified Name"<<endl;
            string newname;
            cin>>newname;
            fout<<newname<<","<<row[1]<<","<<row[2]<<endl;
        //break;9
        }
        else
        {
            fout<<row[0]<<","<<row[1]<<","<<row[2]<<endl;
        }
    }
    fin.close();
    fout.close();
    remove("file1.csv");
    rename("file2.csv","file1.csv");
}

void existnum:: modifynumber(string nam)
{
    fstream fin,fout;
    fin.open("file1.csv",ios::in);
    fout.open("file2.csv",ios::out | ios::app);
    vector<string>row;
    string line,word,temp;
    int cnt=0;
    while(getline(fin,line))
    {
        row.clear();
       // getline(fin,line);
        stringstream s(line);
        while(getline(s,word,','))
        {
            row.push_back(word);
        }
        if(nam==row[0]){
            cnt=1;
            cout<<"Enter the Modified number"<<endl;
            string newnum;
            cin>>newnum;
            fout<<row[0]<<","<<newnum<<","<<row[2]<<endl;
        //break;9
        }
        else
        {
            fout<<row[0]<<","<<row[1]<<","<<row[2]<<endl;
        }
    }
    fin.close();
    fout.close();
    remove("file1.csv");
    rename("file2.csv","file1.csv");
}
void deletenum:: delete_number(string nam)
{
    fstream fin,fout;
    fin.open("file1.csv",ios::in);
    fout.open("file2.csv",ios::out | ios::app);
    vector<string>row;
    string line,word,temp;
    int cnt=0;
    while(getline(fin,line))
    {
        row.clear();
       // getline(fin,line);
        stringstream s(line);
        while(getline(s,word,','))
        {
            row.push_back(word);
        }
        if(nam==row[0]){
            continue;
        }
        else
        {
            fout<<row[0]<<","<<row[1]<<","<<row[2]<<endl;
        }
    }
    fin.close();
    fout.close();
    remove("file1.csv");
    rename("file2.csv","file1.csv");
}
class message :public phonebook
{
    void send_messages(string name);
    void display_sent_messages(string name);
};
void message::send_messages(string name)
{
    fstream fin,fout;
    fin.open("file1.csv",ios::in);
    fout.open("msg.csv",ios::out | ios::app);
    vector<string>row;
    string line,word,temp;
    int cnt=0;
    while(getline(fin,line))
    {
        row.clear();
       // getline(fin,line);
        stringstream s(line);
        while(getline(s,word,','))
        {
            row.push_back(word);
        }
        if(name==row[0]){
            cout<<"Enter your text."<<endl;
            cout<<"To: "<<endl<<row[0]<<endl<<row[1]<<endl;

            string text;
           // cin>>text;
            getchar();
            getline(cin,text);
            fout<<row[0]<<','<<row[1]<<','<<text<<endl;
        }
    }
    fin.close();
    fout.close();
}
void message::display_sent_messages(string name)
{

    fstream fin;
    fin.open("msg.csv",ios::in);
    vector<string>row;
    string line,word,temp;
    int cnt=0;
    while(getline(fin,line))
    {
        row.clear();
        //getline(fin,line);
        stringstream s(line);
        while(getline(s,word,','))
        {
            row.push_back(word);
        }
        if(name==row[0]){
            cnt=1;
            cout<<row[2]<<endl;
            cout<<endl<<endl;
        }
    }
    fin.close();
    if(cnt==0)
    {
        cout<<"Not found"<<endl;
    }
}
/*template
class option
{
public:
    int choice(int i)
    {
        return i;
    }
    int choice(char i)
    {
        return -1;
    }
};
int choiceinput()
{

}*/
int main()
{
  phonebook *phn;
  existnum ex;
  addnum addnumbers;
  deletenum deletenumbers;
  clear_phonebook clr;
    message msg;
  cout<<"*********** ";
  cout<<"Welcome to Phonebook"<<"***********"<<endl;
  cout<<"**********   Menu    ****************"<<endl;
  cout<<endl<<endl;

    cout<<endl<<endl;
    cout<<"1.Add New Contact"<<"     "<<"2.Search for Contact"<<"     "<<"3.Modify Contact"<<endl;
    cout<<endl;
    cout<<"4.Delete Contact"<<"     "<<"6.To send message and view messages  "<<" 5.Clear Phonebook"<<endl;
    cout<<endl;
    cout<<"7.Exit the Phonebook"<<endl;

      int choice;
    while(true)
    {
        cout<<"Enter Your choice"<<endl;
        cout<<endl;
        cin>>choice;
        if(choice==1)
        {
            phn=&addnumbers;
            cout<<"Enter the Name"<<endl;
            string name;
            cin>>name;
            phn->add(name);
            cout<<"Contact Added succesfully"<<endl;
        }
        else if(choice==2)
        {
            phn=&ex;
            string name;
            cout<<"Enter the name of contact to search"<<endl;
            cin>>name;
            phn->display(name);
            cout<<endl;
        }
        else if(choice==3)
        {

            phn=&ex;
            cout<<"Enter 1 to modify number."<<endl;
            cout<<"Enter 2 to modify name."<<endl;
            int n;
            cin>>n;
            if(n==1)
            {
                cout<<"Enter the name to modify the number"<<endl;
                string name;
                cin>>name;
                phn->modifynumber(name);

            }
            else
            {
                cout<<"Enter the name U want to modify"<<endl;
                string name;
                cin>>name;
                phn->modifyname(name);
            }
              cout<<"Contact Modified succesfully"<<endl;
        }
        else if(choice==4)
        {
            phn=&deletenumbers;
            cout<<"Enter the name of contact to delete"<<endl;
            string name;
            cin>>name;
            phn->delete_number(name);
              cout<<"Contact Deleted succesfully"<<endl;
        }
        else if(choice==6)
        {
            cout<<"Are You Sure to clear the Phonebook"<<endl;
            cout<<"Enter Y/y for Yes"<<endl;
            cout<<"Enter N/n for No"<<endl;
            char c;
            cin>>c;
            if(c=='Y' || c=='y')
            {
                phn=&clr;
                phn->clear_all();
                cout<<"Phonebook cleared succesfully"<<endl;
            }
            else
            {
                continue;
            }
        }
        else if(choice==5)
        {
            cout<<"Enter 1 to send message"<<endl;
            cout<<"Enter 2 to view send messages"<<endl;
            int x;
            cin>>x;
            if(x==1)
            {
                phn=&msg;
                cout<<"Enter the name of contact to send message"<<endl;
                string name;
                cin>>name;
                phn->send_messages(name);
                cout<<endl;
            }
            else
            {
                phn=&msg;
                cout<<"Enter the name of contact to view sent messages"<<endl;
                string name;
                cin>>name;
                phn->display_sent_messages(name);
                cout<<endl;
            }
        }
        else if(choice==7)
        {
            cout<<"Thank You"<<endl;
            break;
        }
        }
  return 0;
}