main.cpp

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <cctype>
#include <filesystem>

void addItem();
void viewItem();
void deleteItem();

int main(){

    
    std::cout << "SHOPPING LIST" << '\n';

    while(true){
        std::string choice;
        std::cout  << '\n';
        std::cout << "What would you like to do? add(a), view(v), delete[d], quit[q] >>> ";

        std::getline(std::cin, choice);
        if(choice=="a" || choice=="add" || choice=="ADD"){
            addItem();
        }

        else if(choice =="v" || choice == "view" || choice == "VIEW"){
            viewItem();
        }
        else if(choice=="d"){
            deleteItem();
        }
        else if(choice=="quit" || choice == "q" || choice == "QUIT"){
            break;
        }
        else{
            std::cout << "Invalid Choice." << '\n';
        }
    }

    return 0;
}

void addItem(){

    bool validPrice=false;

    std::string newItem;
    std::string itemPrice;
    std::cout << "Enter the item you would like to add >>> ";
    std::getline(std::cin,newItem);

    while(validPrice==false){

        std::cout << "Enter price of " << newItem << " >>> ";
        std::getline(std::cin,itemPrice);

        bool isNumber = true;

        for(char c : itemPrice){
            if(!std::isdigit(c)){
                isNumber = false;
                break;
            }
        }

    
        if(!isNumber || itemPrice.empty()){
            std::cout << "Price should be a number! \n";
        }

        else{
            std::ofstream out("items.dat", std::ios::app);
            out << newItem << "|" << itemPrice << '\n';

            std::cout << newItem << " added to list. \n";
            validPrice=true;

        }
    

    }


}

void viewItem(){
    std::ifstream in("items.dat");
    if(!in){
        std::cout << "Shopping list is empty and file is NOT created.\n";
        std::cout << "Start by adding things into the shopping list. \n \n";
        return;
    }

    std::string line;
    bool foundSomething = false;

    int i=1;
    while(std::getline(in,line)){
        foundSomething=true;
        std::istringstream ss(line);
        std::string name, price;
        std::getline(ss,name,'|');
        std::getline(ss,price,'|');
        std::cout << i << ") " << name << " - " << price << "$" << '\n';
        i++;
    }

    if(!foundSomething){
        std::cout << "List is empty. \n";
    }
    
}

void deleteItem(){
    int i=1;
    int delChoice;
    std::string line;
    std::ifstream in("items.dat",std::ios::app);
    std::ifstream inTemp("items_temp.dat",std::ios::app);

    while(std::getline(in,line)){
        std::istringstream ss(line);
        std::string name,price;
        std::getline(ss,name,'|');
        std::getline(ss,price,'|');
        std::cout << i << ") " << name << " - " << price << "$" << '\n';
        i++;
    }

    std::cout << "Which one would you like to delete? >>> ";
    std::cin >> delChoice;

    std::cin.clear();
    std::cin.ignore(10000000,'\n');

    std::filesystem::copy_file("items.dat","items_temp.dat", std::filesystem::copy_options::overwrite_existing);
    std::ofstream out("items.dat",std::ios::trunc);

    in.clear();
    in.seekg(0);

    i=1;

    while(std::getline(inTemp,line)){
        if(delChoice==i){
            i++;
            continue;
        }
        else{
            std::istringstream ss(line);
            std::string name,price;
            std::getline(ss,name,'|');
            std::getline(ss,price,'|');
            out << name << "|" << price << '\n';

            i++;
        }
    }

    inTemp.close();
    out.close();
    std::filesystem::remove("items_temp.dat");
}