Notes

Operations

//Leo Vazquez Estrada
//CIS 1202
//March 15, 2023
//Programming Assignment #10

//Personal Library
#include "PLLVE.h"

const int NAME_SIZE = 40;
//Structure
struct Product
{
    long number;
    char name[NAME_SIZE];
    double price;
    int quantity;
};
//Function Prototypes
int getMenu();
void createFile(fstream&);
void displayFile(fstream&);
void displayRecord(fstream&);
void modifyRecord(fstream&);
long byteNum(int);
void showRec(Product);
//Main Code
int main() {
    fstream file;
    int userInput = 0;
    file.open("inventory.dat", ios::beg | ios::in | ios::out | ios::binary);
    createFile(file);
    userInput = getMenu();
    do {
        switch (userInput) {
        case 1: displayFile(file);
            break;
        case 2: displayRecord(file);
            break;
        case 3:modifyRecord(file);
            break;
        case 4: endprogram();
        }
    } while (userInput != 4);
    file.close();
}

//Functions

int getMenu()
{
    int userNum = 0;
    cout << " 1. Display Entire Inventory" << endl;
    cout << " 2. Display a certain Inventory Item" << endl;
    cout << " 3. Modify a Product" << endl;
    cout << " 4. End Program" << endl;
    userNum = validateInt("Enter the number of the action you'd like to take place. ", 1, 4);
    return userNum;
}

void createFile(fstream& file)
{
    vector<Product> products = {
        { 12345, "dog", 11.99, 5 },
        { 12346, "cat", 11.98, 6 },
        { 12347, "rat", 10.99, 7 },
        { 12348, "bird", 12.99, 4 },
        { 12349, "snake", 13.99, 3 },
        { 12350, "hamster", 14.99, 9 }
    };

    file.clear();
    if (!file.fail()) {
        file.write(reinterpret_cast<char*>(products.data()), products.size() * sizeof(Product));
    }
    else {
        cout << "Your File Has Failed To Open" << endl;
    }
}


void displayFile(fstream& file) {
    Product prodInfo;
    int recNum = 0;

    file.clear();
    if (!file.fail()) {
        file.seekg(0, ios::end);
        int fileSize = file.tellg();
        file.seekg(0, ios::beg);

        while (file.tellg() < fileSize) {
            file.read(reinterpret_cast<char*>(&prodInfo), sizeof(prodInfo));
            if (file.gcount() != sizeof(prodInfo)) {
                cout << "Error: could not read product record" << endl;
                break;
            }
            cout << recNum << ". ";
            showRec(prodInfo);
            recNum++;
        }
        file.clear();
    }
    else {
        cout << "Error: could not open file" << endl;
    }
}
void modifyRecord(fstream& file) {
    int userChoice = 0;
    displayFile(file);
    userChoice = validateInt("Enter the number of the record you'd like to modify. ");

    int recNum = userChoice - 1;
    file.seekg(byteNum(recNum));

    Product prodInfo;
    if (file.read(reinterpret_cast<char*>(&prodInfo), sizeof(prodInfo))) {
        cout << "nEnter the new product number: ";
        cin >> prodInfo.number;
        cout << "nEnter the new product name:";
        getline(cin, prodInfo.name);
        cout << "nEnter the new product price: ";
        cin >> prodInfo.price;
        cout << "nEnter the new product quantity: ";
        cin >> prodInfo.quantity;
        file.seekp(byteNum(recNum));
        file.write(reinterpret_cast<char*>(&prodInfo), sizeof(prodInfo));
        showRec(prodInfo);
    }
    else {
        cout << "Record not found." << endl;
    }
}

long byteNum(int recNum) {
    return sizeof(Product) * recNum;
}

void showRec(Product prodInf) {
    cout << "Number: ";
    cout << prodInf.number << " ";
    cout << "Name: ";
    cout << prodInf.name << " ";
    cout << "Price: ";
    cout << prodInf.price << " ";
    cout << "Quantity: ";
    cout << prodInf.quantity << endl;
}