CSVHandler.cpp

#include "CSVHandler.hpp"
#include <fstream>
#include <iostream>
#include <sstream>

using namespace std;

CSVHandler::CSVHandler(const string& filename, BTree& tree)
    : filename(filename), bTree(tree) {}

void CSVHandler::loadCSV() {
    data.clear();

    ifstream file(filename);
    if (!file.is_open()) {
        cerr << "Error: Could not open file " << filename << endl;
        return;
    }

    string line;
    bool firstRow = true;
    while (getline(file, line)) {
        if (line.empty()) continue;

        if (firstRow) {
            firstRow = false;
            continue;  // skip the header line
        }

        stringstream ss(line);
        string value;
        vector<string> row;
        while (getline(ss, value, ',')) row.push_back(value);

        if (row.size() == 4) {
            data.push_back(row);
        } else {
            cerr << "Warning: Row does not have 4 columns and will be skipped: " << line << endl;
        }
    }

    file.close();
    cout << "CSV file loaded successfully!" << endl;
}

void CSVHandler::displayCSV() const {
    for (size_t i = 0; i < data.size(); ++i) {
        cout << i << ": ";
        for (const auto& col : data[i]) cout << col << " ";
        cout << endl;
    }
}

void CSVHandler::addRow(const vector<string>& row) {
    if (row.size() == 4) {
        data.push_back(row);
    } else {
        cout << "Invalid row size!" << endl;
    }
}

void CSVHandler::updateRow(int rowNumber, const vector<string>& newRow) {
    if (rowNumber >= 0 && rowNumber < static_cast<int>(data.size())) {
        if (newRow.size() == 4) {
            data[rowNumber] = newRow;
        } else {
            cout << "Invalid new row size!" << endl;
        }
    } else {
        cout << "Invalid row number!" << endl;
    }
}

void CSVHandler::deleteRow(int rowNumber) {
    if (rowNumber >= 0 && rowNumber < static_cast<int>(data.size())) {
        data.erase(data.begin() + rowNumber);
    } else {
        cout << "Invalid row number!" << endl;
    }
}

void CSVHandler::saveCSV() const {
    ofstream file(filename);
    if (!file.is_open()) {
        cerr << "Error: Could not save file " << filename << endl;
        return;
    }

    file << "ID,Name,Age,Salary" << endl;
    for (const auto& row : data) {
        for (size_t i = 0; i < row.size(); ++i) {
            file << row[i];
            if (i < row.size() - 1) file << ",";
        }
        file << endl;
    }

    file.close();
    cout << "CSV file saved successfully!" << endl;
}

// No longer skips a row - the header was already stripped in loadCSV().
void CSVHandler::loadDataIntoBTree() {
    for (const auto& row : data) {
        if (row.size() != 4) continue;
        try {
            int id = stoi(row[0]);
            string name = row[1];
            int age = stoi(row[2]);
            float salary = stof(row[3]);
            bTree.insert(id, name, age, salary);
        } catch (const invalid_argument& e) {
            cerr << "Error converting data: " << e.what() << endl;
        } catch (const out_of_range& e) {
            cerr << "Error: Data out of range: " << e.what() << endl;
        }
    }
    cout << "Data loaded into BTree successfully!" << endl;
}

void CSVHandler::exportBTreeToCSV() {
    auto records = bTree.extractData();

    ofstream csvFile(filename);
    if (!csvFile.is_open()) {
        cerr << "Failed to open CSV file for writing." << endl;
        return;
    }

    csvFile << "ID,Name,Age,Salary\n";
    for (const auto& record : records) {
        int id;
        string name;
        int age;
        float salary;
        tie(id, name, age, salary) = record;
        csvFile << id << "," << name << "," << age << "," << salary << "\n";
    }

    csvFile.close();
    cout << "BTree data exported to CSV file successfully!" << endl;
}

bool CSVHandler::fileExists(const string& fname) const {
    ifstream f(fname);
    return f.is_open();
}

void CSVHandler::menu() {
    int choice;
    do {
        cout << "\nMenu:\n";
        cout << "1. Load CSV\n";
        cout << "2. Display CSV\n";
        cout << "3. Add Row\n";
        cout << "4. Update Row\n";
        cout << "5. Delete Row\n";
        cout << "6. Save CSV\n";
        cout << "7. Load Data into BTree\n";
        cout << "8. Export BTree to CSV\n";
        cout << "9. Exit\n";
        cout << "Enter your choice: ";
        cin >> choice;

        switch (choice) {
            case 1:
                cout << "Enter CSV file name: ";
                cin >> filename;
                loadCSV();
                break;
            case 2:
                displayCSV();
                break;
            case 3: {
                vector<string> newRow(4);
                cout << "Enter ID: ";
                cin >> newRow[0];
                cout << "Enter Name: ";
                cin.ignore();
                getline(cin, newRow[1]);
                cout << "Enter Age: ";
                cin >> newRow[2];
                cout << "Enter Salary: ";
                cin >> newRow[3];
                addRow(newRow);
                break;
            }
            case 4: {
                int rowNum;
                vector<string> newRow(4);
                cout << "Enter row number to update: ";
                cin >> rowNum;
                cout << "Enter new ID: ";
                cin >> newRow[0];
                cout << "Enter new Name: ";
                cin.ignore();
                getline(cin, newRow[1]);
                cout << "Enter new Age: ";
                cin >> newRow[2];
                cout << "Enter new Salary: ";
                cin >> newRow[3];
                updateRow(rowNum, newRow);
                break;
            }
            case 5: {
                int rowNum;
                cout << "Enter row number to delete: ";
                cin >> rowNum;
                deleteRow(rowNum);
                break;
            }
            case 6:
                saveCSV();
                break;
            case 7:
                loadDataIntoBTree();
                break;
            case 8:
                exportBTreeToCSV();
                break;
            case 9:
                cout << "Exiting..." << endl;
                break;
            default:
                cout << "Invalid choice, try again!" << endl;
        }
    } while (choice != 9);
}