CsvHandler.java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.List;

public class CsvHandler {
    private final String filename;

    public CsvHandler(String filename) {
        this.filename = filename;
    }

    public List<Task> loadTasks() {
        List<Task> tasks = new ArrayList<>();
        File file = new File(filename);
        if (!file.exists()) {
            return tasks; // No saved tasks yet
        }

        BufferedReader reader = new BufferedReader(new FileReader(file));
        String line;
        while ((line = reader.readLine()) != null) {
            if (line.trim().isEmpty()) continue;
            Task task = parseLine(line);
            if (task != null) {
                tasks.add(task);
            }
        }
        System.out.println("Loaded " + tasks.size() + " task(s) from " + filename);
        return tasks;
    }

    public void saveTasks(List<Task> tasks) {
        BufferedWriter writer = new BufferedWriter(new FileWriter(filename));
        for (Task task : tasks) {
            writer.write(formatTask(task));
            writer.newLine();
        }
    }

    private Task parseLine(String line) {
        line = line.trim();
        if (line.isEmpty()) return null;

        if (line.startsWith("\"")) {
            int endQuote = line.indexOf("\"", 1);
            if (endQuote == -1) return null;
            
            String description = line.substring(1, endQuote);
            String rest = line.substring(endQuote + 1).trim();

            if (!rest.startsWith(",")) return null;
            String boolStr = rest.substring(1).trim();
            boolean completed = Boolean.parseBoolean(boolStr);

            return new Task(description, completed);

        } else {
            int comma = line.indexOf(",");
            if (comma == -1) return null;

            String description = line.substring(0, comma).trim();
            String boolStr = line.substring(comma + 1).trim();
            boolean completed = Boolean.parseBoolean(boolStr);

            return new Task(description, completed);
        }
    }

    private String formatTask(Task task) {
        String description = task.getDescription();
        if (description.contains(",") || description.contains("\"")) {
            description = description.replace("\"", "\"\"");
            description = "\"" + description + "\"";
        }
        return description + "," + task.isCompleted();
    }
}