import java.io.*;
import java.util.*;

public class MemberDAOImpl implements MemberDAO {

    private final String filePath;
    private final List<Member> members = new ArrayList<>();

    public MemberDAOImpl(String filePath) {
        this.filePath = filePath;
        load();
    }

    private void load() {
        try (BufferedReader br = new BufferedReader(new FileReader(filePath))) {
            br.readLine(); // skip header
            String line;
            while ((line = br.readLine()) != null) {
                String[] arr = line.split(",");
                members.add(new Member(arr[0], arr[1]));
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public List<Member> getAllMembers() {
        return members;
    }

    @Override
    public Member getById(String id) {
        return members.stream()
                .filter(m -> m.getId().equals(id))
                .findFirst().orElse(null);
    }

    @Override
    public void addMember(Member member) {
        members.add(member);
    }

    @Override
    public void saveAll() {
        try (PrintWriter pw = new PrintWriter(new FileWriter(filePath))) {
            pw.println("ID,Name");
            for (Member m : members) {
                pw.println(m.getId() + "," + m.getName());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}