package tudelft.mentalhealth.perfectfit;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import com.opencsv.CSVParser;
import com.opencsv.CSVParserBuilder;
import com.opencsv.CSVReader;
import com.opencsv.CSVReaderBuilder;

/**
 * The set of example goals. Reads in essentially from goals.csv database.
 * Singleton pattern to avoid re-reading this repeatedly which is useless as the
 * data is immutable.
 * 
 */
public class Goals {
	private static Goals goals = null; // singleton cache

	private final List<GoalLine> lines = new ArrayList<>();

	protected Goals() throws IOException {
		for (String[] line : readAllLines()) {
			lines.add(new GoalLine(line));
		}
	}

	private List<String[]> readAllLines() throws IOException {
		InputStream stream = getClass().getClassLoader()
				.getResourceAsStream("examples_with_user_data.csv");

		try (Reader in = new InputStreamReader(stream)) {

			CSVParser parser = new CSVParserBuilder().withSeparator(',')
					.build();
			// skip the header line
			CSVReader reader = new CSVReaderBuilder(in).withSkipLines(1)
					.withCSVParser(parser).build();

			return reader.readAll();

		}
	}

	public static Goals instance() throws IOException {
		if (goals == null) {
			goals = new Goals();
		}
		return goals;
	}

	@Override
	public String toString() {
		return lines.toString();
	}

	public GoalLine get(int nr) {
		return lines.get(nr);
	}

	public List<GoalLine> all() {
		return Collections.unmodifiableList(lines);
	}

}