Alvaro2112/Money_run

package sdp.moneyrun.database.riddle;

import android.content.Context;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;

import sdp.moneyrun.R;

public class RiddlesDatabase {

    @Nullable
    private static RiddlesDatabase obj;
    @NonNull
    private final ArrayList<Riddle> db;
    private int loc;

    /**
     * This constructor will create a RiddleDatabase by parsing all the riddles for the txt file and creating
     * Riddle objects from each riddle
     *
     * @param context the current context
     */
    private RiddlesDatabase(@NonNull Context context) {


        InputStream inputStream = context.getResources().openRawResource(R.raw.database);
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        db = new ArrayList<>();

        try {
            String csvLine;
            while ((csvLine = reader.readLine()) != null) {
                String[] row = csvLine.split(";");
                db.add(new Riddle(row[0].substring(0, row[0].length() - 3).replace("\"", ""),
                        row[1].replace("\"", ""),
                        row[2].replace("\"", ""),
                        row[3].replace("\"", ""),
                        row[4].replace("\"", ""),
                        row[5].replace("\"", "")));

            }
        } catch (IOException ex) {
            throw new RuntimeException("Error in reading CSV file: " + ex);
        } finally {
            try {
                inputStream.close();
            } catch (IOException e) {
                throw new RuntimeException("Error while closing input stream: " + e);
            }
        }

        Collections.shuffle(this.db);
        loc = 0;

    }

    /**
     * @return Returns the current instance of the riddle database
     */
    @Nullable
    public static RiddlesDatabase getInstance() {
        if (obj == null)
            throw new RuntimeException("Need to create a instance first");

        return obj;
    }

    /**
     * Will create a unique instance of the database by loading all the riddles that are present in the text file into an array of Riddles.
     *
     * @param context current context
     * @return the created instance
     */
    @Nullable
    public static RiddlesDatabase createInstance(@NonNull Context context) {
        if (obj != null)
            throw new RuntimeException("Instance already exists");

        obj = new RiddlesDatabase(context);
        return obj;
    }

    public static void reset() {
        obj = null;
    }

    /**
     * @return the next Riddle in the shuffled array
     */
    public Riddle getRandomRiddle() {
        loc = (loc + 1) % db.size();
        return db.get(loc);
    }


}