LevelGroupManager.java

package de.fau.cs.mad.fly.profile;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.files.FileHandle;
import com.badlogic.gdx.utils.JsonReader;
import com.badlogic.gdx.utils.JsonValue;

import de.fau.cs.mad.fly.I18n;

/**
 * Manage read all levels and level group from json files, nothing more.
 * 
 * 
 * @author Qufang Fan
 */
public class LevelGroupManager {
    private static String LEVEL_FOLDER = "levels/";
    
    private LevelGroupManager() {
        loadLevelGroups(LEVEL_FOLDER);
    }
    
    /**
     * Comparator for the level groups.
     */
    private Comparator<LevelGroup> levelGroupComparator = new Comparator<LevelGroup>() {
        @Override
        public int compare(LevelGroup first, LevelGroup second) {
            if (first.id < second.id) {
                return -1;
            } else if (first.id > second.id) {
                return 1;
            }
            return 0;
        }
    };
    
    private static LevelGroupManager instance;
    
    public static LevelGroupManager getInstance() {
        return instance;
    }
    
    /**
     * Creates the level manager singleton instance.
     */
    public static void createLevelManager() {
        instance = new LevelGroupManager();
    }
    
    /**
     * List of level groups.
     */
    private List<LevelGroup> levelGroups = null;
    
    /**
     * Reads the main folder for the level and opens the sub directories to
     * create level groups.
     * 
     * @param folder
     *            The main folder for the levels.
     */
    private void loadLevelGroups(String folder) {
        if (levelGroups != null)
            return;
        levelGroups = new ArrayList<LevelGroup>();
        JsonReader reader = new JsonReader();
        
        FileHandle dirHandle = Gdx.files.internal(folder);
        FileHandle handle = dirHandle.child("groups.json");
        if (handle != null) {
            JsonValue json = reader.parse(handle);
            JsonValue groups = json.get("groups");
            if (groups != null) {
                for (int i = 0; i < groups.size; i++) {
                    LevelGroup group = new LevelGroup();
                    JsonValue groupJS = groups.get(i);
                    group.id = groupJS.getInt("id");
                    group.name = I18n.t(groupJS.getString("name"));
                    group.path = LEVEL_FOLDER + groupJS.getString("path");
                    levelGroups.add(group);
                }
            }
        }
        Collections.sort(levelGroups, levelGroupComparator);
    }
    
    /**
     * Getter) for the level group list.
     * 
     * @return list of level groups.
     */
    public List<LevelGroup> getLevelGroups() {
        if (levelGroups == null) {
            this.loadLevelGroups(LEVEL_FOLDER);
        }
        return levelGroups;
    }
    
    public LevelGroup getLevelGroup(int id) {
        for (LevelGroup group : getLevelGroups()) {
            if (group.id == id)
                return group;
        }
        return null;
    }
    
    public int getLastGroupID(){
    	return getLevelGroups().get(getLevelGroups().size()-1).id;
    }
    
    public LevelGroup getLastGroup(){
    	return getLevelGroups().get(getLevelGroups().size()-1);
    }
}