package com.test.assets;

import java.util.PriorityQueue;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.files.FileHandle;
import com.badlogic.gdx.graphics.g2d.TextureAtlas;
import com.badlogic.gdx.utils.JsonReader;
import com.badlogic.gdx.utils.JsonValue;

public class AssetsLoader {
    private enum AssetType {
        ATLAS
    }

    private class AssetLoadingTask {
        String name;
        AssetType type;
        String[] params;

        AssetLoadingTask(String name, AssetType type, String... params) {
            this.name = name;
            this.type = type;
            this.params = params;
        }
    }

    private Assets assets = new Assets();
    private PriorityQueue<AssetLoadingTask> loadQueue = new PriorityQueue();

    private int toLoad, loaded;

    public Assets getAssets() {
        return assets;
    }

    public float getProgress() {
        return loaded / toLoad;
    }

    public boolean update() {
        if (loadQueue.size() != 0) {
            loadNextAsset();
            loaded++;

            if (loadQueue.size() == 0)
                return true;
        }

        return false;
    }

    public void loadAtlasesFrom(String pathToPack) {
        FileHandle packFile = Gdx.files.internal(pathToPack);
        JsonValue root = new JsonReader().parse(packFile);
        JsonValue nextValue = root.child;

        while (nextValue != null)
        {
            String name = nextValue.name;
            String data = nextValue.getString("data");
            String images = nextValue.getString("images");

            addTask(name, AssetType.ATLAS, data, images);

            nextValue = nextValue.next;
        }
    }

    private void addTask(String name, AssetType type, String... params) {
        AssetLoadingTask task = new AssetLoadingTask(name, type, params);
        loadQueue.offer(task);

        toLoad++;
    }

    private void loadNextAsset() {
        AssetLoadingTask task = loadQueue.poll();

        if (task.type == AssetType.ATLAS) {
            TextureAtlas atlas = new TextureAtlas(
                Gdx.files.internal(task.params[0]),
                Gdx.files.internal(task.params[1]));

            assets.addAtlas(task.name, atlas);
        }
    }
}