package foo.bar;

typedef AssetDescriptor =
{
    var id: String;
    var type: AssetType;
}

enum AssetType
{
    sound;
    music;
    text;
    font;
    image;
    spriteSheet;
}

private typedef Asset =
{
    var asset: Dynamic;
    var locked: Bool;
}

/**
 *
 */
class AssetManager
{
    static var instance: AssetManager;

    var loadedAssets: Hash<Asset>;

    public var pendingAssets(default, null): Hash<Asset>;

    function new()
    {
        loadedAssets = new Hash<Asset>();
        pendingAssets = new Hash<Asset>();
    }

    public static function createInstance()
    {
        if (instance != null)
            throw "The current instance must first be released with releaseInstance().";
    }

    public static function releaseInstance()
    {
        if (instance == null)
            throw "No instance was previously created.";
    }

    public static function getInstance()
    {
        if (instance == null)
            throw "An instance must first be created with createInstance().";

        return instance;
    }

    public function preloadAsset(descriptor)
    {
        if (loadedAssets.exists(descriptor.id) == true
                || pendingAssets.exists(descriptor.id) == true)
        {
#if debug
            trace("preloadAsset: asset " + descriptor.id + " already loaded or pending.");
#end
            return;
        }

#if debug
        trace("preloadAsset: preloading asset " + descriptor.id + ".");
#end

        // Load the asset based on its type
        //


    }

    public function preloadAssets(assets : Array<AssetDescriptor>)
    {
        for (descriptor in assets)
            preloadAsset(descriptor);
    }

    public function releaseAsset(descriptor)
    {
        if (loadedAssets.remove(descriptor.id) == false)
        {
#if debug
            trace("releaseAsset: asset " + descriptor.id + " was not loaded.");
#end
        }

        if (pendingAssets.remove(descriptor.id) == true)
        {
#if debug
            trace("releaseAsset: asset " + descriptor.id + " was pending.");
#end
        }
    }

    public function releaseAssets(assets: Array<AssetDescriptor>)
    {
        for (descriptor in assets)
            releaseAsset(descriptor);
    }

    public function getAsset(id)
    {
        return loadedAssets.get(id);
    }
}