/**
 *
 *  You can modify and use this source freely
 *  only for the development of application related Live2D.
 *
 *  (c) Live2D Inc. All rights reserved.
 */

//============================================================
//============================================================
//  class PlatformManager     extend IPlatformManager
//============================================================
//============================================================
function PlatformManager()
{

}

//============================================================
//    PlatformManager # loadBytes()
//============================================================
PlatformManager.prototype.loadBytes       = function(path/*String*/, callback)
{
    var request = new XMLHttpRequest();
    request.open("GET", path, true);
    request.responseType = "arraybuffer";
    request.onload = function(){
        switch(request.status){
        case 200:
            callback(request.response);
            break;
        default:
            console.error("Failed to load (" + request.status + ") : " + path);
            break;
        }
    }
    request.send(null);
    //return request;
}

//============================================================
//    PlatformManager # loadString()
//============================================================
PlatformManager.prototype.loadString      = function(path/*String*/)
{
    
    this.loadBytes(path, function(buf) {        
        return buf;
    });
    
}

//============================================================
//    PlatformManager # loadLive2DModel()
//============================================================
PlatformManager.prototype.loadLive2DModel = function(path/*String*/, callback)
{
    var model = null;
    
    // load moc
    this.loadBytes(path, function(buf){
        model = Live2DModelWebGL.loadModel(buf);
        callback(model);
    });

}

//============================================================
//    PlatformManager # loadTexture()
//============================================================
PlatformManager.prototype.loadTexture     = function(model/*ALive2DModel*/, no/*int*/, path/*String*/, callback)
{ 
    // load textures
    var loadedImage = new Image();
    loadedImage.src = path;
        
    var thisRef = this;
    loadedImage.onload = function() {
                
        // create texture
        var canvas = document.getElementById("glcanvas");
        var gl = getWebGLContext(canvas, {premultipliedAlpha : true});
        var texture = gl.createTexture();	 // テクスチャオブジェクトを作成する
        if (!texture){ console.error("Failed to generate gl texture name."); return -1; }

        if(model.isPremultipliedAlpha() == false){
            // 乗算済アルファテクスチャ以外の場合
            gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, 1);
        }
        gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, 1);	// imageを上下反転
        gl.activeTexture(gl.TEXTURE0);
        gl.bindTexture(gl.TEXTURE_2D, texture);
        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, 
                      gl.UNSIGNED_BYTE, loadedImage);
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_NEAREST);
        gl.generateMipmap(gl.TEXTURE_2D);


        // 画像からWebGLテクスチャ化を生成し、モデルに登録
        model.setTexture(no, texture);// モデルにテクスチャをセット
        
        // テクスチャオブジェクトを解放
        texture = null;
        
        if (typeof callback == "function") callback();
    };
    
    loadedImage.onerror = function() { 
        console.error("Failed to load image : " + path); 
    }
}


//============================================================
//    PlatformManager # parseFromBytes(buf)
//    ArrayBuffer から JSON に変換する
//============================================================
PlatformManager.prototype.jsonParseFromBytes = function(buf){
    
    var jsonStr;
    
    // BOMの有無に応じて処理を分ける
    // UTF-8のBOMは0xEF 0xBB 0xBF（10進数：239 187 191）
    var bomCode = new Uint8Array(buf, 0, 3);
    if (bomCode[0] == 239 && bomCode[1] == 187 && bomCode[2] == 191) {
        jsonStr = String.fromCharCode.apply(null, new Uint8Array(buf, 3));
    } else {
        jsonStr = String.fromCharCode.apply(null, new Uint8Array(buf));
    }
    
    var jsonObj = JSON.parse(jsonStr);
    
    return jsonObj;
};


//============================================================
//    PlatformManager # log()
//============================================================
PlatformManager.prototype.log             = function(txt/*String*/)
{
    console.log(txt);
}