//download.js v3.0, by dandavis; 2008-2014. [CCBY2] see http://danml.com/download.html for tests/usage
// v1 landed a FF+Chrome compat way of downloading strings to local un-named files, upgraded to use a hidden frame and optional mime
// v2 added named files via a[download], msSaveBlob, IE (10+) support, and window.URL support for larger+faster saves than dataURLs
// v3 added dataURL and Blob Input, bind-toggle arity, and legacy dataURL fallback was improved with force-download mime and base64 support

// data can be a string, Blob, File, or dataURL




export default function (data, strFileName, strMimeType) {

	var self = window, // this script is only for browsers anyway...
		u = "application/octet-stream", // this default mime also triggers iframe downloads
		m = strMimeType || u,
		x = data,
		D = document,
		a = D.createElement("a"),
		z = function(a){return String(a);},


		B = self.Blob || self.MozBlob || self.WebKitBlob || z,
		BB = self.MSBlobBuilder || self.WebKitBlobBuilder || self.BlobBuilder,
		fn = strFileName || "download",
		blob,
		b,
		ua,
		fr;

	//if(typeof B.bind === 'function' ){ B=B.bind(self); }

	if(String(this)==="true"){ //reverse arguments, allowing download.bind(true, "text/xml", "export.xml") to act as a callback
		x=[x, m];
		m=x[0];
		x=x[1];
	}



	//go ahead and download dataURLs right away
	if(String(x).match(/^data\:[\w+\-]+\/[\w+\-]+[,;]/)){
		return navigator.msSaveBlob ?  // IE10 can't do a[download], only Blobs:
			navigator.msSaveBlob(d2b(x), fn) :
			saver(x) ; // everyone else can save dataURLs un-processed
	}//end if dataURL passed?

	try{

		blob = x instanceof B ?
			x :
			new B([x], {type: m}) ;
	}catch(y){
		if(BB){
			b = new BB();
			b.append([x]);
			blob = b.getBlob(m); // the blob
		}

	}



	function d2b(u) {
		var p= u.split(/[:;,]/),
		t= p[1],
		dec= p[2] == "base64" ? atob : decodeURIComponent,
		bin= dec(p.pop()),
		mx= bin.length,
		i= 0,
		uia= new Uint8Array(mx);

		for(i;i<mx;++i) uia[i]= bin.charCodeAt(i);

		return new B([uia], {type: t});
	 }

	function saver(url, winMode){


		if ('download' in a) { //html5 A[download]
			a.href = url;
			a.setAttribute("download", fn);
			a.innerHTML = "downloading...";
			D.body.appendChild(a);
			setTimeout(function() {
				a.click();
				D.body.removeChild(a);
				if(winMode===true){setTimeout(function(){ self.URL.revokeObjectURL(a.href);}, 250 );}
			}, 66);
			return true;
		}

		//do iframe dataURL download (old ch+FF):
		var f = D.createElement("iframe");
		D.body.appendChild(f);
		if(!winMode){ // force a mime that will download:
			url="data:"+url.replace(/^data:([\w\/\-\+]+)/, u);
		}


		f.src = url;
		setTimeout(function(){ D.body.removeChild(f); }, 333);

	}//end saver


	if (navigator.msSaveBlob) { // IE10+ : (has Blob, but not a[download] or URL)
		return navigator.msSaveBlob(blob, fn);
	}

	if(self.URL){ // simple fast and modern way using Blob and URL:
		saver(self.URL.createObjectURL(blob), true);
	}else{
		// handle non-Blob()+non-URL browsers:
		if(typeof blob === "string" || blob.constructor===z ){
			try{
				return saver( "data:" +  m   + ";base64,"  +  self.btoa(blob)  );
			}catch(y){
				return saver( "data:" +  m   + "," + encodeURIComponent(blob)  );
			}
		}

		// Blob but not URL:
		fr=new FileReader();
		fr.onload=function(e){
			saver(this.result);
		};
		fr.readAsDataURL(blob);
	}
	return true;
} /* end download() */

