create API for downloading the binary package

index.js

@@ -0,0 +1,46 @@
+const fs = require( 'fs' );
+const os = require( 'os' );
+const path = require( 'path' );
+
+const nugget = require( 'nugget' );
+
+const version = require( './package' ).version;
+
+function download( opts, callback ) {
+  if ( typeof opts === 'function' ) {
+    callback = opts;
+    opts = {};
+  }
+
+  const fileVersion = opts.version || version;
+
+  const plaftorm = opts.plaftorm || process.platform;
+  const arch = opts.arch || process.arch;
+
+  const cacheDir = opts.cache || path.join( os.homedir(), '.launchui' );
+
+  const fileName = 'launchui-v' + fileVersion + '-' + plaftorm + '-' + arch + '.zip';
+
+  const zipPath = path.join( cacheDir, fileName );
+
+  if ( !fs.existsSync( zipPath ) ) {
+    if ( !fs.existsSync( cacheDir ) )
+      fs.mkdirSync( cacheDir )
+
+    const url = 'https://github.com/mimecorg/launchui/releases/download/v' + fileVersion + '/' + fileName;
+
+    nugget( url, { target: fileName, dir: cacheDir }, errors => {
+      if ( errors != null )
+        return callback( errors[ 0 ], null );
+
+      callback( null, zipPath );
+    } );
+  } else {
+    callback( null, zipPath );
+  }
+}
+
+module.exports = {
+  version,
+  download
+};