github.com/lxr/google-musicmanager-web

/*

Google Play Music Web Manager presents a simple RESTful web interface for managing your Google Play Music library. It takes a single argument, the TCP address where to start serving (default localhost:8080). The methods and endpoints it supports are as follows:

GET /tracks/
	Returns an HTML listing of all tracks in the user's
	library, from least recently accessed to the most.
	Takes the optional query parameters purchasedOnly={bool}
	to filter only for purchased and promotional tracks,
	updatedMin={RFC3339} to filter out tracks that were
	last modified before the given timestamp, and
	pageToken={string} to page through large result sets.
	(The token for the next page can be found in the
	data-token attribute of the a[rel=next] element, if
	one exists.)

	In the listing, the id attribute of a table row contains
	the ID of the corresponding track.

GET /tracks/{id}
	Redirects the client to a temporary
	sj.googleusercontent.com download URL for the given
	track.  The URL is also contained in the redirect
	response body.

POST /tracks/
	Uploads a new track to the user's library.  The POST
	body must be in multipart form, with `track` being
	the form variable read for the file to upload.  See the
	BUGS section for limitations on uploading.  On success,
	this method redirects back to the track listing.

All endpoints expect the request to carry the access_token and uploader_id cookies, which are a Google OAuth 2.0 token carrying the scope https://www.googleapis.com/auth/musicmanager and the ID of an authorized device under your Play Music account (see https://play.google.com/music/listen#/accountsettings, and inspect the id attribute of the div.device-list-item elements) respectively. For convenience, Google Play Music Web Manager provides the following endpoints for acquiring these cookies:

GET /auth
	Redirects the user to a Google consent page asking the
	user to authorize Google Play Music Web Manager with
	their account.  This page asks for the additional scope
	https://www.googleapis.com/auth/plus.me in order to
	discover the user's Google Account ID, which is used
	to generate the uploader_id cookie.  If authorization
	has been previously granted, this page redirects
	directly back to Google Play Music Web Manager (assuming
	all proper Google cookies are present for the whole
	transaction, i.e. a browser environment.)
	This endpoint takes the optional query parameter
	redirect={path}, which can be used to autoredirect to
	the desired page when the auth flow is complete.

GET /oauth2callback
	This should not be directly called by the user; the
	Google consent page redirects to it once authorization
	has been granted or denied.  If authorization was
	granted, it computes and stores the uploader_id
	and access_token cookies with appropriate expiration
	times and redirects to the next page in the auth flow,
	passing on the redirect query parameter if given to
	/auth.

GET /register
	Authorizes uploader_id as a device under the user's
	Play Music account and with the name "Google Play Music
	Web Manager".  The optional query parameter
	name={string} can be used to change this.  The
	query parameter redirect={path} can be provided to
	autoredirect to the given page on success; otherwise,
	this endpoint simply reports success or failure.

	Remember that there is a limit to how many devices an
	account can have, how many devices one can deauthorize
	in a year, and with how many accounts a device can be
	authorized, so be careful with the uploader_id cookies
	you pass to this endpoint.

The main endpoints redirect to the start of the auth flow if either access_token or uploader_id is missing, and use the redirect query parameter to return back once the flow is completed, so using the interface through a web browser is a relatively seamless experience.

Google Play Music Web Manager can be run either as a standalone web server or on Google App Engine, though the latter comes with a few gotchas. See the source file appengine.go for details.

On startup, Google Play Music Web Manager expects to find in the current working directory a file called credentials.json, which contains web application credentials for a Google Cloud project with the Google+ API enabled, and a Go html/template file static/list.tpl. The latter is included in the default distribution; the former can be acquired by registering a new project in the Google Developers Console (https://console.developers.google.com) and creating a new client ID for a web application under the "Credentials" tab. Note that Google Play Music Web Manager ignores the redirect_uris key of the credentials.json file; the OAuth2 redirect URL is instead generated dynamically by appending "/oauth2callback" to the host on which the request was received.

*/ package main

// BUG(lor): Embedded album art is not currently uploaded.

// BUG(lor): Until someone writes a pure-Go audio transcoding library, // Google Play Music Web Manager can only upload MP3 tracks, and it // cannot perform song matching (beyond detecting which tracks it has // already uploaded).

// BUG(lor): Use of this program may constitute a violation of Google's // terms of service under paragraph 2 of // https://www.google.com/intl/en/policies/terms/#toc-services.