from aiohttp.web import json_response

async def playlist_add(request):
    uuid = request.match_info['uuid']

    try:
        request.app['playlist'].put(uuid)

    except DuplicateTrackError:
        return json_response({
            'err': 'duplicate',
            'msg': 'The track is already present in the playlist.'
        }, status=400)

    else:
        return json_response({}, status=200)