import subprocess
import json
import os


class Alfred(object):
    """
    Bindings for the alfred-json utility
    """
    def __init__(self, unix_sockpath=None):
        if unix_sockpath:
            if os.path.exists(unix_sockpath):
                self.unix_sock = unix_sockpath
            else:
                raise RuntimeError('alfred: invalid unix socket path given')

    def _fetch(self, data_type):
        cmd = ['alfred-json',
               '-z',
               '-f', 'json',
               '-r', data_type]
        if self.unix_sock:
            cmd.extend(['-s', self.unix_sock])

        output = subprocess.check_output(cmd)
        return json.loads(output.decode("utf-8")).values()

    def nodeinfo(self):
        return self._fetch(158)

    def statistics(self):
        return self._fetch(159)

    def vis(self):
        return self._fetch(160)