#!/usr/bin/env python3
import json
from collections import OrderedDict

from dhcpkit.ipv6.server.dhcpctl import DHCPKitControlClient
from typing import Any, Dict

# Change this if you change the default
socket_path = '/var/run/ipv6-dhcpd.sock'


# Output a section
def print_section(data: Dict[str, Any], prefix: str = ''):
    """
    Output the data in Observium app format

    :param data: A dictionary with data
    :param prefix: The current prefix up to this point
    """
    # First see if this item has its own data
    own_data = False
    if prefix:
        # We don't support own data in the root, so only check when there is a prefix
        for value in data.values():
            if not isinstance(value, dict):
                own_data = True
                break

    if own_data:
        # Print this item
        print("<<<app-dhcpkit-{}>>>".format(prefix))
        for key, value in data.items():
            print_values(key, value)

    else:
        # Print sub-items
        for key, value in data.items():
            if isinstance(value, dict):
                print_section(value, prefix="{}-{}".format(prefix, key).strip('-'))


# Output key/value pairs
def print_values(key: str, value: Any):
    """
    Output key/value pairs

    :param key: The key
    :param value: The value(s)
    """
    if isinstance(value, dict):
        # The value is a dictionary, recurse
        for sub_key, sub_value in value.items():
            print_values("{}.{}".format(key, sub_key), sub_value)
    else:
        print("{}:{}".format(key, value))


# Open connection
conn = DHCPKitControlClient(socket_path)
output = conn.execute_command('stats-json')

# Decode json
json_data = '\n'.join(output)
data = json.loads(json_data, object_pairs_hook=OrderedDict)

# Done: disconnect (and process output to empty the buffers)
output = conn.execute_command('quit')
list(output)

# Show the stats
print_section(data)