#!/usr/bin/env python
 # -*- coding: utf-8 -*-

 # Copyright © 2017-2019 Xavier G. <xavier.boobank@kindwolf.org>

 # This work is free. You can redistribute it and/or modify it under the
 # terms of the Do What The Fuck You Want To Public License, Version 2,
 # as published by Sam Hocevar. See the COPYING file for more details.

 """
 boobank-graphite takes a JSON file, as created by boobank-cacher when running
 and caching a "boobank list" command, and sends it to a Graphite instance.
 """

 
 import sys
 import json
 import time
 import socket

 import argparse

 from boobank_utils import DEFAULT_CURRENCY

 
 
 def main():

     """
     Main function.
     """

     args = parse_args()

     accounts = json.load(args.json_file)

     timestamp = time.time()

     graphite_socket = graphite_connect(args.host, args.port)

     for account in accounts.get('data', []):

         send_account(graphite_socket, account, timestamp)
     graphite_socket.close()

 def parse_args():

     """
     Parse command-line arguments.
     """
     description = 'Send the contents of a boobank-cacher JSON file to Graphite.'
     args = argparse.ArgumentParser(description=description)
     args.add_argument('-gh', '--graphite-host', dest='host', default='::1',
                       help='Graphite host; defaults to ::1.')
     args.add_argument('-gp', '--graphite-port', dest='port', default='2003', type=int,
                       help='Graphite port; defaults to 2003.')
     args.add_argument('json_file', nargs='?', type=argparse.FileType('r'), default=sys.stdin,
                       help='JSON file to send to Graphite; defaults to "-" (standard input).')
     return args.parse_args()

 
 def graphite_connect(host, port):

     """
     Connect to the Graphite instance listening on host and port.
     """

     addr_infos = socket.getaddrinfo(host, port, 0, 0, socket.IPPROTO_TCP)
     _, _, _, _, sockaddr = addr_infos[0]
     graphite_socket = socket.socket(socket.AF_INET6, socket.SOCK_STREAM, 0)
     graphite_socket.connect(sockaddr)

     return graphite_socket
 
 def get_path(account):

     """
     Return the path to send to Graphite for the given bank account.
     The following scheme is used:
     bank.<bank id>.<account id>-balance-<currency>
     """
     (account_id, bank) = account['id'].split('@')
     currency = account.get('currency', DEFAULT_CURRENCY).lower()
     return 'bank.%s.%s-balance-%s' % (bank, account_id, currency)

 def send_account(graphite_socket, account, timestamp):
     """
     Send the balance of the given bank account to Graphite over the given TCP
     socket.
     """

     pattern = '%s %.2f %d\n'

     values = (get_path(account), float(account['balance']), int(timestamp))

     line = pattern % values

     graphite_socket.send(line)

 
 if __name__ == '__main__':
     main()