#! /usr/bin/env python

import subprocess
import json
import sys
import re


PHAB_HTTP_URI = "https://secure.phabricator.com/api/"
PHAB_SSH_HOST = "dweller@secure.phabricator.com"
PHAB_SSH_PORT = 22


class ExecutionException(Exception):
    def __init__(self, command, exit_code):
        self.command = command
        self.exit_code = exit_code

def execute(*cmd, **kwargs):
    ''' Execute command.
        returns stdout if execution exited with 0
        raise ExecutionException otherwise.             '''
    if cmd and isinstance(cmd[0], (list, tuple)):
        cmd = cmd[0]
    # print(str(cmd))
    stdin = kwargs.get('stdin')
    p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stdin=subprocess.PIPE)
    stdout, _ = p.communicate(stdin)
    c = p.wait()
    if c != 0:
        raise ExecutionException(' '.join(cmd), c)
    return stdout.strip()

def error(message):
    print
    print '        ' + str(message)
    print
    sys.exit(2)


try:
    output = execute('arc', 'get-config', 'phabricator.uri', 'default')
    match = re.search('Current Value: "(.*)"', output)
    if match is None:
        error('arc is not configured with a `phabricator.uri`')

    api = match.group(1)
    if api != PHAB_HTTP_URI:
        error('arc configuration mismatch: '
              'arc is configured to use `%s`, but expected `%s`' % (
                  api, PHAB_HTTP_URI))
except OSError:
    error('Could not execute `arc`. Check your path. Maybe start a new shell')

try:
    output = execute('arc', 'call-conduit', 'user.whoami', stdin='{}')
except:
    error('arcanist conduit token is not configured!')


output = json.loads(output)

if output['errorMessage'] is not None:
    error(output['errorMessage'])

api_user = output['response']


try:
    output = execute(
        'ssh', '-p ' + str(PHAB_SSH_PORT), PHAB_SSH_HOST,
        'conduit user.whoami',
        stdin='{}')
except ExecutionException:
    error('Failed to connect using SSH. Check your keys')

output = json.loads(output)

if output['error_info'] is not None:
    error(output['error_info'])

ssh_user = output['result']

api_user_name = api_user['userName']
ssh_user_name = ssh_user['userName']

if api_user != ssh_user:
    if api_user_name == ssh_user_name:
        error('Identity mismatch: '
              'API and SSH access provide the same username, but the account'
              'details are different.')
    else:
        error('Identity mismatch: '
              'API token belongs to user `%s`, '
              'but SSH key matches user `%s`' % (
                  api_user_name, ssh_user_name))

print 'Successfuly configured to use arc as user `%s`' % api_user_name