#!/usr/bin/env python

import json
import optparse
import os.path
import sys

sys.path.insert(0, os.path.join(
        os.path.dirname(os.path.dirname(os.path.realpath(__file__))),
        'lib'))
import krb5
import roost

def zuser_is_personal(recip):
    return recip and recip[0] != '@'

def main(args):
    parser = optparse.OptionParser(
        usage='Usage: %prog [OPTIONS] [RECIPIENTS]')
    parser.add_option('-c', dest='klass', metavar='CLASS',
                      help='set the class (default: message)')
    parser.add_option('-i', dest='instance',
                      help='set the instance (default: personal)')
    parser.add_option('-O', default='', dest='opcode',
                      help='set the opcode (default: %default)')
    parser.add_option('-r', default=None, dest='realm',
                      help='set the realm')
    parser.add_option('-s', default=None, dest='signature',
                      help='set the signature')
    parser.add_option('--server', default=roost.DEFAULT_SERVER,
                      help='Roost backend server (default: %default)')
    parser.add_option('--service', default=roost.DEFAULT_SERVICE,
                      help='Service name (default: %default)')
    (options, recips) = parser.parse_args()

    if not recips and options.klass is None and options.instance is None:
        parser.error('Pass a class or recipient')

    if options.klass is None:
        options.klass = 'message'
    if options.instance is None:
        options.instance = 'personal'
    if not recips:
        recips = ['']
    if options.realm is not None:
        recips = ['%s@%s' % (r, options.realm) for r in recips]

    # Get the default principal.
    ctx = krb5.Context()
    ccache = ctx.cc_default()
    principal = ccache.get_principal()
    principal_str = principal.unparse_name()

    # Get an auth token.
    token, _expires = roost.get_auth_token(options, principal_str,
                                           create_user=True)

    # Get the user config for zsig.
    if options.signature is None:
        ret = roost.get(options, token, '/v1/info')
        info = json.loads(ret['info'])
        options.signature = str(info.get('zsig', 'Sent by Roost'))

    # TODO(davidben): Implement the single-dot thing.
    print 'Type your message now.  End with control-D.'
    message = sys.stdin.read().rstrip()

    # Alway staple zephyr creds.
    zephyr = ctx.build_principal('ATHENA.MIT.EDU', ['zephyr', 'zephyr'])
    creds = ccache.get_credentials(principal, zephyr)

    for recip in recips:
        pretty_str = recip
        if not zuser_is_personal(recip):
            pretty_str = 'class %s' % options.klass
        print 'Sending message to %s...' % pretty_str,
        # Build the data.
        data = {
            'message': {
                'class': options.klass,
                'instance': options.instance,
                'recipient': recip,
                'opcode': options.opcode,
                'signature': options.signature,
                'message': message
            },
            'credentials': creds.to_dict(),
        }
        roost.post(options, token, '/v1/zwrite', data)
        print "Sent"

    return 0

if __name__ == '__main__':
    sys.exit(main(sys.argv[1:]))