#!/usr/bin/env python
import json
import logging
from argparse import ArgumentParser, FileType, SUPPRESS
import redis
import yaml
from tornado.gen import coroutine
from tornado.httpclient import AsyncHTTPClient
from tornado.ioloop import IOLoop, PeriodicCallback
from tornado.web import Application
from candolint.utils import lookup_option, timestamp
class CandolintPoller(Application):
    def __init__(self, rconn, targets, interval, debug):
        handlers = []
        super(CandolintPoller, self).__init__(handlers, debug=debug)
        self.rconn = rconn
        self.targets = targets
        self.interval = interval
        IOLoop.instance().add_callback(self.setup)
    @coroutine
    def setup(self):
        for target in self.targets:
            yield self.poll(target)
            @coroutine
            def routine(target=target):
                yield self.poll(target)
            pc = PeriodicCallback(routine, self.interval * 1000)
            pc.start()
    @coroutine
    def poll(self, target):
        url = target['url']
        http = AsyncHTTPClient()
        headers = {}
        if 'etag' in target:
            headers['If-None-Match'] = target['etag']
        logging.debug('Fetching %s', url)
        response = yield http.fetch(url, raise_error=False, headers=headers)
        if response.code == 200:
            data = json.loads(response.body)
            hashes = set(branch['node'] for branch in data['branches'])
            if 'hashes' in target:
                new = hashes - target['hashes']
                base = {
                    'url': url,
                    'scm': 'hg',
                    'repo': target['repo'],
                    'timestamp': timestamp(),
                    'source': target['source']
                }
                self.push(base, new)
                logging.info('Got %d new hash(es) from %s', len(new), url)
            else:
                logging.info('Got %d current hash(es) from %s', len(hashes), url)
            target['hashes'] = hashes
            target['etag'] = response.headers.get('ETag', None)
        elif response.code == 304:
            logging.debug('Not modified: %s', url)
        else:
            logging.error('Error %d fetching %s', response.code, url)
            response.rethrow()
    def push(self, base, changes):
        for change in changes:
            item = base.copy()
            item['change'] = change
            data = json.dumps(item)
            logging.debug('Pushing %s', data)
            self.rconn.rpush('candolint:queue:changes', data)
            logging.info('Pushed a change for %s', item['repo'])
def main():
    parser = ArgumentParser(argument_default=SUPPRESS)
    parser.add_argument(
        '-c', '--config', type=FileType('r'),
        help='configuration file (YAML)')
    parser.add_argument(
        '-d', '--debug', action='store_true', default=False,
        help='enable debugging output')
    group = parser.add_argument_group(
        'queue configuration',
        'these options that can also be specified in the configuration file')
    group.add_argument('--redis-host', help='(default: 127.0.0.1)')
    group.add_argument('--redis-port', type=int, help='(default: 6379)')
    group.add_argument('--redis-password')
    group.add_argument('--interval', type=int, help='(default: 8 hours)')
    args = parser.parse_args()
    config = yaml.safe_load(args.config) if hasattr(args, 'config') else {}
    rhost = lookup_option('redis-host', args, config, default='127.0.0.1')
    rport = lookup_option('redis-port', args, config, default=6379)
    rpass = lookup_option('redis-password', args, config)
    interval = lookup_option('interval', args, config, default=8 * 60 * 60)
    logging.basicConfig(
        level=logging.DEBUG if args.debug else logging.INFO,
        format='%(asctime)s %(levelname)-8s %(message)s')
    if config and 'targets' in config:
        targets = config['targets']
    else:
        logging.warn('No targets defined.')
        targets = []
    logging.debug('Connecting to Redis server')
    rconn = redis.StrictRedis(host=rhost, port=rport, password=rpass, db=0)
    logging.info('Connected to Redis server')
    CandolintPoller(rconn, targets, interval, args.debug)
    IOLoop.instance().start()
if __name__ == '__main__':
    main()