#!/usr/bin/env python
# Copyright (c) 2010-2012 OpenStack, LLC.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import os
import traceback
from ConfigParser import ConfigParser
from cStringIO import StringIO
from sys import exit, argv, stdout
from time import time
from uuid import uuid4

from eventlet import GreenPool, patcher, sleep
from eventlet.pools import Pool

from swiftclient import Connection, get_auth
from swift.common.ring import Ring
from swift.common.utils import compute_eta, get_time_units


def put_container(connpool, container, report):
    global retries_done
    try:
        with connpool.item() as conn:
            conn.put_container(container)
            retries_done += conn.attempts - 1
        if report:
            report(True)
    except Exception:
        if report:
            report(False)
        raise


def put_object(connpool, container, obj, report):
    global retries_done
    try:
        with connpool.item() as conn:
            conn.put_object(container, obj, StringIO(obj),
                            headers={'x-object-meta-dispersion': obj})
            retries_done += conn.attempts - 1
        if report:
            report(True)
    except Exception:
        if report:
            report(False)
        raise


def report(success):
    global begun, created, item_type, next_report, need_to_create, retries_done
    if not success:
        traceback.print_exc()
        exit('Gave up due to error(s).')
    created += 1
    if time() < next_report:
        return
    next_report = time() + 5
    eta, eta_unit = compute_eta(begun, created, need_to_create)
    print '\r\x1B[KCreating %s: %d of %d, %d%s left, %d retries' % (item_type,
          created, need_to_create, round(eta), eta_unit, retries_done),
    stdout.flush()


if __name__ == '__main__':
    global begun, created, item_type, next_report, need_to_create, retries_done
    patcher.monkey_patch()

    conffile = '/etc/swift/dispersion.conf'
    if len(argv) == 2:
        conffile = argv[1]
    elif len(argv) > 2:
        exit('Syntax: %s [conffile]' % argv[0])
    c = ConfigParser()
    if not c.read(conffile):
        exit('Unable to read config file: %s' % conffile)
    conf = dict(c.items('dispersion'))
    swift_dir = conf.get('swift_dir', '/etc/swift')
    dispersion_coverage = int(conf.get('dispersion_coverage', 1))
    retries = int(conf.get('retries', 5))
    concurrency = int(conf.get('concurrency', 25))

    coropool = GreenPool(size=concurrency)
    retries_done = 0

    url, token = get_auth(conf['auth_url'], conf['auth_user'],
                          conf['auth_key'],
                          auth_version=conf.get('auth_version', '1.0'))
    account = url.rsplit('/', 1)[1]
    connpool = Pool(max_size=concurrency)
    connpool.create = lambda: Connection(conf['auth_url'],
                                conf['auth_user'], conf['auth_key'],
                                retries=retries,
                                preauthurl=url, preauthtoken=token)

    container_ring = Ring(swift_dir, ring_name='container')
    parts_left = dict((x, x) for x in xrange(container_ring.partition_count))
    item_type = 'containers'
    created = 0
    retries_done = 0
    need_to_create = need_to_queue = \
        dispersion_coverage / 100.0 * container_ring.partition_count
    begun = next_report = time()
    next_report += 2
    while need_to_queue >= 1:
        container = 'dispersion_%s' % uuid4().hex
        part, _junk = container_ring.get_nodes(account, container)
        if part in parts_left:
            coropool.spawn(put_container, connpool, container, report)
            sleep()
            del parts_left[part]
            need_to_queue -= 1
    coropool.waitall()
    elapsed, elapsed_unit = get_time_units(time() - begun)
    print '\r\x1B[KCreated %d containers for dispersion reporting, %d%s, %d ' \
          'retries' % \
          (need_to_create, round(elapsed), elapsed_unit, retries_done)
    stdout.flush()

    container = 'dispersion_objects'
    put_container(connpool, container, None)
    object_ring = Ring(swift_dir, ring_name='object')
    parts_left = dict((x, x) for x in xrange(object_ring.partition_count))
    item_type = 'objects'
    created = 0
    retries_done = 0
    need_to_create = need_to_queue = \
        dispersion_coverage / 100.0 * object_ring.partition_count
    begun = next_report = time()
    next_report += 2
    while need_to_queue >= 1:
        obj = 'dispersion_%s' % uuid4().hex
        part, _junk = object_ring.get_nodes(account, container, obj)
        if part in parts_left:
            coropool.spawn(put_object, connpool, container, obj, report)
            sleep()
            del parts_left[part]
            need_to_queue -= 1
    coropool.waitall()
    elapsed, elapsed_unit = get_time_units(time() - begun)
    print '\r\x1B[KCreated %d objects for dispersion reporting, %d%s, %d ' \
          'retries' % \
          (need_to_create, round(elapsed), elapsed_unit, retries_done)
    stdout.flush()