#!/usr/bin/env python
# Copyright (c) 2010-2012 OpenStack Foundation
#
# 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 traceback
from ConfigParser import ConfigParser
from cStringIO import StringIO
from optparse import OptionParser
from sys import exit, stdout
from time import time

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

try:
    from swiftclient import get_auth
except ImportError:
    from swift.common.internal_client import get_auth
from swift.common.internal_client import SimpleClient
from swift.common.ring import Ring
from swift.common.utils import compute_eta, get_time_units, config_true_value


insecure = False


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'

    parser = OptionParser(usage='''
Usage: %%prog [options] [conf_file]

[conf_file] defaults to %s'''.strip() % conffile)
    parser.add_option('--container-only', action='store_true', default=False,
                      help='Only run container population')
    parser.add_option('--object-only', action='store_true', default=False,
                      help='Only run object population')
    parser.add_option('--container-suffix-start', type=int, default=0,
                      help='container suffix start value, defaults to 0')
    parser.add_option('--object-suffix-start', type=int, default=0,
                      help='object suffix start value, defaults to 0')
    parser.add_option('--insecure', action='store_true', default=False,
                      help='Allow accessing insecure keystone server. '
                           'The keystone\'s certificate will not be verified.')
    options, args = parser.parse_args()

    if args:
        conffile = args.pop(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 = float(conf.get('dispersion_coverage', 1))
    retries = int(conf.get('retries', 5))
    concurrency = int(conf.get('concurrency', 25))
    endpoint_type = str(conf.get('endpoint_type', 'publicURL'))
    insecure = options.insecure \
        or config_true_value(conf.get('keystone_api_insecure', 'no'))
    container_populate = config_true_value(
        conf.get('container_populate', 'yes')) and not options.object_only
    object_populate = config_true_value(
        conf.get('object_populate', 'yes')) and not options.container_only

    if not (object_populate or container_populate):
        exit("Neither container or object populate is set to run")

    coropool = GreenPool(size=concurrency)
    retries_done = 0

    os_options = {'endpoint_type': endpoint_type}

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

    if container_populate:
        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
        suffix = 0
        while need_to_queue >= 1:
            container = 'dispersion_%d' % suffix
            part, _junk = container_ring.get_nodes(account, container)
            if part in parts_left:
                if suffix >= options.container_suffix_start:
                    coropool.spawn(put_container, connpool, container, report)
                    sleep()
                else:
                    report(True)
                del parts_left[part]
                need_to_queue -= 1
            suffix += 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()

    if object_populate:
        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
        suffix = 0
        while need_to_queue >= 1:
            obj = 'dispersion_%d' % suffix
            part, _junk = object_ring.get_nodes(account, container, obj)
            if part in parts_left:
                if suffix >= options.object_suffix_start:
                    coropool.spawn(
                        put_object, connpool, container, obj, report)
                    sleep()
                else:
                    report(True)
                del parts_left[part]
                need_to_queue -= 1
            suffix += 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()
