# 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.

# NOTE: swift_conn
# You'll see swift_conn passed around a few places in this file. This is the
# source httplib connection of whatever it is attached to.
#   It is used when early termination of reading from the connection should
# happen, such as when a range request is satisfied but there's still more the
# source connection would like to send. To prevent having to read all the data
# that could be left, the source connection can be .close() and then reads
# commence to empty out any buffers.
#   These shenanigans are to ensure all related objects can be garbage
# collected. We've seen objects hang around forever otherwise.

from urllib import unquote

from swift.common.utils import public, csv_append
from swift.common.constraints import check_metadata, MAX_CONTAINER_NAME_LENGTH
from swift.common.http import HTTP_ACCEPTED
from swift.proxy.controllers.base import Controller, delay_denial, \
    cors_validation, clear_info_cache
from swift.common.swob import HTTPBadRequest, HTTPForbidden, \
    HTTPNotFound


class ContainerController(Controller):
    """WSGI controller for container requests"""
    server_type = 'Container'

    # Ensure these are all lowercase
    pass_through_headers = ['x-container-read', 'x-container-write',
                            'x-container-sync-key', 'x-container-sync-to',
                            'x-versions-location']

    def __init__(self, app, account_name, container_name, **kwargs):
        Controller.__init__(self, app)
        self.account_name = unquote(account_name)
        self.container_name = unquote(container_name)

    def _x_remove_headers(self):
        st = self.server_type.lower()
        return ['x-remove-%s-read' % st,
                'x-remove-%s-write' % st,
                'x-remove-versions-location']

    def clean_acls(self, req):
        if 'swift.clean_acl' in req.environ:
            for header in ('x-container-read', 'x-container-write'):
                if header in req.headers:
                    try:
                        req.headers[header] = \
                            req.environ['swift.clean_acl'](header,
                                                           req.headers[header])
                    except ValueError, err:
                        return HTTPBadRequest(request=req, body=str(err))
        return None

    def GETorHEAD(self, req):
        """Handler for HTTP GET/HEAD requests."""
        if not self.account_info(self.account_name, req)[1]:
            return HTTPNotFound(request=req)
        part = self.app.container_ring.get_part(
            self.account_name, self.container_name)
        resp = self.GETorHEAD_base(
            req, _('Container'), self.app.container_ring, part, req.path_info)
        if 'swift.authorize' in req.environ:
            req.acl = resp.headers.get('x-container-read')
            aresp = req.environ['swift.authorize'](req)
            if aresp:
                return aresp
        if not req.environ.get('swift_owner', False):
            for key in ('x-container-read', 'x-container-write',
                        'x-container-sync-key', 'x-container-sync-to'):
                if key in resp.headers:
                    del resp.headers[key]
        return resp

    @public
    @delay_denial
    @cors_validation
    def GET(self, req):
        """Handler for HTTP GET requests."""
        return self.GETorHEAD(req)

    @public
    @delay_denial
    @cors_validation
    def HEAD(self, req):
        """Handler for HTTP HEAD requests."""
        return self.GETorHEAD(req)

    @public
    @cors_validation
    def PUT(self, req):
        """HTTP PUT request handler."""
        error_response = \
            self.clean_acls(req) or check_metadata(req, 'container')
        if error_response:
            return error_response
        if len(self.container_name) > MAX_CONTAINER_NAME_LENGTH:
            resp = HTTPBadRequest(request=req)
            resp.body = 'Container name length of %d longer than %d' % \
                        (len(self.container_name), MAX_CONTAINER_NAME_LENGTH)
            return resp
        account_partition, accounts, container_count = \
            self.account_info(self.account_name, req)
        if not accounts and self.app.account_autocreate:
            self.autocreate_account(req.environ, self.account_name)
            account_partition, accounts, container_count = \
                self.account_info(self.account_name, req)
        if not accounts:
            return HTTPNotFound(request=req)
        if self.app.max_containers_per_account > 0 and \
                container_count >= self.app.max_containers_per_account and \
                self.account_name not in self.app.max_containers_whitelist:
            resp = HTTPForbidden(request=req)
            resp.body = 'Reached container limit of %s' % \
                        self.app.max_containers_per_account
            return resp
        container_partition, containers = self.app.container_ring.get_nodes(
            self.account_name, self.container_name)
        headers = self._backend_requests(req, len(containers),
                                         account_partition, accounts)
        clear_info_cache(self.app, req.environ,
                         self.account_name, self.container_name)
        resp = self.make_requests(
            req, self.app.container_ring,
            container_partition, 'PUT', req.path_info, headers)
        return resp

    @public
    @cors_validation
    def POST(self, req):
        """HTTP POST request handler."""
        error_response = \
            self.clean_acls(req) or check_metadata(req, 'container')
        if error_response:
            return error_response
        account_partition, accounts, container_count = \
            self.account_info(self.account_name, req)
        if not accounts:
            return HTTPNotFound(request=req)
        container_partition, containers = self.app.container_ring.get_nodes(
            self.account_name, self.container_name)
        headers = self.generate_request_headers(req, transfer=True)
        clear_info_cache(self.app, req.environ,
                         self.account_name, self.container_name)
        resp = self.make_requests(
            req, self.app.container_ring, container_partition, 'POST',
            req.path_info, [headers] * len(containers))
        return resp

    @public
    @cors_validation
    def DELETE(self, req):
        """HTTP DELETE request handler."""
        account_partition, accounts, container_count = \
            self.account_info(self.account_name, req)
        if not accounts:
            return HTTPNotFound(request=req)
        container_partition, containers = self.app.container_ring.get_nodes(
            self.account_name, self.container_name)
        headers = self._backend_requests(req, len(containers),
                                         account_partition, accounts)
        clear_info_cache(self.app, req.environ,
                         self.account_name, self.container_name)
        resp = self.make_requests(
            req, self.app.container_ring, container_partition, 'DELETE',
            req.path_info, headers)
        # Indicates no server had the container
        if resp.status_int == HTTP_ACCEPTED:
            return HTTPNotFound(request=req)
        return resp

    def _backend_requests(self, req, n_outgoing,
                          account_partition, accounts):
        headers = [self.generate_request_headers(req, transfer=True)
                   for _junk in range(n_outgoing)]

        for i, account in enumerate(accounts):
            i = i % len(headers)

            headers[i]['X-Account-Partition'] = account_partition
            headers[i]['X-Account-Host'] = csv_append(
                headers[i].get('X-Account-Host'),
                '%(ip)s:%(port)s' % account)
            headers[i]['X-Account-Device'] = csv_append(
                headers[i].get('X-Account-Device'),
                account['device'])

        return headers
