# Microsoft Azure Linux Agent
#
# Copyright 2014 Microsoft Corporation
#
# 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.
#
# Requires Python 2.4+ and Openssl 1.0+
#

import os
import time

import azurelinuxagent.common.conf as conf
import azurelinuxagent.common.logger as logger
import azurelinuxagent.common.utils.fileutil as fileutil
from azurelinuxagent.common.exception import ProvisionError, ProtocolError
from azurelinuxagent.common.future import ustr
from azurelinuxagent.pa.provision.default import ProvisionHandler

"""
On ubuntu image, provision could be disabled.
"""


class UbuntuProvisionHandler(ProvisionHandler):
    def __init__(self):
        super(UbuntuProvisionHandler, self).__init__()

    def run(self):
        # If provision is enabled, run default provision handler
        if conf.get_provision_enabled():
            super(UbuntuProvisionHandler, self).run()
            return

        logger.info("run Ubuntu provision handler")
        provisioned = os.path.join(conf.get_lib_dir(), "provisioned")
        if os.path.isfile(provisioned):
            return

        logger.info("Waiting cloud-init to copy ovf-env.xml.")
        self.wait_for_ovfenv()
        self.protocol_util.get_protocol()
        self.report_not_ready("Provisioning", "Starting")
        logger.info("Sleeping 1 second to avoid throttling.")
        time.sleep(1)
        try:
            logger.info("Wait for ssh host key to be generated.")
            thumbprint = self.wait_for_ssh_host_key()
            fileutil.write_file(provisioned, "")
            logger.info("Finished provisioning")
        except ProvisionError as e:
            logger.error("Provision failed: {0}", e)
            self.report_not_ready("ProvisioningFailed", ustr(e))
            self.report_event(ustr(e))
            return

        self.report_ready(thumbprint)
        self.report_event("Provision succeed", is_success=True)

    def wait_for_ovfenv(self, max_retry=60):
        """
        Wait for cloud-init to copy ovf-env.xml file from provision ISO
        """
        for retry in range(0, max_retry):
            try:
                self.protocol_util.get_ovf_env()
                return
            except ProtocolError:
                if retry < max_retry - 1:
                    logger.info("Wait for cloud-init to copy ovf-env.xml")
                    time.sleep(5)
        raise ProvisionError("ovf-env.xml is not copied")

    def wait_for_ssh_host_key(self, max_retry=60):
        """
        Wait for cloud-init to generate ssh host key
        """
        keypair_type = conf.get_ssh_host_keypair_type()
        path = '/etc/ssh/ssh_host_{0}_key.pub'.format(keypair_type)
        for retry in range(0, max_retry):
            if os.path.isfile(path):
                logger.info("ssh host key found at: {0}".format(path))
                try:
                    thumbprint = self.get_ssh_host_key_thumbprint(keypair_type, chk_err=False)
                    logger.info("Thumbprint obtained from : {0}".format(path))
                    return thumbprint
                except ProvisionError:
                    logger.warn("Could not get thumbprint from {0}".format(path))
            if retry < max_retry - 1:
                logger.info("Wait for ssh host key be generated: {0}".format(path))
                time.sleep(5)
        raise ProvisionError("ssh host key is not generated.")