# Microsoft Azure Linux Agent
#
# Copyright 2018 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 2.6+ and Openssl 1.0+
#
"""
Copy and parse ovf-env.xml from provisioning ISO and local cache
"""
import os  # pylint: disable=W0611
import re  # pylint: disable=W0611
import shutil  # pylint: disable=W0611
import xml.dom.minidom as minidom  # pylint: disable=W0611
import azurelinuxagent.common.logger as logger
from azurelinuxagent.common.exception import ProtocolError
from azurelinuxagent.common.future import ustr  # pylint: disable=W0611
import azurelinuxagent.common.utils.fileutil as fileutil  # pylint: disable=W0611
from azurelinuxagent.common.utils.textutil import parse_doc, findall, find, findtext

OVF_VERSION = "1.0"
OVF_NAME_SPACE = "http://schemas.dmtf.org/ovf/environment/1"
WA_NAME_SPACE = "http://schemas.microsoft.com/windowsazure"

def _validate_ovf(val, msg):
    if val is None:
        raise ProtocolError("Failed to validate OVF: {0}".format(msg))


class OvfEnv(object):
    """
    Read, and process provisioning info from provisioning file OvfEnv.xml
    """
    def __init__(self, xml_text):
        if xml_text is None:
            raise ValueError("ovf-env is None")
        logger.verbose("Load ovf-env.xml")
        self.hostname = None
        self.username = None
        self.user_password = None
        self.customdata = None
        self.disable_ssh_password_auth = True
        self.ssh_pubkeys = []
        self.ssh_keypairs = []
        self.provision_guest_agent = None
        self.parse(xml_text)

    def parse(self, xml_text):
        """
        Parse xml tree, retreiving user and ssh key information.
        Return self.
        """
        wans = WA_NAME_SPACE
        ovfns = OVF_NAME_SPACE

        xml_doc = parse_doc(xml_text)
        
        environment = find(xml_doc, "Environment", namespace=ovfns)
        _validate_ovf(environment, "Environment not found")

        section = find(environment, "ProvisioningSection", namespace=wans)
        _validate_ovf(section, "ProvisioningSection not found")

        version = findtext(environment, "Version", namespace=wans)
        _validate_ovf(version, "Version not found")

        if version > OVF_VERSION:
            logger.warn("Newer provisioning configuration detected. "
                        "Please consider updating waagent")
        
        conf_set = find(section, "LinuxProvisioningConfigurationSet", 
                        namespace=wans)
        _validate_ovf(conf_set, "LinuxProvisioningConfigurationSet not found")

        self.hostname = findtext(conf_set, "HostName", namespace=wans)
        _validate_ovf(self.hostname, "HostName not found")

        self.username = findtext(conf_set, "UserName", namespace=wans)
        _validate_ovf(self.username, "UserName not found")
        
        self.user_password = findtext(conf_set, "UserPassword", namespace=wans)

        self.customdata = findtext(conf_set, "CustomData", namespace=wans)
        
        auth_option = findtext(conf_set, "DisableSshPasswordAuthentication", 
                               namespace=wans)
        if auth_option is not None and auth_option.lower() == "true":
            self.disable_ssh_password_auth = True
        else:
            self.disable_ssh_password_auth = False

        public_keys = findall(conf_set, "PublicKey", namespace=wans)
        for public_key in public_keys:
            path = findtext(public_key, "Path", namespace=wans)
            fingerprint = findtext(public_key, "Fingerprint", namespace=wans)
            value = findtext(public_key, "Value", namespace=wans)
            self.ssh_pubkeys.append((path, fingerprint, value))

        keypairs = findall(conf_set, "KeyPair", namespace=wans)
        for keypair in keypairs:
            path = findtext(keypair, "Path", namespace=wans)
            fingerprint = findtext(keypair, "Fingerprint", namespace=wans)
            self.ssh_keypairs.append((path, fingerprint))

        platform_settings_section = find(environment, "PlatformSettingsSection", namespace=wans)
        _validate_ovf(platform_settings_section, "PlatformSettingsSection not found")

        platform_settings = find(platform_settings_section, "PlatformSettings", namespace=wans)
        _validate_ovf(platform_settings, "PlatformSettings not found")

        self.provision_guest_agent = findtext(platform_settings, "ProvisionGuestAgent", namespace=wans)
        _validate_ovf(self.provision_guest_agent, "ProvisionGuestAgent not found")