# Copyright 2012-2013 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
#     http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file 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 logging
import os
import copy

from botocore.awsrequest import AWSRequest
from botocore.httpsession import URLLib3Session
from botocore.exceptions import ProfileNotFound

from awscli.compat import compat_open
from awscli.argprocess import ParamError


logger = logging.getLogger(__name__)

# These are special cased arguments that do _not_ get the
# special param file processing.  This is typically because it
# refers to an actual URI of some sort and we don't want to actually
# download the content (i.e TemplateURL in cloudformation).
PARAMFILE_DISABLED = set([
    'api-gateway.put-integration.uri',
    'api-gateway.create-integration.integration-uri',
    'api-gateway.update-integration.integration-uri',
    'api-gateway.create-api.target',
    'api-gateway.update-api.target',
    'appstream.create-stack.redirect-url',
    'appstream.create-stack.feedback-url',
    'appstream.update-stack.redirect-url',
    'appstream.update-stack.feedback-url',
    'cloudformation.create-stack.template-url',
    'cloudformation.update-stack.template-url',
    'cloudformation.create-stack-set.template-url',
    'cloudformation.update-stack-set.template-url',
    'cloudformation.create-change-set.template-url',
    'cloudformation.validate-template.template-url',
    'cloudformation.estimate-template-cost.template-url',
    'cloudformation.get-template-summary.template-url',

    'cloudformation.create-stack.stack-policy-url',
    'cloudformation.update-stack.stack-policy-url',
    'cloudformation.set-stack-policy.stack-policy-url',
    # aws cloudformation package --template-file
    'custom.package.template-file',
    # aws cloudformation deploy --template-file
    'custom.deploy.template-file',

    'cloudformation.update-stack.stack-policy-during-update-url',
    'cloudformation.register-type.schema-handler-package',
    # We will want to change the event name to ``s3`` as opposed to
    # custom in the near future along with ``s3`` to ``s3api``.
    'custom.cp.website-redirect',
    'custom.mv.website-redirect',
    'custom.sync.website-redirect',

    'guardduty.create-ip-set.location',
    'guardduty.update-ip-set.location',
    'guardduty.create-threat-intel-set.location',
    'guardduty.update-threat-intel-set.location',
    'comprehend.detect-dominant-language.text',
    'comprehend.batch-detect-dominant-language.text-list',
    'comprehend.detect-entities.text',
    'comprehend.batch-detect-entities.text-list',
    'comprehend.detect-key-phrases.text',
    'comprehend.batch-detect-key-phrases.text-list',
    'comprehend.detect-sentiment.text',
    'comprehend.batch-detect-sentiment.text-list',

    'emr.create-studio.idp-auth-url',

    'iam.create-open-id-connect-provider.url',

    'machine-learning.predict.predict-endpoint',

    'mediatailor.put-playback-configuration.ad-decision-server-url',
    'mediatailor.put-playback-configuration.slate-ad-url',
    'mediatailor.put-playback-configuration.video-content-source-url',

    'rds.copy-db-cluster-snapshot.pre-signed-url',
    'rds.create-db-cluster.pre-signed-url',
    'rds.copy-db-snapshot.pre-signed-url',
    'rds.create-db-instance-read-replica.pre-signed-url',

    'sagemaker.create-notebook-instance.default-code-repository',
    'sagemaker.create-notebook-instance.additional-code-repositories',
    'sagemaker.update-notebook-instance.default-code-repository',
    'sagemaker.update-notebook-instance.additional-code-repositories',

    'serverlessapplicationrepository.create-application.home-page-url',
    'serverlessapplicationrepository.create-application.license-url',
    'serverlessapplicationrepository.create-application.readme-url',
    'serverlessapplicationrepository.create-application.source-code-url',
    'serverlessapplicationrepository.create-application.template-url',
    'serverlessapplicationrepository.create-application-version.source-code-url',
    'serverlessapplicationrepository.create-application-version.template-url',
    'serverlessapplicationrepository.update-application.home-page-url',
    'serverlessapplicationrepository.update-application.readme-url',

    'service-catalog.create-product.support-url',
    'service-catalog.update-product.support-url',

    'ses.create-custom-verification-email-template.failure-redirection-url',
    'ses.create-custom-verification-email-template.success-redirection-url',
    'ses.put-account-details.website-url',
    'ses.update-custom-verification-email-template.failure-redirection-url',
    'ses.update-custom-verification-email-template.success-redirection-url',

    'sqs.add-permission.queue-url',
    'sqs.change-message-visibility.queue-url',
    'sqs.change-message-visibility-batch.queue-url',
    'sqs.delete-message.queue-url',
    'sqs.delete-message-batch.queue-url',
    'sqs.delete-queue.queue-url',
    'sqs.get-queue-attributes.queue-url',
    'sqs.list-dead-letter-source-queues.queue-url',
    'sqs.receive-message.queue-url',
    'sqs.remove-permission.queue-url',
    'sqs.send-message.queue-url',
    'sqs.send-message-batch.queue-url',
    'sqs.set-queue-attributes.queue-url',
    'sqs.purge-queue.queue-url',
    'sqs.list-queue-tags.queue-url',
    'sqs.tag-queue.queue-url',
    'sqs.untag-queue.queue-url',

    's3.copy-object.website-redirect-location',
    's3.create-multipart-upload.website-redirect-location',
    's3.put-object.website-redirect-location',

    # Double check that this has been renamed!
    'sns.subscribe.notification-endpoint',

    'iot.create-job.document-source',
    'translate.translate-text.text',

    'workdocs.create-notification-subscription.notification-endpoint'
])


class ResourceLoadingError(Exception):
    pass


def register_uri_param_handler(session, **kwargs):
    prefix_map = copy.deepcopy(LOCAL_PREFIX_MAP)
    try:
        fetch_url = session.get_scoped_config().get(
            'cli_follow_urlparam', 'true') == 'true'
    except ProfileNotFound:
        # If a --profile is provided that does not exist, loading
        # a value from get_scoped_config will crash the CLI.
        # This function can be called as the first handler for
        # the session-initialized event, which happens before a
        # profile can be created, even if the command would have
        # successfully created a profile. Instead of crashing here
        # on a ProfileNotFound the CLI should just use 'none'.
        fetch_url = True

    if fetch_url:
        prefix_map.update(REMOTE_PREFIX_MAP)

    handler = URIArgumentHandler(prefix_map)
    session.register('load-cli-arg', handler)


class URIArgumentHandler(object):
    def __init__(self, prefixes=None):
        if prefixes is None:
            prefixes = copy.deepcopy(LOCAL_PREFIX_MAP)
            prefixes.update(REMOTE_PREFIX_MAP)
        self._prefixes = prefixes

    def __call__(self, event_name, param, value, **kwargs):
        """Handler that supports param values from URIs."""
        cli_argument = param
        qualified_param_name = '.'.join(event_name.split('.')[1:])
        if qualified_param_name in PARAMFILE_DISABLED or \
                getattr(cli_argument, 'no_paramfile', None):
            return
        else:
            return self._check_for_uri_param(cli_argument, value)

    def _check_for_uri_param(self, param, value):
        if isinstance(value, list) and len(value) == 1:
            value = value[0]
        try:
            return get_paramfile(value, self._prefixes)
        except ResourceLoadingError as e:
            raise ParamError(param.cli_name, str(e))


def get_paramfile(path, cases):
    """Load parameter based on a resource URI.

    It is possible to pass parameters to operations by referring
    to files or URI's.  If such a reference is detected, this
    function attempts to retrieve the data from the file or URI
    and returns it.  If there are any errors or if the ``path``
    does not appear to refer to a file or URI, a ``None`` is
    returned.

    :type path: str
    :param path: The resource URI, e.g. file://foo.txt.  This value
        may also be a non resource URI, in which case ``None`` is returned.

    :type cases: dict
    :param cases: A dictionary of URI prefixes to function mappings
        that a parameter is checked against.

    :return: The loaded value associated with the resource URI.
        If the provided ``path`` is not a resource URI, then a
        value of ``None`` is returned.

    """
    data = None
    if isinstance(path, str):
        for prefix, function_spec in cases.items():
            if path.startswith(prefix):
                function, kwargs = function_spec
                data = function(prefix, path, **kwargs)
    return data


def get_file(prefix, path, mode):
    file_path = os.path.expandvars(os.path.expanduser(path[len(prefix):]))
    try:
        with compat_open(file_path, mode) as f:
            return f.read()
    except UnicodeDecodeError:
        raise ResourceLoadingError(
            'Unable to load paramfile (%s), text contents could '
            'not be decoded.  If this is a binary file, please use the '
            'fileb:// prefix instead of the file:// prefix.' % file_path)
    except (OSError, IOError) as e:
        raise ResourceLoadingError('Unable to load paramfile %s: %s' % (
            path, e))


def get_uri(prefix, uri):
    try:
        session = URLLib3Session()
        r = session.send(AWSRequest('GET', uri).prepare())
        if r.status_code == 200:
            return r.text
        else:
            raise ResourceLoadingError(
                "received non 200 status code of %s" % (
                    r.status_code))
    except Exception as e:
        raise ResourceLoadingError('Unable to retrieve %s: %s' % (uri, e))


LOCAL_PREFIX_MAP = {
    'file://': (get_file, {'mode': 'r'}),
    'fileb://': (get_file, {'mode': 'rb'}),
}


REMOTE_PREFIX_MAP = {
    'http://': (get_uri, {}),
    'https://': (get_uri, {}),
}
