# -*- coding: utf8 -*-
# ============LICENSE_START=======================================================
# org.onap.vvp/validation-scripts
# ===================================================================
# Copyright © 2017 AT&T Intellectual Property. All rights reserved.
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# Unless otherwise specified, all software contained herein is licensed
# under the Apache License, Version 2.0 (the "License");
# you may not use this software except in compliance with the License.
# You may obtain a copy of the License at
#
#             http://www.apache.org/licenses/LICENSE-2.0
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# limitations under the License.
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# Unless otherwise specified, all documentation contained herein is licensed
# under the Creative Commons License, Attribution 4.0 Intl. (the "License");
# you may not use this documentation except in compliance with the License.
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#             https://creativecommons.org/licenses/by/4.0/
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from yaml.constructor import ConstructorError
from yaml.nodes import MappingNode

try:
    from yaml import CLoader as SafeLoader
except ImportError:
    from yaml import SafeLoader


class UniqueKeyLoader(SafeLoader):
    def construct_mapping(self, node, deep=False):
        if not isinstance(node, MappingNode):
            raise ConstructorError(
                None,
                None,
                "expected a mapping node, but found %s" % node.id,
                node.start_mark,
            )
        mapping = {}
        for key_node, value_node in node.value:
            key = self.construct_object(key_node, deep=deep)
            try:
                hash(key)
            except TypeError as exc:
                raise ConstructorError(
                    "while constructing a mapping",
                    node.start_mark,
                    "found unacceptable key (%s)" % exc,
                    key_node.start_mark,
                )
            # check for duplicate keys
            if key in mapping:
                raise ConstructorError(
                    "while constructing a mapping",
                    node.start_mark,
                    "found duplicate key",
                    key_node.start_mark,
                )
            value = self.construct_object(value_node, deep=deep)
            mapping[key] = value
        return mapping