# Copyright (c) 2006-2019  Andrey Golovigin
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

from __future__ import absolute_import, unicode_literals

from collections import OrderedDict

import six
import yaml
from pybtex.database import Entry, Person
from pybtex.database.input import BaseParser


class OrderedDictSafeLoader(yaml.SafeLoader):
    """
    SafeLoader that loads mappings as OrderedDicts.
    """

    def construct_yaml_map(self, node):
        data = OrderedDict()
        yield data
        value = self.construct_mapping(node)
        data.update(value)

    def construct_mapping(self, node, deep=False):
        if isinstance(node, yaml.MappingNode):
            self.flatten_mapping(node)
        else:
            raise yaml.constructor.ConstructorError(None, None,
                'expected a mapping node, but found %s' % node.id, node.start_mark)

        mapping = OrderedDict()
        for key_node, value_node in node.value:
            key = self.construct_object(key_node, deep=deep)
            try:
                hash(key)
            except TypeError as exc:
                raise yaml.constructor.ConstructorError('while constructing a mapping',
                    node.start_mark, 'found unacceptable key (%s)' % exc, key_node.start_mark)
            value = self.construct_object(value_node, deep=deep)
            mapping[key] = value
        return mapping

OrderedDictSafeLoader.add_constructor(
    u'tag:yaml.org,2002:map', OrderedDictSafeLoader.construct_yaml_map
)
OrderedDictSafeLoader.add_constructor(
    u'tag:yaml.org,2002:omap', OrderedDictSafeLoader.construct_yaml_map
)


class Parser(BaseParser):
    default_suffix = '.yaml'
    unicode_io = False

    def parse_stream(self, stream):
        t = yaml.load(stream, Loader=OrderedDictSafeLoader)

        entries = (
            (key, self.process_entry(entry))
            for (key, entry) in t['entries'].items()
        )

        try:
            self.data.add_to_preamble(t['preamble'])
        except KeyError:
            pass

        self.data.add_entries(entries)
        return self.data

    def process_entry(self, entry):
        bib_entry = Entry(entry['type'])
        for (key, value) in entry.items():
            key_lower = key.lower()
            if key_lower in Person.valid_roles:
                for names in value:
                    bib_entry.add_person(Person(**names), key)
            elif key_lower == 'type':
                pass
            else:
                bib_entry.fields[key] = six.text_type(value)
        return bib_entry
