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# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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
#
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# distributed under the License is distributed on an "AS IS" BASIS,
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"""
Utilities for cross-referencing code with specification documents.
"""

import re

from ..extension import parser
from ..utils.collections import OrderedDict
from ..utils.specification import (DSL_SPECIFICATIONS, implements_specification)                    # pylint: disable=unused-import


def iter_specifications():
    """
    Iterates all specification assignments in the codebase.
    """
    def iter_sections(spec, sections):
        for k in sorted(sections.keys(), key=_section_key):
            details = OrderedDict()
            details['code'] = sections[k]['code']
            yield k, _fix_details(sections[k], spec)

    for spec, sections in DSL_SPECIFICATIONS.iteritems():
        yield spec, iter_sections(spec, sections)


def _section_key(value):
    try:
        parts = value.split('-', 1)
        first = (int(v) for v in parts[0].split('.'))
        second = parts[1] if len(parts) > 1 else None
        return (first, second)
    except ValueError:
        return value


def _fix_details(details, spec):
    code = details.get('code')
    doc = details.get('doc')
    url = parser.specification_url().get(spec)

    if (url is not None) and (doc is not None):
        # Look for a URL in ReST docstring that begins with our url
        pattern = r'<?('
        for char in url:
            pattern += r'\s*'
            pattern += re.escape(char)
        pattern += r'[^>]+)>'
        match = re.search(pattern, doc)
        if match:
            url = re.sub(r'\s+', '', match.group(1))

    return OrderedDict((
        ('code', code),
        ('url', url)))