1# This file is dual licensed under the terms of the Apache License, Version
2# 2.0, and the BSD License. See the LICENSE file in the root of this repository
3# for complete details.
4from __future__ import absolute_import, division, print_function
5
6import string
7import re
8
9from pkg_resources.extern.pyparsing import stringStart, stringEnd, originalTextFor, ParseException
10from pkg_resources.extern.pyparsing import ZeroOrMore, Word, Optional, Regex, Combine
11from pkg_resources.extern.pyparsing import Literal as L  # noqa
12from pkg_resources.extern.six.moves.urllib import parse as urlparse
13
14from .markers import MARKER_EXPR, Marker
15from .specifiers import LegacySpecifier, Specifier, SpecifierSet
16
17
18class InvalidRequirement(ValueError):
19    """
20    An invalid requirement was found, users should refer to PEP 508.
21    """
22
23
24ALPHANUM = Word(string.ascii_letters + string.digits)
25
26LBRACKET = L("[").suppress()
27RBRACKET = L("]").suppress()
28LPAREN = L("(").suppress()
29RPAREN = L(")").suppress()
30COMMA = L(",").suppress()
31SEMICOLON = L(";").suppress()
32AT = L("@").suppress()
33
34PUNCTUATION = Word("-_.")
35IDENTIFIER_END = ALPHANUM | (ZeroOrMore(PUNCTUATION) + ALPHANUM)
36IDENTIFIER = Combine(ALPHANUM + ZeroOrMore(IDENTIFIER_END))
37
38NAME = IDENTIFIER("name")
39EXTRA = IDENTIFIER
40
41URI = Regex(r'[^ ]+')("url")
42URL = (AT + URI)
43
44EXTRAS_LIST = EXTRA + ZeroOrMore(COMMA + EXTRA)
45EXTRAS = (LBRACKET + Optional(EXTRAS_LIST) + RBRACKET)("extras")
46
47VERSION_PEP440 = Regex(Specifier._regex_str, re.VERBOSE | re.IGNORECASE)
48VERSION_LEGACY = Regex(LegacySpecifier._regex_str, re.VERBOSE | re.IGNORECASE)
49
50VERSION_ONE = VERSION_PEP440 ^ VERSION_LEGACY
51VERSION_MANY = Combine(VERSION_ONE + ZeroOrMore(COMMA + VERSION_ONE),
52                       joinString=",", adjacent=False)("_raw_spec")
53_VERSION_SPEC = Optional(((LPAREN + VERSION_MANY + RPAREN) | VERSION_MANY))
54_VERSION_SPEC.setParseAction(lambda s, l, t: t._raw_spec or '')
55
56VERSION_SPEC = originalTextFor(_VERSION_SPEC)("specifier")
57VERSION_SPEC.setParseAction(lambda s, l, t: t[1])
58
59MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
60MARKER_EXPR.setParseAction(
61    lambda s, l, t: Marker(s[t._original_start:t._original_end])
62)
63MARKER_SEPERATOR = SEMICOLON
64MARKER = MARKER_SEPERATOR + MARKER_EXPR
65
66VERSION_AND_MARKER = VERSION_SPEC + Optional(MARKER)
67URL_AND_MARKER = URL + Optional(MARKER)
68
69NAMED_REQUIREMENT = \
70    NAME + Optional(EXTRAS) + (URL_AND_MARKER | VERSION_AND_MARKER)
71
72REQUIREMENT = stringStart + NAMED_REQUIREMENT + stringEnd
73
74
75class Requirement(object):
76    """Parse a requirement.
77
78    Parse a given requirement string into its parts, such as name, specifier,
79    URL, and extras. Raises InvalidRequirement on a badly-formed requirement
80    string.
81    """
82
83    # TODO: Can we test whether something is contained within a requirement?
84    #       If so how do we do that? Do we need to test against the _name_ of
85    #       the thing as well as the version? What about the markers?
86    # TODO: Can we normalize the name and extra name?
87
88    def __init__(self, requirement_string):
89        try:
90            req = REQUIREMENT.parseString(requirement_string)
91        except ParseException as e:
92            raise InvalidRequirement(
93                "Invalid requirement, parse error at \"{0!r}\"".format(
94                    requirement_string[e.loc:e.loc + 8]))
95
96        self.name = req.name
97        if req.url:
98            parsed_url = urlparse.urlparse(req.url)
99            if not (parsed_url.scheme and parsed_url.netloc) or (
100                    not parsed_url.scheme and not parsed_url.netloc):
101                raise InvalidRequirement("Invalid URL given")
102            self.url = req.url
103        else:
104            self.url = None
105        self.extras = set(req.extras.asList() if req.extras else [])
106        self.specifier = SpecifierSet(req.specifier)
107        self.marker = req.marker if req.marker else None
108
109    def __str__(self):
110        parts = [self.name]
111
112        if self.extras:
113            parts.append("[{0}]".format(",".join(sorted(self.extras))))
114
115        if self.specifier:
116            parts.append(str(self.specifier))
117
118        if self.url:
119            parts.append("@ {0}".format(self.url))
120
121        if self.marker:
122            parts.append("; {0}".format(self.marker))
123
124        return "".join(parts)
125
126    def __repr__(self):
127        return "<Requirement({0!r})>".format(str(self))
128