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 urllib import parse as urlparse
13
14from ._typing import TYPE_CHECKING
15from .markers import MARKER_EXPR, Marker
16from .specifiers import LegacySpecifier, Specifier, SpecifierSet
17
18if TYPE_CHECKING:  # pragma: no cover
19    from typing import List
20
21
22class InvalidRequirement(ValueError):
23    """
24    An invalid requirement was found, users should refer to PEP 508.
25    """
26
27
28ALPHANUM = Word(string.ascii_letters + string.digits)
29
30LBRACKET = L("[").suppress()
31RBRACKET = L("]").suppress()
32LPAREN = L("(").suppress()
33RPAREN = L(")").suppress()
34COMMA = L(",").suppress()
35SEMICOLON = L(";").suppress()
36AT = L("@").suppress()
37
38PUNCTUATION = Word("-_.")
39IDENTIFIER_END = ALPHANUM | (ZeroOrMore(PUNCTUATION) + ALPHANUM)
40IDENTIFIER = Combine(ALPHANUM + ZeroOrMore(IDENTIFIER_END))
41
42NAME = IDENTIFIER("name")
43EXTRA = IDENTIFIER
44
45URI = Regex(r"[^ ]+")("url")
46URL = AT + URI
47
48EXTRAS_LIST = EXTRA + ZeroOrMore(COMMA + EXTRA)
49EXTRAS = (LBRACKET + Optional(EXTRAS_LIST) + RBRACKET)("extras")
50
51VERSION_PEP440 = Regex(Specifier._regex_str, re.VERBOSE | re.IGNORECASE)
52VERSION_LEGACY = Regex(LegacySpecifier._regex_str, re.VERBOSE | re.IGNORECASE)
53
54VERSION_ONE = VERSION_PEP440 ^ VERSION_LEGACY
55VERSION_MANY = Combine(
56    VERSION_ONE + ZeroOrMore(COMMA + VERSION_ONE), joinString=",", adjacent=False
57)("_raw_spec")
58_VERSION_SPEC = Optional(((LPAREN + VERSION_MANY + RPAREN) | VERSION_MANY))
59_VERSION_SPEC.setParseAction(lambda s, l, t: t._raw_spec or "")
60
61VERSION_SPEC = originalTextFor(_VERSION_SPEC)("specifier")
62VERSION_SPEC.setParseAction(lambda s, l, t: t[1])
63
64MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
65MARKER_EXPR.setParseAction(
66    lambda s, l, t: Marker(s[t._original_start : t._original_end])
67)
68MARKER_SEPARATOR = SEMICOLON
69MARKER = MARKER_SEPARATOR + MARKER_EXPR
70
71VERSION_AND_MARKER = VERSION_SPEC + Optional(MARKER)
72URL_AND_MARKER = URL + Optional(MARKER)
73
74NAMED_REQUIREMENT = NAME + Optional(EXTRAS) + (URL_AND_MARKER | VERSION_AND_MARKER)
75
76REQUIREMENT = stringStart + NAMED_REQUIREMENT + stringEnd
77# pkg_resources.extern.pyparsing isn't thread safe during initialization, so we do it eagerly, see
78# issue #104
79REQUIREMENT.parseString("x[]")
80
81
82class Requirement(object):
83    """Parse a requirement.
84
85    Parse a given requirement string into its parts, such as name, specifier,
86    URL, and extras. Raises InvalidRequirement on a badly-formed requirement
87    string.
88    """
89
90    # TODO: Can we test whether something is contained within a requirement?
91    #       If so how do we do that? Do we need to test against the _name_ of
92    #       the thing as well as the version? What about the markers?
93    # TODO: Can we normalize the name and extra name?
94
95    def __init__(self, requirement_string):
96        # type: (str) -> None
97        try:
98            req = REQUIREMENT.parseString(requirement_string)
99        except ParseException as e:
100            raise InvalidRequirement(
101                'Parse error at "{0!r}": {1}'.format(
102                    requirement_string[e.loc : e.loc + 8], e.msg
103                )
104            )
105
106        self.name = req.name
107        if req.url:
108            parsed_url = urlparse.urlparse(req.url)
109            if parsed_url.scheme == "file":
110                if urlparse.urlunparse(parsed_url) != req.url:
111                    raise InvalidRequirement("Invalid URL given")
112            elif not (parsed_url.scheme and parsed_url.netloc) or (
113                not parsed_url.scheme and not parsed_url.netloc
114            ):
115                raise InvalidRequirement("Invalid URL: {0}".format(req.url))
116            self.url = req.url
117        else:
118            self.url = None
119        self.extras = set(req.extras.asList() if req.extras else [])
120        self.specifier = SpecifierSet(req.specifier)
121        self.marker = req.marker if req.marker else None
122
123    def __str__(self):
124        # type: () -> str
125        parts = [self.name]  # type: List[str]
126
127        if self.extras:
128            parts.append("[{0}]".format(",".join(sorted(self.extras))))
129
130        if self.specifier:
131            parts.append(str(self.specifier))
132
133        if self.url:
134            parts.append("@ {0}".format(self.url))
135            if self.marker:
136                parts.append(" ")
137
138        if self.marker:
139            parts.append("; {0}".format(self.marker))
140
141        return "".join(parts)
142
143    def __repr__(self):
144        # type: () -> str
145        return "<Requirement({0!r})>".format(str(self))
146