"""
Regex for URIs

These regex are directly derived from the collected ABNF in RFC3986
(except for DIGIT, ALPHA and HEXDIG, defined by RFC2234).

They should be processed with re.VERBOSE.

Thanks Mark Nottingham for this code - https://gist.github.com/138549
"""
from __future__ import unicode_literals

import re

# basics

DIGIT = r"[\x30-\x39]"

ALPHA = r"[\x41-\x5A\x61-\x7A]"

HEXDIG = r"[\x30-\x39A-Fa-f]"

#   pct-encoded   = "%" HEXDIG HEXDIG
pct_encoded = r" %% %(HEXDIG)s %(HEXDIG)s" % locals()

#   unreserved    = ALPHA / DIGIT / "-" / "." / "_" / "~"
unreserved = r"(?: %(ALPHA)s | %(DIGIT)s | \- | \. | _ | ~ )" % locals()

# gen-delims    = ":" / "/" / "?" / "#" / "[" / "]" / "@"
gen_delims = r"(?: : | / | \? | \# | \[ | \] | @ )"

#   sub-delims    = "!" / "$" / "&" / "'" / "(" / ")"
#                 / "*" / "+" / "," / ";" / "="
sub_delims = r"""(?: ! | \$ | & | ' | \( | \) |
                     \* | \+ | , | ; | = )"""

#   pchar         = unreserved / pct-encoded / sub-delims / ":" / "@"
pchar = r"(?: %(unreserved)s | %(pct_encoded)s | %(sub_delims)s | : | @ )" % locals(
)

#   reserved      = gen-delims / sub-delims
reserved = r"(?: %(gen_delims)s | %(sub_delims)s )" % locals()


# scheme

#   scheme        = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
scheme = r"%(ALPHA)s (?: %(ALPHA)s | %(DIGIT)s | \+ | \- | \. )*" % locals()


# authority

#   dec-octet     = DIGIT                 ; 0-9
#                 / %x31-39 DIGIT         ; 10-99
#                 / "1" 2DIGIT            ; 100-199
#                 / "2" %x30-34 DIGIT     ; 200-249
#                 / "25" %x30-35          ; 250-255
dec_octet = r"""(?: %(DIGIT)s |
                    [\x31-\x39] %(DIGIT)s |
                    1 %(DIGIT)s{2} |
                    2 [\x30-\x34] %(DIGIT)s |
                    25 [\x30-\x35]
                )
""" % locals()

#  IPv4address   = dec-octet "." dec-octet "." dec-octet "." dec-octet
IPv4address = r"%(dec_octet)s \. %(dec_octet)s \. %(dec_octet)s \. %(dec_octet)s" % locals(
)

#  h16           = 1*4HEXDIG
h16 = r"(?: %(HEXDIG)s ){1,4}" % locals()

#  ls32          = ( h16 ":" h16 ) / IPv4address
ls32 = r"(?: (?: %(h16)s : %(h16)s ) | %(IPv4address)s )" % locals()

#   IPv6address   =                            6( h16 ":" ) ls32
#                 /                       "::" 5( h16 ":" ) ls32
#                 / [               h16 ] "::" 4( h16 ":" ) ls32
#                 / [ *1( h16 ":" ) h16 ] "::" 3( h16 ":" ) ls32
#                 / [ *2( h16 ":" ) h16 ] "::" 2( h16 ":" ) ls32
#                 / [ *3( h16 ":" ) h16 ] "::"    h16 ":"   ls32
#                 / [ *4( h16 ":" ) h16 ] "::"              ls32
#                 / [ *5( h16 ":" ) h16 ] "::"              h16
#                 / [ *6( h16 ":" ) h16 ] "::"
IPv6address = r"""(?:                                  (?: %(h16)s : ){6} %(ls32)s |
                                                    :: (?: %(h16)s : ){5} %(ls32)s |
                                            %(h16)s :: (?: %(h16)s : ){4} %(ls32)s |
                         (?: %(h16)s : )    %(h16)s :: (?: %(h16)s : ){3} %(ls32)s |
                         (?: %(h16)s : ){2} %(h16)s :: (?: %(h16)s : ){2} %(ls32)s |
                         (?: %(h16)s : ){3} %(h16)s ::     %(h16)s :      %(ls32)s |
                         (?: %(h16)s : ){4} %(h16)s ::                    %(ls32)s |
                         (?: %(h16)s : ){5} %(h16)s ::                    %(h16)s  |
                         (?: %(h16)s : ){6} %(h16)s ::
                  )
""" % locals()

#   IPvFuture     = "v" 1*HEXDIG "." 1*( unreserved / sub-delims / ":" )
IPvFuture = r"v %(HEXDIG)s+ \. (?: %(unreserved)s | %(sub_delims)s | : )+" % locals()

#   IP-literal    = "[" ( IPv6address / IPvFuture  ) "]"
IP_literal = r"\[ (?: %(IPv6address)s | %(IPvFuture)s ) \]" % locals()

#   reg-name      = *( unreserved / pct-encoded / sub-delims )
reg_name = r"(?: %(unreserved)s | %(pct_encoded)s | %(sub_delims)s )*" % locals()

#   userinfo      = *( unreserved / pct-encoded / sub-delims / ":" )
userinfo = r"(?: %(unreserved)s | %(pct_encoded)s | %(sub_delims)s | : )" % locals(
)

#   host          = IP-literal / IPv4address / reg-name
host = r"(?: %(IP_literal)s | %(IPv4address)s | %(reg_name)s )" % locals()

#   port          = *DIGIT
port = r"(?: %(DIGIT)s )*" % locals()

#   authority     = [ userinfo "@" ] host [ ":" port ]
authority = r"(?: %(userinfo)s @)? %(host)s (?: : %(port)s)?" % locals()

# Path

#   segment       = *pchar
segment = r"%(pchar)s*" % locals()

#   segment-nz    = 1*pchar
segment_nz = r"%(pchar)s+" % locals()

#   segment-nz-nc = 1*( unreserved / pct-encoded / sub-delims / "@" )
#                 ; non-zero-length segment without any colon ":"
segment_nz_nc = r"(?: %(unreserved)s | %(pct_encoded)s | %(sub_delims)s | @ )+" % locals()

#   path-abempty  = *( "/" segment )
path_abempty = r"(?: / %(segment)s )*" % locals()

#   path-absolute = "/" [ segment-nz *( "/" segment ) ]
path_absolute = r"/ (?: %(segment_nz)s (?: / %(segment)s )* )?" % locals()

#   path-noscheme = segment-nz-nc *( "/" segment )
path_noscheme = r"%(segment_nz_nc)s (?: / %(segment)s )*" % locals()

#   path-rootless = segment-nz *( "/" segment )
path_rootless = r"%(segment_nz)s (?: / %(segment)s )*" % locals()

#   path-empty    = 0<pchar>
path_empty = r""  # FIXME

#   path          = path-abempty    ; begins with "/" or is empty
#                 / path-absolute   ; begins with "/" but not "//"
#                 / path-noscheme   ; begins with a non-colon segment
#                 / path-rootless   ; begins with a segment
#                 / path-empty      ; zero characters
path = r"""(?: %(path_abempty)s |
               %(path_absolute)s |
               %(path_noscheme)s |
               %(path_rootless)s |
               %(path_empty)s
            )
""" % locals()

### Query and Fragment

#   query         = *( pchar / "/" / "?" )
query = r"(?: %(pchar)s | / | \? )*" % locals()

#   fragment      = *( pchar / "/" / "?" )
fragment = r"(?: %(pchar)s | / | \? )*" % locals()

# URIs

#   hier-part     = "//" authority path-abempty
#                 / path-absolute
#                 / path-rootless
#                 / path-empty
hier_part = r"""(?: (?: // %(authority)s %(path_abempty)s ) |
                    %(path_absolute)s |
                    %(path_rootless)s |
                    %(path_empty)s
                )
""" % locals()

#   relative-part = "//" authority path-abempty
#                 / path-absolute
#                 / path-noscheme
#                 / path-empty
relative_part = r"""(?: (?: // %(authority)s %(path_abempty)s ) |
                        %(path_absolute)s |
                        %(path_noscheme)s |
                        %(path_empty)s
                    )
""" % locals()

# relative-ref  = relative-part [ "?" query ] [ "#" fragment ]
relative_ref = r"%(relative_part)s (?: \? %(query)s)? (?: \# %(fragment)s)?" % locals(
)

# URI           = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
URI = r"^(?: %(scheme)s : %(hier_part)s (?: \? %(query)s )? (?: \# %(fragment)s )? )$" % locals(
)

#   URI-reference = URI / relative-ref
URI_reference = r"^(?: %(URI)s | %(relative_ref)s )$" % locals()

#   absolute-URI  = scheme ":" hier-part [ "?" query ]
absolute_URI = r"^(?: %(scheme)s : %(hier_part)s (?: \? %(query)s )? )$" % locals(
)


def is_uri(uri):
    return re.match(URI, uri, re.VERBOSE)


def is_uri_reference(uri):
    return re.match(URI_reference, uri, re.VERBOSE)


def is_absolute_uri(uri):
    return re.match(absolute_URI, uri, re.VERBOSE)