"""distutils.fancy_getopt

Wrapper around the standard getopt module that provides the following
additional features:
 * short and long options are tied together
 * options have help strings, so fancy_getopt could potentially
 create a complete usage summary
 * options set attributes of a passed-in object
"""

import sys, string, re
import getopt
from distutils.errors import *

# Much like command_re in distutils.core, this is close to but not quite
# the same as a Python NAME -- except, in the spirit of most GNU
# utilities, we use '-' in place of '_'. (The spirit of LISP lives on!)
# The similarities to NAME are again not a coincidence...
longopt_pat = r'[a-zA-Z](?:[a-zA-Z0-9-]*)'
longopt_re = re.compile(r'^%s$' % longopt_pat)

# For recognizing "negative alias" options, eg. "quiet=!verbose"
neg_alias_re = re.compile("^(%s)=!(%s)$" % (longopt_pat, longopt_pat))

# This is used to translate long options to legitimate Python identifiers
# (for use as attributes of some object).
longopt_xlate = str.maketrans('-', '_')

class FancyGetopt:
 """Wrapper around the standard 'getopt()' module that provides some
 handy extra functionality:
 * short and long options are tied together
 * options have help strings, and help text can be assembled
 from them
 * options set attributes of a passed-in object
 * boolean options can have "negative aliases" -- eg. if
 --quiet is the "negative alias" of --verbose, then "--quiet"
 on the command line sets 'verbose' to false
 """

 def __init__(self, option_table=None):
 # The option table is (currently) a list of tuples. The
 # tuples may have 3 or four values:
 # (long_option, short_option, help_string [, repeatable])
 # if an option takes an argument, its long_option should have '='
 # appended; short_option should just be a single character, no ':'
 # in any case. If a long_option doesn't have a corresponding
 # short_option, short_option should be None. All option tuples
 # must have long options.
 self.option_table = option_table

 # 'option_index' maps long option names to entries in the option
 # table (ie. those 3-tuples).
 self.option_index = {}
 if self.option_table:
 self._build_index()

 # 'alias' records (duh) alias options; {'foo': 'bar'} means
 # --foo is an alias for --bar
 self.alias = {}

 # 'negative_alias' keeps track of options that are the boolean
 # opposite of some other option
 self.negative_alias = {}

 # These keep track of the information in the option table. We
 # don't actually populate these structures until we're ready to
 # parse the command-line, since the 'option_table' passed in here
 # isn't necessarily the final word.
 self.short_opts = []
 self.long_opts = []
 self.short2long = {}
 self.attr_name = {}
 self.takes_arg = {}

 # And 'option_order' is filled up in 'getopt()'; it records the
 # original order of options (and their values) on the command-line,
 # but expands short options, converts aliases, etc.
 self.option_order = []

 def _build_index(self):
 self.option_index.clear()
 for option in self.option_table:
 self.option_index[option[0]] = option

 def set_option_table(self, option_table):
 self.option_table = option_table
 self._build_index()

 def add_option(self, long_option, short_option=None, help_string=None):
 if long_option in self.option_index:
 raise DistutilsGetoptError(
 "option conflict: already an option '%s'" % long_option)
 else:
 option = (long_option, short_option, help_string)
 self.option_table.append(option)
 self.option_index[long_option] = option

 def has_option(self, long_option):
 """Return true if the option table for this parser has an
 option with long name 'long_option'."""
 return long_option in self.option_index

 def get_attr_name(self, long_option):
 """Translate long option name 'long_option' to the form it
 has as an attribute of some object: ie., translate hyphens
 to underscores."""
 return long_option.translate(longopt_xlate)

 def _check_alias_dict(self, aliases, what):
 assert isinstance(aliases, dict)
 for (alias, opt) in aliases.items():
 if alias not in self.option_index:
 raise DistutilsGetoptError(("invalid %s '%s': "
 "option '%s' not defined") % (what, alias, alias))
 if opt not in self.option_index:
 raise DistutilsGetoptError(("invalid %s '%s': "
 "aliased option '%s' not defined") % (what, alias, opt))

 def set_aliases(self, alias):
 """Set the aliases for this option parser."""
 self._check_alias_dict(alias, "alias")
 self.alias = alias

 def set_negative_aliases(self, negative_alias):
 """Set the negative aliases for this option parser.
 'negative_alias' should be a dictionary mapping option names to
 option names, both the key and value must already be defined
 in the option table."""
 self._check_alias_dict(negative_alias, "negative alias")
 self.negative_alias = negative_alias

 def _grok_option_table(self):
 """Populate the various data structures that keep tabs on the
 option table. Called by 'getopt()' before it can do anything
 worthwhile.
 """
 self.long_opts = []
 self.short_opts = []
 self.short2long.clear()
 self.repeat = {}

 for option in self.option_table:
 if len(option) == 3:
 long, short, help = option
 repeat = 0
 elif len(option) == 4:
 long, short, help, repeat = option
 else:
 # the option table is part of the code, so simply
 # assert that it is correct
 raise ValueError("invalid option tuple: %r" % (option,))

 # Type- and value-check the option names
 if not isinstance(long, str) or len(long) < 2:
 raise DistutilsGetoptError(("invalid long option '%s': "
 "must be a string of length >= 2") % long)

 if (not ((short is None) or
 (isinstance(short, str) and len(short) == 1))):
 raise DistutilsGetoptError("invalid short option '%s': "
 "must a single character or None" % short)

 self.repeat[long] = repeat
 self.long_opts.append(long)

 if long[-1] == '=': # option takes an argument?
 if short: short = short + ':'
 long = long[0:-1]
 self.takes_arg[long] = 1
 else:
 # Is option is a "negative alias" for some other option (eg.
 # "quiet" == "!verbose")?
 alias_to = self.negative_alias.get(long)
 if alias_to is not None:
 if self.takes_arg[alias_to]:
 raise DistutilsGetoptError(
 "invalid negative alias '%s': "
 "aliased option '%s' takes a value"
 % (long, alias_to))

 self.long_opts[-1] = long # XXX redundant?!
 self.takes_arg[long] = 0

 # If this is an alias option, make sure its "takes arg" flag is
 # the same as the option it's aliased to.
 alias_to = self.alias.get(long)
 if alias_to is not None:
 if self.takes_arg[long] != self.takes_arg[alias_to]:
 raise DistutilsGetoptError(
 "invalid alias '%s': inconsistent with "
 "aliased option '%s' (one of them takes a value, "
 "the other doesn't"
 % (long, alias_to))

 # Now enforce some bondage on the long option name, so we can
 # later translate it to an attribute name on some object. Have
 # to do this a bit late to make sure we've removed any trailing
 # '='.
 if not longopt_re.match(long):
 raise DistutilsGetoptError(
 "invalid long option name '%s' "
 "(must be letters, numbers, hyphens only" % long)

 self.attr_name[long] = self.get_attr_name(long)
 if short:
 self.short_opts.append(short)
 self.short2long[short[0]] = long

 def getopt(self, args=None, object=None):
 """Parse command-line options in args. Store as attributes on object.

 If 'args' is None or not supplied, uses 'sys.argv[1:]'. If
 'object' is None or not supplied, creates a new OptionDummy
 object, stores option values there, and returns a tuple (args,
 object). If 'object' is supplied, it is modified in place and
 'getopt()' just returns 'args'; in both cases, the returned
 'args' is a modified copy of the passed-in 'args' list, which
 is left untouched.
 """
 if args is None:
 args = sys.argv[1:]
 if object is None:
 object = OptionDummy()
 created_object = True
 else:
 created_object = False

 self._grok_option_table()

 short_opts = ' '.join(self.short_opts)
 try:
 opts, args = getopt.getopt(args, short_opts, self.long_opts)
 except getopt.error as msg:
 raise DistutilsArgError(msg)

 for opt, val in opts:
 if len(opt) == 2 and opt[0] == '-': # it's a short option
 opt = self.short2long[opt[1]]
 else:
 assert len(opt) > 2 and opt[:2] == '--'
 opt = opt[2:]

 alias = self.alias.get(opt)
 if alias:
 opt = alias

 if not self.takes_arg[opt]: # boolean option?
 assert val == '', "boolean option can't have value"
 alias = self.negative_alias.get(opt)
 if alias:
 opt = alias
 val = 0
 else:
 val = 1

 attr = self.attr_name[opt]
 # The only repeating option at the moment is 'verbose'.
 # It has a negative option -q quiet, which should set verbose = 0.
 if val and self.repeat.get(attr) is not None:
 val = getattr(object, attr, 0) + 1
 setattr(object, attr, val)
 self.option_order.append((opt, val))

 # for opts
 if created_object:
 return args, object
 else:
 return args

 def get_option_order(self):
 """Returns the list of (option, value) tuples processed by the
 previous run of 'getopt()'. Raises RuntimeError if
 'getopt()' hasn't been called yet.
 """
 if self.option_order is None:
 raise RuntimeError("'getopt()' hasn't been called yet")
 else:
 return self.option_order

 def generate_help(self, header=None):
 """Generate help text (a list of strings, one per suggested line of
 output) from the option table for this FancyGetopt object.
 """
 # Blithely assume the option table is good: probably wouldn't call
 # 'generate_help()' unless you've already called 'getopt()'.

 # First pass: determine maximum length of long option names
 max_opt = 0
 for option in self.option_table:
 long = option[0]
 short = option[1]
 l = len(long)
 if long[-1] == '=':
 l = l - 1
 if short is not None:
 l = l + 5 # " (-x)" where short == 'x'
 if l > max_opt:
 max_opt = l

 opt_width = max_opt + 2 + 2 + 2 # room for indent + dashes + gutter

 # Typical help block looks like this:
 # --foo controls foonabulation
 # Help block for longest option looks like this:
 # --flimflam set the flim-flam level
 # and with wrapped text:
 # --flimflam set the flim-flam level (must be between
 # 0 and 100, except on Tuesdays)
 # Options with short names will have the short name shown (but
 # it doesn't contribute to max_opt):
 # --foo (-f) controls foonabulation
 # If adding the short option would make the left column too wide,
 # we push the explanation off to the next line
 # --flimflam (-l)
 # set the flim-flam level
 # Important parameters:
 # - 2 spaces before option block start lines
 # - 2 dashes for each long option name
 # - min. 2 spaces between option and explanation (gutter)
 # - 5 characters (incl. space) for short option name

 # Now generate lines of help text. (If 80 columns were good enough
 # for Jesus, then 78 columns are good enough for me!)
 line_width = 78
 text_width = line_width - opt_width
 big_indent = ' ' * opt_width
 if header:
 lines = [header]
 else:
 lines = ['Option summary:']

 for option in self.option_table:
 long, short, help = option[:3]
 text = wrap_text(help, text_width)
 if long[-1] == '=':
 long = long[0:-1]

 # Case 1: no short option at all (makes life easy)
 if short is None:
 if text:
 lines.append(" --%-*s %s" % (max_opt, long, text[0]))
 else:
 lines.append(" --%-*s " % (max_opt, long))

 # Case 2: we have a short option, so we have to include it
 # just after the long option
 else:
 opt_names = "%s (-%s)" % (long, short)
 if text:
 lines.append(" --%-*s %s" %
 (max_opt, opt_names, text[0]))
 else:
 lines.append(" --%-*s" % opt_names)

 for l in text[1:]:
 lines.append(big_indent + l)
 return lines

 def print_help(self, header=None, file=None):
 if file is None:
 file = sys.stdout
 for line in self.generate_help(header):
 file.write(line + "\n")


def fancy_getopt(options, negative_opt, object, args):
 parser = FancyGetopt(options)
 parser.set_negative_aliases(negative_opt)
 return parser.getopt(args, object)


WS_TRANS = {ord(_wschar) : ' ' for _wschar in string.whitespace}

def wrap_text(text, width):
 """wrap_text(text : string, width : int) -> [string]

 Split 'text' into multiple lines of no more than 'width' characters
 each, and return the list of strings that results.
 """
 if text is None:
 return []
 if len(text) <= width:
 return [text]

 text = text.expandtabs()
 text = text.translate(WS_TRANS)
 chunks = re.split(r'( +|-+)', text)
 chunks = [ch for ch in chunks if ch] # ' - ' results in empty strings
 lines = []

 while chunks:
 cur_line = [] # list of chunks (to-be-joined)
 cur_len = 0 # length of current line

 while chunks:
 l = len(chunks[0])
 if cur_len + l <= width: # can squeeze (at least) this chunk in
 cur_line.append(chunks[0])
 del chunks[0]
 cur_len = cur_len + l
 else: # this line is full
 # drop last chunk if all space
 if cur_line and cur_line[-1][0] == ' ':
 del cur_line[-1]
 break

 if chunks: # any chunks left to process?
 # if the current line is still empty, then we had a single
 # chunk that's too big too fit on a line -- so we break
 # down and break it up at the line width
 if cur_len == 0:
 cur_line.append(chunks[0][0:width])
 chunks[0] = chunks[0][width:]

 # all-whitespace chunks at the end of a line can be discarded
 # (and we know from the re.split above that if a chunk has
 # *any* whitespace, it is *all* whitespace)
 if chunks[0][0] == ' ':
 del chunks[0]

 # and store this line in the list-of-all-lines -- as a single
 # string, of course!
 lines.append(''.join(cur_line))

 return lines


def translate_longopt(opt):
 """Convert a long option name to a valid Python identifier by
 changing "-" to "_".
 """
 return opt.translate(longopt_xlate)


class OptionDummy:
 """Dummy class just used as a place to hold command-line option
 values as instance attributes."""

 def __init__(self, options=[]):
 """Create a new OptionDummy instance. The attributes listed in
 'options' will be initialized to None."""
 for opt in options:
 setattr(self, opt, None)


if __name__ == "__main__":
 text = """\
Tra-la-la, supercalifragilisticexpialidocious.
How *do* you spell that odd word, anyways?
(Someone ask Mary -- she'll know [or she'll
say, "How should I know?"].)"""

 for w in (10, 20, 30, 40):
 print("width: %d" % w)
 print("\n".join(wrap_text(text, w)))
 print()