# ignore.py - ignored file handling for mercurial

#

# Copyright 2007 Matt Mackall <mpm@selenic.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2, incorporated herein by reference.

from i18n import _

import util, match

import re

_commentre = None

def _parselines(fp):

    for line in fp:

        if "#" in line:

            global _commentre

            if not _commentre:

                _commentre = re.compile(r'((^|[^\\])(\\\\)*)#.*')

            # remove comments prefixed by an even number of escapes

            line = _commentre.sub(r'\1', line)

            # fixup properly escaped comments that survived the above

            line = line.replace("\\#", "#")

        line = line.rstrip()

        if line:

            yield line

def ignore(root, files, warn):

    '''return the contents of .hgignore files as a list of patterns.

    the files parsed for patterns include:

    .hgignore in the repository root

    any additional files specified in the [ui] section of ~/.hgrc

    trailing white space is dropped.

    the escape character is backslash.

    comments start with #.

    empty lines are skipped.

    lines can be of the following formats:

    syntax: regexp # defaults following lines to non-rooted regexps

    syntax: glob   # defaults following lines to non-rooted globs

    re:pattern     # non-rooted regular expression

    glob:pattern   # non-rooted glob

    pattern        # pattern of the current default type'''

    syntaxes = {'re': 'relre:', 'regexp': 'relre:', 'glob': 'relglob:'}

    pats = {}

    for f in files:

        try:

            pats[f] = []

            fp = open(f)

            syntax = 'relre:'

            for line in _parselines(fp):

                if line.startswith('syntax:'):

                    s = line[7:].strip()

                    try:

                        syntax = syntaxes[s]

                    except KeyError:

                        warn(_("%s: ignoring invalid syntax '%s'\n") % (f, s))

                    continue

                pat = syntax + line

                for s, rels in syntaxes.iteritems():

                    if line.startswith(rels):

                        pat = line

                        break

                    elif line.startswith(s+':'):

                        pat = rels + line[len(s)+1:]

                        break

                pats[f].append(pat)

        except IOError, inst:

            if f != files[0]:

                warn(_("skipping unreadable ignore file '%s': %s\n") %

                     (f, inst.strerror))

    allpats = []

    [allpats.extend(patlist) for patlist in pats.values()]

    if not allpats:

        return util.never

    try:

        ignorefunc = match.match(root, '', [], allpats)

    except util.Abort:

        # Re-raise an exception where the src is the right file

        for f, patlist in pats.iteritems():

            try:

                match.match(root, '', [], patlist)

            except util.Abort, inst:

                raise util.Abort('%s: %s' % (f, inst[0]))

    return ignorefunc