# config.py - configuration parsing for Mercurial

#

#  Copyright 2009 Matt Mackall <mpm@selenic.com> and others

#

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

# GNU General Public License version 2 or any later version.

from i18n import _

import error, util

import os, errno

class config(object):

    def __init__(self, data=None):

        self._data = {}

        self._source = {}

        self._unset = []

        if data:

            for k in data._data:

                self._data[k] = data[k].copy()

            self._source = data._source.copy()

    def copy(self):

        return config(self)

    def __contains__(self, section):

        return section in self._data

    def __getitem__(self, section):

        return self._data.get(section, {})

    def __iter__(self):

        for d in self.sections():

            yield d

    def update(self, src):

        for s, n in src._unset:

            if s in self and n in self._data[s]:

                del self._data[s][n]

                del self._source[(s, n)]

        for s in src:

            if s not in self:

                self._data[s] = util.sortdict()

            self._data[s].update(src._data[s])

        self._source.update(src._source)

    def get(self, section, item, default=None):

        return self._data.get(section, {}).get(item, default)

    def backup(self, section, item):

        """return a tuple allowing restore to reinstall a previous value

        The main reason we need it is because it handles the "no data" case.

        """

        try:

            value = self._data[section][item]

            source = self.source(section, item)

            return (section, item, value, source)

        except KeyError:

            return (section, item)

    def source(self, section, item):

        return self._source.get((section, item), "")

    def sections(self):

        return sorted(self._data.keys())

    def items(self, section):

        return self._data.get(section, {}).items()

    def set(self, section, item, value, source=""):

        if section not in self:

            self._data[section] = util.sortdict()

        self._data[section][item] = value

        if source:

            self._source[(section, item)] = source

    def restore(self, data):

        """restore data returned by self.backup"""

        if len(data) == 4:

            # restore old data

            section, item, value, source = data

            self._data[section][item] = value

            self._source[(section, item)] = source

        else:

            # no data before, remove everything

            section, item = data

            if section in self._data:

                self._data[section].pop(item, None)

            self._source.pop((section, item), None)

    def parse(self, src, data, sections=None, remap=None, include=None):

        sectionre = util.re.compile(r'\[([^\[]+)\]')

        itemre = util.re.compile(r'([^=\s][^=]*?)\s*=\s*(.*\S|)')

        contre = util.re.compile(r'\s+(\S|\S.*\S)\s*$')

        emptyre = util.re.compile(r'(;|#|\s*$)')

        commentre = util.re.compile(r'(;|#)')

        unsetre = util.re.compile(r'%unset\s+(\S+)')

        includere = util.re.compile(r'%include\s+(\S|\S.*\S)\s*$')

        section = ""

        item = None

        line = 0

        cont = False

        for l in data.splitlines(True):

            line += 1

            if line == 1 and l.startswith('\xef\xbb\xbf'):

                # Someone set us up the BOM

                l = l[3:]

            if cont:

                if commentre.match(l):

                    continue

                m = contre.match(l)

                if m:

                    if sections and section not in sections:

                        continue

                    v = self.get(section, item) + "\n" + m.group(1)

                    self.set(section, item, v, "%s:%d" % (src, line))

                    continue

                item = None

                cont = False

            m = includere.match(l)

            if m:

                inc = util.expandpath(m.group(1))

                base = os.path.dirname(src)

                inc = os.path.normpath(os.path.join(base, inc))

                if include:

                    try:

                        include(inc, remap=remap, sections=sections)

                    except IOError, inst:

                        if inst.errno != errno.ENOENT:

                            raise error.ParseError(_("cannot include %s (%s)")

                                                   % (inc, inst.strerror),

                                                   "%s:%s" % (src, line))

                continue

            if emptyre.match(l):

                continue

            m = sectionre.match(l)

            if m:

                section = m.group(1)

                if remap:

                    section = remap.get(section, section)

                if section not in self:

                    self._data[section] = util.sortdict()

                continue

            m = itemre.match(l)

            if m:

                item = m.group(1)

                cont = True

                if sections and section not in sections:

                    continue

                self.set(section, item, m.group(2), "%s:%d" % (src, line))

                continue

            m = unsetre.match(l)

            if m:

                name = m.group(1)

                if sections and section not in sections:

                    continue

                if self.get(section, name) is not None:

                    del self._data[section][name]

                self._unset.append((section, name))

                continue

            raise error.ParseError(l.rstrip(), ("%s:%s" % (src, line)))

    def read(self, path, fp=None, sections=None, remap=None):

        if not fp:

            fp = util.posixfile(path)

        self.parse(path, fp.read(), sections, remap, self.read)