#  sourceslist.py - Provide an abstraction of the sources.list
#
#  Copyright (c) 2004-2009 Canonical Ltd.
#  Copyright (c) 2004 Michiel Sikkes
#  Copyright (c) 2006-2007 Sebastian Heinlein
#
#  Authors: Michiel Sikkes <michiel@eyesopened.nl>
#           Michael Vogt <mvo@debian.org>
#           Sebastian Heinlein <glatzor@ubuntu.com>
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License as
#  published by the Free Software Foundation; either version 2 of the
#  License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
#  USA

import glob
import logging
import os.path
import re
import shutil
import time

import apt_pkg
from distinfo import DistInfo
from apt.deprecation import function_deprecated_by
#from apt_pkg import gettext as _


# some global helpers


def is_mirror(master_uri, compare_uri):
    """ check if the given add_url is idential or a mirror of orig_uri
        e.g. master_uri = archive.ubuntu.com
            compare_uri = de.archive.ubuntu.com
            -> True
    """
    # remove traling spaces and "/"
    compare_uri = compare_uri.rstrip("/ ")
    master_uri = master_uri.rstrip("/ ")
    # uri is identical
    if compare_uri == master_uri:
        #print "Identical"
        return True
    # add uri is a master site and orig_uri has the from "XX.mastersite"
    # (e.g. de.archive.ubuntu.com)
    try:
        compare_srv = compare_uri.split("//")[1]
        master_srv = master_uri.split("//")[1]
        #print "%s == %s " % (add_srv, orig_srv)
    except IndexError: # ok, somethings wrong here
        #print "IndexError"
        return False
    # remove the leading "<country>." (if any) and see if that helps
    if "." in compare_srv and \
           compare_srv[compare_srv.index(".")+1:] == master_srv:
        #print "Mirror"
        return True
    return False


def uniq(s):
    """ simple and efficient way to return uniq list """
    return list(set(s))


class SourceEntry(object):
    """ single sources.list entry """

    def __init__(self, line, file=None):
        self.invalid = False            # is the source entry valid
        self.disabled = False           # is it disabled ('#' in front)
        self.type = ""                  # what type (deb, deb-src)
        self.architectures = []         # architectures
        self.uri = ""                   # base-uri
        self.dist = ""                  # distribution (dapper, edgy, etc)
        self.comps = []                 # list of available componetns
                                        # (may empty)
        self.comment = ""               # (optional) comment
        self.line = line                # the original sources.list line
        if file is None:
            file = apt_pkg.config.find_dir(
                "Dir::Etc")+apt_pkg.config.find("Dir::Etc::sourcelist")
        self.file = file               # the file that the entry is located in
        self.parse(line)
        self.template = None           # type DistInfo.Suite
        self.children = []

    def __eq__(self, other):
        """ equal operator for two sources.list entries """
        return (self.disabled == other.disabled and
                self.type == other.type and
                self.uri == other.uri and
                self.dist == other.dist and
                self.comps == other.comps)

    def mysplit(self, line):
        """ a split() implementation that understands the sources.list
            format better and takes [] into account (for e.g. cdroms) """
        line = line.strip()
        pieces = []
        tmp = ""
        # we are inside a [..] block
        p_found = False
        space_found = False
        for i in range(len(line)):
            if line[i] == "[" and not space_found:
                p_found=True
                tmp += line[i]
            elif line[i] == "]":
                p_found=False
                tmp += line[i]
            elif space_found and not line[i].isspace():
                # we skip one or more space
                space_found = False
                pieces.append(tmp)
                tmp = line[i]
            elif line[i].isspace() and not p_found:
                # found a whitespace
                space_found = True
            else:
                tmp += line[i]
        # append last piece
        if len(tmp) > 0:
            pieces.append(tmp)
        return pieces

    def parse(self, line):
        """ parse a given sources.list (textual) line and break it up
            into the field we have """
        line = self.line.strip()
        #print line
        # check if the source is enabled/disabled
        if line == "" or line == "#": # empty line
            self.invalid = True
            return
        if line[0] == "#":
            self.disabled = True
            pieces = line[1:].strip().split()
            # if it looks not like a disabled deb line return
            if not pieces[0] in ("rpm", "rpm-src", "deb", "deb-src"):
                self.invalid = True
                return
            else:
                line = line[1:]
        # check for another "#" in the line (this is treated as a comment)
        i = line.find("#")
        if i > 0:
            self.comment = line[i+1:]
            line = line[:i]
        # source is ok, split it and see what we have
        pieces = self.mysplit(line)
        # Sanity check
        if len(pieces) < 3:
            self.invalid = True
            return
        # Type, deb or deb-src
        self.type = pieces[0].strip()
        # Sanity check
        if self.type not in ("deb", "deb-src", "rpm", "rpm-src"):
            self.invalid = True
            return

        if pieces[1].strip()[0] == "[":
            options = pieces.pop(1).strip("[]").split(";")
            for option in options:
                try:
                    key, value = option.split("=", 1)
                except Exception:
                    self.invalid = True
                else:
                    if key == "arch":
                        self.architectures = value.split(",")
                    else:
                        self.invalid = True
            
        # URI
        self.uri = pieces[1].strip()
        if len(self.uri) < 1:
            self.invalid = True
        # distro and components (optional)
        # Directory or distro
        self.dist = pieces[2].strip()
        if len(pieces) > 3:
            # List of components
            self.comps = pieces[3:]
        else:
            self.comps = []

    def set_enabled(self, new_value):
        """ set a line to enabled or disabled """
        self.disabled = not new_value
        # enable, remove all "#" from the start of the line
        if new_value:
            self.line = self.line.lstrip().lstrip('#')
        else:
            # disabled, add a "#"
            if self.line.strip()[0] != "#":
                self.line = "#" + self.line

    def __str__(self):
        """ debug helper """
        return self.str().strip()

    def str(self):
        """ return the current line as string """
        if self.invalid:
            return self.line
        line = ""
        if self.disabled:
            line = "# "

        line += self.type

        if self.architectures:
            line += " [arch=%s]" % ",".join(self.architectures)
        line += " %s %s" % (self.uri, self.dist)
        if len(self.comps) > 0:
            line += " " + " ".join(self.comps)
        if self.comment != "":
            line += " #"+self.comment
        line += "\n"
        return line


class NullMatcher(object):
    """ a Matcher that does nothing """

    def match(self, s):
        return True


class SourcesList(object):
    """ represents the full sources.list + sources.list.d file """

    def __init__(self,
                 withMatcher=True,
                 matcherPath="/usr/share/python-apt/templates/"):
        self.list = []          # the actual SourceEntries Type
        if withMatcher:
            self.matcher = SourceEntryMatcher(matcherPath)
        else:
            self.matcher = NullMatcher()
        self.refresh()

    def refresh(self):
        """ update the list of known entries """
        self.list = []
        # read sources.list
        file = apt_pkg.config.find_file("Dir::Etc::sourcelist")
        self.load(file)
        # read sources.list.d
        partsdir = apt_pkg.config.find_dir("Dir::Etc::sourceparts")
        for file in glob.glob("%s/*.list" % partsdir):
            self.load(file)
        # check if the source item fits a predefined template
        for source in self.list:
            if not source.invalid:
                self.matcher.match(source)

    def __iter__(self):
        """ simple iterator to go over self.list, returns SourceEntry
            types """
        for entry in self.list:
            yield entry
        raise StopIteration

    def __find(self, *predicates, **attrs):
        for source in self.list:
            if (all(getattr(source, key) == attrs[key] for key in attrs) and
                all(predicate(source) for predicate in predicates)):
                yield source

    def add(self, type, uri, dist, orig_comps, comment="", pos=-1, file=None, architectures=[]):
        """
        Add a new source to the sources.list.
        The method will search for existing matching repos and will try to
        reuse them as far as possible
        """

        architectures = set(architectures)
        # create a working copy of the component list so that
        # we can modify it later
        comps = orig_comps[:]
        sources = self.__find(lambda s: set(s.architectures) == architectures,
                              disabled=False, invalid=False, type=type, uri=uri,
                              dist=dist)
        # check if we have this source already in the sources.list
        for source in sources:
            for new_comp in comps:
                if new_comp in source.comps:
                    # we have this component already, delete it
                    # from the new_comps list
                    del comps[comps.index(new_comp)]
                    if len(comps) == 0:
                        return source

        sources = self.__find(lambda s: set(s.architectures) == architectures,
                              invalid=False, type=type, uri=uri, dist=dist)
                                 
        for source in sources:
            # if there is a repo with the same (type, uri, dist) just add the
            # components
            if source.disabled and set(source.comps) == comps:
                source.disabled = False
                return source
            elif not source.disabled:
                source.comps = uniq(source.comps + comps)
                return source
        # there isn't any matching source, so create a new line and parse it
        line = type
        if architectures:
            line += " [arch=%s]" % ",".join(architectures)
        line += " %s %s" % (uri, dist)
        for c in comps:
            line = line + " " + c
        if comment != "":
            line = "%s #%s\n" % (line, comment)
        line = line + "\n"
        new_entry = SourceEntry(line)
        if file is not None:
            new_entry.file = file
        self.matcher.match(new_entry)
        self.list.insert(pos, new_entry)
        return new_entry

    def remove(self, source_entry):
        """ remove the specified entry from the sources.list """
        self.list.remove(source_entry)

    def restore_backup(self, backup_ext):
        " restore sources.list files based on the backup extension "
        file = apt_pkg.config.find_file("Dir::Etc::sourcelist")
        if os.path.exists(file+backup_ext) and \
            os.path.exists(file):
            shutil.copy(file+backup_ext, file)
        # now sources.list.d
        partsdir = apt_pkg.config.find_dir("Dir::Etc::sourceparts")
        for file in glob.glob("%s/*.list" % partsdir):
            if os.path.exists(file+backup_ext):
                shutil.copy(file+backup_ext, file)

    if apt_pkg._COMPAT_0_7:
        restoreBackup = function_deprecated_by(restore_backup)

    def backup(self, backup_ext=None):
        """ make a backup of the current source files, if no backup extension
            is given, the current date/time is used (and returned) """
        already_backuped = set()
        if backup_ext is None:
            backup_ext = time.strftime("%y%m%d.%H%M")
        for source in self.list:
            if not source.file in already_backuped \
                and os.path.exists(source.file):
                shutil.copy(source.file, "%s%s" % (source.file, backup_ext))
        return backup_ext

    def load(self, file):
        """ (re)load the current sources """
        try:
            with open(file, "r") as f:
                for line in f:
                    source = SourceEntry(line, file)
                    self.list.append(source)
        except:
            logging.warn("could not open file '%s'\n" % file)

    def save(self):
        """ save the current sources """
        files = {}
        # write an empty default config file if there aren't any sources
        if len(self.list) == 0:
            path = apt_pkg.config.find_file("Dir::Etc::sourcelist")
            header = (
                "## See sources.list(5) for more information, especialy\n"
                "# Remember that you can only use http, ftp or file URIs\n"
                "# CDROMs are managed through the apt-cdrom tool.\n")

            with open(path, "w") as f:
                f.write(header)
            return

        try:
            for source in self.list:
                if source.file not in files:
                    files[source.file] = open(source.file, "w")
                files[source.file].write(source.str())
        finally:
            for f in files:
                files[f].close()

    def check_for_relations(self, sources_list):
        """get all parent and child channels in the sources list"""
        parents = []
        used_child_templates = {}
        for source in sources_list:
            # try to avoid checking uninterressting sources
            if source.template is None:
                continue
            # set up a dict with all used child templates and corresponding
            # source entries
            if source.template.child:
                key = source.template
                if key not in used_child_templates:
                    used_child_templates[key] = []
                temp = used_child_templates[key]
                temp.append(source)
            else:
                # store each source with children aka. a parent :)
                if len(source.template.children) > 0:
                    parents.append(source)
        #print self.used_child_templates
        #print self.parents
        return (parents, used_child_templates)


class SourceEntryMatcher(object):
    """ matcher class to make a source entry look nice
        lots of predefined matchers to make it i18n/gettext friendly
        """

    def __init__(self, matcherPath):
        self.templates = []
        # Get the human readable channel and comp names from the channel .infos
        spec_files = glob.glob("%s/*.info" % matcherPath)
        for f in spec_files:
            f = os.path.basename(f)
            i = f.find(".info")
            f = f[0:i]
            dist = DistInfo(f, base_dir=matcherPath)
            for template in dist.templates:
                if template.match_uri is not None:
                    self.templates.append(template)
        return

    def match(self, source):
        """Add a matching template to the source"""
        found = False
        for template in self.templates:
            if (re.search(template.match_uri, source.uri) and
                re.match(template.match_name, source.dist) and
                # deb is a valid fallback for deb-src (if that is not
                # definied, see #760035
                (source.type == template.type or template.type == "deb")):
                found = True
                source.template = template
                break
            elif (template.is_mirror(source.uri) and
                re.match(template.match_name, source.dist)):
                found = True
                source.template = template
                break
        return found


# some simple tests
if __name__ == "__main__":
    apt_pkg.init_config()
    sources = SourcesList()

    for entry in sources:
        logging.info("entry %s" % entry.str())
        #print entry.uri

    mirror = is_mirror("http://archive.ubuntu.com/ubuntu/",
                       "http://de.archive.ubuntu.com/ubuntu/")
    logging.info("is_mirror(): %s" % mirror)

    logging.info(is_mirror("http://archive.ubuntu.com/ubuntu",
                    "http://de.archive.ubuntu.com/ubuntu/"))
    logging.info(is_mirror("http://archive.ubuntu.com/ubuntu/",
                    "http://de.archive.ubuntu.com/ubuntu"))