# Copyright 2007 Bryan O'Sullivan <bos@serpentine.com>

# Copyright 2007 Alexis S. L. Carvalho <alexis@cecm.usp.br>

#

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

# the GNU General Public License, incorporated herein by reference.

import shlex

from mercurial.i18n import _

from mercurial import util

from common import SKIPREV, converter_source

def rpairs(name):

    e = len(name)

    while e != -1:

        yield name[:e], name[e+1:]

        e = name.rfind('/', 0, e)

class filemapper(object):

    '''Map and filter filenames when importing.

    A name can be mapped to itself, a new name, or None (omit from new

    repository).'''

    def __init__(self, ui, path=None):

        self.ui = ui

        self.include = {}

        self.exclude = {}

        self.rename = {}

        if path:

            if self.parse(path):

                raise util.Abort(_('errors in filemap'))

    def parse(self, path):

        errs = 0

        def check(name, mapping, listname):

            if name in mapping:

                self.ui.warn(_('%s:%d: %r already in %s list\n') %

                             (lex.infile, lex.lineno, name, listname))

                return 1

            return 0

        lex = shlex.shlex(open(path), path, True)

        lex.wordchars += '!@#$%^&*()-=+[]{}|;:,./<>?'

        cmd = lex.get_token()

        while cmd:

            if cmd == 'include':

                name = lex.get_token()

                errs += check(name, self.exclude, 'exclude')

                self.include[name] = name

            elif cmd == 'exclude':

                name = lex.get_token()

                errs += check(name, self.include, 'include')

                errs += check(name, self.rename, 'rename')

                self.exclude[name] = name

            elif cmd == 'rename':

                src = lex.get_token()

                dest = lex.get_token()

                errs += check(src, self.exclude, 'exclude')

                self.rename[src] = dest

            elif cmd == 'source':

                errs += self.parse(lex.get_token())

            else:

                self.ui.warn(_('%s:%d: unknown directive %r\n') %

                             (lex.infile, lex.lineno, cmd))

                errs += 1

            cmd = lex.get_token()

        return errs

    def lookup(self, name, mapping):

        for pre, suf in rpairs(name):

            try:

                return mapping[pre], pre, suf

            except KeyError, err:

                pass

        return '', name, ''

    def __call__(self, name):

        if self.include:

            inc = self.lookup(name, self.include)[0]

        else:

            inc = name

        if self.exclude:

            exc = self.lookup(name, self.exclude)[0]

        else:

            exc = ''

        if not inc or exc:

            return None

        newpre, pre, suf = self.lookup(name, self.rename)

        if newpre:

            if newpre == '.':

                return suf

            if suf:

                return newpre + '/' + suf

            return newpre

        return name

    def active(self):

        return bool(self.include or self.exclude or self.rename)

# This class does two additional things compared to a regular source:

#

# - Filter and rename files.  This is mostly wrapped by the filemapper

#   class above. We hide the original filename in the revision that is

#   returned by getchanges to be able to find things later in getfile

#   and getmode.

#

# - Return only revisions that matter for the files we're interested in.

#   This involves rewriting the parents of the original revision to

#   create a graph that is restricted to those revisions.

#

#   This set of revisions includes not only revisions that directly

#   touch files we're interested in, but also merges that merge two

#   or more interesting revisions.

class filemap_source(converter_source):

    def __init__(self, ui, baseconverter, filemap):

        super(filemap_source, self).__init__(ui)

        self.base = baseconverter

        self.filemapper = filemapper(ui, filemap)

        self.commits = {}

        # if a revision rev has parent p in the original revision graph, then

        # rev will have parent self.parentmap[p] in the restricted graph.

        self.parentmap = {}

        # self.wantedancestors[rev] is the set of all ancestors of rev that

        # are in the restricted graph.

        self.wantedancestors = {}

        self.convertedorder = None

        self._rebuilt = False

        self.origparents = {}

        self.children = {}

        self.seenchildren = {}

    def setrevmap(self, revmap):

        # rebuild our state to make things restartable

        #

        # To avoid calling getcommit for every revision that has already

        # been converted, we rebuild only the parentmap, delaying the

        # rebuild of wantedancestors until we need it (i.e. until a

        # merge).

        #

        # We assume the order argument lists the revisions in

        # topological order, so that we can infer which revisions were

        # wanted by previous runs.

        self._rebuilt = not revmap

        seen = {SKIPREV: SKIPREV}

        dummyset = util.set()

        converted = []

        for rev in revmap.order:

            mapped = revmap[rev]

            wanted = mapped not in seen

            if wanted:

                seen[mapped] = rev

                self.parentmap[rev] = rev

            else:

                self.parentmap[rev] = seen[mapped]

            self.wantedancestors[rev] = dummyset

            arg = seen[mapped]

            if arg == SKIPREV:

                arg = None

            converted.append((rev, wanted, arg))

        self.convertedorder = converted

        return self.base.setrevmap(revmap)

    def rebuild(self):

        if self._rebuilt:

            return True

        self._rebuilt = True

        self.parentmap.clear()

        self.wantedancestors.clear()

        self.seenchildren.clear()

        for rev, wanted, arg in self.convertedorder:

            if rev not in self.origparents:

                self.origparents[rev] = self.getcommit(rev).parents

            if arg is not None:

                self.children[arg] = self.children.get(arg, 0) + 1

        for rev, wanted, arg in self.convertedorder:

            parents = self.origparents[rev]

            if wanted:

                self.mark_wanted(rev, parents)

            else:

                self.mark_not_wanted(rev, arg)

            self._discard(arg, *parents)

        return True

    def getheads(self):

        return self.base.getheads()

    def getcommit(self, rev):

        # We want to save a reference to the commit objects to be able

        # to rewrite their parents later on.

        c = self.commits[rev] = self.base.getcommit(rev)

        for p in c.parents:

            self.children[p] = self.children.get(p, 0) + 1

        return c

    def _discard(self, *revs):

        for r in revs:

            if r is None:

                continue

            self.seenchildren[r] = self.seenchildren.get(r, 0) + 1

            if self.seenchildren[r] == self.children[r]:

                del self.wantedancestors[r]

                del self.parentmap[r]

                del self.seenchildren[r]

                if self._rebuilt:

                    del self.children[r]

    def wanted(self, rev, i):

        # Return True if we're directly interested in rev.

        #

        # i is an index selecting one of the parents of rev (if rev

        # has no parents, i is None).  getchangedfiles will give us

        # the list of files that are different in rev and in the parent

        # indicated by i.  If we're interested in any of these files,

        # we're interested in rev.

        try:

            files = self.base.getchangedfiles(rev, i)

        except NotImplementedError:

            raise util.Abort(_("source repository doesn't support --filemap"))

        for f in files:

            if self.filemapper(f):

                return True

        return False

    def mark_not_wanted(self, rev, p):

        # Mark rev as not interesting and update data structures.

        if p is None:

            # A root revision. Use SKIPREV to indicate that it doesn't

            # map to any revision in the restricted graph.  Put SKIPREV

            # in the set of wanted ancestors to simplify code elsewhere

            self.parentmap[rev] = SKIPREV

            self.wantedancestors[rev] = util.set((SKIPREV,))

            return

        # Reuse the data from our parent.

        self.parentmap[rev] = self.parentmap[p]

        self.wantedancestors[rev] = self.wantedancestors[p]

    def mark_wanted(self, rev, parents):

        # Mark rev ss wanted and update data structures.

        # rev will be in the restricted graph, so children of rev in

        # the original graph should still have rev as a parent in the

        # restricted graph.

        self.parentmap[rev] = rev

        # The set of wanted ancestors of rev is the union of the sets

        # of wanted ancestors of its parents. Plus rev itself.

        wrev = util.set()

        for p in parents:

            wrev.update(self.wantedancestors[p])

        wrev.add(rev)

        self.wantedancestors[rev] = wrev

    def getchanges(self, rev):

        parents = self.commits[rev].parents

        if len(parents) > 1:

            self.rebuild()

        # To decide whether we're interested in rev we:

        #

        # - calculate what parents rev will have if it turns out we're

        #   interested in it.  If it's going to have more than 1 parent,

        #   we're interested in it.

        #

        # - otherwise, we'll compare it with the single parent we found.

        #   If any of the files we're interested in is different in the

        #   the two revisions, we're interested in rev.

        # A parent p is interesting if its mapped version (self.parentmap[p]):

        # - is not SKIPREV

        # - is still not in the list of parents (we don't want duplicates)

        # - is not an ancestor of the mapped versions of the other parents

        mparents = []

        wp = None

        for i, p1 in enumerate(parents):

            mp1 = self.parentmap[p1]

            if mp1 == SKIPREV or mp1 in mparents:

                continue

            for p2 in parents:

                if p1 == p2 or mp1 == self.parentmap[p2]:

                    continue

                if mp1 in self.wantedancestors[p2]:

                    break

            else:

                mparents.append(mp1)

                wp = i

        if wp is None and parents:

            wp = 0

        self.origparents[rev] = parents

        if len(mparents) < 2 and not self.wanted(rev, wp):

            # We don't want this revision.

            # Update our state and tell the convert process to map this

            # revision to the same revision its parent as mapped to.

            p = None

            if parents:

                p = parents[wp]

            self.mark_not_wanted(rev, p)

            self.convertedorder.append((rev, False, p))

            self._discard(*parents)

            return self.parentmap[rev]

        # We want this revision.

        # Rewrite the parents of the commit object

        self.commits[rev].parents = mparents

        self.mark_wanted(rev, parents)

        self.convertedorder.append((rev, True, None))

        self._discard(*parents)

        # Get the real changes and do the filtering/mapping.

        # To be able to get the files later on in getfile and getmode,

        # we hide the original filename in the rev part of the return

        # value.

        changes, copies = self.base.getchanges(rev)

        newnames = {}

        files = []

        for f, r in changes:

            newf = self.filemapper(f)

            if newf:

                files.append((newf, (f, r)))

                newnames[f] = newf

        ncopies = {}

        for c in copies:

            newc = self.filemapper(c)

            if newc:

                newsource = self.filemapper(copies[c])

                if newsource:

                    ncopies[newc] = newsource

        return files, ncopies

    def getfile(self, name, rev):

        realname, realrev = rev

        return self.base.getfile(realname, realrev)

    def getmode(self, name, rev):

        realname, realrev = rev

        return self.base.getmode(realname, realrev)

    def gettags(self):

        return self.base.gettags()