# git.py - git support for the convert extension

#

#  Copyright 2005-2009 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 __future__ import absolute_import

import os

from mercurial.i18n import _

from mercurial import (

    config,

    error,

    node as nodemod,

)

from . import (

    common,

)

class submodule(object):

    def __init__(self, path, node, url):

        self.path = path

        self.node = node

        self.url = url

    def hgsub(self):

        return "%s = [git]%s" % (self.path, self.url)

    def hgsubstate(self):

        return "%s %s" % (self.node, self.path)

# Keys in extra fields that should not be copied if the user requests.

bannedextrakeys = {

    # Git commit object built-ins.

    'tree',

    'parent',

    'author',

    'committer',

    # Mercurial built-ins.

    'branch',

    'close',

}

class convert_git(common.converter_source, common.commandline):

    # Windows does not support GIT_DIR= construct while other systems

    # cannot remove environment variable. Just assume none have

    # both issues.

    def _gitcmd(self, cmd, *args, **kwargs):

        return cmd('--git-dir=%s' % self.path, *args, **kwargs)

    def gitrun0(self, *args, **kwargs):

        return self._gitcmd(self.run0, *args, **kwargs)

    def gitrun(self, *args, **kwargs):

        return self._gitcmd(self.run, *args, **kwargs)

    def gitrunlines0(self, *args, **kwargs):

        return self._gitcmd(self.runlines0, *args, **kwargs)

    def gitrunlines(self, *args, **kwargs):

        return self._gitcmd(self.runlines, *args, **kwargs)

    def gitpipe(self, *args, **kwargs):

        return self._gitcmd(self._run3, *args, **kwargs)

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

        super(convert_git, self).__init__(ui, path, revs=revs)

        common.commandline.__init__(self, ui, 'git')

        # Pass an absolute path to git to prevent from ever being interpreted

        # as a URL

        path = os.path.abspath(path)

        if os.path.isdir(path + "/.git"):

            path += "/.git"

        if not os.path.exists(path + "/objects"):

            raise common.NoRepo(_("%s does not look like a Git repository") %

                                path)

        # The default value (50) is based on the default for 'git diff'.

        similarity = ui.configint('convert', 'git.similarity')

        if similarity < 0 or similarity > 100:

            raise error.Abort(_('similarity must be between 0 and 100'))

        if similarity > 0:

            self.simopt = ['-C%d%%' % similarity]

            findcopiesharder = ui.configbool('convert', 'git.findcopiesharder')

            if findcopiesharder:

                self.simopt.append('--find-copies-harder')

            renamelimit = ui.configint('convert', 'git.renamelimit')

            self.simopt.append('-l%d' % renamelimit)

        else:

            self.simopt = []

        common.checktool('git', 'git')

        self.path = path

        self.submodules = []

        self.catfilepipe = self.gitpipe('cat-file', '--batch')

        self.copyextrakeys = self.ui.configlist('convert', 'git.extrakeys')

        banned = set(self.copyextrakeys) & bannedextrakeys

        if banned:

            raise error.Abort(_('copying of extra key is forbidden: %s') %

                              _(', ').join(sorted(banned)))

        committeractions = self.ui.configlist('convert', 'git.committeractions')

        messagedifferent = None

        messagealways = None

        for a in committeractions:

            if a.startswith(('messagedifferent', 'messagealways')):

                k = a

                v = None

                if '=' in a:

                    k, v = a.split('=', 1)

                if k == 'messagedifferent':

                    messagedifferent = v or 'committer:'

                elif k == 'messagealways':

                    messagealways = v or 'committer:'

        if messagedifferent and messagealways:

            raise error.Abort(_('committeractions cannot define both '

                                'messagedifferent and messagealways'))

        dropcommitter = 'dropcommitter' in committeractions

        replaceauthor = 'replaceauthor' in committeractions

        if dropcommitter and replaceauthor:

            raise error.Abort(_('committeractions cannot define both '

                                'dropcommitter and replaceauthor'))

        if dropcommitter and messagealways:

            raise error.Abort(_('committeractions cannot define both '

                                'dropcommitter and messagealways'))

        if not messagedifferent and not messagealways:

            messagedifferent = 'committer:'

        self.committeractions = {

            'dropcommitter': dropcommitter,

            'replaceauthor': replaceauthor,

            'messagedifferent': messagedifferent,

            'messagealways': messagealways,

        }

    def after(self):

        for f in self.catfilepipe:

            f.close()

    def getheads(self):

        if not self.revs:

            output, status = self.gitrun('rev-parse', '--branches', '--remotes')

            heads = output.splitlines()

            if status:

                raise error.Abort(_('cannot retrieve git heads'))

        else:

            heads = []

            for rev in self.revs:

                rawhead, ret = self.gitrun('rev-parse', '--verify', rev)

                heads.append(rawhead[:-1])

                if ret:

                    raise error.Abort(_('cannot retrieve git head "%s"') % rev)

        return heads

    def catfile(self, rev, type):

        if rev == nodemod.nullhex:

            raise IOError

        self.catfilepipe[0].write(rev+'\n')

        self.catfilepipe[0].flush()

        info = self.catfilepipe[1].readline().split()

        if info[1] != type:

            raise error.Abort(_('cannot read %r object at %s') % (type, rev))

        size = int(info[2])

        data = self.catfilepipe[1].read(size)

        if len(data) < size:

            raise error.Abort(_('cannot read %r object at %s: unexpected size')

                             % (type, rev))

        # read the trailing newline

        self.catfilepipe[1].read(1)

        return data

    def getfile(self, name, rev):

        if rev == nodemod.nullhex:

            return None, None

        if name == '.hgsub':

            data = '\n'.join([m.hgsub() for m in self.submoditer()])

            mode = ''

        elif name == '.hgsubstate':

            data = '\n'.join([m.hgsubstate() for m in self.submoditer()])

            mode = ''

        else:

            data = self.catfile(rev, "blob")

            mode = self.modecache[(name, rev)]

        return data, mode

    def submoditer(self):

        null = nodemod.nullhex

        for m in sorted(self.submodules, key=lambda p: p.path):

            if m.node != null:

                yield m

    def parsegitmodules(self, content):

        """Parse the formatted .gitmodules file, example file format:

        [submodule "sub"]\n

        \tpath = sub\n

        \turl = git://giturl\n

        """

        self.submodules = []

        c = config.config()

        # Each item in .gitmodules starts with whitespace that cant be parsed

        c.parse('.gitmodules', '\n'.join(line.strip() for line in

                               content.split('\n')))

        for sec in c.sections():

            s = c[sec]

            if 'url' in s and 'path' in s:

                self.submodules.append(submodule(s['path'], '', s['url']))

    def retrievegitmodules(self, version):

        modules, ret = self.gitrun('show', '%s:%s' % (version, '.gitmodules'))

        if ret:

            # This can happen if a file is in the repo that has permissions

            # 160000, but there is no .gitmodules file.

            self.ui.warn(_("warning: cannot read submodules config file in "

                           "%s\n") % version)

            return

        try:

            self.parsegitmodules(modules)

        except error.ParseError:

            self.ui.warn(_("warning: unable to parse .gitmodules in %s\n")

                         % version)

            return

        for m in self.submodules:

            node, ret = self.gitrun('rev-parse', '%s:%s' % (version, m.path))

            if ret:

                continue

            m.node = node.strip()

    def getchanges(self, version, full):

        if full:

            raise error.Abort(_("convert from git does not support --full"))

        self.modecache = {}

        cmd = ['diff-tree','-z', '--root', '-m', '-r'] + self.simopt + [version]

        output, status = self.gitrun(*cmd)

        if status:

            raise error.Abort(_('cannot read changes in %s') % version)

        changes = []

        copies = {}

        seen = set()

        entry = None

        subexists = [False]

        subdeleted = [False]

        difftree = output.split('\x00')

        lcount = len(difftree)

        i = 0

        def add(entry, f, isdest):

            seen.add(f)

            h = entry[3]

            p = (entry[1] == "100755")

            s = (entry[1] == "120000")

            renamesource = (not isdest and entry[4][0] == 'R')

            if f == '.gitmodules':

                if skipsubmodules:

                    return

                subexists[0] = True

                if entry[4] == 'D' or renamesource:

                    subdeleted[0] = True

                    changes.append(('.hgsub', nodemod.nullhex))

                else:

                    changes.append(('.hgsub', ''))

            elif entry[1] == '160000' or entry[0] == ':160000':

                if not skipsubmodules:

                    subexists[0] = True

            else:

                if renamesource:

                    h = nodemod.nullhex

                self.modecache[(f, h)] = (p and "x") or (s and "l") or ""

                changes.append((f, h))

        while i < lcount:

            l = difftree[i]

            i += 1

            if not entry:

                if not l.startswith(':'):

                    continue

                entry = l.split()

                continue

            f = l

            if entry[4][0] == 'C':

                copysrc = f

                copydest = difftree[i]

                i += 1

                f = copydest

                copies[copydest] = copysrc

            if f not in seen:

                add(entry, f, False)

            # A file can be copied multiple times, or modified and copied

            # simultaneously. So f can be repeated even if fdest isn't.

            if entry[4][0] == 'R':

                # rename: next line is the destination

                fdest = difftree[i]

                i += 1

                if fdest not in seen:

                    add(entry, fdest, True)

                    # .gitmodules isn't imported at all, so it being copied to

                    # and fro doesn't really make sense

                    if f != '.gitmodules' and fdest != '.gitmodules':

                        copies[fdest] = f

            entry = None

        if subexists[0]:

            if subdeleted[0]:

                changes.append(('.hgsubstate', nodemod.nullhex))

            else:

                self.retrievegitmodules(version)

                changes.append(('.hgsubstate', ''))

        return (changes, copies, set())

    def getcommit(self, version):

        c = self.catfile(version, "commit") # read the commit hash

        end = c.find("\n\n")

        message = c[end + 2:]

        message = self.recode(message)

        l = c[:end].splitlines()

        parents = []

        author = committer = None

        extra = {}

        for e in l[1:]:

            n, v = e.split(" ", 1)

            if n == "author":

                p = v.split()

                tm, tz = p[-2:]

                author = " ".join(p[:-2])

                if author[0] == "<": author = author[1:-1]

                author = self.recode(author)

            if n == "committer":

                p = v.split()

                tm, tz = p[-2:]

                committer = " ".join(p[:-2])

                if committer[0] == "<": committer = committer[1:-1]

                committer = self.recode(committer)

            if n == "parent":

                parents.append(v)

            if n in self.copyextrakeys:

                extra[n] = v

        if self.committeractions['dropcommitter']: