# 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.

import os

import subprocess

from mercurial import util, config

from mercurial.node import hex, nullid

from mercurial.i18n import _

from common import NoRepo, commit, converter_source, checktool

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)

class convert_git(converter_source):

    # Windows does not support GIT_DIR= construct while other systems

    # cannot remove environment variable. Just assume none have

    # both issues.

    if util.safehasattr(os, 'unsetenv'):

        def gitopen(self, s, err=None):

            prevgitdir = os.environ.get('GIT_DIR')

            os.environ['GIT_DIR'] = self.path

            try:

                if err == subprocess.PIPE:

                    (stdin, stdout, stderr) = util.popen3(s)

                    return stdout

                elif err == subprocess.STDOUT:

                    return self.popen_with_stderr(s)

                else:

                    return util.popen(s, 'rb')

            finally:

                if prevgitdir is None:

                    del os.environ['GIT_DIR']

                else:

                    os.environ['GIT_DIR'] = prevgitdir

        def gitpipe(self, s):

            prevgitdir = os.environ.get('GIT_DIR')

            os.environ['GIT_DIR'] = self.path

            try:

                return util.popen3(s)

            finally:

                if prevgitdir is None:

                    del os.environ['GIT_DIR']

                else:

                    os.environ['GIT_DIR'] = prevgitdir

    else:

        def gitopen(self, s, err=None):

            if err == subprocess.PIPE:

                (sin, so, se) = util.popen3('GIT_DIR=%s %s' % (self.path, s))

                return so

            elif err == subprocess.STDOUT:

                    return self.popen_with_stderr(s)

            else:

                return util.popen('GIT_DIR=%s %s' % (self.path, s), 'rb')

        def gitpipe(self, s):

            return util.popen3('GIT_DIR=%s %s' % (self.path, s))

    def popen_with_stderr(self, s):

        p = subprocess.Popen(s, shell=True, bufsize=-1,

                             close_fds=util.closefds,

                             stdin=subprocess.PIPE,

                             stdout=subprocess.PIPE,

                             stderr=subprocess.STDOUT,

                             universal_newlines=False,

                             env=None)

        return p.stdout

    def gitread(self, s):

        fh = self.gitopen(s)

        data = fh.read()

        return data, fh.close()

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

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

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

            path += "/.git"

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

            raise 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', default=50)

        if similarity < 0 or similarity > 100:

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

        if similarity > 0:

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

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

                                             False)

            if findcopiesharder:

                self.simopt += ' --find-copies-harder'

        else:

            self.simopt = ''

        checktool('git', 'git')

        self.path = path

        self.submodules = []

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

    def after(self):

        for f in self.catfilepipe:

            f.close()

    def getheads(self):

        if not self.rev:

            heads, ret = self.gitread('git rev-parse --branches --remotes')

            heads = heads.splitlines()

        else:

            heads, ret = self.gitread("git rev-parse --verify %s" % self.rev)

            heads = [heads[:-1]]

        if ret:

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

        return heads

    def catfile(self, rev, type):

        if rev == hex(nullid):

            raise IOError

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

        self.catfilepipe[0].flush()

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

        if info[1] != type:

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

        size = int(info[2])

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

        if len(data) < size:

            raise util.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 == hex(nullid):

            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 = hex(nullid)

        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 \t that cant be parsed

        c.parse('.gitmodules', content.replace('\t',''))

        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.gitread("git show %s:%s" % (version, '.gitmodules'))

        if ret:

            raise util.Abort(_('cannot read submodules config file in %s') %

                             version)

        self.parsegitmodules(modules)

        for m in self.submodules:

            node, ret = self.gitread("git rev-parse %s:%s" % (version, m.path))

            if ret:

                continue

            m.node = node.strip()

    def getchanges(self, version, full):

        if full:

            raise util.Abort(_("convert from git do not support --full"))

        self.modecache = {}

        fh = self.gitopen("git diff-tree -z --root -m -r %s %s" % (

            self.simopt, version))

        changes = []

        copies = {}

        seen = set()

        entry = None

        subexists = [False]

        subdeleted = [False]

        difftree = fh.read().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':

                subexists[0] = True

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

                    subdeleted[0] = True

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

                else:

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

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

                subexists[0] = True

            else:

                if renamesource:

                    h = hex(nullid)

                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 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] in 'RC':

                # rename or copy: 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 fh.close():

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

        if subexists[0]:

            if subdeleted[0]:

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

            else:

                self.retrievegitmodules(version)

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

    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

        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 committer and committer != author:

            message += "\ncommitter: %s\n" % committer

        tzs, tzh, tzm = tz[-5:-4] + "1", tz[-4:-2], tz[-2:]

        tz = -int(tzs) * (int(tzh) * 3600 + int(tzm))

        date = tm + " " + str(tz)

        c = commit(parents=parents, date=date, author=author, desc=message,

                   rev=version)

        return c

    def numcommits(self):

        return len([None for _ in self.gitopen('git rev-list --all')])

    def gettags(self):

        tags = {}

        alltags = {}

        fh = self.gitopen('git ls-remote --tags "%s"' % self.path,

                          err=subprocess.STDOUT)

        prefix = 'refs/tags/'

        # Build complete list of tags, both annotated and bare ones

        for line in fh:

            line = line.strip()

            if line.startswith("error:") or line.startswith("fatal:"):

                raise util.Abort(_('cannot read tags from %s') % self.path)

            node, tag = line.split(None, 1)

            if not tag.startswith(prefix):

                continue

            alltags[tag[len(prefix):]] = node

        if fh.close():

            raise util.Abort(_('cannot read tags from %s') % self.path)

        # Filter out tag objects for annotated tag refs

        for tag in alltags:

            if tag.endswith('^{}'):

                tags[tag[:-3]] = alltags[tag]

            else:

                if tag + '^{}' in alltags:

                    continue

                else:

                    tags[tag] = alltags[tag]

        return tags

    def getchangedfiles(self, version, i):

        changes = []

        if i is None:

            fh = self.gitopen("git diff-tree --root -m -r %s" % version)

            for l in fh:

                if "\t" not in l:

                    continue

                m, f = l[:-1].split("\t")

                changes.append(f)

        else:

            fh = self.gitopen('git diff-tree --name-only --root -r %s '

                              '"%s^%s" --' % (version, version, i + 1))