# git support for the convert extension

import os

from mercurial import util

from common import NoRepo, commit, converter_source, checktool

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 hasattr(os, 'unsetenv'):

        def gitcmd(self, s):

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

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

            try:

                return util.popen(s, 'rb')

            finally:

                if prevgitdir is None:

                    del os.environ['GIT_DIR']

                else:

                    os.environ['GIT_DIR'] = prevgitdir

    else:

        def gitcmd(self, s):

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

    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 repo" % path)

        checktool('git', 'git')

        self.path = path

    def getheads(self):

        if not self.rev:

            return self.gitcmd('git rev-parse --branches --remotes').read().splitlines()

        else:

            fh = self.gitcmd("git rev-parse --verify %s" % self.rev)

            return [fh.read()[:-1]]

    def catfile(self, rev, type):

        if rev == "0" * 40: raise IOError()

        fh = self.gitcmd("git cat-file %s %s" % (type, rev))

        return fh.read()

    def getfile(self, name, rev):

        return self.catfile(rev, "blob")

    def getmode(self, name, rev):

        return self.modecache[(name, rev)]

    def getchanges(self, version):

        self.modecache = {}

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

        changes = []

        seen = {}

        entry = None

        for l in fh.read().split('\x00'):

            if not entry:

                if not l.startswith(':'):

                    continue

                entry = l

                continue

            f = l

            if f not in seen:

                seen[f] = 1

                entry = entry.split()

                h = entry[3]

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

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

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

                changes.append((f, h))

            entry = None

        return (changes, {})

    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()

        manifest = l[0].split()[1]

        parents = []

        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)

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

            if n == "parent": parents.append(v)

        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 gettags(self):

        tags = {}

        fh = self.gitcmd('git ls-remote --tags "%s"' % self.path)

        prefix = 'refs/tags/'

        for line in fh:

            line = line.strip()

            if not line.endswith("^{}"):

                continue

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

            if not tag.startswith(prefix):

                continue

            tag = tag[len(prefix):-3]

            tags[tag] = node

        return tags

    def getchangedfiles(self, version, i):

        changes = []

        if i is None:

            fh = self.gitcmd("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)

            fh.close()

        else:

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

                             % (version, version, i+1))

            changes = [f.rstrip('\n') for f in fh]

            fh.close()

        return changes