#! /bin/bash
# Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
# Contact: http://www.qt-project.org/legal
#
# You may use this file under the terms of the 3-clause BSD license.
# See the file LICENSE from this package for details.
#

set -e # exit on any error

# FIXME: use git config for that
MIRROR_ROOT=/data/repos
GIT_BIN=/usr/bin/git
UPDATE_LOCK=$HOME/.update_codereview_lock

# don't retry; pronounce 1h+ old locks as dead
lockfile -r 0 -l 3600 $UPDATE_LOCK
trap 'rm -f $UPDATE_LOCK' EXIT

cd $MIRROR_ROOT

# first mark all mirrors as deletable
for i in `find -type d -name '*.git' -prune | cut -c3-`; do
    touch $i/delete-me
done

# then get a current list of projects
rawproj=`ssh -p 29418 codereview.qt-project.org gerrit ls-projects`
allproj=`echo "$rawproj" | grep -v '^\{graveyard\}/'`
# this test ensures that the list is complete, identified by the trailing graveyard projects
if test x"$allproj" = x"$rawproj"; then
    echo "List of projects from gerrit is incomplete." >&2
    exit 1
fi

# then create the respective mirrors
for i in `echo "$allproj" | grep -v '^All-'`; do (
    mkdir -p $i.git
    cd $i.git
    rm -f delete-me
    test -f config || $GIT_BIN init --bare
    $GIT_BIN config remote.origin.fetch '+refs/heads/*:refs/heads/*' heads
    $GIT_BIN config remote.origin.fetch '+refs/staging/*:refs/staging/*' staging
    $GIT_BIN config remote.origin.url "ssh://codereview.qt-project.org:29418/$i.git"
); done

# then update all active mirrors and purge the orphaned ones
for i in `find -type d -name '*.git' -prune | cut -c3-`; do (
    if test -f $i/delete-me; then
        rm -rf $i
    else
        cd $i
        if ! test -s HEAD; then
            echo "Note: HEAD of $i is bogus." >&2
            echo "ref: refs/heads/master" > HEAD
        fi
        $GIT_BIN remote show origin | sed -n 's,^  HEAD branch: ,ref: refs/heads/,p' > new-HEAD
        test -s new-HEAD && mv new-HEAD HEAD || echo "Cannot obtain HEAD for $i" >&2
        $GIT_BIN fetch -p -q -u origin
#        $GIT_BIN gc
        chown -R --reference $MIRROR_ROOT .
    fi
); done