#!/bin/sh
# ----------------------------------------------------------------------
# In a git "working copy" checkout the given entity (branch, tag,
# changeset). In case of a branch pull the latest changes, in every
# other case leave it in detached HEAD state. This script performs no
# directory changes, so start it in the target directory!
#
# Authors:  Alexander Dahl <post@lespocky.de>
#
# Copyright 2011,2013 Alexander Dahl
# ----------------------------------------------------------------------

ENTITY="$1"
BRANCH_EXISTS="no"

print_usage() {
    echo "Usage: $0 checkoutentity"
}

if [ -z "$1" ]
then
    print_usage
    exit 1
fi

if git fetch
then
    echo 'Git fetch successful!'
else
    exit $?
fi

if git checkout "$1"
then
    echo 'Git checkout successful!'
else
    exit $?
fi

for branch in $(git branch | cut -c3-)
do
    if [ "${ENTITY}" = "${branch}" ]
    then
        BRANCH_EXISTS="yes"
    fi
done

if [ "${BRANCH_EXISTS}" = "yes" ]
then
    git pull
fi

if git submodule update --init --recursive
then
    echo 'Git submodule update successful!'
else
    exit $?
fi

exit 0