#!/bin/bash
#
# Copyright (c) 2010, Benjamin C. Meyer <ben@meyerhome.net>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. Neither the name of the project nor the
#    names of its contributors may be used to endorse or promote products
#    derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ''AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

function hook_dirs
{
    if [ ! -z "${1}" ] ; then
        hook="/${1}"
    else
        hook=""
    fi
    echo "${HOME}/.git_hooks${hook}"
    echo "${PWD}/git_hooks${hook}"
    echo "`git config hooks.global`"${hook}
}

function list_hooks_in_dir
{
    find "${1}" -executable -type f 2>/dev/null | grep -v "^.$" | sort -V
}

function run_hooks
{
    dir="${1}"
    if [[ -z ${dir} || ! -d "${dir}" ]] ; then
        echo "run_hooks requires a directory name as an argument."
        return 1
    fi
    shift 1
    for hook in `list_hooks_in_dir "${dir}"`
    do
        export last_run_hook="${hook} $@"
        if [ ! -z ${GIT_HOOKS_VERBOSE} ] ; then
            echo -n "@@ Running hook: "
            echo -n `basename \`dirname "${hook}"\``
            echo "/`basename "${hook}"`"
        fi
        ${hook} "$@"
    done
}

function run_hook
{
    set -e
    hook=`basename "${1}"`
    if [ -z ${hook} ] ; then
        echo "run requires a hook argument"
        return 1
    fi
    shift 1
    for dir in `hook_dirs "${hook}"`; do
        if [ ! -d "${dir}" ] ; then
            continue
        fi
        run_hooks "${dir}" "$@"
    done
    set +e
}

function install_hooks
{
    GITDIR=`git rev-parse --git-dir`
    if [ ! $? -eq 0 ] ; then
        echo "$1 must be run inside a git repository"
        return 1
    fi
    cd $GITDIR
    if [ "${1}" = "--install" ] ; then
        mv hooks hooks.old
        mkdir hooks
        cd hooks
        for file in applypatch-msg commit-msg post-applypatch post-checkout post-commit post-merge post-receive pre-applypatch pre-auto-gc pre-commit prepare-commit-msg pre-rebase pre-receive update
        do
            echo '#!/bin/bash
git-hooks run "$0" "$@"' > "${file}"
            chmod +x "${file}"
        done
    else
        if [ ! -d hooks.old ] ; then
            echo "Error, hooks.old doesn't exists, aborting uninstall to not destroy something"
            return 1
        fi
        rm -rf hooks
        mv hooks.old hooks
    fi
}

function list_hooks
{
    while [ ! -d ".git" ] ; do
        cd ..
    done
    cat .git/hooks/pre-commit | grep 'git-hooks' > /dev/null 2> /dev/null
    if [ $? = 0 ] ; then
        echo -n "Git hooks ARE installed in this repository."
    else
        echo -n "Git hooks are NOT installed in this repository."
    fi

    echo '  Listing User, Project, and Global hooks:'
    echo '---'
    for dir in `hook_dirs`; do
        echo "${dir}:"
        for hook in `list_hooks_in_dir "${dir}"` ; do
            echo -n `basename \`dirname "${hook}"\``
            echo -e "/`basename "${hook}"` \t- `${hook} --about`"
        done
        echo ""
    done
}

function report_error {
    echo "Hook failed: $last_run_hook"
    exit 1
}

case $1 in
    run )
        if [ ! -z "${GIT_DIR}" ] ; then
            unset GIT_DIR
        fi
        shift
        trap report_error ERR
        run_hook "$@"
        ;;
    --install|--uninstall )
        install_hooks "$1"
        ;;
    -h|--help )
        echo 'Git Hooks'
        echo ''
        echo 'Options:'
        echo '    --install      Replace existing hooks in this repository with a call to'
        echo '                   git hooks run [hook].  Move old hooks directory to hooks.old'
        echo '    --uninstall    Remove existing hooks in this repository and rename hooks.old'
        echo '                   back to hooks'
        echo "    run [cmd]      Run the hooks for cmd (such as pre-commit)"
        echo "    (no arguments) Show currently installed hooks"
        ;;
    * )
        list_hooks
        ;;
esac