#!/bin/sh

OPTIONS_SPEC="\
$(basename $0) [options] [<remote> [<branch>]]
--
k,gitk      visualize unmerged differences
r,rebase    perform a rebase
m,merge     perform a merge
"
SUBDIRECTORY_OK=t
. "$(git --exec-path)/git-sh-setup"
require_work_tree

lbranch=$(git symbolic-ref HEAD | sed -e s~refs/heads/~~)
remote=$(git config --get "branch.$lbranch.remote" || echo origin)
branch=$(git config --get "branch.$lbranch.merge" || echo "refs/heads/$lbranch")

case "$(git config --bool --get madcoder.up-gitk)" in
    true) gitk=gitk;;
    *)    gitk=:
esac
case "$(git config --bool --get "branch.$lbranch.rebase")" in
    true) action=rebase;;
    *)    action=;;
esac

while test $# != 0; do
    case "$1" in
        -k|--gitk)
            shift; gitk=gitk;;
        --no-gitk)
            shift; gitk=:;;
        -r|--rebase)
            shift; action=rebase;;
        --no-rebase)
            shift; rebase=${rebase#rebase};;
        -m|--merge)
            shift; action=merge;;
        --no-merge)
            shift; rebase=${rebase#merge};;
        --)
            shift; break;;
        *)
            usage;;
    esac
done

case $# in
    0) ;;
    1) remote="$1";;
    2) remote="$1"; branch="$2";;
    *) usage;;
esac

git remote update
if git config remote.mob.fetch >/dev/null 2>/dev/null; then
    git remote prune mob
fi
if test `git rev-list .."${remote}/${branch#refs/heads/}" -- | wc -l` = 0; then
    echo "Current branch $lbranch is up to date."
    exit 0
fi

$gitk HEAD..."${remote}/${branch#refs/heads/}" --
if test -z "$action"; then
    echo -n "(r)ebase/(m)erge/(q)uit ? "
    read ans
    case "$ans" in
        r*) action=rebase;;
        m*) action=merge;;
        *)  exit 0;;
    esac
fi

no_changes () {
	git diff-index --quiet --cached HEAD --ignore-submodules -- &&
	git diff-files --quiet --ignore-submodules
}

unclean=
no_changes || unclean=t


case "$action" in
    rebase)
        test -z "$unclean" || git stash save "git-up stash"
        git rebase "${remote}/${branch#refs/heads/}"
        cd "$(dirname "$(git rev-parse --git-dir)")" && git submodule update --rebase
        ;;
    merge)
        test -z "$unclean" || git stash save "git-up stash"
        git merge "${remote}/${branch#refs/heads/}"
        ;;
    *)
        echo 1>&2 "no action specified"
        exit 1
        ;;
esac

if test -n "$unclean"; then
    if test  -d "$(git rev-parse --git-dir)/../.dotest"; then
        echo ""
        echo "run 'git stash apply' when rebase is finished"
    else
        git stash pop
    fi
fi