env/utils/shgit

# shgit
# Written in 2019 by Lucas
# CC0 1.0 Universal/Public domain - No rights reserved
#
# To the extent possible under law, the author(s) have dedicated all
# copyright and related and neighboring rights to this software to the
# public domain worldwide. This software is distributed without any
# warranty. You should have received a copy of the CC0 Public Domain
# Dedication along with this software. If not, see
# <http://creativecommons.org/publicdomain/zero/1.0/>.

shgit()
{
	: ${SHGIT_BEGIN:=} ${SHGIT_END:= } ${SHGIT_SEP:=:}

	gitdir=$(git rev-parse --git-dir 2>/dev/null) && [ -n "$gitdir" ] ||
	    return

	symbolic=$(git symbolic-ref --short HEAD 2>/dev/null)
	name=${symbolic:-}
	if [ -z "$name" ]; then
		hash=$(git rev-parse --short HEAD 2>/dev/null)
		name=${hash:-"?"}
	fi

	rb=
	rbdir="$gitdir/rebase-merge"
	if [ -d "$rbdir" ]; then
		rb="${SHGIT_SEP}REBASE"
		read -r name <"$rbdir/head-name"
		name=${name##*/}
		[ -f "$rbdir/interactive" ] && rb="$rb-i"
		rbcount=$(wc -l <"$rbdir/done")
		read -r rbtotal <"$rbdir/end"
		rb="$rb ${rbcount##* }/$rbtotal"
	fi

	status=
	[ -n "$(git status --porcelain)" ] && status="${SHGIT_SEP}*"

	commits=$(git rev-list --left-right --count @{upstream}...HEAD \
	    2>/dev/null | {
		t=
		IFS="	" read -r behind ahead
		[ ${behind:-0} -gt 0 ] && t=$t"v$behind"
		[ ${ahead:-0} -gt 0 ] && t=$t"^$ahead"
		[ -n "$t" ] && printf "%s" "$SHGIT_SEP" "$t"
	})

	printf "%s%s%s" "$SHGIT_BEGIN" "$name$rb$status$commits" "$SHGIT_END"
}