#!/bin/sh

setvar USAGE = ""(edit [-F <file> | -m <msg>] | show) [commit]""
source git-sh-setup

test -z $1 && usage
setvar ACTION = "$1"; shift

test -z $GIT_NOTES_REF && setvar GIT_NOTES_REF = "$(git config core.notesref)"
test -z $GIT_NOTES_REF && setvar GIT_NOTES_REF = ""refs/notes/commits""

setvar MESSAGE = ''
while test $# != 0
{
	case (1) {
	-m {
		test $ACTION = "edit" || usage
		shift
		if test "$Argc" = "0" {
			die "error: option -m needs an argument"
		} else {
			if test -z $MESSAGE {
				setvar MESSAGE = "$1"
			} else {
				setvar MESSAGE = ""$MESSAGE

$1""
			}
			shift
		}
		}
	-F {
		test $ACTION = "edit" || usage
		shift
		if test "$Argc" = "0" {
			die "error: option -F needs an argument"
		} else {
			if test -z $MESSAGE {
				setvar MESSAGE = "$(cat "$1")"
			} else {
				setvar MESSAGE = ""$MESSAGE

$(cat "$1")""
			}
			shift
		}
		}
	-* {
		usage
		}
	* {
		break
		}
	}
}

setvar COMMIT = $(git rev-parse --verify --default HEAD "$@") ||
die "Invalid commit: $[join(ARGV)]"

case (ACTION) {
edit {
	if test ${GIT_NOTES_REF#refs/notes/} = $GIT_NOTES_REF {
		die "Refusing to edit notes in $GIT_NOTES_REF (outside of refs/notes/)"
	}

	setvar MSG_FILE = ""$GIT_DIR/new-notes-$COMMIT""
	setvar GIT_INDEX_FILE = ""$MSG_FILE.idx""
	export GIT_INDEX_FILE

	trap '
		test -f "$MSG_FILE" && rm "$MSG_FILE"
		test -f "$GIT_INDEX_FILE" && rm "$GIT_INDEX_FILE"
	' 0

	setvar CURRENT_HEAD = $(git show-ref "$GIT_NOTES_REF" | cut -f 1 -d ' ')
	if test -z $CURRENT_HEAD {
		setvar PARENT = ''
	} else {
		setvar PARENT = ""-p $CURRENT_HEAD""
		git read-tree $GIT_NOTES_REF || die "Could not read index"
	}

	if test -z $MESSAGE {''
		GIT_NOTES_REF= git log -1 $COMMIT | sed "s/^/#/" > "$MSG_FILE"
		if test ! -z $CURRENT_HEAD {
			git cat-file blob :$COMMIT >> "$MSG_FILE" 2> /dev/null
		}
		setvar core_editor = "$(git config core.editor)"
		${GIT_EDITOR:-${core_editor:-${VISUAL:-${EDITOR:-vi}}}} $MSG_FILE
	} else {
		echo $MESSAGE > "$MSG_FILE"
	}

	grep -v ^# < "$MSG_FILE" | git stripspace > "$MSG_FILE".processed
	mv "$MSG_FILE".processed $MSG_FILE
	if test -s $MSG_FILE {
		setvar BLOB = $(git hash-object -w "$MSG_FILE") ||
			die "Could not write into object database"
		git update-index --add --cacheinfo 0644 $BLOB $COMMIT ||
			die "Could not write index"
	} else {
		test -z $CURRENT_HEAD &&
			die "Will not initialise with empty tree"
		git update-index --force-remove $COMMIT ||
			die "Could not update index"
	}

	setvar TREE = $(git write-tree) || die "Could not write tree"
	setvar NEW_HEAD = $(echo Annotate $COMMIT | git commit-tree $TREE $PARENT) ||
		die "Could not annotate"
	git update-ref -m "Annotate $COMMIT" \
		$GIT_NOTES_REF $NEW_HEAD $CURRENT_HEAD
}
show {
	git rev-parse -q --verify "$GIT_NOTES_REF":$COMMIT > /dev/null ||
		die "No note for commit $COMMIT."
	git show "$GIT_NOTES_REF":$COMMIT
}
* {
	usage
}
}