#!/usr/bin/env bash
# Display git-tracked files (or with -d, just directories) as a compact tree.
# With -u, show untracked files instead.
# With -u -I, show all untracked files, including ignored ones.
# With a REGEX argument, show only the paths it matches.
# Requires hledger (with a version <1.40, remove the -n below).

set -e

usage() {
    cat <<EOF
gtree [-d] [REGEX] - list some or all git-tracked files as an indented tree.
Directories are shown with a trailing slash.
REGEX is a case-insensitive grep regexp matching the relative file paths.
-d: show directories only
-u: show untracked files instead
-I: with -u, also show ignored untracked files

Examples:
gtree
gtree -d
gtree -u
gtree yaml
gtree '(^|/)((bsd)?m|sh)ake'
EOF
    exit
}

ARGS=()
while [[ $# -gt 0 ]]; do
    key="$1"
    case $key in
        -h|--help)
            HELP=1
            shift
            ;;
        -d)
            D=1
            shift
            ;;
        -u)
            U=1
            shift
            ;;
        -I)
            I=1
            shift
            ;;
        *)
            if [[ "$1" != -* ]]
            then
                ARGS+=("$1")
                shift
            else
                >&2 echo "Error: unknown option $1"
                exit 1
            fi
            ;;
    esac
done
if [[ $HELP = 1 ]]; then usage; exit; fi

REGEX="${ARGS[0]:-.}"
ROOT=$(pwd)
GITLS="git ls-files ${U:+-o $(if [[ $I = 1 ]]; then echo ''; else echo '--exclude-standard'; fi)}"
# XXX the hledger accounts trick doesn't work for paths with double spaces in them
$GITLS \
    | grep -iE "$REGEX" \
    | sed -e 's%/%/:%g' -e "s%^%account $ROOT/:%" \
    | hledger -n -f- accounts -t \
    | grep -E "$(if [[ $D = 1 ]]; then echo '/$'; else echo '.'; fi)"