#!/usr/bin/env bash
# deepdive-help -- Shows help
# > deepdive help [COMMAND]
##
# Author: Jaeho Shin <netj@cs.stanford.edu>
# Created: 2015-07-30
set -eu

: ${TMPDIR:=/tmp}

if [[ $# -gt 0 ]]; then
    Cmd=$1; shift
    exe=deepdive-"$Cmd"
    if exePath=$(type -p "$exe"); then
        exec usage "$exePath"
    else
        usage "$0" "$Cmd: invalid COMMAND" || true  # continue to enumerate available ones
    fi
else
    usage "$0"
fi

# enumerate available COMMANDs discoverable from PATH
echo
echo "# Available COMMANDs are:"
IFS=:
tmp=$(mktemp -d "$TMPDIR"/deepdive-usage.XXXXXXX)
trap 'rm -rf "$tmp"' EXIT
for path in $PATH; do
    for exe in "$path"/deepdive-*; do
        [ -x "$exe" ] || continue
        usage "$exe" | head -1 | sed -n '/ -- / s/.* -- //p' >>"$tmp"/desc
        cmd=${exe##*/deepdive-}
        echo "deepdive $cmd  #"
    done
done | column -t >"$tmp"/commands
paste "$tmp"/commands "$tmp"/desc