#!/bin/sh

help() { echo "help - get help for shell commands or programs

USAGE:
	help [OPTION...] <QUERY>

OPTIONS:
	-a  show all available help
	-h  show this help message
	"; }

while getopts 'avh' o; do case "$o" in
	a) aflag=0;;
	h) help; exit ;;
	*) printf "help: invalid option -- '%s'" "$OPTARG" ;;
esac done
shift $((OPTIND - 1))

[ "$#" -lt 1 ] && help >&2 && exit 2


##############################################################
###    H E L P    F U N C T I O N S    I N    O R D E R    ###
##############################################################

man_query() {
  man -w "$query" >/dev/null 2>&1 || return 2
  man -a "$query"
}

info_query() {
	# if command -v info
  [ -n "$(info --where "$query")" ] || return 2
  info --vi-keys --all "$query"
}

show_script() {
  file="$(which "$query" 2>/dev/null)" || return 2
  "${PAGER:-less}" "$file"
}

cmd_help() {
	if content="$($query -h 2>/dev/null)"; then
		printf "$ %s -h" "$query"
  elif content="$($query --help 2>/dev/null)"; then
		printf "$ %s --help" "$query"
	else
		return 2
	fi
	printf '\n%s\n' "$content" | "${PAGER:-less}" -X
	echo
}

tldr_query() {
  content="$(tldr --color=always "$query" 2>/dev/null)" || return 2
  printf "\n$ tldr '%s'\n%s\n\n" "$query" "$content" | "${PAGER:-less}" -X
}

pkg_info() {
	if command -v pacman >/dev/null; then
		cmd="$ pacman -Si $query"
		info="$(pacman -Si "$query" 2>/dev/null)" || return 2
	elif command -v apt >/dev/null; then
		cmd="$ apt show $query"
		info="$(apt show "$query" 2>/dev/null)" || return 2
	elif command -v pkg >/dev/null; then
		cmd="$ pkg info $query"
		info="$(pkg info "$query" 2>/dev/null)" || return 2
	else
		return
	fi
	[ -z "$info" ] && return 2
  printf "\n%s\n%s\n\n" "$cmd" "$info" | "${PAGER:-less}" -X
}

##########################################################
###    E N D    O F    H E L P    F U N C T I O N S    ###
##########################################################


help_funcs="$(sed -ne "/^###    H E L P/,/^###    E N D/ s/^\([a-zA-Z0-9_]\+\)\(\).*/\1/p" "$0")"
main() {
	if [ "$aflag" = 0 ]; then
		eval "$help_funcs"
	else
		eval "$(echo "$help_funcs" | sed -z 's/\n/||/g' | sed 's/||$//')"
	fi
}

query="$*"
[ -f "$query" ] && { "${PAGER:-less}" "$query"; exit 0; }
[ -d "$query" ] &&
	{ ls -AlFh --color --group-directories-first -- "$query"; exit 0; }

command -V "$query" 2>/dev/null && { echo; export HELP_FOUND=1; }

main || [ "$HELP_FOUND" = 1 ] ||
	{ echo "No help found for '$query'" >&2; exit 2; }