## vim:ft=zsh
## wrapper around man, finfo, etc
## Usage: help <topic>
typeset -a methods
typeset method topic
typeset -i found check_only all
methods=(man zshfunction zshbuiltin apt)

while [[ ${1} == -* ]] {
	case ${1} in
		-a|--all) all=1 ;;
		-c|--check-only) check_only=1 ;;
		-t|--topic) topic=${2}; shift ;;
		-|--) shift; break ;;
		*) echo "unknown option: ${1}" ;;
	esac
	shift
}

function help_check_man      { man -w ${1} &> /dev/null }
function help_check_zshfunction { whichf ${1} &> /dev/null }
function help_check_zshbuiltin  { (( ${+builtins[$1]} )) }
function help_check_apt {
	[[ ${commands[$1]} != ${HOME}* ]] && [[ -n ${commands[$1]} ]] && [[ -n ${commands[apt-file]} ]]
}

function help_show_man       { man ${1} }
function help_show_zshfunction  { finfo ${1} }
function help_show_zshbuiltin   { man zshbuiltins | less -p "       ${1}" }
function help_show_apt {
	apt-cache show ${(s/:/)$(apt-file search -F ${commands[$1]})[1]}
}

if [[ -z ${1} ]] {
	echo "Usage: help <command>" > /dev/stderr
	return 1
}

for method in ${methods}; {
	if [[ -n ${topic} && ${method} != ${topic} ]] {
		continue
	}
	if help_check_${method} ${1}; then
		((found++))
		if ((check_only)) {
			echo ${method}
			continue
		}
		help_show_${method} ${1}
		((all)) || break
	fi
}

if ((found == 0)) {
	echo "Sorry, no clue." > /dev/stderr
	return 1
}