POSIX_Scripts/plumber

#!/bin/sh -e

web_handler()
{
    # Choose a random invidious instance to distribute load.
    # Good digital citizenship is important, you know.
    rand_inst()
    {
	case $(($(rand)%6)) in
	    0) printf "vid.puffyan.us"           ;;
	    1) printf "inv.riverside.rocks"      ;;
	    2) printf "invidious.kavin.rocks"    ;;
	    3) printf "invidious-us.kavin.rocks" ;;
	    4) printf "invidious.osi.kr"         ;;
	    5) printf "invidio.xamh.de"          ;;
	esac
    }

    case "${1}" in
	*youtu*) exec Links "$(printf "%s" "${1}"|sed -ne \
			   "s&\(http.*://\).*\(/.*\)&\1$(rand_inst)\2&p")" & ;;
	*reddit*) exec Links "$(printf "%s" "${1}"|sed -ne \
			   "s&\(http.*://\).*\(/.*/\)&\1libredd.it\2&p")" &  ;;
	*4chan.org*) exec Links "$(printf "%s" "${1}"|sed -ne \
			      "s&4chan&4channel&p")" &                       ;;
	*) exec Links "${1}" & ;;
    esac
}

edgecase()
{
    err()
    {
	printf "Plumber wasn't able to find a way to handle the following URI.\n%s\nError code: %s\nProbable reason: %s\n" "${1}" "${2}" "${3}"|xmessage -file - &
	exit 1
    }

    case "${2}" in
	0) set -- "${1}" "${2}" "Some other error." ;;
	1) set -- "${1}" "${2}" "It doesn't exist on the local filesystem." ;;
	2) set -- "${1}" "${2}" "There was a parsing error."
    esac

    err "${@}"
}

cleanse_prefix()
{
    if [ "$(printf "%s" "${1}"|cut -b1)" = 'f' ]
    then
	printf "%s\n" "$(printf "%s" "${1}"|sed -ne 's&file://\(.*\)&\1&p')"
    else
	printf "%s" "${1}"
    fi
}

cleanse_spaces()
{
    if [ "$(echo "${1}"|grep -c '%20')" = '1' ]
    then
	printf "%s\n" "${1}"|sed -e 's&%20&  *&g'
    else
	printf "%s\n" "${1}"
    fi
}

cleanse_leftparen()
{
    if [ "$(echo "${1}"|grep -c '%28')" = '1' ]
    then
	printf "%s\n" "${1}"|sed -e 's&%28&(&g'
    else
	printf "%s\n" "${1}"
    fi
}

cleanse_rightparen()
{
    if [ "$(echo "${1}"|grep -c '%29')" = '1' ]
    then
	printf "%s\n" "${1}"|sed -e 's&%29&)&g'
    else
	printf "%s\n" "${1}"
    fi
}


local_handler()
{


    set -- "$(cleanse_prefix "${1}")"
    set -- "$(cleanse_leftparen "${1}")"
    set -- "$(cleanse_rightparen "${1}")"


    if [ -e "${1}" ]
    then
	mime="$(file --mime-type -b "${1}")"

	case ${mime} in
	    *html*) exec Links "${1}" &  ;;
	    text*)  exec xless "${1}" &  ;;
	    video*) exec fpv   "${1}" &  ;;
	    audio*) exec fpm   "${1}" &  ;;
	    image*) exec iview "${1}" &  ;;
	    *pdf)   exec gv    "${1}" &  ;;
	    *)      set -- "${1}" "2"         ;; #Abort.
	esac
    else
	# Set the error code and throw an error.
	set -- "${1}" "1"
	edgecase "${@}"
    fi
}

# Commented lines will have support in the future.
case "$(printf "%s" "${1}"|cut -b 1,2,3,4)" in
    #    gopher) err "${@}"      ;;
    http)   web_handler "${@}"   ;;
    file)   local_handler "${@}" ;;
    #    ftp)    err "${@}"      ;;
    #    ssh)    err "${@}"      ;;
    *) firstchar=$(printf "%s" "${1}"|cut -b1)
       if [ "${firstchar}" = '~' ] || [ "${firstchar}" = '/' ]
       then
	   local_handler "${@}"
       else
	   set -- "${1}" "2"
	   edgecase "${@}"
       fi
esac

exit