#!/bin/sh

PROMPT='=='
SHOW='show'

cleanup () {
	rm -f "$TMPFILE";
}

go () {
	printf '%s\r\n' "$1" | nc "$2" "$3"
}

usage() {
	printf '%s\n' \
	    'usage:' \
	    '  visit a Gopher URL:' \
	    "     $0 <URL>" \
	    '  init links:' \
	    "     $0 -i" \
	    '  show this help:' \
	    "   $0 -h" \
	    '' \
	    'In a gopher page, just type:' \
	    "  !./g % LINE" \
	    'to visit the resource at LINE, or:' \
	    "  !./d % LINE" \
	    'to download the resource at LINE\n'\
	    "  !./v URL" \
	    'to visit a Gopher URL' 
	exit 0
}

goto_url(){
        URL="$(echo "$1" | sed 's,gopher://,,g')"
        hostport=$(echo "$URL" | cut -d "/" -f 1)
        host="$(echo "$hostport" | cut -d ":" -f 1)"
        port="$(echo "$hostport" | cut -s -d ":" -f 2)"
        [ -z "$port" ] && port='70'
        type=$(echo "$URL" | cut -s -d "/" -f 2)
        [ -z "$type" ] && {
		type='1'
                sel="/"
		go "$sel" "$host" "$port"
		return
        }
        [ -n "${type#?}" ] && echo "Invalid Gopher URL" >&2 && exit 1
        ## Check if type is a valid one
        type="$(echo $type | sed -n '/^[0-9ITghis+]$/p')"
        [ -z "${type}" ] && echo "Invalid Gopher URL" >&2 && exit 1
        sel=/$(echo "$URL" | cut -s -d "/" -f 3-)
        go "$sel" "$host" "$port"
}



trap cleanup INT QUIT HUP ABRT TERM

[ "$#" -lt 1 ] || [ "$1" = "-h" ] && usage

script_name="$(basename "$0")"

if [ "${script_name}" = "gophed" ] && [ "$1" = "-i" ]; then
	ln -sf "$0" g
	ln -sf "$0" d
	ln -sf "$0" v
	exit 0
fi


if [ "$script_name" = "gophed" ] || [ "$script_name" = "v" ]; then
	sel="$(printf '%s' "$1" | sed -E 's:/:+:g')"
	TMPFILE="$(mktemp "/tmp/gophed_${2}_${sel}_$3.XXXXXXXXXXXXXXXXXXX")"
	goto_url "$1" > "$TMPFILE"
	while read -r line; do echo "$line"; done | ed -p "$PROMPT" "$TMPFILE" 
	cleanup
	exit 0
fi

if [ "$script_name" = "g" ] || [ "$script_name" = "d" ]; then
	LINE=$(awk "{if (NR == $2) print \$0;}" $1)
	RESOURCE="$(printf '%s' "$LINE" | cut -d '	' -f 2)"
	HOST="$(printf '%s' "$LINE" | cut -d '	' -f 3)"
	PORT="$(printf '%s' "$LINE" | awk -F '	' '{ match($4,/[[:digit:]]+/); print substr($4,RSTART,RLENGTH) }')"

	if [ "$script_name" = "g" ]; then
		SEL="$(printf '%s' "$RESOURCE" | sed -E 's:/:+:g')"
		TMPFILE="$(mktemp "/tmp/gophed_${HOST}_${SEL}_$PORT.XXXXXXXXXXXXXXXXXXX")"
		go "$RESOURCE" "$HOST" "$PORT" > "$TMPFILE"
		while read -r line; do echo "$line"; done | ed -p "$PROMPT" "$TMPFILE"
	fi
	if [ "$script_name" = "d" ]; then
		DIR_RESOURCE="$(dirname "$RESOURCE")"
		printf 'Download %s in %s\n' "$RESOURCE" "$HOST$RESOURCE"
		mkdir -p "$HOST/$DIR_RESOURCE"
		go "$RESOURCE" "$HOST" "$PORT" > "$HOST$RESOURCE"
	fi
	cleanup
	exit 0
fi
printf '%s: command not found\n' "$script_name"

cleanup

exit 1