#!/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 resource:' \
	    "     $0 <path> <server> <port>" \
	    '  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'
	exit 0
}

trap cleanup INT QUIT HUP KILL ABRT TERM

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

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

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

if [ "$script_name" = gophed ] || [ "$script_name" = v ]; then
	sel="$(printf '%s' "$1" | sed -r 's:/:+:g')"
	TMPFILE="$(mktemp "/tmp/gophed_${2}_${sel}_$3.XXXXXXXXXXXXXXXXXXX")"
	go "$1" "$2" "$3" > "$TMPFILE"
	cat "$SHOW" - | ed -p "$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' "$RESOURCE" | sed -r 's:/:+:g')"
		TMPFILE="$(mktemp "/tmp/gophed_${HOST}_${SEL}_$PORT.XXXXXXXXXXXXXXXXXXX")"
		go "$RESOURCE" "$HOST" "$PORT" > "$TMPFILE"
		cat "$SHOW" - | 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$RESOURCE"
	fi
	cleanup
	exit 0
fi
printf '%s: command not found\n' "$scriptname"

cleanup

exit 1