#!/bin/sh

### read from $1 and print on stdout a list of MENU selectors IDs
### in the format:
###
### 1|SELECTOR|HOST|PORT|SHA256
###
### where SHA256 is the SHA256SUM of "1|SELECTOR|HOST|PORT"
###
### *** DRY RUN ***
###
### If run as burrow?* (i.e., "burrow" followed by at least one 
### character), burrow will run in DRY MODE, i.e., it will just check
###  if the id provided as input exists, and then exit.
###
###------------------------------------------------
###
### (C) 2018 Vincenzo 'KatolaZ' Nicosia <katolaz@freaknet.org>
###
### Use, modify, redistribute under the terms of the GNU General 
### Public License version 3 or, at your option, any other version.
### 
## function
get_dirs(){
	src_type=$(echo "$1" | cut -d "|" -f 1)
	src_sel=$(echo "$1" | cut -d "|" -f 2 | cut -d "?" -f 1)
	src_host=$(echo "$1" | cut -d "|" -f 3)
	src_port=$(echo "$1" | cut -d "|" -f 4)
	src_id=$(echo "$1" | cut -d "|" -f 5)
	##echo "src_sel: \"${src_sel}\"" >&2
	OLDIFS=$IFS
	#IFS=$'\t\n'
	IFS="|"
	src_dir=$(echo "${src_id}" | cut -c -2)
	touch "${src_dir}/${src_id}"
	while read name sel host port; do
		##echo "sel: \"$sel\"" >&2
		[ "$sel" = "Err" -o -z "$sel" ] && continue
		TYPE=$(echo "$name" | cut -c 1)
		[ "$TYPE" = "i" ] && continue
		dst_sel=$(echo "$sel" | cut -d "?" -f 1)
		##echo "dst_sel: \"${dst_sel}\"" >&2 
		[ "${dst_sel}" = "${src_sel}" -a "${src_type}" = "$TYPE" \
		    -a "${src_host}" = "$host"  -a "${src_port}" = "$port" ] && continue;
		port=$(echo $port | sed -r -e 's/\r//g')
		dir_id=$(echo "${TYPE}|${sel}|${host}|${port}" | sed 's/^1||/1|\/|/g')
		dest_id=$(echo "${dir_id}" | sha256sum | cut -d " " -f 1 )
		echo "${src_id}" "${dest_id}" >&2
		[ "${TYPE}" = "1" ] && {
			echo "${dir_id}|${dest_id}" | tee -a ${src_dir}/${src_id}
		}
	done 
	IFS="$OLDIFS"
}


### get a MENU selector ID (as generated by get_dirs) and retrieves it
### from the gopherspace
### 
## function
retrieve_selector(){
	sel="$1"
	SEL=$(echo "$1" | cut -d "|" -f 2)
	HOST=$(echo "$1" | cut -d "|" -f 3)
	PORT=$(echo "$1" | cut -d "|" -f 4)
	printf "${SEL}\r\n" | netcat -w 5 "${HOST}" "${PORT}"

}

###
### Check if a given selector has been visited. In that case, just
### output the corresponding file (which contains all the outgoing links 
### of the selector) and exits
###
## function
check_selector_present(){
	sel_id="$1"
	sel_dir="$(echo ${sel_id} | cut -c -2)"
	[ -d "${sel_dir}" -a -f "${sel_dir}/${sel_id}" ] && echo "${SRC}" >>present && exit
##	{
	## if at least one of the neighbours of sel_id is missing, cat the entire list of
        ## neighbours to be re-visited and exit
##		for i in $(cat ${sel_dir}/${sel_id}); do 
##			i_dir="$(echo ${i} | cut -c -2)"
##			[ ! -f ${i_dir}/${i} ] && cat "${sel_dir}/${sel_id}" && break
##		done
##		exit
##	}
	[ ! -d "${sel_dir}" ] && mkdir -p "${sel_dir}"
}

[ $# -lt 1 ] && echo "Usage: $0 <gopherlink>" && exit 1


SRC="$1"

src_id=$(echo "$SRC" | cut -d "|" -f 5 )

check_selector_present "${src_id}"

echo "selector ${src_id} not found" >> logfile.txt

MYNAME=$(basename $0)

if [ -z "${MYNAME##burrow}" ]; then  
	retrieve_selector "$SRC" | sed -r -e 's/\t/|/g' | get_dirs "$SRC"
fi