#!/usr/bin/env bash

# TODO:
# + trap exit signals to cleanup all temp files and cancel all jobs
# + run in batches to prevent spawning way too many processes
# + detect when piping into another application and suppress colors?
# + temp file control (or none for no disk space)?
# + command line options or env vars?
#		+ --tlds "com,net,org"
#		+ --max-concurrent-whois-jobs
#		+ --avail-regex and --timeout-regex

# suggested usage: ./check_domain | tee /tmp/chkdmn && sort /tmp/chkdmn

# constants
AVAIL_REGEX='^No match|^NOT FOUND|^Not fo|AVAILABLE|^No Data Fou|has not been regi|No entri'
TIMEOUT_REGEX='^Timeout'

COLOR_RESET="\x1b[0m" COLOR_GREEN="\x1b[32m"
COLOR_YELLOW="\x1b[33m"
COLOR_RED="\x1b[31m"

DOMAINS=( \
	'.com' '.net' '.org' '.eu' '.in' '.it' '.sk' '.ac' '.ae' '.af' '.ag' '.al' \
	'.am' '.as' '.at' '.ax' '.be' '.bi' '.bo' '.by' '.bz' '.cc' '.cd' '.cf' '.cg' \
	'.ch' '.ci' '.cl' '.cm' '.cn' '.co' '.cr' '.cx' '.cz' '.dk' '.dm' '.do' '.ec' \
	'.ee' '.es' '.fi' '.fm' '.fo' '.ga' '.gd' '.gf' '.gg' '.gl' '.gp' '.gq' '.gr' \
	'.gs' '.gt' '.gy' '.hk' '.hm' '.hn' '.ht' '.id' '.im' '.in' '.io' '.ir' '.is' \
	'.je' '.ke' '.kg' '.kz' '.la' '.lc' '.li' '.lt' '.lu' '.lv' '.ly' '.me' '.mg' \
	'.mk' '.ml' '.mn' '.mq' '.ms' '.mu' '.mw' '.mx' '.na' '.ne' '.ng' '.nl' '.nu' \
	'.nz' '.pe' '.ph' '.pk' '.pl' '.pr' '.pt' '.pw' '.qa' '.ro' '.rs' '.ru' '.rw' \
	'.sb' '.sc' '.sd' '.se' '.sh' '.si' '.sl' '.sr' '.st' '.su' '.sx' '.sg' '.tk' \
	'.tl' '.to' '.tv' '.tw' '.ug' '.vc' '.ve' '.vg' '.vn' '.vu' '.ws' \
	)

# check dependencies
if command -v whois >/dev/null 2>&1; then
	:
else
	echo "You need to install whois before proceeding!"
	exit 2
fi

# check arguments
if [ "$#" == "0" ]; then
	echo "You need to supply at least one argument!"
	exit 1
fi

# main function
check_domain() {
	if [ "$#" == "0" ]; then
		echo "No domain specified."
		return
	fi

	local domain="$1"
	# create a unique temporary file
	TMP=$(mktemp "${domain}_XXX")
	# dump whois output into temp file
	whois "$domain" > "$TMP" 2>&1
	# check contents and output appropriately
	if egrep -q "$AVAIL_REGEX" "$TMP" > /dev/null 2>&1; then
		echo -e "$COLOR_GREEN$domain / probably available$COLOR_RESET"
	elif egrep -q "$TIMEOUT_REGEX" "$TMP" > /dev/null 2>&1; then
		echo -e "$COLOR_YELLOW$domain / timed out$COLOR_RESET"
	else
		echo -e "$COLOR_RED$domain / unavailable$COLOR_RESET"
	fi
	rm "$TMP"
}

# iterate all provided domain names combined with all TLDs and check them
# concurrently
elements=${#DOMAINS[@]}
while (( "$#" )); do
	for (( i=0; i<$elements; i++ )); do
		D="$1${DOMAINS[${i}]}"
		check_domain "${D}" &
	done
	shift
done
wait