#!/usr/bin/env bash
#
# Author: Georg Voell - georg.voell@standby.cloud
# Version: @(#)check-port 3.3.1 16.03.2026 (c)2026 Standby.cloud
# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
#
# This script can be used free of charge. Use it as is or customize as needed. It is not guaranteed to be
# error free and you will not be reimbursed for any damage it may cause.
#
#@  Checks if port can be reached over the internet (ingres).
#@
#@Usage: check-port [options] port
#@  Options:
#@    -h, --help           : Displays helptext.
#@    -v, --version        : Displays the version of the script.
#@    -o, --output <string>: Output format: <string> can be "line", "keys", "json", "etsv", "tsv" or "table" (default).
#@  Port: Can be a specific port or a port range e.g. '22-25,80,443' e.g. 80 (for http)
#
# Exit codes:
#  01: Unknown or wrong parameter.
#  02: **curl** not found. This script needs **curl** to perform.
#  03: No internet connection.
#  99: User interrupt.
#
# Update history:
#
# V 3.0.0 02.05.2020 New version
# V 3.0.1 03.06.2020 Using transfer instead of curl
# V 3.0.2 11.06.2020 Using library
# V 3.0.3 21.05.2023 Using HTTPS instead of HTTP
# V 3.1.0 05.06.2023 New copyright
# V 3.2.0 11.09.2024 New minor version
# V 3.2.1 13.10.2024 Don't use convert-json and jq
# V 3.3.0 19.01.2026 Revised with support of Claude Code
# V 3.3.1 16.03.2026 Optimized: replaced backticks with $(); [ ] with [[ ]];
#                    echo|grep with [[ == -* ]]; removed UUOC
#

# Find executable bash library and source it
lib=$(command -v lib.bash 2>/dev/null)
if [[ -n "$lib" ]]; then
	source "$lib"
else
	progdir=$(dirname "$0")
	if [[ -r "${progdir}/lib.bash" ]]; then
		source "${progdir}/lib.bash"
	else
		echo "Unexpected error: Unable to locate bash library 'lib.bash'."
		exit 1
	fi
fi

# Set the Base URL
url="https://ifconfig.co/port"

# Preset
param=""
maxchecks=25        # Maximal number of port checks
formatstr=""        # Print result in table format

# Check parameters: Loop until all parameters are used up
while [[ $# -gt 0 ]]; do
	pname="${1}"
	case "$1" in
		-o | --output)
			shift
			if [[ -n "$1" ]]; then
				if [[ -z "$formatstr" ]]; then
					formatstr=$(ToLower "$1")
					case "$formatstr" in
						etsv|tsv|line|keys|table|json) ;;
						*) errstr="Unknown format '$formatstr' after parameter '$pname'. Please choose from 'table', 'line', 'keys', 'etsv', 'tsv' or 'json'." ;;
					esac
				else
					errstr="Option '$pname' used more then once."
				fi
				shift
			else
				errstr="Please specify a format ('tsv', 'line', 'table' or 'json') after parameter '$pname'."
			fi
			;;
		-v | --version)
			shift
			showversion=true
			;;
		-h | --help)
			shift
			showhelp=true
			;;
		*)
			shift
			if [[ "$pname" == -* ]]; then
				errstr="Unknown option '$pname'."
			else
				if [[ -z "$errstr" ]]; then
					if [[ -z "$param" ]]; then
						param=$(ToLower "$pname")
					else
						errstr="Port was already specified '$param'. Unknown additional parameter: '$pname'."
					fi
				fi
			fi
			;;
	esac
done

# Plausibility checks
if [[ -z "$errstr" && -z "$param" ]]; then
	errstr="No port number given."
else
	if [[ -z "$formatstr" ]]; then
		formatstr="table"
	fi
fi

# Display help or error message
DisplayHelp

# Check if we have curl in path
curl=$(filecheck -x curl)

if [[ -z "$curl" ]]; then
	exitcode=2
	errormsg $exitcode "($progstr) No 'curl' in '$PATH'. Please install first e.g. 'sudo yum -y install curl'."
	exit $exitcode
else
	myip=$(get-ip ip)
	if [[ -z "$myip" ]]; then
		exitcode=3
		errormsg $exitcode "($progstr) No connection to the Internet. Can't check ports."
		exit $exitcode
	else
		# Convert port range
		convert-number "$param" --max 65535 --padding 5 > "$scratchfile"
		# Read ports - avoid UUOC with direct redirect
		ports=$(head -n $maxchecks "$scratchfile" | tr '\n' ' ')

		printf "%s\t%s\t%s\n" "ip" "port" "reachable" > "${scratchfile}.out"
		for port in $ports; do
			result=""
			while [[ -z "$result" ]]; do
				# Get result from server
				transfer --quiet "${url}/${port}" --export "$scratchfile"
				stat=$?

				if [[ $stat -eq 0 ]]; then
					result=$(head -n 1 "$scratchfile")
					if [[ "$result" == "{"* ]]; then
						port=$(grep '"port":'     "$scratchfile" | cut -d':' -f2 | tr -d '" ,')
						reachable=$(grep '"reachable":' "$scratchfile" | cut -d':' -f2 | tr -d '" ,')
						printf "%s\t%s\t%s\n" "$myip" "/$port/" "/$reachable/" >> "${scratchfile}.out"
					fi
				fi
			done
		done

		result=$(filecheck -sl "${scratchfile}.out")
		if [[ "$result" == "${scratchfile}.out" ]]; then
			if [[ "$formatstr" == "json" ]]; then
				print-table --import "${scratchfile}.out" --output "$formatstr" \
					| sed 's|\("contentItems":.*\)|\1,\n  "creator": "'"$progstr"'"|'
			else
				print-table --import "${scratchfile}.out" --output "$formatstr"
			fi
		fi
	fi
fi

# Cleanup and exit
Cleanup
exit $exitcode