#!/bin/bash
DEFAULT_TOKENFILE=${HOME}/.telegram/bottoken
DEFAULT_CHATFILE=${HOME}/.telegram/chatid
TOKENFILE=${DEFAULT_TOKENFILE}
CHATFILE=${DEFAULT_CHATFILE}

function die() {
    echo "FATAL:  $*" >&2
    exit 1
}

function usage() {
    echo "usage:  $0 [OPTIONS] \"text to send\""
    echo
    echo "Instructs telegram bot to send the supplied message to a chat."
    echo
    echo "OPTIONS"
    echo "         -b  filename       Override default bot token file (${DEFAULT_TOKENFILE})"
    echo "         -c  filename       Override default chat id token file (${DEFAULT_CHATFILE})"
    echo
    echo "Needs these files to work:"
    echo "   File with telegram bot token: ${DEFAULT_TOKENFILE}"
    echo "   File with telegram chat id:   ${DEFAULT_CHATFILE}"
}

ARGS="b:c:h"
while getopts "$ARGS" i; do
	case "$i" in
		b)
                        TOKENFILE=$OPTARG
			;;
		c)
                        CHATFILE=$OPTARG
			;;
		h)
			usage;
                        exit 1;
			;;
		*)
			usage;
                        exit 1;
			;;
	esac
done
shift $((OPTIND - 1))


if [[ $# -ne 1 ]]; then
    usage
    exit 1
fi

[[ ! -e ${TOKENFILE} ]] && die "bot token file '${TOKENFILE}' doesn't exist";
[[ ! -e ${CHATFILE} ]] && die "chat id file '${CHATFILE}' doesn't exist";

TOKEN=$(egrep  -v '^#' "$TOKENFILE")
CHAT=$(egrep -v '^#' "$CHATFILE")

[[ -z ${TOKEN} ]] && die "bot token file '${TOKENFILE}' appears empty";
[[ -z ${CHAT} ]] && die "chat id file '${CHATFILE}' appears empty";

msg="$*"

res=$(curl -s --data "text=$msg" --data "chat_id=$CHAT" 'https://api.telegram.org/bot'$TOKEN'/sendMessage' 2>&1)
rv=$?
[[ $rv -ne 0 ]] && fatal "curl failed"
status=$(jq -r .ok <<<"${res}")
[[ $status != "true" ]] && die "telegram API returned failure:  ${res}"
exit 0