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

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

function usage() {
    echo "usage:  $0 \"text to send\""
    echo
    echo "Instructs telegram bot to send the supplied message to a chat."
    echo
    echo "Needs these files to work:"
    echo "File with telegram bot token: ${TOKENFILE}"
    echo "File with telegram chat id:   ${CHATFILE}"
}

if [[ $1 == "-h" || $# -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