#!/usr/bin/env rc

flag e +

API=https://api.pushover.net/1/messages.json

fn usage {
	echo 'usage: pushover.rcsh [send] [-t title] [-p priority] [-s sound] [-d device] [-u url] [-U url_title] [--retry seconds] [--expire seconds] [--html | --monospace] [--dry-run] message...' >[1=2]
	echo '       pushover.rcsh validate [-d device]' >[1=2]
	echo '       pushover.rcsh receipt RECEIPT' >[1=2]
	echo '       pushover.rcsh cancel-receipt RECEIPT' >[1=2]
	echo >[1=2]
	echo environment: >[1=2]
	echo '  PUSHOVER_TOKEN  application API token' >[1=2]
	echo '  PUSHOVER_USER   user or group key' >[1=2]
	echo >[1=2]
	echo examples: >[1=2]
	echo '  pushover.rcsh -t "Traefik alert" "Traefik is not 3/3 ready"' >[1=2]
	echo '  pushover.rcsh -p 1 -s siren "High-priority ingress alert"' >[1=2]
	exit 1
}

fn post {
	curl -sS $*
}

fn invalid {
	echo $* >[1=2]
	exit 1
}

fn validate_priority {
	if (! ~ $1 -2 -1 0 1 2) {
		invalid 'Invalid priority: '^$1^' (expected -2, -1, 0, 1, or 2)'
	}
}

fn validate_uint {
	if (! ~ `{printf %s $2 | awk '/^[0-9]+$/ { print "ok" }'} ok) {
		invalid 'Invalid '^$1^': '^$2^' (expected a positive integer)'
	}
	if (~ $2 0) {
		invalid 'Invalid '^$1^': '^$2^' (expected a positive integer)'
	}
}

fn validate_url {
	if (~ $1 *' '* *'	'*) {
		invalid 'Invalid URL: '^$1^' (must not contain whitespace)'
	}
	if (! ~ $1 http://?* https://?*) {
		invalid 'Invalid URL: '^$1^' (expected http://... or https://...)'
	}
}

fn validate_sound {
	if (! ~ $1 pushover bike bugle cashregister classical cosmic falling gamelan incoming intermission magic mechanical pianobar siren spacealarm tugboat alien climb persistent echo updown vibrate none) {
		invalid 'Invalid sound: '^$1^' (expected a built-in Pushover sound name)'
	}
}

fn validate_device {
	if (~ $1 ()) {
		return
	}
	if (! whatis jq >/dev/null >[2=1]) {
		invalid 'Cannot validate device without jq in PATH'
	}
	ok=`{curl -sS --max-time 5 \
		--form-string token=^$PUSHOVER_TOKEN \
		--form-string user=^$PUSHOVER_USER \
		--form-string device=^$1 \
		https://api.pushover.net/1/users/validate.json \
		| jq -r 'if .status == 1 then "ok" else "bad" end'}
	if (! ~ $ok ok) {
		invalid 'Invalid device: '^$1
	}
}

if (~ $PUSHOVER_TOKEN ()) {
	echo PUSHOVER_TOKEN is required >[1=2]
	exit 1
}
if (~ $PUSHOVER_USER ()) {
	echo PUSHOVER_USER is required >[1=2]
	exit 1
}

cmd=send
if (~ $1 send validate receipt cancel-receipt) {
	cmd=$1
	shift
}

switch($cmd) {
case validate
	device=()
	while(! ~ $1 ()) {
		switch($1) {
			case -d --device
				shift
				device=$1
			case -h --help
				usage
			case *
				echo Unknown argument: $1 >[1=2]
				exit 1
		}
		shift
	}
	form=(--form-string token=^$PUSHOVER_TOKEN --form-string user=^$PUSHOVER_USER)
	if (! ~ $device ()) {
		form=($form --form-string device=^$device)
	}
	post $form https://api.pushover.net/1/users/validate.json
	exit $status

case receipt
	if (! ~ $#* 1) {
		usage
	}
	post --form-string token=^$PUSHOVER_TOKEN https://api.pushover.net/1/receipts/$1.json
	exit $status

case cancel-receipt
	if (! ~ $#* 1) {
		usage
	}
	post --form-string token=^$PUSHOVER_TOKEN https://api.pushover.net/1/receipts/$1/cancel.json
	exit $status
}

host=`{hostname}
title=$host^' cli alert'
priority=0
sound=()
device=()
url=()
url_title=()
retry=60
expire=3600
html=0
monospace=0
dry_run=0

while(! ~ $1 ()) {
	switch($1) {
		case -t --title
			shift
			title=$1
		case -p --priority
			shift
			priority=$1
			validate_priority $priority
		case -s --sound
			shift
			sound=$1
			validate_sound $sound
		case -d --device
			shift
			device=$1
		case -u --url
			shift
			url=$1
			validate_url $url
		case -U --url-title
			shift
			url_title=$1
		case --retry
			shift
			retry=$1
		case --expire
			shift
			expire=$1
		case --html
			html=1
		case --monospace
			monospace=1
		case --dry-run
			dry_run=1
		case -h --help
			usage
		case *
			break
	}
	shift
}

if (~ $#* 0) {
	usage
}

validate_priority $priority
validate_uint retry $retry
validate_uint expire $expire
if (~ $priority 2) {
	if (! ~ $retry [3-9][0-9] [1-9][0-9][0-9]* ) {
		invalid 'Invalid retry: '^$retry^' (priority 2 requires at least 30 seconds)'
	}
	if (! ~ $expire [1-9] [1-9][0-9] [1-9][0-9][0-9] [1-9][0-9][0-9][0-9] 10[0-7][0-9][0-9] 10800) {
		invalid 'Invalid expire: '^$expire^' (priority 2 requires at most 10800 seconds)'
	}
}
if (! ~ $priority 2) {
	if (! ~ $retry 60) {
		invalid '--retry is only valid with priority 2'
	}
	if (! ~ $expire 3600) {
		invalid '--expire is only valid with priority 2'
	}
}
if (! ~ $url ()) {
	validate_url $url
}
if (~ $url () && ! ~ $url_title ()) {
	invalid '--url-title requires --url'
}
if (~ $html 1 && ~ $monospace 1) {
	invalid '--html and --monospace cannot be used together'
}
if (! ~ $sound ()) {
	validate_sound $sound
}
validate_device $device

message=$"*#"
form=(--form-string token=^$PUSHOVER_TOKEN \
	--form-string user=^$PUSHOVER_USER \
	--form-string title=^$"title \
	--form-string message=^$"message \
	--form-string priority=^$priority)

if (! ~ $sound ()) {
	form=($form --form-string sound=^$sound)
}
if (! ~ $device ()) {
	form=($form --form-string device=^$device)
}
if (! ~ $url ()) {
	form=($form --form-string url=^$url)
}
if (! ~ $url_title ()) {
	form=($form --form-string url_title=^$"url_title)
}
if (~ $html 1) {
	form=($form --form-string html=1)
}
if (~ $monospace 1) {
	form=($form --form-string monospace=1)
}
if (~ $priority 2) {
	form=($form --form-string retry=^$retry --form-string expire=^$expire)
}

if (~ $dry_run 1) {
	echo token='(redacted)'
	echo user='(redacted)'
	echo title=$"title
	echo message=$"message
	echo priority=$priority
	if (! ~ $sound ()) {
		echo sound=$sound
	}
	if (! ~ $device ()) {
		echo device=$device
	}
	if (! ~ $url ()) {
		echo url=$url
	}
	if (! ~ $url_title ()) {
		echo url_title=$"url_title
	}
	if (~ $html 1) {
		echo html=1
	}
	if (~ $monospace 1) {
		echo monospace=1
	}
	if (~ $priority 2) {
		echo retry=$retry
		echo expire=$expire
	}
	exit 0
}

post $form $API