module main

import net.http
import time

// metrics_response returns a Prometheus / OpenMetrics formatted response.
fn (mut app App) metrics_response() http.Response {
	mut lines := []string{}

	// HELP/TYPE headers
	lines << '# HELP ntfy_bridge_uptime_seconds Seconds since the bridge started.'
	lines << '# TYPE ntfy_bridge_uptime_seconds gauge'
	lines << 'ntfy_bridge_uptime_seconds ${app.uptime_seconds()}'

	lines << '# HELP ntfy_bridge_notifications_total Total notifications sent (all sources).'
	lines << '# TYPE ntfy_bridge_notifications_total counter'
	lines << 'ntfy_bridge_notifications_total ${app.stats.total_notifications}'

	lines << '# HELP ntfy_bridge_errors_total Total publish errors.'
	lines << '# TYPE ntfy_bridge_errors_total counter'
	lines << 'ntfy_bridge_errors_total ${app.stats.errors}'

	lines << '# HELP ntfy_bridge_notifications_by_source Notifications by source type.'
	lines << '# TYPE ntfy_bridge_notifications_by_source counter'
	for source, count in app.stats.by_source {
		lines << 'ntfy_bridge_notifications_by_source{source="${source}"} ${count}'
	}

	lines << '# HELP ntfy_bridge_poll_up Health check polling status (1=up, 0=down).'
	lines << '# TYPE ntfy_bridge_poll_up gauge'
	for url, is_up in app.poll_state {
		val := if is_up { '1' } else { '0' }
		safe_url := url.replace('"', '\\"')
		lines << 'ntfy_bridge_poll_up{url="${safe_url}"} ${val}'
	}

	lines << '# HELP ntfy_bridge_http_polls_total Total HTTP poll checks performed.'
	lines << '# TYPE ntfy_bridge_http_polls_total counter'
	lines << 'ntfy_bridge_http_polls_total ${app.stats.http_polls}'

	lines << '# HELP ntfy_bridge_silence_active Whether notification silence is active.'
	lines << '# TYPE ntfy_bridge_silence_active gauge'
	now := time.now()
	silence_val := if now.unix() < app.silence_until.unix() { '1' } else { '0' }
	lines << 'ntfy_bridge_silence_active ${silence_val}'

	lines << '# HELP ntfy_bridge_silence_remaining_seconds Seconds remaining in current silence.'
	lines << '# TYPE ntfy_bridge_silence_remaining_seconds gauge'
	remaining := if time.now() < app.silence_until {
		(app.silence_until - time.now()) / time.second
	} else {
		0
	}
	lines << 'ntfy_bridge_silence_remaining_seconds ${remaining}'

	// EOF
	lines << '# EOF'

	return http.Response{
		status_code: 200
		header:      http.Header{}
		body:        lines.join('\n') + '\n'
	}
}

// uptime_seconds returns the number of seconds since the server started.
fn (app App) uptime_seconds() i64 {
	now := time.now()
	diff := now.unix() - app.start_time.unix()
	return i64(diff)
}