#!/usr/bin/env php
<?php
/* Copyright (C) 2026 Moko Consulting <hello@mokoconsulting.tech>
 *
 * This file is part of a Moko Consulting project.
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * FILE INFORMATION
 * DEFGROUP: MokoStandards.Scripts.Monitoring
 * INGROUP: MokoStandards
 * REPO: https://git.mokoconsulting.tech/MokoConsulting/moko-platform
 * PATH: /monitoring/uptime-probe.php
 * VERSION: 01.00.00
 * BRIEF: Check uptime and response time for a list of URLs
 */

declare(strict_types=1);

final class UptimeProbe
{
	/** @var array<string, mixed> */
	private array $args = [];

	/** @var array<array{url: string, status: int, time: float, result: string, error: string}> */
	private array $results = [];

	public function run(): int
	{
		$this->args = $this->parseArgs();

		$urls = $this->resolveUrls();

		if (count($urls) === 0) {
			$this->log('No URLs provided. Use --urls <file> or --url <single-url>.');
			return 1;
		}

		$timeout = (int) ($this->args['timeout'] ?? 15);

		foreach ($urls as $url) {
			$this->log("Probing: {$url}");
			$entry = $this->probe($url, $timeout);
			$this->results[] = $entry;
		}

		$hasFailure = false;
		foreach ($this->results as $r) {
			if ($r['result'] === 'FAIL') {
				$hasFailure = true;
				break;
			}
		}

		if (!empty($this->args['json'])) {
			$this->outputJson();
		} else {
			$this->outputTable();
		}

		if ($hasFailure && !empty($this->args['notify'])) {
			$this->sendNotification();
		}

		return $hasFailure ? 1 : 0;
	}

	/**
	 * @return array<string, mixed>
	 */
	private function parseArgs(): array
	{
		$args = [
			'urls'    => null,
			'url'     => null,
			'timeout' => 15,
			'notify'  => null,
			'json'    => false,
		];

		$argv = $_SERVER['argv'] ?? [];
		$argc = count($argv);

		for ($i = 1; $i < $argc; $i++) {
			switch ($argv[$i]) {
				case '--urls':
					$args['urls'] = $argv[++$i] ?? null;
					break;
				case '--url':
					$args['url'] = $argv[++$i] ?? null;
					break;
				case '--timeout':
					$args['timeout'] = (int) ($argv[++$i] ?? 15);
					break;
				case '--notify':
					$args['notify'] = $argv[++$i] ?? null;
					break;
				case '--json':
					$args['json'] = true;
					break;
			}
		}

		return $args;
	}

	/**
	 * @return list<string>
	 */
	private function resolveUrls(): array
	{
		$urls = [];

		if (!empty($this->args['urls'])) {
			$file = $this->args['urls'];
			if (!is_file($file) || !is_readable($file)) {
				$this->log("Cannot read URL file: {$file}");
				return [];
			}
			$lines = file($file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
			if ($lines !== false) {
				foreach ($lines as $line) {
					$line = trim($line);
					if ($line !== '' && $line[0] !== '#') {
						$urls[] = $line;
					}
				}
			}
		}

		if (!empty($this->args['url'])) {
			$urls[] = trim($this->args['url']);
		}

		return $urls;
	}

	/**
	 * @return array{url: string, status: int, time: float, result: string, error: string}
	 */
	private function probe(string $url, int $timeout): array
	{
		$entry = [
			'url'    => $url,
			'status' => 0,
			'time'   => 0.0,
			'result' => 'FAIL',
			'error'  => '',
		];

		$context = stream_context_create([
			'http' => [
				'method'          => 'GET',
				'timeout'         => $timeout,
				'follow_location' => 1,
				'max_redirects'   => 5,
				'ignore_errors'   => true,
			],
			'ssl' => [
				'verify_peer'      => true,
				'verify_peer_name' => true,
			],
		]);

		$start = microtime(true);
		$body = @file_get_contents($url, false, $context);
		$elapsed = round(microtime(true) - $start, 3);
		$entry['time'] = $elapsed;

		if ($body === false) {
			$entry['error'] = 'Connection failed or timed out';
			return $entry;
		}

		// Parse status code from $http_response_header
		$statusCode = 0;
		if (isset($http_response_header) && is_array($http_response_header)) {
			foreach ($http_response_header as $header) {
				if (preg_match('/^HTTP\/[\d.]+ (\d{3})/', $header, $m)) {
					$statusCode = (int) $m[1];
				}
			}
		}
		$entry['status'] = $statusCode;

		// Check for PHP fatal errors in the response body
		$fatalPatterns = [
			'Fatal error:',
			'Parse error:',
			'Uncaught Exception',
			'Uncaught Error',
			'Stack trace:',
		];

		foreach ($fatalPatterns as $pattern) {
			if (stripos($body, $pattern) !== false) {
				$entry['error'] = "PHP fatal error detected in response body";
				return $entry;
			}
		}

		if ($statusCode >= 200 && $statusCode < 400) {
			$entry['result'] = 'PASS';
		} else {
			$entry['error'] = "HTTP {$statusCode}";
		}

		return $entry;
	}

	private function outputTable(): void
	{
		$colUrl    = 4;
		$colStatus = 6;
		$colTime   = 6;
		$colResult = 6;

		foreach ($this->results as $r) {
			$colUrl = max($colUrl, strlen($r['url']));
		}

		$colUrl = min($colUrl, 60);

		$fmt = "%-{$colUrl}s | %-{$colStatus}s | %-{$colTime}s | %-{$colResult}s";

		$this->log('');
		$this->log(sprintf($fmt, 'URL', 'Status', 'Time', 'Result'));
		$this->log(str_repeat('-', $colUrl + $colStatus + $colTime + $colResult + 10));

		foreach ($this->results as $r) {
			$urlDisplay = strlen($r['url']) > 60 ? substr($r['url'], 0, 57) . '...' : $r['url'];
			$timeStr    = $r['time'] . 's';
			$statusStr  = $r['status'] > 0 ? (string) $r['status'] : 'ERR';
			$this->log(sprintf($fmt, $urlDisplay, $statusStr, $timeStr, $r['result']));
		}

		$this->log('');
	}

	private function outputJson(): void
	{
		echo json_encode($this->results, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES) . "\n";
	}

	private function sendNotification(): void
	{
		$ntfyUrl = $this->args['notify'];
		if (empty($ntfyUrl)) {
			return;
		}

		$failures = [];
		foreach ($this->results as $r) {
			if ($r['result'] === 'FAIL') {
				$failures[] = $r['url'] . ' (' . ($r['error'] ?: 'HTTP ' . $r['status']) . ')';
			}
		}

		$message = "Uptime probe failures:\n" . implode("\n", $failures);

		$ch = curl_init($ntfyUrl);
		if ($ch === false) {
			$this->log('Failed to initialise curl for notification.');
			return;
		}

		curl_setopt_array($ch, [
			CURLOPT_POST           => true,
			CURLOPT_POSTFIELDS     => $message,
			CURLOPT_RETURNTRANSFER => true,
			CURLOPT_TIMEOUT        => 10,
			CURLOPT_HTTPHEADER     => [
				'Title: Uptime Probe Alert',
				'Priority: high',
			],
		]);

		$result = curl_exec($ch);
		if ($result === false) {
			$this->log('Notification failed: ' . curl_error($ch));
		} else {
			$this->log('Notification sent.');
		}

		curl_close($ch);
	}

	private function log(string $message): void
	{
		fwrite(STDERR, $message . "\n");
	}
}

$probe = new UptimeProbe();
exit($probe->run());