<?php

/**
 * This file is part of the Tracy (https://tracy.nette.org)
 * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
 */

declare(strict_types=1);

namespace Tracy;


/**
 * Logger.
 */
class Logger implements ILogger
{
	/** @var string|null name of the directory where errors should be logged */
	public $directory;

	/** @var string|array|null email or emails to which send error notifications */
	public $email;

	/** @var string|null sender of email notifications */
	public $fromEmail;

	/** @var mixed interval for sending email is 2 days */
	public $emailSnooze = '2 days';

	/** @var callable handler for sending emails */
	public $mailer;

	/** @var BlueScreen|null */
	private $blueScreen;


	/**
	 * @param  string|array|null  $email
	 */
	public function __construct(?string $directory, $email = null, BlueScreen $blueScreen = null)
	{
		$this->directory = $directory;
		$this->email = $email;
		$this->blueScreen = $blueScreen;
		$this->mailer = [$this, 'defaultMailer'];
	}


	/**
	 * Logs message or exception to file and sends email notification.
	 * @param  mixed  $message
	 * @param  string  $level  one of constant ILogger::INFO, WARNING, ERROR (sends email), EXCEPTION (sends email), CRITICAL (sends email)
	 * @return string|null logged error filename
	 */
	public function log($message, $level = self::INFO)
	{
		if (!$this->directory) {
			throw new \LogicException('Logging directory is not specified.');
		} elseif (!is_dir($this->directory)) {
			throw new \RuntimeException("Logging directory '$this->directory' is not found or is not directory.");
		}

		$exceptionFile = $message instanceof \Throwable
			? $this->getExceptionFile($message, $level)
			: null;
		$line = static::formatLogLine($message, $exceptionFile);
		$file = $this->directory . '/' . strtolower($level ?: self::INFO) . '.log';

		if (!@file_put_contents($file, $line . PHP_EOL, FILE_APPEND | LOCK_EX)) { // @ is escalated to exception
			throw new \RuntimeException("Unable to write to log file '$file'. Is directory writable?");
		}

		if ($exceptionFile) {
			$this->logException($message, $exceptionFile);
		}

		if (in_array($level, [self::ERROR, self::EXCEPTION, self::CRITICAL], true)) {
			$this->sendEmail($message);
		}

		return $exceptionFile;
	}


	/**
	 * @param  mixed  $message
	 */
	public static function formatMessage($message): string
	{
		if ($message instanceof \Throwable) {
			while ($message) {
				$tmp[] = ($message instanceof \ErrorException
					? Helpers::errorTypeToString($message->getSeverity()) . ': ' . $message->getMessage()
					: Helpers::getClass($message) . ': ' . $message->getMessage() . ($message->getCode() ? ' #' . $message->getCode() : '')
				) . ' in ' . $message->getFile() . ':' . $message->getLine();
				$message = $message->getPrevious();
			}
			$message = implode("\ncaused by ", $tmp);

		} elseif (!is_string($message)) {
			$message = Dumper::toText($message);
		}

		return trim($message);
	}


	/**
	 * @param  mixed  $message
	 */
	public static function formatLogLine($message, string $exceptionFile = null): string
	{
		return implode(' ', [
			@date('[Y-m-d H-i-s]'), // @ timezone may not be set
			preg_replace('#\s*\r?\n\s*#', ' ', static::formatMessage($message)),
			' @  ' . Helpers::getSource(),
			$exceptionFile ? ' @@  ' . basename($exceptionFile) : null,
		]);
	}


	public function getExceptionFile(\Throwable $exception, string $level = self::EXCEPTION): string
	{
		while ($exception) {
			$data[] = [
				get_class($exception), $exception->getMessage(), $exception->getCode(), $exception->getFile(), $exception->getLine(),
				array_map(function (array $item): array { unset($item['args']); return $item; }, $exception->getTrace()),
			];
			$exception = $exception->getPrevious();
		}
		$hash = substr(md5(serialize($data)), 0, 10);
		$dir = strtr($this->directory . '/', '\\/', DIRECTORY_SEPARATOR . DIRECTORY_SEPARATOR);
		foreach (new \DirectoryIterator($this->directory) as $file) {
			if (strpos($file->getBasename(), $hash)) {
				return $dir . $file;
			}
		}
		return $dir . $level . '--' . @date('Y-m-d--H-i') . "--$hash.html"; // @ timezone may not be set
	}


	/**
	 * Logs exception to the file if file doesn't exist.
	 * @return string logged error filename
	 */
	protected function logException(\Throwable $exception, string $file = null): string
	{
		$file = $file ?: $this->getExceptionFile($exception);
		$bs = $this->blueScreen ?: new BlueScreen;
		$bs->renderToFile($exception, $file);
		return $file;
	}


	/**
	 * @param  mixed  $message
	 */
	protected function sendEmail($message): void
	{
		$snooze = is_numeric($this->emailSnooze)
			? $this->emailSnooze
			: @strtotime($this->emailSnooze) - time(); // @ timezone may not be set

		if (
			$this->email
			&& $this->mailer
			&& @filemtime($this->directory . '/email-sent') + $snooze < time() // @ file may not exist
			&& @file_put_contents($this->directory . '/email-sent', 'sent') // @ file may not be writable
		) {
			($this->mailer)($message, implode(', ', (array) $this->email));
		}
	}


	/**
	 * Default mailer.
	 * @param  mixed  $message
	 * @internal
	 */
	public function defaultMailer($message, string $email): void
	{
		$host = preg_replace('#[^\w.-]+#', '', $_SERVER['HTTP_HOST'] ?? php_uname('n'));
		$parts = str_replace(
			["\r\n", "\n"],
			["\n", PHP_EOL],
			[
				'headers' => implode("\n", [
					'From: ' . ($this->fromEmail ?: "noreply@$host"),
					'X-Mailer: Tracy',
					'Content-Type: text/plain; charset=UTF-8',
					'Content-Transfer-Encoding: 8bit',
				]) . "\n",
				'subject' => "PHP: An error occurred on the server $host",
				'body' => static::formatMessage($message) . "\n\nsource: " . Helpers::getSource(),
			]
		);

		mail($email, $parts['subject'], $parts['body'], $parts['headers']);
	}
}