<?php
/**
 * Send an email (abstraction for synchronous/asynchronous modes)
 *
 * @copyright   Copyright (C) 2010-2024 Combodo SAS
 * @license     http://opensource.org/licenses/AGPL-3.0
 */

namespace Combodo\iTop\Core\Email;

use AsyncSendEmail;
use Combodo\iTop\Core\Authentication\Client\OAuth\OAuthClientProviderFactory;
use DOMDocument;
use DOMXPath;
use EMail;
use Exception;
use ExecutionKPI;
use InlineImage;
use IssueLog;
use Laminas\Mail\Header\ContentType;
use Laminas\Mail\Header\InReplyTo;
use Laminas\Mail\Header\MessageId;
use Laminas\Mail\Message;
use Combodo\iTop\Core\Authentication\Client\Smtp\Oauth;
use Laminas\Mail\Transport\File;
use Laminas\Mail\Transport\FileOptions;
use Laminas\Mail\Transport\Sendmail;
use Laminas\Mail\Transport\Smtp;
use Laminas\Mail\Transport\SmtpOptions;
use Laminas\Mime\Mime;
use Laminas\Mime\Part;
use MetaModel;
use Pelago\Emogrifier\CssInliner;
use Pelago\Emogrifier\HtmlProcessor\CssToAttributeConverter;
use Pelago\Emogrifier\HtmlProcessor\HtmlPruner;
use Symfony\Component\CssSelector\Exception\ParseException;

class EMailLaminas extends Email
{
	// Serialization formats
	const ORIGINAL_FORMAT = 1; // Original format, consisting in serializing the whole object, inculding the Swift Mailer's object.
	// Did not work with attachements since their binary representation cannot be stored as a valid UTF-8 string
	const FORMAT_V2 = 2; // New format, only the raw data are serialized (base64 encoded if needed)

	protected $m_aData; // For storing data to serialize

	protected $m_oMessage;

	/**
	 * @noinspection PhpMissingParentConstructorInspection
	 * @noinspection MagicMethodsValidityInspection
	 */
	public function __construct()
	{
		$this->m_aData = array();
		$this->m_oMessage = new Message();
		$this->m_oMessage->setEncoding('UTF-8');

		$this->InitRecipientFrom();
	}

	/**
	 * Custom serialization method
	 * No longer use the brute force "serialize" method since
	 * 1) It does not work with binary attachments (since they cannot be stored in a UTF-8 text field)
	 * 2) The size tends to be quite big (sometimes ten times the size of the email)
	 */
	public function SerializeV2()
	{
		return serialize($this->m_aData);
	}

	/**
	 * Custom de-serialization method
	 *
	 * @param string $sSerializedMessage The serialized representation of the message
	 *
	 * @return \EMail
	 */
	public static function UnSerializeV2($sSerializedMessage)
	{
		$aData = unserialize($sSerializedMessage);
		$oMessage = new Email();

		if (array_key_exists('body', $aData)) {
			$oMessage->SetBody($aData['body']['body'], $aData['body']['mimeType']);
		}
		if (array_key_exists('message_id', $aData)) {
			$oMessage->SetMessageId($aData['message_id']);
		}
		if (array_key_exists('bcc', $aData)) {
			$oMessage->SetRecipientBCC($aData['bcc']);
		}
		if (array_key_exists('cc', $aData)) {
			$oMessage->SetRecipientCC($aData['cc']);
		}
		if (array_key_exists('from', $aData)) {
			$oMessage->SetRecipientFrom($aData['from']['address'], $aData['from']['label']);
		}
		if (array_key_exists('reply_to', $aData)) {
			$oMessage->SetRecipientReplyTo($aData['reply_to']['address'], $aData['reply_to']['label']);
		}
		if (array_key_exists('to', $aData)) {
			$oMessage->SetRecipientTO($aData['to']);
		}
		if (array_key_exists('subject', $aData)) {
			$oMessage->SetSubject($aData['subject']);
		}

		if (array_key_exists('headers', $aData)) {
			foreach ($aData['headers'] as $sKey => $sValue) {
				$oMessage->AddToHeader($sKey, $sValue);
			}
		}
		if (array_key_exists('parts', $aData)) {
			foreach ($aData['parts'] as $aPart) {
				$oMessage->AddPart($aPart['text'], $aPart['mimeType']);
			}
		}
		if (array_key_exists('attachments', $aData)) {
			foreach ($aData['attachments'] as $aAttachment) {
				$oMessage->AddAttachment(base64_decode($aAttachment['data']), $aAttachment['filename'], $aAttachment['mimeType']);
			}
		}

		return $oMessage;
	}

	protected function SendAsynchronous(&$aIssues, $oLog = null)
	{
		try {
			AsyncSendEmail::AddToQueue($this, $oLog);
		}
		catch (Exception $e) {
			$aIssues = array($e->GetMessage());

			return EMAIL_SEND_ERROR;
		}
		$aIssues = array();

		return EMAIL_SEND_PENDING;
	}

	public static function GetMailer()
	{
		return new EMailLaminas();
	}

	/**
	 * @throws \Exception
	 */
	protected function SendSynchronous(&$aIssues, $oLog = null)
	{

		$this->LoadConfig();

		$sTransport = self::$m_oConfig->Get('email_transport');
		switch ($sTransport) {
			case 'SMTP':
				$sHost = self::$m_oConfig->Get('email_transport_smtp.host');
				$sPort = self::$m_oConfig->Get('email_transport_smtp.port');
				$sEncryption = self::$m_oConfig->Get('email_transport_smtp.encryption');
				$sUserName = self::$m_oConfig->Get('email_transport_smtp.username');
				$sPassword = self::$m_oConfig->Get('email_transport_smtp.password');
				$bVerifyPeer = static::$m_oConfig->Get('email_transport_smtp.verify_peer');

				$oTransport = new Smtp();
				$aOptions = [];
				$aConnectionConfig = [];

				$aOptions['host'] = $sHost;
				$aOptions['port'] = $sPort;

				$aConnectionConfig['ssl'] = $sEncryption;
				$aConnectionConfig['novalidatecert'] = !$bVerifyPeer;

				if (strlen($sPassword) > 0) {
					$aConnectionConfig['username'] = $sUserName;
					$aConnectionConfig['password'] = $sPassword;
					$aOptions['connection_class'] = 'login';
				} else {
					$aOptions['connection_class'] = 'smtp';
				}

				$aOptions['connection_config'] = $aConnectionConfig;

				$oOptions = new SmtpOptions($aOptions);
				$oTransport->setOptions($oOptions);
				break;

			case 'SMTP_OAuth':
				$sHost = self::$m_oConfig->Get('email_transport_smtp.host');
				$sPort = self::$m_oConfig->Get('email_transport_smtp.port');
				$sEncryption = self::$m_oConfig->Get('email_transport_smtp.encryption');
				$sUserName = self::$m_oConfig->Get('email_transport_smtp.username');

				$oTransport = new Smtp();
				$aOptions = [
					'host'              => $sHost,
					'port'              => $sPort,
					'connection_class'  => 'Laminas\Mail\Protocol\Smtp\Auth\Oauth',
					'connection_config' => [
						'ssl' => $sEncryption,
					],
				];
				if (strlen($sUserName) > 0) {
					$aOptions['connection_config']['username'] = $sUserName;
				}
				$oOptions = new SmtpOptions($aOptions);
				$oTransport->setOptions($oOptions);

				Oauth::setProvider(OAuthClientProviderFactory::GetProviderForSMTP());
				break;

			case 'Null':
				$oTransport = new Smtp();
				break;

			case 'LogFile':
				$oTransport = new File();
				$aOptions = new FileOptions([
					'path' => APPROOT.'log/',
					'callback' => function() { return 'mail.log'; }
				]);
				$oTransport->setOptions($aOptions);
				break;

			case 'PHPMail':
			default:
				$oTransport = new Sendmail();
		}

		$oKPI = new ExecutionKPI();
		try {
			$oTransport->send($this->m_oMessage);
			$aIssues = array();
			$oKPI->ComputeStats('Email Sent', 'Succeded');

			return EMAIL_SEND_OK;
		}
		catch (Laminas\Mail\Transport\Exception\RuntimeException $e) {
			IssueLog::Warning('Email sending failed: '.$e->getMessage());
			$aIssues = array($e->getMessage());
			$oKPI->ComputeStats('Email Sent', 'Error received');

			return EMAIL_SEND_ERROR;
		}
		catch (Exception $e) {
			$oKPI->ComputeStats('Email Sent', 'Error received');
			throw $e;
		}
	}

	/**
	 * Reprocess the body of the message (if it is an HTML message)
	 * to replace the URL of images based on attachments by a link
	 * to an embedded image (i.e. cid:....) and returns images to be attached as an array
	 *
	 * @param string $sBody Email body to process/alter
	 *
	 * @return array Array of Part that needs to be added as inline attachment later to render as embed
	 * @throws \ArchivedObjectException
	 * @throws \CoreException
	 */
	protected function EmbedInlineImages(string &$sBody)
	{
		$oDOMDoc = new DOMDocument();
		$oDOMDoc->preserveWhiteSpace = true;
		@$oDOMDoc->loadHTML('<?xml encoding="UTF-8"?>'.$sBody); // For loading HTML chunks where the character set is not specified

		$oXPath = new DOMXPath($oDOMDoc);
		$sXPath = '//img[@'.InlineImage::DOM_ATTR_ID.']';
		$oImagesList = $oXPath->query($sXPath);
		$oImagesContent = new \Laminas\Mime\Message();
		$aImagesParts = [];
		if ($oImagesList->length != 0) {
			foreach ($oImagesList as $oImg) {
				$iAttId = $oImg->getAttribute(InlineImage::DOM_ATTR_ID);
				$oAttachment = MetaModel::GetObject('InlineImage', $iAttId, false, true /* Allow All Data */);
				if ($oAttachment) {
					$sImageSecret = $oImg->getAttribute('data-img-secret');
					$sAttachmentSecret = $oAttachment->Get('secret');
					if ($sImageSecret !== $sAttachmentSecret) {
						// @see N°1921
						// If copying from another iTop we could get an IMG pointing to an InlineImage with wrong secret
						continue;
					}

					$oDoc = $oAttachment->Get('contents');

					$sCid = uniqid('', true);

					$oNewAttachment = new Part($oDoc->GetData());
					$oNewAttachment->id = $sCid;
					$oNewAttachment->type = $oDoc->GetMimeType();
					$oNewAttachment->filename = $oDoc->GetFileName();
					$oNewAttachment->disposition = Mime::DISPOSITION_INLINE;
					$oNewAttachment->encoding = Mime::ENCODING_BASE64;

					$oImagesContent->addPart($oNewAttachment);
					$oImg->setAttribute('src', 'cid:'.$sCid);
					$aImagesParts[] = $oNewAttachment;
				}
			}
		}
		$sBody = $oDOMDoc->saveHTML();

		return $aImagesParts;
	}

	/**
	 * Sends an e-mail.
	 *
	 * @param string[] $aIssues Array to add any potentially encountered issues to.
	 * @param int|bool $iSyncAsync Specify whether the e-mail will be sent per default configuration, or whether there will be a forced (a)synchronous sending. One of Email::ENUM_SEND_* constants. To support legacy, it also allows a boolean (true = send synchronous). 
	 * @param Object|null $oLog Log
	 *
	 * @details By default, the send method will respect the preference to send e-mails in an (a)synchronous way as defined in the iTop configuration by the administrator.
	 * In some use cases, it may be necessary to override this behavior. For example, for some tests it may be best if e-mails are always sent instantly (synchronous).
	 * Asynchronous may be preferred when sending a lot of bulk e-mails at once, to avoid hitting rate limits of e-mail providers (e.g. customer survey extension).
	 *
	 * @since 3.2.0 Previously, $iSyncAsync was a boolean ($bForceSynchronous) and this method only allowed to forcefully send e-mails synchronously even when the default was asynchronous.
	 *
	 * @return
	 */
	public function Send(&$aIssues, $iSyncAsync = Email::ENUM_SEND_DEFAULT, $oLog = null)
	{
		//select a default sender if none is provided.
		if (empty($this->m_aData['from']['address']) && !empty($this->m_aData['to'])) {
			$this->SetRecipientFrom($this->m_aData['to']);
		}

		// In previous iTop versions, $iSyncAsync was $bForceSynchronous. To retain backward compatibility, this check is in place.
		if($iSyncAsync === true) {
			// This legacy mode forces synchronous sending, ignoring whatever default was configured.
			return $this->SendSynchronous($aIssues, $oLog);
		} else {
			
			switch($iSyncAsync) {
				
				case Email::ENUM_SEND_FORCE_SYNCHRONOUS:
					return $this->SendSynchronous($aIssues, $oLog);
				
				case Email::ENUM_SEND_FORCE_ASYNCHRONOUS:
					return $this->SendAsynchronous($aIssues, $oLog);
					
				case Email::ENUM_SEND_DEFAULT:
				default:
				
					// Default behavior.
					$oConfig = $this->LoadConfig();
					$bConfigASYNC = $oConfig->Get('email_asynchronous');
					if($bConfigASYNC) {
						return $this->SendAsynchronous($aIssues, $oLog);
					} else {
						return $this->SendSynchronous($aIssues, $oLog);
					}
			}
		}
	}

	public function AddToHeader($sKey, $sValue)
	{
		if (!array_key_exists('headers', $this->m_aData)) {
			$this->m_aData['headers'] = array();
		}
		$this->m_aData['headers'][$sKey] = $sValue;

		if (strlen($sValue) > 0) {
			$oHeaders = $this->m_oMessage->getHeaders();
			$oHeaders->addHeaderLine($sKey, $sValue);
		}
	}

	public function SetMessageId($sId)
	{
		$this->m_aData['message_id'] = $sId;

		// Note: The email library will add the angle brackets for you
		// so let's remove the angle brackets if present, for historical reasons
		$sId = str_replace(array('<', '>'), '', $sId);

		$this->m_oMessage->getHeaders()->addHeader((new MessageId())->setId($sId));
	}

	public function SetReferences($sReferences)
	{
		$this->AddToHeader('References', $sReferences);
	}

	/**
	 * Set the "In-Reply-To" header to allow emails to group as a conversation in modern mail clients (GMail, Outlook 2016+, ...)
	 *
	 * @link https://en.wikipedia.org/wiki/Email#Header_fields
	 *
	 * @param string $sMessageId
	 *
	 * @since 3.0.1 N°4849
	 */
	public function SetInReplyTo(string $sMessageId)
	{
		// Note: Laminas will add the angle brackets for you
		// so let's remove the angle brackets if present, for historical reasons
		$sId = str_replace(array('<', '>'), '', $sMessageId);

		$this->m_oMessage->getHeaders()->addHeader((new InReplyTo())->setIds([$sId]));
	}

	/**
	 * Set current Email body and process inline images.
	 *
	 * @param $sBody
	 * @param string $sMimeType
	 * @param null $sCustomStyles
	 *
	 * @return void
	 * @throws \ArchivedObjectException
	 * @throws \CoreException
	 * @throws \Symfony\Component\CssSelector\Exception\ParseException
	 */
	public function SetBody($sBody, $sMimeType = Mime::TYPE_HTML, $sCustomStyles = null)
	{
		$oBody = new \Laminas\Mime\Message();
		$aAdditionalParts = [];

		if ($sMimeType === Mime::TYPE_HTML) {
			$sBody = static::InlineCssIntoBodyContent($sBody, $sCustomStyles);
		}
		$this->m_aData['body'] = array('body' => $sBody, 'mimeType' => $sMimeType);

		// We don't want these modifications in m_aData['body'], otherwise it'll ruin asynchronous mail as they go through this method twice
		if ($sMimeType === Mime::TYPE_HTML) {
			$aAdditionalParts = $this->EmbedInlineImages($sBody);
		}

		// Add body content to as a new part
		$oNewPart = new Part($sBody);
		$oNewPart->encoding = Mime::ENCODING_8BIT;
		$oNewPart->type = $sMimeType;
		$oNewPart->charset = 'UTF-8';
		$oBody->addPart($oNewPart);

		// Add additional images as new body parts
		foreach ($aAdditionalParts as $oAdditionalPart) {
			$oBody->addPart($oAdditionalPart);
		}

		$this->m_oMessage->setBody($oBody);
	}

	/**
	 * Add a new part to the existing body
	 *
	 * @param $sText
	 * @param string $sMimeType
	 *
	 * @return void
	 */
	public function AddPart($sText, $sMimeType = Mime::TYPE_HTML)
	{
		if (!array_key_exists('parts', $this->m_aData)) {
			$this->m_aData['parts'] = array();
		}
		$this->m_aData['parts'][] = array('text' => $sText, 'mimeType' => $sMimeType);
		$oNewPart = new Part($sText);
		$oNewPart->encoding = Mime::ENCODING_8BIT;
		$oNewPart->type = $sMimeType;

		// setBody called only to refresh Content-Type to multipart/mixed
		$this->m_oMessage->setBody($this->m_oMessage->getBody()->addPart($oNewPart));
	}

	public function AddAttachment($data, $sFileName, $sMimeType)
	{
		if (!array_key_exists('attachments', $this->m_aData)) {
			$this->m_aData['attachments'] = array();
		}
		$this->m_aData['attachments'][] = array('data' => base64_encode($data), 'filename' => $sFileName, 'mimeType' => $sMimeType);
		$oNewAttachment = new Part($data);
		$oNewAttachment->type = $sMimeType;
		$oNewAttachment->filename = $sFileName;
		$oNewAttachment->disposition = Mime::DISPOSITION_ATTACHMENT;
		$oNewAttachment->encoding = Mime::ENCODING_BASE64;

		// setBody called only to refresh Content-Type to multipart/mixed
		$this->m_oMessage->setBody($this->m_oMessage->getBody()->addPart($oNewAttachment));
	}

	public function SetSubject($sSubject)
	{
		$this->m_aData['subject'] = $sSubject;
		$this->m_oMessage->setSubject($sSubject);
	}

	public function GetSubject()
	{
		return $this->m_oMessage->getSubject();
	}

	/**
	 * Helper to transform and sanitize addresses
	 * - get rid of empty addresses
	 */
	protected function AddressStringToArray($sAddressCSVList)
	{
		$aAddresses = array();
		foreach (explode(',', $sAddressCSVList) as $sAddress) {
			$sAddress = trim($sAddress);
			if (strlen($sAddress) > 0) {
				$aAddresses[] = $sAddress;
			}
		}

		return $aAddresses;
	}

	public function SetRecipientTO($sAddress)
	{
		$this->m_aData['to'] = $sAddress;
		if (!empty($sAddress)) {
			$aAddresses = $this->AddressStringToArray($sAddress);
			$this->m_oMessage->setTo($aAddresses);
		}
	}

	public function GetRecipientTO($bAsString = false)
	{
		$aRes = $this->m_oMessage->getTo();
		if ($aRes === null || $aRes->count() === 0) {
			// There is no "To" header field
			$aRes = array();
		}
		if ($bAsString) {
			$aStrings = array();
			foreach ($aRes as $oEmail) {
				$sName = $oEmail->getName();
				$sEmail = $oEmail->getEmail();
				if (is_null($sName)) {
					$aStrings[] = $sEmail;
				} else {
					$sName = str_replace(array('<', '>'), '', $sName);
					$aStrings[] = "$sName <$sEmail>";
				}
			}

			return implode(', ', $aStrings);
		} else {
			return $aRes;
		}
	}

	public function SetRecipientCC($sAddress)
	{
		$this->m_aData['cc'] = $sAddress;
		if (!empty($sAddress)) {
			$aAddresses = $this->AddressStringToArray($sAddress);
			$this->m_oMessage->setCc($aAddresses);
		}
	}

	public function SetRecipientBCC($sAddress)
	{
		$this->m_aData['bcc'] = $sAddress;
		if (!empty($sAddress)) {
			$aAddresses = $this->AddressStringToArray($sAddress);
			$this->m_oMessage->setBcc($aAddresses);
		}
	}

	public function SetRecipientFrom($sAddress, $sLabel = '')
	{
		$this->m_aData['from'] = array('address' => $sAddress, 'label' => $sLabel);
		if ($sLabel != '') {
			$this->m_oMessage->setFrom(array($sAddress => $sLabel));
		} else if (!empty($sAddress)) {
			$this->m_oMessage->setFrom($sAddress);
		}
	}

	public function SetRecipientReplyTo($sAddress, $sLabel = '')
	{
		$this->m_aData['reply_to'] = array('address' => $sAddress, 'label' => $sLabel);
		if ($sLabel != '') {
			$this->m_oMessage->setReplyTo(array($sAddress => $sLabel));
		} else if (!empty($sAddress)) {
			$this->m_oMessage->setReplyTo($sAddress);
		}
	}

	/**
	 * @param string $sBody
	 * @param string $sCustomStyles
	 *
	 * @return string
	 * @throws \Symfony\Component\CssSelector\Exception\ParseException
	 * @noinspection PhpUnnecessaryLocalVariableInspection
	 */
	protected static function InlineCssIntoBodyContent($sBody, $sCustomStyles): string
	{
		if (is_null($sCustomStyles)) {
			return $sBody;
		}

		$oDomDocument = CssInliner::fromHtml($sBody)->inlineCss($sCustomStyles)->getDomDocument();
		HtmlPruner::fromDomDocument($oDomDocument)->removeElementsWithDisplayNone();
		$sBody = CssToAttributeConverter::fromDomDocument($oDomDocument)->convertCssToVisualAttributes()->render(); // Adds html/body tags if not already present

		return $sBody;
	}

}