<?php
/**
 * Invoice Ninja (https://invoiceninja.com).
 *
 * @link https://github.com/invoiceninja/invoiceninja source repository
 *
 * @copyright Copyright (c) 2021. Invoice Ninja LLC (https://invoiceninja.com)
 *
 * @license https://www.elastic.co/licensing/elastic-license
 */

namespace App\Helpers\Mail;

use Illuminate\Mail\Transport\Transport;
use Illuminate\Support\Str;
use Microsoft\Graph\Graph;
use Microsoft\Graph\Model\UploadSession;
use Swift_Mime_SimpleMessage;

class Office365MailTransport extends Transport
{
    public function __construct()
    {
    }

    public function send(Swift_Mime_SimpleMessage $message, &$failedRecipients = null)
    {
        $this->beforeSendPerformed($message);

        $graph = new Graph();
        $token = $message->getHeaders()->get('GmailToken')->getValue();

        $graph->setAccessToken($token);

        // Special treatment if the message has too large attachments
        $messageBody = $this->getBody($message, true);
        $messageBodySizeMb = json_encode($messageBody);
        $messageBodySizeMb = strlen($messageBodySizeMb);
        $messageBodySizeMb = $messageBodySizeMb / 1048576; //byte -> mb

        if ($messageBodySizeMb >= 4) {
            unset($messageBody);
            $graphMessage = $graph->createRequest('POST', '/users/'.key($message->getFrom()).'/messages')
                ->attachBody($this->getBody($message))
                ->setReturnType(\Microsoft\Graph\Model\Message::class)
                ->execute();

            foreach ($message->getChildren() as $attachment) {
                if ($attachment instanceof \Swift_Mime_SimpleMimeEntity) {
                    $fileName = $attachment->getHeaders()->get('Content-Type')->getParameter('name');
                    $content = $attachment->getBody();
                    $fileSize = strlen($content);
                    $size = $fileSize / 1048576; //byte -> mb
                    $id = $attachment->getId();
                    $attachmentMessage = [
                        'AttachmentItem' => [
                            'attachmentType' => 'file',
                            'name' => $fileName,
                            'size' => strlen($content),
                        ],
                    ];

                    if ($size <= 3) { //ErrorAttachmentSizeShouldNotBeLessThanMinimumSize if attachment <= 3mb, then we need to add this
                        $attachmentBody = [
                            '@odata.type' => '#microsoft.graph.fileAttachment',
                            'name' => $attachment->getHeaders()->get('Content-Type')->getParameter('name'),
                            'contentType' => $attachment->getBodyContentType(),
                            'contentBytes' => base64_encode($attachment->getBody()),
                            'contentId'    => $id,
                        ];

                        $addAttachment = $graph->createRequest('POST', '/users/'.key($message->getFrom()).'/messages/'.$graphMessage->getId().'/attachments')
                            ->attachBody($attachmentBody)
                            ->setReturnType(UploadSession::class)
                            ->execute();
                    } else {
                        //upload the files in chunks of 4mb....
                        $uploadSession = $graph->createRequest('POST', '/users/'.key($message->getFrom()).'/messages/'.$graphMessage->getId().'/attachments/createUploadSession')
                            ->attachBody($attachmentMessage)
                            ->setReturnType(UploadSession::class)
                            ->execute();

                        $fragSize = 1024 * 1024 * 4; //4mb at once...
                        $numFragments = ceil($fileSize / $fragSize);
                        $contentChunked = str_split($content, $fragSize);
                        $bytesRemaining = $fileSize;

                        $i = 0;
                        while ($i < $numFragments) {
                            $chunkSize = $numBytes = $fragSize;
                            $start = $i * $fragSize;
                            $end = $i * $fragSize + $chunkSize - 1;
                            if ($bytesRemaining < $chunkSize) {
                                $chunkSize = $numBytes = $bytesRemaining;
                                $end = $fileSize - 1;
                            }
                            $data = $contentChunked[$i];
                            $content_range = 'bytes '.$start.'-'.$end.'/'.$fileSize;
                            $headers = [
                                'Content-Length' => $numBytes,
                                'Content-Range' => $content_range,
                            ];
                            $client = new \GuzzleHttp\Client();
                            $tmp = $client->put($uploadSession->getUploadUrl(), [
                                'headers'         => $headers,
                                'body'            => $data,
                                'allow_redirects' => false,
                                'timeout'         => 1000,
                            ]);
                            $result = $tmp->getBody().'';
                            $result = json_decode($result); //if body == empty, then the file was successfully uploaded
                            $bytesRemaining = $bytesRemaining - $chunkSize;
                            $i++;
                        }
                    }
                }
            }

            //definetly send the message
            $graph->createRequest('POST', '/users/'.key($message->getFrom()).'/messages/'.$graphMessage->getId().'/send')->execute();
        } else {
            try {
                $graphMessage = $graph->createRequest('POST', '/users/'.key($message->getFrom()).'/sendmail')
                    ->attachBody($messageBody)
                    ->setReturnType(\Microsoft\Graph\Model\Message::class)
                    ->execute();
            } catch (\Exception $e) {
                sleep(5);
                $graphMessage = $graph->createRequest('POST', '/users/'.key($message->getFrom()).'/sendmail')
                    ->attachBody($messageBody)
                    ->setReturnType(\Microsoft\Graph\Model\Message::class)
                    ->execute();
            }
        }

        $this->sendPerformed($message);

        return $this->numberOfRecipients($message);
    }

    /**
     * Get body for the message.
     *
     * @param \Swift_Mime_SimpleMessage $message
     * @param bool $withAttachments
     * @return array
     */
    protected function getBody(Swift_Mime_SimpleMessage $message, $withAttachments = false)
    {
        $messageData = [
            'from' => [
                'emailAddress' => [
                    'address' => key($message->getFrom()),
                    'name' => current($message->getFrom()),
                ],
            ],
            'toRecipients' => $this->getTo($message),
            'ccRecipients' => $this->getCc($message),
            'bccRecipients' => $this->getBcc($message),
            'replyTo' => $this->getReplyTo($message),
            'subject' => $message->getSubject(),
            'body' => [
                'contentType' => $message->getBodyContentType() == 'text/html' ? 'html' : 'text',
                'content' => $message->getBody(),
            ],
        ];

        if ($withAttachments) {
            $messageData = ['message' => $messageData];
            //add attachments if any
            $attachments = [];
            foreach ($message->getChildren() as $attachment) {
                if ($attachment instanceof \Swift_Mime_SimpleMimeEntity && $attachment->getContentType() != 'text/plain') {
                    $attachments[] = [
                        '@odata.type' => '#microsoft.graph.fileAttachment',
                        'name' => $attachment->getHeaders()->get('Content-Type')->getParameter('name'),
                        'contentType' => $attachment->getBodyContentType(),
                        'contentBytes' => base64_encode($attachment->getBody()),
                        'contentId'    => $attachment->getId(),
                    ];
                }
            }
            if (count($attachments) > 0) {
                $messageData['message']['attachments'] = $attachments;
            }
        }

        return $messageData;
    }

    /**
     * Get the "to" payload field for the API request.
     *
     * @param \Swift_Mime_SimpleMessage $message
     * @return string
     */
    protected function getTo(Swift_Mime_SimpleMessage $message)
    {
        return collect((array) $message->getTo())->map(function ($display, $address) {
            return $display ? [
                'emailAddress' => [
                    'address' => $address,
                    'name' => $display,
                ],
            ] : [
                'emailAddress' => [
                    'address' => $address,
                ],
            ];
        })->values()->toArray();
    }

    /**
     * Get the "Cc" payload field for the API request.
     *
     * @param \Swift_Mime_SimpleMessage $message
     * @return string
     */
    protected function getCc(Swift_Mime_SimpleMessage $message)
    {
        return collect((array) $message->getCc())->map(function ($display, $address) {
            return $display ? [
                'emailAddress' => [
                    'address' => $address,
                    'name' => $display,
                ],
            ] : [
                'emailAddress' => [
                    'address' => $address,
                ],
            ];
        })->values()->toArray();
    }

    /**
     * Get the "replyTo" payload field for the API request.
     *
     * @param \Swift_Mime_SimpleMessage $message
     * @return string
     */
    protected function getReplyTo(Swift_Mime_SimpleMessage $message)
    {
        return collect((array) $message->getReplyTo())->map(function ($display, $address) {
            return $display ? [
                'emailAddress' => [
                    'address' => $address,
                    'name' => $display,
                ],
            ] : [
                'emailAddress' => [
                    'address' => $address,
                ],
            ];
        })->values()->toArray();
    }

    /**
     * Get the "Bcc" payload field for the API request.
     *
     * @param \Swift_Mime_SimpleMessage $message
     * @return string
     */
    protected function getBcc(Swift_Mime_SimpleMessage $message)
    {
        return collect((array) $message->getBcc())->map(function ($display, $address) {
            return $display ? [
                'emailAddress' => [
                    'address' => $address,
                    'name' => $display,
                ],
            ] : [
                'emailAddress' => [
                    'address' => $address,
                ],
            ];
        })->values()->toArray();
    }

    /**
     * Get all of the contacts for the message.
     *
     * @param \Swift_Mime_SimpleMessage $message
     * @return array
     */
    protected function allContacts(Swift_Mime_SimpleMessage $message)
    {
        return array_merge(
            (array) $message->getTo(),
            (array) $message->getCc(),
            (array) $message->getBcc(),
            (array) $message->getReplyTo()
        );
    }
}