<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Mime;

use Symfony\Component\Mime\Exception\LogicException;
use Symfony\Component\Mime\Part\AbstractPart;
use Symfony\Component\Mime\Part\DataPart;
use Symfony\Component\Mime\Part\Multipart\AlternativePart;
use Symfony\Component\Mime\Part\Multipart\MixedPart;
use Symfony\Component\Mime\Part\Multipart\RelatedPart;
use Symfony\Component\Mime\Part\TextPart;

/**
 * @author Fabien Potencier <fabien@symfony.com>
 */
class Email extends Message
{
    public const PRIORITY_HIGHEST = 1;
    public const PRIORITY_HIGH = 2;
    public const PRIORITY_NORMAL = 3;
    public const PRIORITY_LOW = 4;
    public const PRIORITY_LOWEST = 5;

    private const PRIORITY_MAP = [
        self::PRIORITY_HIGHEST => 'Highest',
        self::PRIORITY_HIGH => 'High',
        self::PRIORITY_NORMAL => 'Normal',
        self::PRIORITY_LOW => 'Low',
        self::PRIORITY_LOWEST => 'Lowest',
    ];

    /**
     * @var resource|string|null
     */
    private $text;

    private ?string $textCharset = null;

    /**
     * @var resource|string|null
     */
    private $html;

    private ?string $htmlCharset = null;
    private array $attachments = [];
    private ?AbstractPart $cachedBody = null; // Used to avoid wrong body hash in DKIM signatures with multiple parts (e.g. HTML + TEXT) due to multiple boundaries.

    /**
     * @return $this
     */
    public function subject(string $subject): static
    {
        return $this->setHeaderBody('Text', 'Subject', $subject);
    }

    public function getSubject(): ?string
    {
        return $this->getHeaders()->getHeaderBody('Subject');
    }

    /**
     * @return $this
     */
    public function date(\DateTimeInterface $dateTime): static
    {
        return $this->setHeaderBody('Date', 'Date', $dateTime);
    }

    public function getDate(): ?\DateTimeImmutable
    {
        return $this->getHeaders()->getHeaderBody('Date');
    }

    /**
     * @return $this
     */
    public function returnPath(Address|string $address): static
    {
        return $this->setHeaderBody('Path', 'Return-Path', Address::create($address));
    }

    public function getReturnPath(): ?Address
    {
        return $this->getHeaders()->getHeaderBody('Return-Path');
    }

    /**
     * @return $this
     */
    public function sender(Address|string $address): static
    {
        return $this->setHeaderBody('Mailbox', 'Sender', Address::create($address));
    }

    public function getSender(): ?Address
    {
        return $this->getHeaders()->getHeaderBody('Sender');
    }

    /**
     * @return $this
     */
    public function addFrom(Address|string ...$addresses): static
    {
        return $this->addListAddressHeaderBody('From', $addresses);
    }

    /**
     * @return $this
     */
    public function from(Address|string ...$addresses): static
    {
        return $this->setListAddressHeaderBody('From', $addresses);
    }

    /**
     * @return Address[]
     */
    public function getFrom(): array
    {
        return $this->getHeaders()->getHeaderBody('From') ?: [];
    }

    /**
     * @return $this
     */
    public function addReplyTo(Address|string ...$addresses): static
    {
        return $this->addListAddressHeaderBody('Reply-To', $addresses);
    }

    /**
     * @return $this
     */
    public function replyTo(Address|string ...$addresses): static
    {
        return $this->setListAddressHeaderBody('Reply-To', $addresses);
    }

    /**
     * @return Address[]
     */
    public function getReplyTo(): array
    {
        return $this->getHeaders()->getHeaderBody('Reply-To') ?: [];
    }

    /**
     * @return $this
     */
    public function addTo(Address|string ...$addresses): static
    {
        return $this->addListAddressHeaderBody('To', $addresses);
    }

    /**
     * @return $this
     */
    public function to(Address|string ...$addresses): static
    {
        return $this->setListAddressHeaderBody('To', $addresses);
    }

    /**
     * @return Address[]
     */
    public function getTo(): array
    {
        return $this->getHeaders()->getHeaderBody('To') ?: [];
    }

    /**
     * @return $this
     */
    public function addCc(Address|string ...$addresses): static
    {
        return $this->addListAddressHeaderBody('Cc', $addresses);
    }

    /**
     * @return $this
     */
    public function cc(Address|string ...$addresses): static
    {
        return $this->setListAddressHeaderBody('Cc', $addresses);
    }

    /**
     * @return Address[]
     */
    public function getCc(): array
    {
        return $this->getHeaders()->getHeaderBody('Cc') ?: [];
    }

    /**
     * @return $this
     */
    public function addBcc(Address|string ...$addresses): static
    {
        return $this->addListAddressHeaderBody('Bcc', $addresses);
    }

    /**
     * @return $this
     */
    public function bcc(Address|string ...$addresses): static
    {
        return $this->setListAddressHeaderBody('Bcc', $addresses);
    }

    /**
     * @return Address[]
     */
    public function getBcc(): array
    {
        return $this->getHeaders()->getHeaderBody('Bcc') ?: [];
    }

    /**
     * Sets the priority of this message.
     *
     * The value is an integer where 1 is the highest priority and 5 is the lowest.
     *
     * @return $this
     */
    public function priority(int $priority): static
    {
        if ($priority > 5) {
            $priority = 5;
        } elseif ($priority < 1) {
            $priority = 1;
        }

        return $this->setHeaderBody('Text', 'X-Priority', sprintf('%d (%s)', $priority, self::PRIORITY_MAP[$priority]));
    }

    /**
     * Get the priority of this message.
     *
     * The returned value is an integer where 1 is the highest priority and 5
     * is the lowest.
     */
    public function getPriority(): int
    {
        [$priority] = sscanf($this->getHeaders()->getHeaderBody('X-Priority') ?? '', '%[1-5]');

        return $priority ?? 3;
    }

    /**
     * @param resource|string|null $body
     *
     * @return $this
     */
    public function text($body, string $charset = 'utf-8'): static
    {
        if (null !== $body && !\is_string($body) && !\is_resource($body)) {
            throw new \TypeError(sprintf('The body must be a string, a resource or null (got "%s").', get_debug_type($body)));
        }

        $this->cachedBody = null;
        $this->text = $body;
        $this->textCharset = $charset;

        return $this;
    }

    /**
     * @return resource|string|null
     */
    public function getTextBody()
    {
        return $this->text;
    }

    public function getTextCharset(): ?string
    {
        return $this->textCharset;
    }

    /**
     * @param resource|string|null $body
     *
     * @return $this
     */
    public function html($body, string $charset = 'utf-8'): static
    {
        if (null !== $body && !\is_string($body) && !\is_resource($body)) {
            throw new \TypeError(sprintf('The body must be a string, a resource or null (got "%s").', get_debug_type($body)));
        }

        $this->cachedBody = null;
        $this->html = $body;
        $this->htmlCharset = $charset;

        return $this;
    }

    /**
     * @return resource|string|null
     */
    public function getHtmlBody()
    {
        return $this->html;
    }

    public function getHtmlCharset(): ?string
    {
        return $this->htmlCharset;
    }

    /**
     * @param resource|string $body
     *
     * @return $this
     */
    public function attach($body, string $name = null, string $contentType = null): static
    {
        if (!\is_string($body) && !\is_resource($body)) {
            throw new \TypeError(sprintf('The body must be a string or a resource (got "%s").', get_debug_type($body)));
        }

        $this->cachedBody = null;
        $this->attachments[] = ['body' => $body, 'name' => $name, 'content-type' => $contentType, 'inline' => false];

        return $this;
    }

    /**
     * @return $this
     */
    public function attachFromPath(string $path, string $name = null, string $contentType = null): static
    {
        $this->cachedBody = null;
        $this->attachments[] = ['path' => $path, 'name' => $name, 'content-type' => $contentType, 'inline' => false];

        return $this;
    }

    /**
     * @param resource|string $body
     *
     * @return $this
     */
    public function embed($body, string $name = null, string $contentType = null): static
    {
        if (!\is_string($body) && !\is_resource($body)) {
            throw new \TypeError(sprintf('The body must be a string or a resource (got "%s").', get_debug_type($body)));
        }

        $this->cachedBody = null;
        $this->attachments[] = ['body' => $body, 'name' => $name, 'content-type' => $contentType, 'inline' => true];

        return $this;
    }

    /**
     * @return $this
     */
    public function embedFromPath(string $path, string $name = null, string $contentType = null): static
    {
        $this->cachedBody = null;
        $this->attachments[] = ['path' => $path, 'name' => $name, 'content-type' => $contentType, 'inline' => true];

        return $this;
    }

    /**
     * @return $this
     */
    public function attachPart(DataPart $part): static
    {
        $this->cachedBody = null;
        $this->attachments[] = ['part' => $part];

        return $this;
    }

    /**
     * @return array|DataPart[]
     */
    public function getAttachments(): array
    {
        $parts = [];
        foreach ($this->attachments as $attachment) {
            $parts[] = $this->createDataPart($attachment);
        }

        return $parts;
    }

    public function getBody(): AbstractPart
    {
        if (null !== $body = parent::getBody()) {
            return $body;
        }

        return $this->generateBody();
    }

    public function ensureValidity()
    {
        $this->ensureBodyValid();

        if ('1' === $this->getHeaders()->getHeaderBody('X-Unsent')) {
            throw new LogicException('Cannot send messages marked as "draft".');
        }

        parent::ensureValidity();
    }

    private function ensureBodyValid(): void
    {
        if (null === $this->text && null === $this->html && !$this->attachments) {
            throw new LogicException('A message must have a text or an HTML part or attachments.');
        }
    }

    /**
     * Generates an AbstractPart based on the raw body of a message.
     *
     * The most "complex" part generated by this method is when there is text and HTML bodies
     * with related images for the HTML part and some attachments:
     *
     * multipart/mixed
     *         |
     *         |------------> multipart/related
     *         |                      |
     *         |                      |------------> multipart/alternative
     *         |                      |                      |
     *         |                      |                       ------------> text/plain (with content)
     *         |                      |                      |
     *         |                      |                       ------------> text/html (with content)
     *         |                      |
     *         |                       ------------> image/png (with content)
     *         |
     *          ------------> application/pdf (with content)
     */
    private function generateBody(): AbstractPart
    {
        if (null !== $this->cachedBody) {
            return $this->cachedBody;
        }

        $this->ensureBodyValid();

        [$htmlPart, $attachmentParts, $inlineParts] = $this->prepareParts();

        $part = null === $this->text ? null : new TextPart($this->text, $this->textCharset);
        if (null !== $htmlPart) {
            if (null !== $part) {
                $part = new AlternativePart($part, $htmlPart);
            } else {
                $part = $htmlPart;
            }
        }

        if ($inlineParts) {
            $part = new RelatedPart($part, ...$inlineParts);
        }

        if ($attachmentParts) {
            if ($part) {
                $part = new MixedPart($part, ...$attachmentParts);
            } else {
                $part = new MixedPart(...$attachmentParts);
            }
        }

        return $this->cachedBody = $part;
    }

    private function prepareParts(): ?array
    {
        $names = [];
        $htmlPart = null;
        $html = $this->html;
        if (null !== $html) {
            $htmlPart = new TextPart($html, $this->htmlCharset, 'html');
            $html = $htmlPart->getBody();

            $regexes = [
                '<img\s+[^>]*src\s*=\s*(?:([\'"])cid:([^"]+)\\1|cid:([^>\s]+))',
                '<\w+\s+[^>]*background\s*=\s*(?:([\'"])cid:([^"]+)\\1|cid:([^>\s]+))',
            ];
            $tmpMatches = [];
            foreach ($regexes as $regex) {
                preg_match_all('/'.$regex.'/i', $html, $tmpMatches);
                $names = array_merge($names, $tmpMatches[2], $tmpMatches[3]);
            }
            $names = array_filter(array_unique($names));
        }

        // usage of reflection is a temporary workaround for missing getters that will be added in 6.2
        $dispositionRef = new \ReflectionProperty(TextPart::class, 'disposition');
        $dispositionRef->setAccessible(true);
        $nameRef = new \ReflectionProperty(TextPart::class, 'name');
        $nameRef->setAccessible(true);
        $attachmentParts = $inlineParts = [];
        foreach ($this->attachments as $attachment) {
            $part = $this->createDataPart($attachment);
            if (isset($attachment['part'])) {
                $attachment['name'] = $nameRef->getValue($part);
            }

            foreach ($names as $name) {
                if ($name !== $attachment['name']) {
                    continue;
                }
                if (isset($inlineParts[$name])) {
                    continue 2;
                }
                $part->setDisposition('inline');
                $html = str_replace('cid:'.$name, 'cid:'.$part->getContentId(), $html);
                $part->setName($part->getContentId());

                break;
            }

            if ('inline' === $dispositionRef->getValue($part)) {
                $inlineParts[$attachment['name']] = $part;
            } else {
                $attachmentParts[] = $part;
            }
        }
        if (null !== $htmlPart) {
            $htmlPart = new TextPart($html, $this->htmlCharset, 'html');
        }

        return [$htmlPart, $attachmentParts, array_values($inlineParts)];
    }

    private function createDataPart(array $attachment): DataPart
    {
        if (isset($attachment['part'])) {
            return $attachment['part'];
        }

        if (isset($attachment['body'])) {
            $part = new DataPart($attachment['body'], $attachment['name'] ?? null, $attachment['content-type'] ?? null);
        } else {
            $part = DataPart::fromPath($attachment['path'] ?? '', $attachment['name'] ?? null, $attachment['content-type'] ?? null);
        }
        if ($attachment['inline']) {
            $part->asInline();
        }

        return $part;
    }

    /**
     * @return $this
     */
    private function setHeaderBody(string $type, string $name, $body): static
    {
        $this->getHeaders()->setHeaderBody($type, $name, $body);

        return $this;
    }

    private function addListAddressHeaderBody(string $name, array $addresses)
    {
        if (!$header = $this->getHeaders()->get($name)) {
            return $this->setListAddressHeaderBody($name, $addresses);
        }
        $header->addAddresses(Address::createArray($addresses));

        return $this;
    }

    /**
     * @return $this
     */
    private function setListAddressHeaderBody(string $name, array $addresses): static
    {
        $addresses = Address::createArray($addresses);
        $headers = $this->getHeaders();
        if ($header = $headers->get($name)) {
            $header->setAddresses($addresses);
        } else {
            $headers->addMailboxListHeader($name, $addresses);
        }

        return $this;
    }

    /**
     * @internal
     */
    public function __serialize(): array
    {
        if (\is_resource($this->text)) {
            $this->text = (new TextPart($this->text))->getBody();
        }

        if (\is_resource($this->html)) {
            $this->html = (new TextPart($this->html))->getBody();
        }

        foreach ($this->attachments as $i => $attachment) {
            if (isset($attachment['body']) && \is_resource($attachment['body'])) {
                $this->attachments[$i]['body'] = (new TextPart($attachment['body']))->getBody();
            }
        }

        return [$this->text, $this->textCharset, $this->html, $this->htmlCharset, $this->attachments, parent::__serialize()];
    }

    /**
     * @internal
     */
    public function __unserialize(array $data): void
    {
        [$this->text, $this->textCharset, $this->html, $this->htmlCharset, $this->attachments, $parentData] = $data;

        parent::__unserialize($parentData);
    }
}
