Genkgo\Mail\AlternativeText

Complexity

Total Complexity

28

Size/Duplication

Total Lines	280
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	0

Test Coverage

Coverage

94.07%

Importance

Changes

0

11 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	4	1
A	__toString()	0	4	1
A	normalizeSpace()	0	10	1
B	fromHtml()	0	28	3
A	updateParagraphsAndBreaksToNewLine()	0	21	3
B	wrapSymbols()	0	30	3
B	updateLists()	0	58	7
A	updateImages()	0	12	2
A	updateHorizontalRule()	0	9	2
A	removeHead()	0	8	2
B	updateLinks()	0	42	3

<?php
declare(strict_types=1);

namespace Genkgo\Mail;

final class AlternativeText
{
    /**
     * @var string
     */
    private $text;

    /**
     * AlternativeText constructor.
     * @param string $text
     */
    public function __construct(string $text)
    {
        $this->text = $text;
    }

    /**
     * @return string
     */
    public function __toString(): string
    {
        return $this->normalizeSpace($this->text);
    }

    /**
     * @param string $string
     * @return string
     */
    private function normalizeSpace(string $string): string
    {
        return wordwrap(
            str_replace(
                ["  ", "\n ", " \n", "\t"],
                [" ", "\n", "\n", "    "],
                trim($string)
            )
        );
    }

    /**
     * @param string $html AlternativeText
     * @return AlternativeText
     */
    public static function fromHtml(string $html): AlternativeText
    {
        $html = preg_replace('/\h\h+/', ' ', $html);
        $html = preg_replace('/\v/', '', $html);
        $text = new self($html);

        try {
            $document = new \DOMDocument();
            $result = @$document->loadHTML($text->text);
            if ($result === false) {
                throw new \DOMException('Incorrect HTML');
            }

            $text->wrapSymbols($document);
            $text->updateHorizontalRule($document);
            $text->updateLists($document);
            $text->updateImages($document);
            $text->updateLinks($document);
            $text->removeHead($document);
            $text->updateParagraphsAndBreaksToNewLine($document);

            $text->text = $document->textContent;
        } catch (\DOMException $e) {
            $text->text = strip_tags($text);
        }

        return $text;
    }

    /**
     * @param \DOMDocument $document
     */
    private function updateParagraphsAndBreaksToNewLine(\DOMDocument $document): void
    {
        $xpath = new \DOMXPath($document);
        $break = [
            'br' => "\n",
            'ul' => "\n",
            'ol' => "\n",
            'dl' => "\n",
        ];

        /** @var \DOMElement $element */
        foreach ($xpath->query('//p|//br|//h1|//h2|//h3|//h4|//h5|//h6|//ul|//ol|//dl|//hr') as $element) {
            if (isset($break[$element->nodeName])) {
                $textNode = $document->createTextNode($break[$element->nodeName]);
            } else {
                $textNode = $document->createTextNode("\n\n");
            }

            $element->appendChild($textNode);
        }
    }

    /**
     * @param \DOMDocument $document
     */
    private function wrapSymbols(\DOMDocument $document): void
    {
        $xpath = new \DOMXPath($document);
        $wrap = [
            'h1' => "*",
            'h2' => "**",
            'h3' => "***",
            'h4' => "****",
            'h5' => "*****",
            'h6' => "******",
            'strong' => "*",
            'b' => "*",
            'em' => "*",
            'i' => "*",
        ];

        /** @var \DOMElement $element */
        foreach ($xpath->query('//h1|//h2|//h3|//h4|//h5|//h6|//strong|//b|//em|//i') as $element) {
            $element->appendChild(
                $document->createTextNode($wrap[$element->nodeName])
            );

            if ($element->firstChild !== null) {
                $element->insertBefore(
                    $document->createTextNode($wrap[$element->nodeName]),
                    $element->firstChild
                );
            }
        }
    }

    /**
     * @param \DOMDocument $document
     */
    private function updateLists(\DOMDocument $document): void
    {
        $xpath = new \DOMXPath($document);

        /** @var \DOMElement $element */
        foreach ($xpath->query('//ul/li') as $element) {
            if ($element->firstChild !== null) {
                $element->insertBefore(
                    $document->createTextNode("\t- "),
                    $element->firstChild
                );
            } else {
                $element->appendChild(
                    $document->createTextNode("\t- ")
                );
            }

            $element->appendChild(
                $document->createTextNode("\n")
            );
        }

        /** @var \DOMElement $element */
        foreach ($xpath->query('//ol/li') as $element) {
            $itemPath = new \DOMXPath($document);
            $itemNumber = (int)$itemPath->evaluate('string(count(preceding-sibling::li))', $element) + 1;
            $text = sprintf("\t%d. ", $itemNumber);

            if ($element->firstChild !== null) {
                $element->insertBefore(
                    $document->createTextNode($text),
                    $element->firstChild
                );
            } else {
                $element->appendChild(
                    $document->createTextNode($text)
                );
            }

            $element->appendChild(
                $document->createTextNode("\n")
            );
        }

        /** @var \DOMElement $element */
        foreach ($xpath->query('//dl/dt') as $element) {
            $element->appendChild(
                $document->createTextNode(': ')
            );
        }

        /** @var \DOMElement $element */
        foreach ($xpath->query('//dl/dd') as $element) {
            $element->appendChild(
                $document->createTextNode("\n")
            );
        }
    }

    /**
     * @param \DOMDocument $document
     */
    private function updateImages(\DOMDocument $document): void
    {
        $xpath = new \DOMXPath($document);

        /** @var \DOMElement $element */
        foreach ($xpath->query('//img[@src and @alt]') as $element) {
            $link = $document->createElement('a');
            $link->setAttribute('href', $element->getAttribute('src'));
            $link->textContent = $element->getAttribute('alt');
            $element->parentNode->replaceChild($link, $element);
        }
    }

    /**
     * @param \DOMDocument $document
     */
    private function updateHorizontalRule(\DOMDocument $document): void
    {
        $xpath = new \DOMXPath($document);

        /** @var \DOMElement $element */
        foreach ($xpath->query('//hr') as $element) {
            $element->textContent = str_repeat('=', 78);
        }
    }

    /**
     * @param \DOMDocument $document
     */
    private function updateLinks(\DOMDocument $document): void
    {
        $xpath = new \DOMXPath($document);
        $item = 1;
        $conversion = [
            '0' => "\u{2070}",
            '1' => "\u{2071}",
            '2' => "\u{00B2}",
            '3' => "\u{00B3}",
            '4' => "\u{2074}",
            '5' => "\u{2075}",
            '6' => "\u{2076}",
            '7' => "\u{2077}",
            '8' => "\u{2078}",
            '9' => "\u{2079}",
        ];

        /** @var \DOMElement $element */
        foreach ($xpath->query('//a[@href and @href != .]') as $element) {
            $itemString = (string) $item;
            $itemUnicode = '';
            for ($i = 0, $j = strlen($itemString); $i < $j; $i++) {
                $itemUnicode .= $conversion[$itemString[$i]];
            }

            $document->documentElement->appendChild(
                $document->createTextNode(
                    sprintf(
                        "[%s] %s\n",
                        $itemUnicode,
                        $element->getAttribute('href')
                    )
                )
            );

            $element->appendChild(
                $document->createTextNode($itemUnicode)
            );

            $item++;
        }
    }

    /**
     * @param \DOMDocument $document
     */
    private function removeHead(\DOMDocument $document): void
    {
        $heads = $document->getElementsByTagName('head');
        while ($heads->length > 0) {
            $head = $heads->item(0);
            $head->parentNode->removeChild($head);
        }
    }
}