designly1/Helper.class.php

## build.bin.php
<?php
try {
    require_once(__DIR__ . '/config.inc.php');
    require_once(DIR . '/inc/build.inc.php');

    // Fetch posts
    doLog('Fetching posts');
    define('URL', BLOG_BASE_URL . '?content=true');
    $json = json_decode(Helper::getUtf8(URL),  true);
    if (!$json || empty($json)) {
        throw new Exception('Failed to fetch posts');
    }

    doLog('Removing old files');
    $rmfiles = PUB_DIR . '/*.html';
    `rm -f $rmfiles`;

    doLog('Building post pages');
    $postCards = Helper::buildPostCards($json, 9);
    $meta = [];

    foreach ($json as $post) {
        $thisUrl = 'https://blog.designly.biz/' . $post['slug'];
        $data = Helper::buildPostData($post);
        $data['POSTS'] = implode("\n", $postCards);
        $page = new Page(COMP_DIR . '/post.html', $data);
        ob_start();
        $page->render();
        $content = ob_get_clean();
        $file = PUB_DIR . '/' . $post['slug'] . '.html';
        $putres = file_put_contents($file, $content);
        doLog("Writing $file: " . ($putres ? "OK" : "FAIL"));

        $meta[] = array_filter($post, function ($key) {
            return $key !== 'content';
        }, ARRAY_FILTER_USE_KEY);
    }

    // Write meta data to json file
    file_put_contents(DATA_DIR . '/postMeta.json', json_encode($meta));
    file_put_contents(DATA_DIR . '/posts.json', json_encode($json));

    // Create index page
    doLog('Building index page');
    // Get tags list
    $tags = Helper::getAllUniqueTags($json);
    $tagList = Helper::buildTagList($tags);
    // Generate page
    $thisUrl = 'https://blog.designly.biz';
    $page = new Page(COMP_DIR . '/home.html', [
        'PAGE_TITLE' => 'Blog',
        'POSTS' => implode("\n", $postCards),
        'tagList' => $tagList,
    ]);
    $page->write(PUB_DIR . '/index.html');

    // Generate sitemap
    $sitemap = new DOMDocument('1.0', 'UTF-8');

    $urlset = $sitemap->createElement('urlset');
    $urlset->setAttribute('xmlns', 'http://www.sitemaps.org/schemas/sitemap/0.9');
    $urlset->setAttribute('xmlns:image', 'http://www.google.com/schemas/sitemap-image/1.1');
    $sitemap->appendChild($urlset);

    foreach ($json as $post) {
        $thisUrl = 'https://blog.designly.biz/' . $post['slug'];

        $url = $sitemap->createElement('url');

        $loc = $sitemap->createElement('loc');
        $loc->appendChild($sitemap->createTextNode($thisUrl));
        $url->appendChild($loc);

        // Add image
        $image = $sitemap->createElement('image:image');

        $imageUrl = $post['coverImage']; // Replace with your image URL
        $imageLoc = $sitemap->createElement('image:loc');
        $imageLoc->appendChild($sitemap->createTextNode($imageUrl));
        $image->appendChild($imageLoc);

        $url->appendChild($image);

        $urlset->appendChild($url);
    }

    // Save the sitemap to a file
    $sitemap->formatOutput = true;
    $sitemap->save(PUB_DIR . '/sitemaps/posts.xml');
} catch (Exception $e) {
    doLog($e->getMessage());
}

## Helper.class.php
<?php

class Helper
{
    static public function buildPostData($post)
    {
        // get css files
        $css = "";
        foreach (BLOG_CSS_FILES as $file) {
            $css .= "<link rel=\"stylesheet\" href=\"$file\" />\n";
        }
        // Configure image path
        $coverImage = str_replace('cdn.designly.biz', 'cdn.designly.biz/imgr',  $post['coverImage']);
        $coverImageSrcSet = Helper::mkSrcSet($post['coverImage']);

        // Create tags
        $tags = [];
        foreach ($post['tagsCollection']['items'] as $t) {
            $tag = $t['tag'];
            $slug = $t['slug'];
            $tags[] = "<a href=\"/tag/$slug\">#$tag</a>";
        }

        // Configure title
        $title = $post['title'] . ' | Designly';

        $data = [
            ...$post,
            'CSS_FILES' => $css,
            'PAGE_TITLE' => $title,
            'postId' => $post['sys']['id'],
            'coverImageThumb' => $coverImage . '?w=400&q=75',
            'coverImagePost' => $coverImage . '?w=1200&q=75',
            'coverImageSrcSet' => $coverImageSrcSet,
            'tagList' => implode("\n", $tags),
            'ogImage' => $coverImage,
            'ogTitle' => $post['title'],
            'description' => $post['excerpt'],
        ];

        return $data;
    }

    static public function buildTemplate($template, $data)
    {
        $html = Page::parseTemplate($template);
        $html = Page::replaceKeys($html, $data);
        $html = Page::cleanUpTags($html);

        return $html;
    }

    static public function buildPostCard($post)
    {
        $post = self::buildPostData($post);

        return self::buildTemplate(COMP_DIR . '/postItem.html', $post);
    }

    static public function buildPostCards($posts, $numCards = null)
    {
        if (!$numCards) {
            $numCards = count($posts);
        }
        $cards = [];
        for ($i = 0; $i < $numCards; $i++) {
            $cards[] = self::buildPostCard($posts[$i]);
            if (($i + 1) % 3 === 0) {
                $ad = self::buildTemplate(COMP_DIR . '/googleAdFeed.html', []);
                $cards[] = $ad;
            }
        }

        return $cards;
    }

    static public function mkSrcSet($src)
    {
        $src = str_replace('cdn.designly.biz', 'cdn.designly.biz/imgr', $src);
        $srcset = [];
        $sizes = [1024, 640, 320];
        foreach ($sizes as $size) {
            $srcset[] = "$src?w=$size&q=75 " . $size . "w";
        }

        return implode(", ", $srcset);
    }

    static public function getUtf8($fn)
    {
        $content = file_get_contents($fn);

        $content = mb_convert_encoding(
            $content,
            'UTF-8',
            'auto'
        );

        return $content;
    }

    static public function render404()
    {
        http_response_code(404);
        $page = new Page(COMP_DIR . '/404.html', [
            'title' => '404 Not Found',
        ]);
        $page->render();
        exit;
    }

    static public function balanceText($text, $lineLength)
    {
        // split the text into words
        $words = explode(" ", $text);

        // initialize variables
        $currentLine = "";
        $output = "";

        // loop through each word
        foreach ($words as $word) {
            // add the current word to the current line
            $tempLine = $currentLine . " " . $word;

            // if the current line is too long, add it to the output with a <br> tag
            if (strlen($tempLine) > $lineLength) {
                $output .= $currentLine . "<br>";
                $currentLine = $word;
            } else {
                $currentLine = $tempLine;
            }
        }

        // add the final line to the output
        $output .= $currentLine;

        return $output;
    }

    static public function cosineSimilarity($embedding1, $embedding2)
    {
        // Calculate the dot product of the two embeddings
        $dot_product = 0;
        for ($i = 0; $i < count($embedding1); $i++) {
            $dot_product += $embedding1[$i] * $embedding2[$i];
        }

        // Calculate the magnitude of the first embedding
        $magnitude1 = 0;
        foreach ($embedding1 as $value) {
            $magnitude1 += $value * $value;
        }
        $magnitude1 = sqrt($magnitude1);

        // Calculate the magnitude of the second embedding
        $magnitude2 = 0;
        foreach ($embedding2 as $value) {
            $magnitude2 += $value * $value;
        }
        $magnitude2 = sqrt($magnitude2);

        // Calculate the cosine similarity
        $cosine_similarity = $dot_product / ($magnitude1 * $magnitude2);

        return $cosine_similarity;
    }

    static public function vectorSearch($term)
    {
        $term = trim($term);
        $term = strip_tags($term);
        $term = preg_replace("/[^A-Za-z0-9 ]/", '', $term);

        $client = OpenAI::client($_ENV['OPENAI_KEY']);

        $response = $client->embeddings()->create([
            'model' => 'text-embedding-ada-002',
            'input' => $term,
        ]);
        $emb = $response->embeddings[0];

        $embs = json_decode(file_get_contents(DIR . '/data/embeddings.json'), true);
        $results = [];
        foreach ($embs as $e) {
            $results[] = [
                'similarity' => Helper::cosineSimilarity($e['embedding'], $emb->embedding),
                'slug' => $e['slug'],
                'chunk' => $e['chunk']
            ];
        }

        usort($results, function ($a, $b) {
            return $b['similarity'] <=> $a['similarity'];
        });

        return $results;
    }

    static public function rateLimit($limit = 10,  $timeFrame = 60)
    {
        $ipAddress = $_SERVER['REMOTE_ADDR']; // Get the client's IP address

        $filePath = '/tmp/rate_limit_' . $ipAddress; // File path where request data is stored

        // Read the file if it exists, if not initialize an empty array
        $data = file_exists($filePath) ? json_decode(file_get_contents($filePath), true) : [];

        if (!isset($data['resetTime']) || time() > $data['resetTime']) {
            // Reset the requests and set new resetTime
            $data['requests'] = 1;
            $data['resetTime'] = time() + $timeFrame;
        } else {
            // If we're within the time frame, increment 'requests'
            $data['requests']++;
        }

        // If the request limit has been exceeded, send a 429 'Too Many Requests' response
        if ($data['requests'] > $limit) {
            http_response_code(429);
            echo "Rate limit exceeded. Try again later.";
            exit;
        }

        // Save the updated data back to the file
        file_put_contents($filePath, json_encode($data));
    }

    static public function getPostsByTagSlug($tagSlug)
    {
        $posts = json_decode(file_get_contents(DIR . '/data/postMeta.json'), true);
        $filteredPosts = [];

        foreach ($posts as $post) {
            $tagsCollection = $post['tagsCollection']['items'];

            foreach ($tagsCollection as $tag) {
                if ($tag['slug'] === $tagSlug) {
                    $filteredPosts[] = $post;
                    break;
                }
            }
        }

        return $filteredPosts;
    }

    static public function getAllUniqueTags($posts)
    {
        $uniqueTags = [];

        foreach ($posts as $post) {
            $tagsCollection = $post['tagsCollection']['items'];

            foreach ($tagsCollection as $tag) {
                $tagSlug = $tag['slug'];

                if (!isset($uniqueTags[$tagSlug])) {
                    $tagName = $tag['tag'];
                    $uniqueTags[$tagSlug] = $tagName;
                }
            }
        }

        asort($uniqueTags);

        return $uniqueTags;
    }

    static public function buildTagList($tags)
    {
        $tagsList = [];
        foreach ($tags as $slug => $name) {
            $tagsList[] = "<a href=\"/tag/$slug\">#$name</a>";
        }
        return implode("\n", $tagsList);
    }
}

## Page.class.php
<?php
class Page
{
    private $title;
    private $content;
    private $data;
    private $template;

    static public function replaceKeys($string, $array)
    {
        return preg_replace_callback('/{{(.*?)}}/', function ($matches) use ($array) {
            return isset($array[$matches[1]]) ? $array[$matches[1]] : $matches[0];
        }, $string);
    }

    static public function cleanUpTags($string)
    {
        return preg_replace('/{{.*?}}/', '', $string);
    }

    static public function removeEmptyLines($str)
    {
        // Split the string into an array of lines
        $lines = explode("\n", $str);

        // Loop through each line and remove if it's empty or contains only whitespace
        foreach ($lines as $key => $line) {
            if (trim($line) === '') {
                unset($lines[$key]);
            }
        }

        // Re-join the remaining lines and return the result
        return implode("\n", $lines);
    }

    static public function includeTemplateFiles($str)
    {
        global $thisUrl;
        return preg_replace_callback('/{{inc:(.*?)}}/', function ($matches) {
            $file = COMP_DIR . trim($matches[1]) . '.html';
            if (file_exists($file)) {
                ob_start();
                require $file;
                $content = ob_get_clean();

                return $content;
            } else {
                throw new RuntimeException('Template file not found: ' . $file);
            }
        }, $str);
    }

    static public function minifyHtml($html)
    {
        $search = array(
            '/\>[^\S ]+/s',  // strip whitespaces after tags, except space
            '/[^\S ]+\</s',  // strip whitespaces before tags, except space
            '/(\s)+/s'       // shorten multiple whitespace sequences
        );
        $replace = array(
            '>',
            '<',
            '\\1'
        );
        return preg_replace($search, $replace, $html);
    }


    static public function prettifyHtml($html)
    {
        $html = self::minifyHtml($html);
        $doc = new DOMDocument();
        $doc->loadHTML($html, LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);

        // Set some options to make the output prettier
        $doc->preserveWhiteSpace = false;
        $doc->formatOutput = true;

        // Convert the DOMDocument back to a string of HTML
        return $doc->saveHTML();
    }

    static public function hashDir($dir)
    {
        $timestamps = array();
        $iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($dir));
        foreach ($iterator as $file) {
            if ($file->isFile()) {
                $timestamps[] = $file->getMTime();
            }
        }
        sort($timestamps);
        $hash = hash('sha256', implode('', $timestamps));
        return $hash;
    }

    static public function parseTemplate($file)
    {
        global $thisUrl;
        ob_start();
        require($file);
        $content = ob_get_clean();

        return $content;
    }

    static public function insertCopyButtons($html)
    {
        $dom = new DOMDocument();
        $dom->formatOutput = false;
        $dom->loadHTML(mb_convert_encoding($html, 'HTML-ENTITIES', 'UTF-8'));

        // Format code blocks
        $pres = $dom->getElementsByTagName('pre');
        foreach ($pres as $pre) {
            $div = $dom->createElement('div');
            $div->setAttribute('class', 'code-wrapper shadow-lg');
            $pre->parentNode->insertBefore($div, $pre);
            $div->appendChild($pre);

            $span1 = $dom->createElement('span');
            $span1->setAttribute('class', 'mac1');
            $div->insertBefore($span1);
            $span2 = $dom->createElement('span');
            $span2->setAttribute('class', 'mac2');
            $div->insertBefore($span2);
            $span3 = $dom->createElement('span');
            $span3->setAttribute('class', 'mac3');
            $div->insertBefore($span3);

            $button = $dom->createElement('button');
            $button->setAttribute('class', 'code-button');
            $button->setAttribute('aria-label', 'Copy to clipboard');
            $i = $dom->createElement('i');
            $i->setAttribute('class', 'fa-solid fa-copy code-copy-icon');
            $button->appendChild($i);
            $div->appendChild($button);
        }

        // Format images
        $imgs = $dom->getElementsByTagName('img');
        foreach ($imgs as $img) {
            $img->setAttribute('class', 'blog-post-image');
            $img->setAttribute('width', '1920');
            $img->setAttribute('height', '1080');
            $src = $img->getAttribute('src');
            $src = str_replace('d340jo5zum8tsx.cloudfront.net', 'cdn.designly.biz',  $src);
            $img->setAttribute('data-original', $src);
            $srcset = Helper::mkSrcSet($src);
            $src = str_replace('cdn.designly.biz', 'cdn.designly.biz/imgr',  $src);
            $src .= '?w=1200&q=75';
            $img->setAttribute('src', $src);
            $img->setAttribute('srcset', $srcset);
        }

        // Format links
        $links = $dom->getElementsByTagName('a');
        foreach ($links as $link) {
            $link->setAttribute('rel', 'noreferrer noopener');
            $link->setAttribute('target', '_blank');
        }

        $modifiedHtml = $dom->saveHTML();
        $modifiedHtml = preg_replace('/^.*?<body.*?>|<\/body>.*$/si', '', $modifiedHtml);
        $modifiedHtml = preg_replace('/^.*?<html.*?>|<\/html>.*$/si', '', $modifiedHtml);

        return $modifiedHtml;
    }

    public function __construct($template, $data)
    {
        if (!defined('MAIN_TEMPLATE_FILE')) {
            throw new RuntimeException('MAIN_TEMPLATE_FILE not defined');
        }
        if (!file_exists(MAIN_TEMPLATE_FILE)) {
            throw new RuntimeException('MAIN_TEMPLATE_FILE not found');
        }
        $this->template = $template;
        $this->data = $data;

        return $this->build();
    }

    public function build()
    {
        global $thisUrl;
        if (!file_exists($this->template)) {
            throw new RuntimeException('Template not found');
        }
        // Get main template
        ob_start();
        require MAIN_TEMPLATE_FILE;
        $this->content = ob_get_clean();

        // Get page template
        ob_start();
        require $this->template;
        $pageContent = ob_get_clean();
        // Insert page content
        $this->content = str_replace('{{PAGE::CONTENT}}', $pageContent, $this->content);
        // Include template files
        $this->content = self::includeTemplateFiles($this->content);
        // Insert code copy buttons
        if (isset($this->data['content'])) {
            $this->data['content'] = self::insertCopyButtons($this->data['content']);
        }
        // Insert data keys
        $this->content = self::replaceKeys($this->content, $this->data);
        // Clean up tags
        $this->content = self::cleanUpTags($this->content);
        // Remove empty lines
        $this->content = self::removeEmptyLines($this->content);

        return true;
    }

    public function render()
    {
        header('Content-Type: text/html; charset=utf-8');
        echo $this->content;
    }

    public function write($filename)
    {
        return file_put_contents($filename, $this->content);
    }

    public function setTitle($title)
    {
        $this->title = $title;
    }

    public function getTitle()
    {
        return $this->title;
    }

    public function setContent($content)
    {
        $this->content = $content;
    }

    public function getContent()
    {
        return $this->content;
    }

    public function setData($data)
    {
        $this->data = $data;
    }

    public function getData()
    {
        return $this->data;
    }

    public function setTemplate($template)
    {
        $this->template = $template;
    }

    public function getTemplate()
    {
        return $this->template;
    }
}
	<?php
	try {
	require_once(__DIR__ . '/config.inc.php');
	require_once(DIR . '/inc/build.inc.php');

	// Fetch posts
	doLog('Fetching posts');
	define('URL', BLOG_BASE_URL . '?content=true');
	$json = json_decode(Helper::getUtf8(URL), true);
	if (!$json \|\| empty($json)) {
	throw new Exception('Failed to fetch posts');
	}

	doLog('Removing old files');
	$rmfiles = PUB_DIR . '/*.html';
	`rm -f $rmfiles`;

	doLog('Building post pages');
	$postCards = Helper::buildPostCards($json, 9);
	$meta = [];

	foreach ($json as $post) {
	$thisUrl = 'https://blog.designly.biz/' . $post['slug'];
	$data = Helper::buildPostData($post);
	$data['POSTS'] = implode("\n", $postCards);
	$page = new Page(COMP_DIR . '/post.html', $data);
	ob_start();
	$page->render();
	$content = ob_get_clean();
	$file = PUB_DIR . '/' . $post['slug'] . '.html';
	$putres = file_put_contents($file, $content);
	doLog("Writing $file: " . ($putres ? "OK" : "FAIL"));

	$meta[] = array_filter($post, function ($key) {
	return $key !== 'content';
	}, ARRAY_FILTER_USE_KEY);
	}

	// Write meta data to json file
	file_put_contents(DATA_DIR . '/postMeta.json', json_encode($meta));
	file_put_contents(DATA_DIR . '/posts.json', json_encode($json));

	// Create index page
	doLog('Building index page');
	// Get tags list
	$tags = Helper::getAllUniqueTags($json);
	$tagList = Helper::buildTagList($tags);
	// Generate page
	$thisUrl = 'https://blog.designly.biz';
	$page = new Page(COMP_DIR . '/home.html', [
	'PAGE_TITLE' => 'Blog',
	'POSTS' => implode("\n", $postCards),
	'tagList' => $tagList,
	]);
	$page->write(PUB_DIR . '/index.html');

	// Generate sitemap
	$sitemap = new DOMDocument('1.0', 'UTF-8');

	$urlset = $sitemap->createElement('urlset');
	$urlset->setAttribute('xmlns', 'http://www.sitemaps.org/schemas/sitemap/0.9');
	$urlset->setAttribute('xmlns:image', 'http://www.google.com/schemas/sitemap-image/1.1');
	$sitemap->appendChild($urlset);

	foreach ($json as $post) {
	$thisUrl = 'https://blog.designly.biz/' . $post['slug'];

	$url = $sitemap->createElement('url');

	$loc = $sitemap->createElement('loc');
	$loc->appendChild($sitemap->createTextNode($thisUrl));
	$url->appendChild($loc);

	// Add image
	$image = $sitemap->createElement('image:image');

	$imageUrl = $post['coverImage']; // Replace with your image URL
	$imageLoc = $sitemap->createElement('image:loc');
	$imageLoc->appendChild($sitemap->createTextNode($imageUrl));
	$image->appendChild($imageLoc);

	$url->appendChild($image);

	$urlset->appendChild($url);
	}

	// Save the sitemap to a file
	$sitemap->formatOutput = true;
	$sitemap->save(PUB_DIR . '/sitemaps/posts.xml');
	} catch (Exception $e) {
	doLog($e->getMessage());
	}
	<?php

	class Helper
	{
	static public function buildPostData($post)
	{
	// get css files
	$css = "";
	foreach (BLOG_CSS_FILES as $file) {
	$css .= "<link rel=\"stylesheet\" href=\"$file\" />\n";
	}
	// Configure image path
	$coverImage = str_replace('cdn.designly.biz', 'cdn.designly.biz/imgr', $post['coverImage']);
	$coverImageSrcSet = Helper::mkSrcSet($post['coverImage']);

	// Create tags
	$tags = [];
	foreach ($post['tagsCollection']['items'] as $t) {
	$tag = $t['tag'];
	$slug = $t['slug'];
	$tags[] = "<a href=\"/tag/$slug\">#$tag</a>";
	}

	// Configure title
	$title = $post['title'] . ' \| Designly';

	$data = [
	...$post,
	'CSS_FILES' => $css,
	'PAGE_TITLE' => $title,
	'postId' => $post['sys']['id'],
	'coverImageThumb' => $coverImage . '?w=400&q=75',
	'coverImagePost' => $coverImage . '?w=1200&q=75',
	'coverImageSrcSet' => $coverImageSrcSet,
	'tagList' => implode("\n", $tags),
	'ogImage' => $coverImage,
	'ogTitle' => $post['title'],
	'description' => $post['excerpt'],
	];

	return $data;
	}

	static public function buildTemplate($template, $data)
	{
	$html = Page::parseTemplate($template);
	$html = Page::replaceKeys($html, $data);
	$html = Page::cleanUpTags($html);

	return $html;
	}

	static public function buildPostCard($post)
	{
	$post = self::buildPostData($post);

	return self::buildTemplate(COMP_DIR . '/postItem.html', $post);
	}

	static public function buildPostCards($posts, $numCards = null)
	{
	if (!$numCards) {
	$numCards = count($posts);
	}
	$cards = [];
	for ($i = 0; $i < $numCards; $i++) {
	$cards[] = self::buildPostCard($posts[$i]);
	if (($i + 1) % 3 === 0) {
	$ad = self::buildTemplate(COMP_DIR . '/googleAdFeed.html', []);
	$cards[] = $ad;
	}
	}

	return $cards;
	}

	static public function mkSrcSet($src)
	{
	$src = str_replace('cdn.designly.biz', 'cdn.designly.biz/imgr', $src);
	$srcset = [];
	$sizes = [1024, 640, 320];
	foreach ($sizes as $size) {
	$srcset[] = "$src?w=$size&q=75 " . $size . "w";
	}

	return implode(", ", $srcset);
	}

	static public function getUtf8($fn)
	{
	$content = file_get_contents($fn);

	$content = mb_convert_encoding(
	$content,
	'UTF-8',
	'auto'
	);

	return $content;
	}

	static public function render404()
	{
	http_response_code(404);
	$page = new Page(COMP_DIR . '/404.html', [
	'title' => '404 Not Found',
	]);
	$page->render();
	exit;
	}

	static public function balanceText($text, $lineLength)
	{
	// split the text into words
	$words = explode(" ", $text);

	// initialize variables
	$currentLine = "";
	$output = "";

	// loop through each word
	foreach ($words as $word) {
	// add the current word to the current line
	$tempLine = $currentLine . " " . $word;

	// if the current line is too long, add it to the output with a <br> tag
	if (strlen($tempLine) > $lineLength) {
	$output .= $currentLine . "<br>";
	$currentLine = $word;
	} else {
	$currentLine = $tempLine;
	}
	}

	// add the final line to the output
	$output .= $currentLine;

	return $output;
	}

	static public function cosineSimilarity($embedding1, $embedding2)
	{
	// Calculate the dot product of the two embeddings
	$dot_product = 0;
	for ($i = 0; $i < count($embedding1); $i++) {
	$dot_product += $embedding1[$i] * $embedding2[$i];
	}

	// Calculate the magnitude of the first embedding
	$magnitude1 = 0;
	foreach ($embedding1 as $value) {
	$magnitude1 += $value * $value;
	}
	$magnitude1 = sqrt($magnitude1);

	// Calculate the magnitude of the second embedding
	$magnitude2 = 0;
	foreach ($embedding2 as $value) {
	$magnitude2 += $value * $value;
	}
	$magnitude2 = sqrt($magnitude2);

	// Calculate the cosine similarity
	$cosine_similarity = $dot_product / ($magnitude1 * $magnitude2);

	return $cosine_similarity;
	}

	static public function vectorSearch($term)
	{
	$term = trim($term);
	$term = strip_tags($term);
	$term = preg_replace("/[^A-Za-z0-9 ]/", '', $term);

	$client = OpenAI::client($_ENV['OPENAI_KEY']);

	$response = $client->embeddings()->create([
	'model' => 'text-embedding-ada-002',
	'input' => $term,
	]);
	$emb = $response->embeddings[0];

	$embs = json_decode(file_get_contents(DIR . '/data/embeddings.json'), true);
	$results = [];
	foreach ($embs as $e) {
	$results[] = [
	'similarity' => Helper::cosineSimilarity($e['embedding'], $emb->embedding),
	'slug' => $e['slug'],
	'chunk' => $e['chunk']
	];
	}

	usort($results, function ($a, $b) {
	return $b['similarity'] <=> $a['similarity'];
	});

	return $results;
	}

	static public function rateLimit($limit = 10, $timeFrame = 60)
	{
	$ipAddress = $_SERVER['REMOTE_ADDR']; // Get the client's IP address

	$filePath = '/tmp/rate_limit_' . $ipAddress; // File path where request data is stored

	// Read the file if it exists, if not initialize an empty array
	$data = file_exists($filePath) ? json_decode(file_get_contents($filePath), true) : [];

	if (!isset($data['resetTime']) \|\| time() > $data['resetTime']) {
	// Reset the requests and set new resetTime
	$data['requests'] = 1;
	$data['resetTime'] = time() + $timeFrame;
	} else {
	// If we're within the time frame, increment 'requests'
	$data['requests']++;
	}

	// If the request limit has been exceeded, send a 429 'Too Many Requests' response
	if ($data['requests'] > $limit) {
	http_response_code(429);
	echo "Rate limit exceeded. Try again later.";
	exit;
	}

	// Save the updated data back to the file
	file_put_contents($filePath, json_encode($data));
	}

	static public function getPostsByTagSlug($tagSlug)
	{
	$posts = json_decode(file_get_contents(DIR . '/data/postMeta.json'), true);
	$filteredPosts = [];

	foreach ($posts as $post) {
	$tagsCollection = $post['tagsCollection']['items'];

	foreach ($tagsCollection as $tag) {
	if ($tag['slug'] === $tagSlug) {
	$filteredPosts[] = $post;
	break;
	}
	}
	}

	return $filteredPosts;
	}

	static public function getAllUniqueTags($posts)
	{
	$uniqueTags = [];

	foreach ($posts as $post) {
	$tagsCollection = $post['tagsCollection']['items'];

	foreach ($tagsCollection as $tag) {
	$tagSlug = $tag['slug'];

	if (!isset($uniqueTags[$tagSlug])) {
	$tagName = $tag['tag'];
	$uniqueTags[$tagSlug] = $tagName;
	}
	}
	}

	asort($uniqueTags);

	return $uniqueTags;
	}

	static public function buildTagList($tags)
	{
	$tagsList = [];
	foreach ($tags as $slug => $name) {
	$tagsList[] = "<a href=\"/tag/$slug\">#$name</a>";
	}
	return implode("\n", $tagsList);
	}
	}
	<?php
	class Page
	{
	private $title;
	private $content;
	private $data;
	private $template;

	static public function replaceKeys($string, $array)
	{
	return preg_replace_callback('/{{(.*?)}}/', function ($matches) use ($array) {
	return isset($array[$matches[1]]) ? $array[$matches[1]] : $matches[0];
	}, $string);
	}

	static public function cleanUpTags($string)
	{
	return preg_replace('/{{.*?}}/', '', $string);
	}

	static public function removeEmptyLines($str)
	{
	// Split the string into an array of lines
	$lines = explode("\n", $str);

	// Loop through each line and remove if it's empty or contains only whitespace
	foreach ($lines as $key => $line) {
	if (trim($line) === '') {
	unset($lines[$key]);
	}
	}

	// Re-join the remaining lines and return the result
	return implode("\n", $lines);
	}

	static public function includeTemplateFiles($str)
	{
	global $thisUrl;
	return preg_replace_callback('/{{inc:(.*?)}}/', function ($matches) {
	$file = COMP_DIR . trim($matches[1]) . '.html';
	if (file_exists($file)) {
	ob_start();
	require $file;
	$content = ob_get_clean();

	return $content;
	} else {
	throw new RuntimeException('Template file not found: ' . $file);
	}
	}, $str);
	}

	static public function minifyHtml($html)
	{
	$search = array(
	'/\>[^\S ]+/s', // strip whitespaces after tags, except space
	'/[^\S ]+\</s', // strip whitespaces before tags, except space
	'/(\s)+/s' // shorten multiple whitespace sequences
	);
	$replace = array(
	'>',
	'<',
	'\\1'
	);
	return preg_replace($search, $replace, $html);
	}


	static public function prettifyHtml($html)
	{
	$html = self::minifyHtml($html);
	$doc = new DOMDocument();
	$doc->loadHTML($html, LIBXML_HTML_NOIMPLIED \| LIBXML_HTML_NODEFDTD);

	// Set some options to make the output prettier
	$doc->preserveWhiteSpace = false;
	$doc->formatOutput = true;

	// Convert the DOMDocument back to a string of HTML
	return $doc->saveHTML();
	}

	static public function hashDir($dir)
	{
	$timestamps = array();
	$iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($dir));
	foreach ($iterator as $file) {
	if ($file->isFile()) {
	$timestamps[] = $file->getMTime();
	}
	}
	sort($timestamps);
	$hash = hash('sha256', implode('', $timestamps));
	return $hash;
	}

	static public function parseTemplate($file)
	{
	global $thisUrl;
	ob_start();
	require($file);
	$content = ob_get_clean();

	return $content;
	}

	static public function insertCopyButtons($html)
	{
	$dom = new DOMDocument();
	$dom->formatOutput = false;
	$dom->loadHTML(mb_convert_encoding($html, 'HTML-ENTITIES', 'UTF-8'));

	// Format code blocks
	$pres = $dom->getElementsByTagName('pre');
	foreach ($pres as $pre) {
	$div = $dom->createElement('div');
	$div->setAttribute('class', 'code-wrapper shadow-lg');
	$pre->parentNode->insertBefore($div, $pre);
	$div->appendChild($pre);

	$span1 = $dom->createElement('span');
	$span1->setAttribute('class', 'mac1');
	$div->insertBefore($span1);
	$span2 = $dom->createElement('span');
	$span2->setAttribute('class', 'mac2');
	$div->insertBefore($span2);
	$span3 = $dom->createElement('span');
	$span3->setAttribute('class', 'mac3');
	$div->insertBefore($span3);

	$button = $dom->createElement('button');
	$button->setAttribute('class', 'code-button');
	$button->setAttribute('aria-label', 'Copy to clipboard');
	$i = $dom->createElement('i');
	$i->setAttribute('class', 'fa-solid fa-copy code-copy-icon');
	$button->appendChild($i);
	$div->appendChild($button);
	}

	// Format images
	$imgs = $dom->getElementsByTagName('img');
	foreach ($imgs as $img) {
	$img->setAttribute('class', 'blog-post-image');
	$img->setAttribute('width', '1920');
	$img->setAttribute('height', '1080');
	$src = $img->getAttribute('src');
	$src = str_replace('d340jo5zum8tsx.cloudfront.net', 'cdn.designly.biz', $src);
	$img->setAttribute('data-original', $src);
	$srcset = Helper::mkSrcSet($src);
	$src = str_replace('cdn.designly.biz', 'cdn.designly.biz/imgr', $src);
	$src .= '?w=1200&q=75';
	$img->setAttribute('src', $src);
	$img->setAttribute('srcset', $srcset);
	}

	// Format links
	$links = $dom->getElementsByTagName('a');
	foreach ($links as $link) {
	$link->setAttribute('rel', 'noreferrer noopener');
	$link->setAttribute('target', '_blank');
	}

	$modifiedHtml = $dom->saveHTML();
	$modifiedHtml = preg_replace('/^.?<body.?>\|<\/body>.*$/si', '', $modifiedHtml);
	$modifiedHtml = preg_replace('/^.?<html.?>\|<\/html>.*$/si', '', $modifiedHtml);

	return $modifiedHtml;
	}

	public function __construct($template, $data)
	{
	if (!defined('MAIN_TEMPLATE_FILE')) {
	throw new RuntimeException('MAIN_TEMPLATE_FILE not defined');
	}
	if (!file_exists(MAIN_TEMPLATE_FILE)) {
	throw new RuntimeException('MAIN_TEMPLATE_FILE not found');
	}
	$this->template = $template;
	$this->data = $data;

	return $this->build();
	}

	public function build()
	{
	global $thisUrl;
	if (!file_exists($this->template)) {
	throw new RuntimeException('Template not found');
	}
	// Get main template
	ob_start();
	require MAIN_TEMPLATE_FILE;
	$this->content = ob_get_clean();

	// Get page template
	ob_start();
	require $this->template;
	$pageContent = ob_get_clean();
	// Insert page content
	$this->content = str_replace('{{PAGE::CONTENT}}', $pageContent, $this->content);
	// Include template files
	$this->content = self::includeTemplateFiles($this->content);
	// Insert code copy buttons
	if (isset($this->data['content'])) {
	$this->data['content'] = self::insertCopyButtons($this->data['content']);
	}
	// Insert data keys
	$this->content = self::replaceKeys($this->content, $this->data);
	// Clean up tags
	$this->content = self::cleanUpTags($this->content);
	// Remove empty lines
	$this->content = self::removeEmptyLines($this->content);

	return true;
	}

	public function render()
	{
	header('Content-Type: text/html; charset=utf-8');
	echo $this->content;
	}

	public function write($filename)
	{
	return file_put_contents($filename, $this->content);
	}

	public function setTitle($title)
	{
	$this->title = $title;
	}

	public function getTitle()
	{
	return $this->title;
	}

	public function setContent($content)
	{
	$this->content = $content;
	}

	public function getContent()
	{
	return $this->content;
	}

	public function setData($data)
	{
	$this->data = $data;
	}

	public function getData()
	{
	return $this->data;
	}

	public function setTemplate($template)
	{
	$this->template = $template;
	}

	public function getTemplate()
	{
	return $this->template;
	}
	}