fibable/lib/ArticleParser.php

<?php

final class ArticleParser
{

    const PATTERN_DATE = "|\./data/articles/([0-9]+)/([0-9]+)/([0-9]+)/([0-9]+).txt|";
    const PATTERN_TAGS = "/^\{(([a-zA-Z0-9]+,*)+)\}$/";
    const PATTERN_IMG = "/^([a-zA-Z0-9\-_\.]+\.(jpg|png)) \((.*)\)$/";
    const PATTERN_BOLD = "/\*([^*]*)\*/";
    const PATTERN_ITALIC = "|/([^/]*)/|";
    const PATTERN_UNDERLINE = "/_([^_]*)_/";
    const REPLACE_DATE = "$1-$2-$3";
    const REPLACE_REF = "$4";
    const REPLACE_BOLD = "<strong>$1</strong>";
    const REPLACE_ITALIC = "<em>$1</em>";
    const REPLACE_UNDERLINE = "<u>$1</u>";

    private bool $in_p = false;
    private array $content = [];
    private array $p = [];

    public function parse(string $file_path): Article
    {
        $article = new Article();
        $article->date = preg_replace(self::PATTERN_DATE, self::REPLACE_DATE, $file_path);
        $article->ref = preg_replace(self::PATTERN_DATE, self::REPLACE_REF, $file_path);
        $lines = file($file_path, FILE_IGNORE_NEW_LINES);
        foreach ($lines as $line) {
            if (substr($line, 0, 2) === "# ") {
                $article->title = substr($line, 2);
                continue;
            }
            if (substr($line, 0, 3) === "## ") {
                $this->closeParagraph();
                $this->content[] = "<h3>" . substr($line, 3) . "</h3>";
                continue;
            }
            if (substr($line, 0, 4) === "### ") {
                $this->closeParagraph();
                $this->content[] = "<h4>" . substr($line, 4) . "</h4>";
                continue;
            }
            if (substr($line, 0, 5) === "#### ") {
                $this->closeParagraph();
                $this->content[] = "<h5>" . substr($line, 5) . "</h5>";
                continue;
            }
            if (preg_match(self::PATTERN_TAGS, $line, $matches)) {
                $article->tags = explode(",", $matches[1]);
                continue;
            }
            if (preg_match(self::PATTERN_IMG, $line, $matches)) {
                $this->closeParagraph();
                $this->content[] = "<figure>";
                $this->content[] = "    <img src=\"" . dirname($file_path) . "/$matches[1]\" alt=\"$matches[3]\">";
                $this->content[] = "    <figcaption>$matches[3]</figcaption>";
                $this->content[] = "</figure>";
                continue;
            }
            if ($line === "") {
                $this->closeParagraph();
                continue;
            } else {
                if (!$this->in_p) {
                    $this->content[] = "<p>";
                    $this->in_p = true;
                }
                $this->p[] = $this->parseLine($line);
            }
        }
        $this->closeParagraph();
        array_unshift($this->content,
            "<header>",
            "    <h2>" . $article->title . "</h2>",
            "    <nav>" . $this->getHtmlTags($article->tags) . "</nav>",
            "</header>"
        );
        $this->content[] = "<footer>" .
            preg_replace("/([0-9]+)\-([0-9]+)-([0-9]+)/", "$3/$2/$1", $article->date) .
            "</footer>";
        $view_path = "./data/cache/{$article->date}_{$article->ref}.phtml";
        file_put_contents($view_path, "            " . implode("\n            ", $this->content) . "\n");
        $article->view = $view_path;
        $this->content = [];
        return $article;
    }

    private function closeParagraph()
    {
        if ($this->in_p) {
            $this->content[] = "    " . implode("<br>", $this->p);
            $this->content[] = "</p>";
            $this->in_p = false;
            $this->p = [];
        }
    }

    private function parseLine(string $line): string
    {
        $patterns = [
            self::PATTERN_BOLD,
            self::PATTERN_ITALIC,
            self::PATTERN_UNDERLINE
        ];
        $replacements = [
            self::REPLACE_BOLD,
            self::REPLACE_ITALIC,
            self::REPLACE_UNDERLINE
        ];
        return preg_replace($patterns, $replacements, htmlspecialchars($line, ENT_HTML5, UTF-8));
    }

    private function getHtmlTags(array $tags): string
    {
        $html = "";
        foreach ($tags as $tag) {
            $html .= "<a href=\"?view=tags&tag=$tag\" class=\"tag\">$tag</a>";
        }
        return $html;
    }

}