mapguesser/src/View/Linker.php

<?php namespace MapGuesser\View;

class Linker
{
    const INLINE_ASSET_LIMIT = 2000;

    private string $view;

    public function __construct(string $view)
    {
        $this->view = $view;
    }

    public function generate(): void
    {
        $input = ROOT . '/views/' . $this->view . '.php';

        $temporaryFiles = [];
        $sections = ['externalCss' => '', 'inlineCss' => '', 'externalJs' => '', 'inlineJs' => ''];
        $extra = ['', ''];

        do {
            $parser = new Parser($input);
            $fragment = $parser->parse();

            $extends = $fragment->getExtends();

            $this->generateAssets($fragment, $sections);

            $sections = array_merge($sections, $fragment->getSections()); //TODO: detect if section defined multiple times
            $extra[0] = $fragment->getExtra()[0] . $extra[0];
            $extra[1] = $extra[1] . $fragment->getExtra()[1];

            if ($extends === null) {
                $this->writeFinal($extra, $input, ROOT . '/cache/views/' . $this->view . '.php');
                break;
            }

            $tmpFile = tempnam(sys_get_temp_dir(), 'mapg-view-');
            $temporaryFiles[] = $tmpFile;

            $this->extendTemplate($sections, ROOT . '/views/' . $extends . '.php', $tmpFile);

            $input = $tmpFile;
        } while (true);

        foreach ($temporaryFiles as $tmpFile) {
            unlink($tmpFile);
        }
    }

    private function extendTemplate(array $sections, string $file, string $output): void
    {
        $inputFileHandle = fopen($file, 'r');
        if (!$inputFileHandle) {
            throw new \Exception('Cannot open file ' . $file);
        }

        $outputFileHandle = fopen($output, 'w');
        if (!$outputFileHandle) {
            throw new \Exception('Cannot open file ' . $output . 'for writing.');
        }

        $lineNumber = 0;
        while (($line = fgets($inputFileHandle)) !== false) {
            ++$lineNumber;

            if (preg_match('/^\s*@yields\(\'([\w\/]+)\'\)\s*$/', $line, $matches)) {
                if (isset($sections[$matches[1]])) {
                    fwrite($outputFileHandle, $sections[$matches[1]]);
                }
            } else {
                fwrite($outputFileHandle, $line);
            }
        }

        fclose($inputFileHandle);
        fclose($outputFileHandle);
    }

    private function writeFinal(array $extra, string $file, string $output): void
    {
        $dirname = pathinfo($output, PATHINFO_DIRNAME);
        if (!is_dir($dirname)) {
            mkdir($dirname, 0755, true);
        }

        $inputFileHandle = fopen($file, 'r');
        if (!$inputFileHandle) {
            throw new \Exception('Cannot open file ' . $file);
        }

        $outputFileHandle = fopen($output, 'w');
        if (!$outputFileHandle) {
            throw new \Exception('Cannot open file ' . $output . 'for writing.');
        }

        fwrite($outputFileHandle, $extra[0]);
        while (($line = fgets($inputFileHandle)) !== false) {
            fwrite($outputFileHandle, $line);
        }
        fwrite($outputFileHandle, $extra[1]);

        fclose($inputFileHandle);
        fclose($outputFileHandle);
    }

    private function generateAssets(ParsedFragment $fragment, array &$sections)
    {
        foreach ($fragment->getCss() as $cssFile) {
            $asset = $this->parseAsset($cssFile);
            if (isset($asset['code'])) {
                $sections['inlineCss'] .= '<style>' . PHP_EOL;
                $sections['inlineCss'] .= $asset['code'];
                $sections['inlineCss'] .= '</style>' . PHP_EOL;
            } elseif (isset($asset['file'])) {
                $sections['externalCss'] .= '<link href="' . $asset['file'] . '" rel="stylesheet">' . PHP_EOL;
            }
        }

        foreach ($fragment->getJs() as $jsFile) {
            $asset = $this->parseAsset($jsFile);
            if (isset($asset['code'])) {
                $sections['inlineJs'] .= '<script>' . PHP_EOL;
                $sections['inlineJs'] .= $asset['code'];
                $sections['inlineJs'] .= '</script>' . PHP_EOL;
            } elseif (isset($asset['file'])) {
                $sections['externalJs'] .= '<script src="' . $asset['file'] . '"></script>' . PHP_EOL;
            }
        }
    }

    private function parseAsset(string $asset): array
    {
        $output = [];

        if (preg_match('/^[\w\/\.]+$/', $asset)) {
            if (
                empty($_ENV['DEV']) &&
                filesize(ROOT . '/public/static/' . $asset) < self::INLINE_ASSET_LIMIT
            ) {
                $output['code'] = file_get_contents(ROOT . '/public/static/' . $asset);
            } else {
                $output['file'] = '<?= $_ENV[\'STATIC_ROOT\'] ?>/' . $asset . '?rev=<?= REVISION ?>';
            }
        } else {
            $output['file'] = $asset;
        }

        return $output;
    }
}