class Crap4j

final class Crap4j {
    private readonly int $threshold;
    public function __construct(int $threshold = 30) {
        $this->threshold = $threshold;
    }
    
    /**
     * @throws WriteOperationFailedException
     */
    public function process(CodeCoverage $coverage, ?string $target = null, ?string $name = null) : string {
        $document = new DOMDocument('1.0', 'UTF-8');
        $document->formatOutput = true;
        $root = $document->createElement('crap_result');
        $document->appendChild($root);
        $project = $document->createElement('project', is_string($name) ? $name : '');
        $root->appendChild($project);
        $root->appendChild($document->createElement('timestamp', date('Y-m-d H:i:s')));
        $stats = $document->createElement('stats');
        $methodsNode = $document->createElement('methods');
        $report = $coverage->getReport();
        unset($coverage);
        $fullMethodCount = 0;
        $fullCrapMethodCount = 0;
        $fullCrapLoad = 0;
        $fullCrap = 0;
        foreach ($report as $item) {
            $namespace = 'global';
            if (!$item instanceof File) {
                continue;
            }
            $file = $document->createElement('file');
            $file->setAttribute('name', $item->pathAsString());
            $classes = $item->classesAndTraits();
            foreach ($classes as $className => $class) {
                foreach ($class['methods'] as $methodName => $method) {
                    $crapLoad = $this->crapLoad((double) $method['crap'], $method['ccn'], $method['coverage']);
                    $fullCrap += $method['crap'];
                    $fullCrapLoad += $crapLoad;
                    $fullMethodCount++;
                    if ($method['crap'] >= $this->threshold) {
                        $fullCrapMethodCount++;
                    }
                    $methodNode = $document->createElement('method');
                    if (!empty($class['namespace'])) {
                        $namespace = $class['namespace'];
                    }
                    $methodNode->appendChild($document->createElement('package', $namespace));
                    $methodNode->appendChild($document->createElement('className', $className));
                    $methodNode->appendChild($document->createElement('methodName', $methodName));
                    $methodNode->appendChild($document->createElement('methodSignature', htmlspecialchars($method['signature'])));
                    $methodNode->appendChild($document->createElement('fullMethod', htmlspecialchars($method['signature'])));
                    $methodNode->appendChild($document->createElement('crap', (string) $this->roundValue((double) $method['crap'])));
                    $methodNode->appendChild($document->createElement('complexity', (string) $method['ccn']));
                    $methodNode->appendChild($document->createElement('coverage', (string) $this->roundValue($method['coverage'])));
                    $methodNode->appendChild($document->createElement('crapLoad', (string) round($crapLoad)));
                    $methodsNode->appendChild($methodNode);
                }
            }
        }
        $stats->appendChild($document->createElement('name', 'Method Crap Stats'));
        $stats->appendChild($document->createElement('methodCount', (string) $fullMethodCount));
        $stats->appendChild($document->createElement('crapMethodCount', (string) $fullCrapMethodCount));
        $stats->appendChild($document->createElement('crapLoad', (string) round($fullCrapLoad)));
        $stats->appendChild($document->createElement('totalCrap', (string) $fullCrap));
        $crapMethodPercent = 0;
        if ($fullMethodCount > 0) {
            $crapMethodPercent = $this->roundValue(100 * $fullCrapMethodCount / $fullMethodCount);
        }
        $stats->appendChild($document->createElement('crapMethodPercent', (string) $crapMethodPercent));
        $root->appendChild($stats);
        $root->appendChild($methodsNode);
        $buffer = $document->saveXML();
        if ($target !== null) {
            if (!str_contains($target, '://')) {
                Filesystem::createDirectory(dirname($target));
            }
            if (@file_put_contents($target, $buffer) === false) {
                throw new WriteOperationFailedException($target);
            }
        }
        return $buffer;
    }
    private function crapLoad(float $crapValue, int $cyclomaticComplexity, float $coveragePercent) : float {
        $crapLoad = 0;
        if ($crapValue >= $this->threshold) {
            $crapLoad += $cyclomaticComplexity * (1.0 - $coveragePercent / 100);
            $crapLoad += $cyclomaticComplexity / $this->threshold;
        }
        return $crapLoad;
    }
    private function roundValue(float $value) : float {
        return round($value, 2);
    }

}