class DataProvider

final class DataProvider {
    
    /**
     * @psalm-param class-string $className
     * @psalm-param non-empty-string $methodName
     *
     * @throws InvalidDataProviderException
     */
    public function providedData(string $className, string $methodName) : ?array {
        $dataProvider = MetadataRegistry::parser()->forMethod($className, $methodName)
            ->isDataProvider();
        $testWith = MetadataRegistry::parser()->forMethod($className, $methodName)
            ->isTestWith();
        if ($dataProvider->isEmpty() && $testWith->isEmpty()) {
            return $this->dataProvidedByTestWithAnnotation($className, $methodName);
        }
        if ($dataProvider->isNotEmpty()) {
            $data = $this->dataProvidedByMethods($className, $methodName, $dataProvider);
        }
        else {
            $data = $this->dataProvidedByMetadata($testWith);
        }
        if ($data === []) {
            throw new InvalidDataProviderException('Empty data set provided by data provider');
        }
        foreach ($data as $key => $value) {
            if (!is_array($value)) {
                throw new InvalidDataProviderException(sprintf('Data set %s is invalid', is_int($key) ? '#' . $key : '"' . $key . '"'));
            }
        }
        return $data;
    }
    
    /**
     * @psalm-param class-string $className
     * @psalm-param non-empty-string $methodName
     *
     * @throws InvalidDataProviderException
     */
    private function dataProvidedByMethods(string $className, string $methodName, MetadataCollection $dataProvider) : array {
        $testMethod = new Event\Code\ClassMethod($className, $methodName);
        $methodsCalled = [];
        $result = [];
        foreach ($dataProvider as $_dataProvider) {
            assert($_dataProvider instanceof DataProviderMetadata);
            $dataProviderMethod = new Event\Code\ClassMethod($_dataProvider->className(), $_dataProvider->methodName());
            Event\Facade::emitter()->dataProviderMethodCalled($testMethod, $dataProviderMethod);
            $methodsCalled[] = $dataProviderMethod;
            try {
                $class = new ReflectionClass($_dataProvider->className());
                $method = $class->getMethod($_dataProvider->methodName());
                $object = null;
                if (!$method->isPublic()) {
                    Event\Facade::emitter()->testTriggeredPhpunitDeprecation($this->valueObjectForTestMethodWithoutTestData($className, $methodName), sprintf('Data Provider method %s::%s() is not public', $_dataProvider->className(), $_dataProvider->methodName()));
                }
                if (!$method->isStatic()) {
                    Event\Facade::emitter()->testTriggeredPhpunitDeprecation($this->valueObjectForTestMethodWithoutTestData($className, $methodName), sprintf('Data Provider method %s::%s() is not static', $_dataProvider->className(), $_dataProvider->methodName()));
                    $object = $class->newInstanceWithoutConstructor();
                }
                if ($method->getNumberOfParameters() === 0) {
                    $data = $method->invoke($object);
                }
                else {
                    Event\Facade::emitter()->testTriggeredPhpunitDeprecation($this->valueObjectForTestMethodWithoutTestData($className, $methodName), sprintf('Data Provider method %s::%s() expects an argument', $_dataProvider->className(), $_dataProvider->methodName()));
                    $data = $method->invoke($object, $_dataProvider->methodName());
                }
            } catch (Throwable $e) {
                Event\Facade::emitter()->dataProviderMethodFinished($testMethod, ...$methodsCalled);
                throw new InvalidDataProviderException($e->getMessage(), $e->getCode(), $e);
            }
            foreach ($data as $key => $value) {
                if (is_int($key)) {
                    $result[] = $value;
                }
                elseif (is_string($key)) {
                    if (array_key_exists($key, $result)) {
                        Event\Facade::emitter()->dataProviderMethodFinished($testMethod, ...$methodsCalled);
                        throw new InvalidDataProviderException(sprintf('The key "%s" has already been defined by a previous data provider', $key));
                    }
                    $result[$key] = $value;
                }
                else {
                    throw new InvalidDataProviderException(sprintf('The key must be an integer or a string, %s given', get_debug_type($key)));
                }
            }
        }
        Event\Facade::emitter()->dataProviderMethodFinished($testMethod, ...$methodsCalled);
        return $result;
    }
    private function dataProvidedByMetadata(MetadataCollection $testWith) : array {
        $result = [];
        foreach ($testWith as $_testWith) {
            assert($_testWith instanceof TestWith);
            $result[] = $_testWith->data();
        }
        return $result;
    }
    
    /**
     * @psalm-param class-string $className
     *
     * @throws InvalidDataProviderException
     */
    private function dataProvidedByTestWithAnnotation(string $className, string $methodName) : ?array {
        $docComment = (new ReflectionMethod($className, $methodName))->getDocComment();
        if ($docComment === false) {
            return null;
        }
        $docComment = str_replace("\r\n", "\n", $docComment);
        $docComment = preg_replace('/\\n\\s*\\*\\s?/', "\n", $docComment);
        $docComment = substr($docComment, 0, -1);
        $docComment = rtrim($docComment, "\n");
        if (!preg_match('/@testWith\\s+/', $docComment, $matches, PREG_OFFSET_CAPTURE)) {
            return null;
        }
        $offset = strlen($matches[0][0]) + (int) $matches[0][1];
        $annotationContent = substr($docComment, $offset);
        $data = [];
        foreach (explode("\n", $annotationContent) as $candidateRow) {
            $candidateRow = trim($candidateRow);
            if ($candidateRow === '' || $candidateRow[0] !== '[') {
                break;
            }
            $dataSet = json_decode($candidateRow, true);
            if (json_last_error() !== JSON_ERROR_NONE) {
                throw new InvalidDataProviderException('The data set for the @testWith annotation cannot be parsed: ' . json_last_error_msg());
            }
            $data[] = $dataSet;
        }
        if (!$data) {
            throw new InvalidDataProviderException('The data set for the @testWith annotation cannot be parsed.');
        }
        return $data;
    }
    
    /**
     * @psalm-param class-string $className
     * @psalm-param non-empty-string $methodName
     *
     * @throws MoreThanOneDataSetFromDataProviderException
     */
    private function valueObjectForTestMethodWithoutTestData(string $className, string $methodName) : TestMethod {
        $location = Reflection::sourceLocationFor($className, $methodName);
        return new TestMethod($className, $methodName, $location['file'], $location['line'], Event\Code\TestDoxBuilder::fromClassNameAndMethodName($className, $methodName), MetadataRegistry::parser()->forClassAndMethod($className, $methodName), TestDataCollection::fromArray([]));
    }

}