HLTech / pact-gen

import com.hltech.pact.gen.domain.client.model.Param;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.bind.annotation.ValueConstants;

import java.lang.reflect.Parameter;

import java.util.Arrays;

import java.util.List;

import java.util.Map;

import java.util.Optional;

import java.util.stream.Collectors;

import java.util.stream.Stream;

public final class RequestParametersExtractor {

    private RequestParametersExtractor() {}

    private static Stream<Param> extractParamsFromAnnotation(String[] path) {

        if (path.length < 1) {

            return Stream.empty();

        }

        String[] splitPath = path[0].split("\\?");

        if (splitPath.length < 2) {

            return Stream.empty();

        }

        return Arrays.stream(splitPath[1].split("&"))

            .map(paramString -> Param.builder()

                .name(paramString.split("=")[0])

                .defaultValue(paramString.split("=")[1])

                .build());

    }

    private static Stream<Param> extractParamsFromMethod(Parameter[] parameters) {

        return Arrays.stream(parameters)

            .filter(param -> param.getAnnotation(RequestParam.class) != null)

            .filter(param -> param.getType() != Map.class)

            .map(RequestParametersExtractor::extractParam);

    }

    private static Param extractParam(Parameter param) {

        Param.ParamBuilder builder = Param.builder();

        extractParamDefaultValue(param).ifPresent(builder::defaultValue);

        List<Class<?>> paramTypes = TypeExtractor.extractParameterTypesFromType(param.getParameterizedType());

        return builder

            .name(extractParamName(param))

            .type(param.getType())

            .genericArgumentType(paramTypes.isEmpty() ? null : paramTypes.get(0))

            .build();

    }

    private static Optional<Object> extractParamDefaultValue(Parameter param) {

        RequestParam annotation = param.getAnnotation(RequestParam.class);

        if (annotation.defaultValue().equals(ValueConstants.DEFAULT_NONE) || annotation.defaultValue().isEmpty()) {

            return Optional.empty();

        }

        return Optional.of(annotation.defaultValue());

    }

    private static String extractParamName(Parameter param) {

        RequestParam annotation = param.getAnnotation(RequestParam.class);

        if (!annotation.name().isEmpty()) {

            return annotation.name();

        } else if (!annotation.value().isEmpty()) {

            return annotation.value();

        }

        return param.getName();

    }

}