HLTech / pact-gen

import com.google.common.collect.Lists;

import com.hltech.pact.gen.domain.client.ClientMethodRepresentationExtractor;

import com.hltech.pact.gen.domain.client.annotation.handlers.AnnotatedMethodHandler;

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

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

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

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

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

import com.hltech.pact.gen.domain.client.util.RawHeadersParser;

import com.hltech.pact.gen.domain.client.util.TypeExtractor;

import org.springframework.http.HttpStatus;

import java.lang.reflect.Method;

import java.util.Arrays;

import java.util.Collection;

import java.util.List;

import java.util.stream.Collectors;

public class FeignMethodRepresentationExtractor implements ClientMethodRepresentationExtractor {

    private final Collection<AnnotatedMethodHandler> annotatedMethodHandlers;

    @Override

    public ClientMethodRepresentation extractClientMethodRepresentation(Method clientMethod) {

        return ClientMethodRepresentation.builder()

            .requestRepresentation(extractRequestProperties(clientMethod))

            .responseRepresentationList(extractResponseProperties(clientMethod))

            .build();

    }

    private RequestRepresentation extractRequestProperties(Method feignClientMethod) {

        return this.annotatedMethodHandlers.stream()

            .filter(annotationHandler -> annotationHandler.isSupported(feignClientMethod))

            .findFirst().orElseThrow(() -> new IllegalArgumentException("Unknown HTTP method"))

            .handle(feignClientMethod);

    }

    private static List<ResponseRepresentation> extractResponseProperties(Method feignClientMethod) {

        feignClientMethod.getGenericReturnType();

        List<ResponseRepresentation> results = Arrays

            .stream(feignClientMethod.getDeclaredAnnotationsByType(InteractionInfo.class))

            .map(annotation -> populateResponse(

                annotation.responseStatus(),

                RawHeadersParser.parseAll(annotation.responseHeaders()),

                feignClientMethod,

                annotation.description()))

            .collect(Collectors.toList());

        return !results.isEmpty() ? results :

            Lists.newArrayList(populateResponse(HttpStatus.OK, Lists.newArrayList(), feignClientMethod, ""));

    }

    private static ResponseRepresentation populateResponse(

        HttpStatus status, List<Param> headers, Method feignClientMethod, String description) {

        return ResponseRepresentation.builder()

            .status(status)

            .headers(headers)

            .body(Body.builder()

                .type(feignClientMethod.getReturnType())

                .genericArgumentTypes(

                    TypeExtractor.extractParameterTypesFromType(feignClientMethod.getGenericReturnType()))

                .build())

            .description(description)

            .build();

    }

}