/*

* Copyright 2013 Netflix, Inc.

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*/

package feign.jaxrs;

import java.lang.annotation.Annotation;

import java.lang.reflect.Method;

import java.util.ArrayList;

import java.util.Collection;

import javax.ws.rs.Consumes;

import javax.ws.rs.FormParam;

import javax.ws.rs.HeaderParam;

import javax.ws.rs.HttpMethod;

import javax.ws.rs.Path;

import javax.ws.rs.PathParam;

import javax.ws.rs.Produces;

import javax.ws.rs.QueryParam;

import feign.Contract;

import feign.MethodMetadata;

import static feign.Util.checkState;

import static feign.Util.emptyToNull;

/**

* Please refer to the <a href="https://github.com/Netflix/feign/tree/master/feign-jaxrs">Feign

* JAX-RS README</a>.

*/

public final class JAXRSContract extends Contract.BaseContract {

static final String ACCEPT = "Accept";

static final String CONTENT_TYPE = "Content-Type";

// Protected so unittest can call us

// XXX: Should parseAndValidateMetadata(Class, Method) be public instead? The old deprecated parseAndValidateMetadata(Method) was public..

@Override

protected MethodMetadata parseAndValidateMetadata(Class<?> targetType, Method method) {

return super.parseAndValidateMetadata(targetType, method);

}

@Override

protected void processAnnotationOnClass(MethodMetadata data, Class<?> clz) {

Path path = clz.getAnnotation(Path.class);

if (path != null) {

String pathValue = emptyToNull(path.value());

checkState(pathValue != null, "Path.value() was empty on type %s", clz.getName());

if (!pathValue.startsWith("/")) {

pathValue = "/" + pathValue;

}

if (pathValue.endsWith("/")) {

// Strip off any trailing slashes, since the template has already had slashes appropriately added

pathValue = pathValue.substring(0, pathValue.length() - 1);

}

data.template().insert(0, pathValue);

}

Consumes consumes = clz.getAnnotation(Consumes.class);

if (consumes != null) {

handleConsumesAnnotation(data, consumes, clz.getName());

}

Produces produces = clz.getAnnotation(Produces.class);

if (produces != null) {

handleProducesAnnotation(data, produces, clz.getName());

}

}

@Override

protected void processAnnotationOnMethod(MethodMetadata data, Annotation methodAnnotation,

Method method) {

Class<? extends Annotation> annotationType = methodAnnotation.annotationType();

HttpMethod http = annotationType.getAnnotation(HttpMethod.class);

if (http != null) {

checkState(data.template().method() == null,

"Method %s contains multiple HTTP methods. Found: %s and %s", method.getName(),

data.template().method(), http.value());

data.template().method(http.value());

} else if (annotationType == Path.class) {

String pathValue = emptyToNull(Path.class.cast(methodAnnotation).value());

checkState(pathValue != null, "Path.value() was empty on method %s", method.getName());

String methodAnnotationValue = Path.class.cast(methodAnnotation).value();

if (!methodAnnotationValue.startsWith("/") && !data.template().url().endsWith("/")) {

methodAnnotationValue = "/" + methodAnnotationValue;

}

// jax-rs allows whitespace around the param name, as well as an optional regex. The contract should

// strip these out appropriately.

methodAnnotationValue = methodAnnotationValue.replaceAll("\\{\\s*(.+?)\\s*(:.+?)?\\}", "\\{$1\\}");

data.template().append(methodAnnotationValue);

} else if (annotationType == Produces.class) {

handleProducesAnnotation(data, (Produces) methodAnnotation, "method " + method.getName());

} else if (annotationType == Consumes.class) {

handleConsumesAnnotation(data, (Consumes) methodAnnotation, "method " + method.getName());

}

}

private void handleProducesAnnotation(MethodMetadata data, Produces produces, String name) {

String[] serverProduces = produces.value();

String clientAccepts = serverProduces.length == 0 ? null : emptyToNull(serverProduces[0]);

checkState(clientAccepts != null, "Produces.value() was empty on %s", name);

data.template().header(ACCEPT, (String) null); // remove any previous produces

data.template().header(ACCEPT, clientAccepts);

}

private void handleConsumesAnnotation(MethodMetadata data, Consumes consumes, String name) {

String[] serverConsumes = consumes.value();

String clientProduces = serverConsumes.length == 0 ? null : emptyToNull(serverConsumes[0]);

checkState(clientProduces != null, "Consumes.value() was empty on %s", name);

data.template().header(CONTENT_TYPE, (String) null); // remove any previous consumes

data.template().header(CONTENT_TYPE, clientProduces);

}

@Override

protected boolean processAnnotationsOnParameter(MethodMetadata data, Annotation[] annotations,

int paramIndex) {

boolean isHttpParam = false;

for (Annotation parameterAnnotation : annotations) {

Class<? extends Annotation> annotationType = parameterAnnotation.annotationType();

if (annotationType == PathParam.class) {

String name = PathParam.class.cast(parameterAnnotation).value();

checkState(emptyToNull(name) != null, "PathParam.value() was empty on parameter %s",

paramIndex);

nameParam(data, name, paramIndex);

isHttpParam = true;

} else if (annotationType == QueryParam.class) {

String name = QueryParam.class.cast(parameterAnnotation).value();

checkState(emptyToNull(name) != null, "QueryParam.value() was empty on parameter %s",

paramIndex);

Collection<String> query = addTemplatedParam(data.template().queries().get(name), name);

data.template().query(name, query);

nameParam(data, name, paramIndex);

isHttpParam = true;

} else if (annotationType == HeaderParam.class) {

String name = HeaderParam.class.cast(parameterAnnotation).value();

checkState(emptyToNull(name) != null, "HeaderParam.value() was empty on parameter %s",

paramIndex);

Collection<String> header = addTemplatedParam(data.template().headers().get(name), name);

data.template().header(name, header);

nameParam(data, name, paramIndex);

isHttpParam = true;

} else if (annotationType == FormParam.class) {

String name = FormParam.class.cast(parameterAnnotation).value();

checkState(emptyToNull(name) != null, "FormParam.value() was empty on parameter %s",

paramIndex);

data.formParams().add(name);

nameParam(data, name, paramIndex);

isHttpParam = true;

}

}

return isHttpParam;

}

// Not using override as the super-type's method is deprecated and will be removed.

protected Collection<String> addTemplatedParam(Collection<String> possiblyNull, String name) {

if (possiblyNull == null) {

possiblyNull = new ArrayList<String>();

}

possiblyNull.add(String.format("{%s}", name));

return possiblyNull;

}

}