package act.util;

/*-

* #%L

* ACT Framework

* %%

* Copyright (C) 2014 - 2017 ActFramework

* %%

* 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.

* #L%

*/

import act.handler.builtin.controller.RequestHandlerProxy;

import org.osgl.util.E;

import org.osgl.util.S;

import java.lang.annotation.*;

import java.util.HashMap;

import java.util.Map;

import javax.inject.Singleton;

/**

* Mark an action handler method result can be cached

*/

@Retention(RetentionPolicy.RUNTIME)

@Target(ElementType.METHOD)

public @interface CacheFor {

/**

* Application specify the ID of the CacheFor and use it

* to reset cache

*/

String id() default "";

/**

* Specify cache expiration time in seconds

*

* Default value: `60 * 60`, i.e. one hour

*

* @return the expiration time

*/

int value() default 60 * 60;

/**

* Specify the keys to extract parameter/post variables to build the final

* cache key.

*

* If not supplied then framework will try to iterate through all query

* parameters to build the cache key

*

* @return the keys that should be used to build the final cache key

*/

String[] keys() default {};

/**

* In some edge case (e.g. facebook post to app to get the landing page) POST

* is treated as GET, we should allow cache the result in that case.

*

* default value: `false`

*

* @return `true` if enable cache on POST request

*/

boolean supportPost() default false;

/**

* Specify it shall use `private` for `Cache-Control`

*

* default value: `false`.

*

* @return

*/

boolean usePrivate() default false;

/**

* Suppress `Cache-Control` header setting.

*

* default value: `false`

*

* @return

*/

boolean noCacheControl() default false;

/**

* Indicate Do not cache result into local server cache

*

* This is useful when the result is coming from an external

* system that might or might not change. In which case we

* really just want to calculate the result's etag and compare

* it with request's `If-None-Match` header.

*

* Default value is `false`.

*/

boolean eTagOnly() default false;

/**

* Set `no-cache` to `Cache-Control` header.

*

* Default value: the value of {@link #eTagOnly()}

*/

boolean noCache() default false;

@Singleton

class Manager extends LogSupportedDestroyableBase {

private Map<String, RequestHandlerProxy> proxyLookup = new HashMap<>();

@Override

protected void releaseResources() {

proxyLookup.clear();

proxyLookup = null;

}

public void register(String key, RequestHandlerProxy proxy) {

RequestHandlerProxy existing = proxyLookup.put(key, proxy);

E.illegalStateIf(null != existing, "proxy already registered with key[%s]: %s", key, proxy);

}

/**

* Reset CacheFor cache for a request handler specified by controller class and

* request handler method name.

* @param controllerClass

* the host class of the handler method

* @param requestHandlerName

* the request handler method name

*/

public void resetCache(Class<?> controllerClass, String requestHandlerName) {

String key = S.pathConcat(controllerClass.getName(), '.', requestHandlerName);

resetCache(key);

}

/**

* Reset CacheFor cache for a request handler specified

* by {@link CacheFor#id()}.

*

* @param cacheForId

* the cacheFor id

*/

public void resetCache(String cacheForId) {

RequestHandlerProxy proxy = proxyLookup.get(cacheForId);

if (null == proxy) {

warn("Cannot find proxy by key: " + cacheForId);

} else {

proxy.resetCache();

}

}

}

}