/*-
 * ========================LICENSE_START=================================
 * Bucket4j
 * %%
 * Copyright (C) 2015 - 2020 Vladimir Bukhtoyarov
 * %%
 * 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.
 * =========================LICENSE_END==================================
 */

package io.github.bucket4j.grid.infinispan;

import io.github.bucket4j.BucketConfiguration;
import io.github.bucket4j.Nothing;
import io.github.bucket4j.grid.CommandResult;
import io.github.bucket4j.grid.GridBucketState;
import io.github.bucket4j.grid.GridCommand;
import io.github.bucket4j.grid.GridProxy;
import io.github.bucket4j.grid.jcache.JCacheEntryProcessor;
import org.infinispan.commons.CacheException;
import org.infinispan.commons.api.functional.EntryView;
import org.infinispan.commons.api.functional.FunctionalMap;
import org.infinispan.util.SerializableFunction;

import java.io.Serializable;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;

public class InfinispanProxy<K extends Serializable> implements GridProxy<K> {

    private final FunctionalMap.ReadWriteMap<K, GridBucketState> readWriteMap;

    public InfinispanProxy(FunctionalMap.ReadWriteMap<K, GridBucketState> readWriteMap) {
        this.readWriteMap = readWriteMap;
    }

    @Override
    public <T extends Serializable> CommandResult<T> execute(K key, GridCommand<T> command) {
        JCacheEntryProcessor<K, T> entryProcessor = JCacheEntryProcessor.executeProcessor(command);
        return invokeSync(key, entryProcessor);
    }

    @Override
    public void createInitialState(K key, BucketConfiguration configuration) {
        JCacheEntryProcessor<K, Nothing> entryProcessor = JCacheEntryProcessor.initStateProcessor(configuration);
        invokeSync(key, entryProcessor);
    }

    @Override
    public <T extends Serializable> T createInitialStateAndExecute(K key, BucketConfiguration configuration, GridCommand<T> command) {
        JCacheEntryProcessor<K, T> entryProcessor = JCacheEntryProcessor.initStateAndExecuteProcessor(command, configuration);
        CommandResult<T> result = invokeSync(key, entryProcessor);
        return result.getData();
    }

    @Override
    public <T extends Serializable> CompletableFuture<CommandResult<T>> executeAsync(K key, GridCommand<T> command) {
        JCacheEntryProcessor<K, T> entryProcessor = JCacheEntryProcessor.executeProcessor(command);
        return invokeAsync(key, entryProcessor);
    }

    @Override
    public <T extends Serializable> CompletableFuture<T> createInitialStateAndExecuteAsync(K key, BucketConfiguration configuration, GridCommand<T> command) {
        JCacheEntryProcessor<K, T> entryProcessor = JCacheEntryProcessor.initStateAndExecuteProcessor(command, configuration);
        CompletableFuture<CommandResult<T>> result = invokeAsync(key, entryProcessor);
        return result.thenApply(CommandResult::getData);
    }

    @Override
    public Optional<BucketConfiguration> getConfiguration(K key) {
        try {
            SerializableFunction<EntryView.ReadWriteEntryView<K, GridBucketState>, GridBucketState> findFunction =
                    (SerializableFunction<EntryView.ReadWriteEntryView<K, GridBucketState>, GridBucketState>)
                    entry -> entry.find().orElse(null);
            GridBucketState state = readWriteMap.eval(key, findFunction).get();
            if (state == null) {
                return Optional.empty();
            } else {
                return Optional.of(state.getConfiguration());
            }
        } catch (InterruptedException | ExecutionException e) {
            throw new CacheException(e);
        }
    }

    @Override
    public boolean isAsyncModeSupported() {
        return true;
    }

    private <T extends Serializable> CommandResult<T> invokeSync(final K key, final JCacheEntryProcessor<K, T> entryProcessor) {
        try {
            return readWriteMap.eval(key, new SerializableFunctionAdapter<>(entryProcessor)).get();
        } catch (InterruptedException | ExecutionException e) {
            throw new CacheException(e);
        }
    }

    private <T extends Serializable> CompletableFuture<CommandResult<T>> invokeAsync(final K key, final JCacheEntryProcessor<K, T> entryProcessor) {
        return readWriteMap.eval(key, new SerializableFunctionAdapter<>(entryProcessor));
    }

}