/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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 org.apache.tinkerpop.gremlin.tinkergraph.process.computer;

import org.apache.tinkerpop.gremlin.process.computer.Memory;
import org.apache.tinkerpop.gremlin.process.computer.MemoryComputeKey;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.function.BinaryOperator;

/**
 * @author Marko A. Rodriguez (http://markorodriguez.com)
 */
public final class TinkerWorkerMemory implements Memory.Admin {

    private final TinkerMemory mainMemory;
    private final Map<String, Object> workerMemory = new HashMap<>();
    private final Map<String, BinaryOperator<Object>> reducers = new HashMap<>();

    public TinkerWorkerMemory(final TinkerMemory mainMemory) {
        this.mainMemory = mainMemory;
        for (final MemoryComputeKey key : this.mainMemory.memoryKeys.values()) {
            this.reducers.put(key.getKey(), key.clone().getReducer());
        }
    }

    @Override
    public Set<String> keys() {
        return this.mainMemory.keys();
    }

    @Override
    public void incrIteration() {
        this.mainMemory.incrIteration();
    }

    @Override
    public void setIteration(final int iteration) {
        this.mainMemory.setIteration(iteration);
    }

    @Override
    public int getIteration() {
        return this.mainMemory.getIteration();
    }

    @Override
    public void setRuntime(final long runTime) {
        this.mainMemory.setRuntime(runTime);
    }

    @Override
    public long getRuntime() {
        return this.mainMemory.getRuntime();
    }

    @Override
    public boolean isInitialIteration() {
        return this.mainMemory.isInitialIteration();
    }

    @Override
    public <R> R get(final String key) throws IllegalArgumentException {
        return this.mainMemory.get(key);
    }

    @Override
    public void set(final String key, final Object value) {
        this.mainMemory.set(key, value);
    }

    @Override
    public void add(final String key, final Object value) {
        this.mainMemory.checkKeyValue(key, value);
        final Object v = this.workerMemory.get(key);
        this.workerMemory.put(key, null == v ? value : this.reducers.get(key).apply(v, value));
    }

    @Override
    public String toString() {
        return this.mainMemory.toString();
    }

    protected void complete() {
        for (final Map.Entry<String, Object> entry : this.workerMemory.entrySet()) {
            this.mainMemory.add(entry.getKey(), entry.getValue());
        }
        this.workerMemory.clear();
    }
}