/*
 * Copyright (c) 2010-2012 Grid Dynamics Consulting Services, Inc, All Rights Reserved
 * http://www.griddynamics.com
 *
 * This library is free software; you can redistribute it and/or modify it under the terms of
 * the Apache License; either
 * version 2.0 of the License, or any later version.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.griddynamics.jagger.invoker;

import com.griddynamics.jagger.coordinator.NodeContext;
import com.griddynamics.jagger.engine.e1.Provider;
import com.griddynamics.jagger.util.JavaSystemClock;
import com.griddynamics.jagger.util.SystemClock;

public class QueryPoolScenarioFactory<Q, R, E> implements ScenarioFactory<Q, R, E> {
    private Class<Invoker<Q, R, E>> invokerClazz;
    private QueryPoolLoadBalancer<Q, E> loadBalancer;
    private SystemClock systemClock = new JavaSystemClock();
    
    private Iterable<Q> queryProvider;
    private Iterable<E> endpointProvider;
    
    private Provider<Invoker> invokerProvider;

    @Override
    public Scenario<Q, R, E> get(NodeContext nodeContext, KernelInfo kernelInfo) {
    
        Invoker<Q, R, E> invoker = instantiateInvoker(nodeContext);
        
        initLoadBalancer(kernelInfo);
        
        return new QueryPoolScenario<Q, R, E>(invoker, loadBalancer.provide(), systemClock);
    }
    
    private Invoker<Q, R, E> instantiateInvoker(final NodeContext nodeContext) {
        // TODO: to remove request to context after JFG-1090
        Invoker<Q, R, E> invoker = nodeContext.getService(invokerClazz);
        if (invokerProvider != null) {
            invoker = invokerProvider.provide();
        }
    
        if (invoker == null) {
            throw new IllegalArgumentException("Service for class + '" + invokerClazz.getCanonicalName()
                                               + "' not found!");
        }
        
        return invoker;
    }
    
    private void initLoadBalancer(KernelInfo kernelInfo) {
        if (endpointProvider != null) {
            loadBalancer.setEndpointProvider(getEndpointProvider());
        }
        if (queryProvider != null) {
            loadBalancer.setQueryProvider(getQueryProvider());
        }
    
        loadBalancer.setKernelInfo(kernelInfo);
        
        loadBalancer.init();
    }

    //@Required
    public void setInvokerClazz(Class<Invoker<Q, R, E>> invokerClazz) {
        this.invokerClazz = invokerClazz;
    }

    //@Required
    public void setLoadBalancer(QueryPoolLoadBalancer<Q, E> loadBalancer) {
        this.loadBalancer = loadBalancer;
    }

    public void setSystemClock(SystemClock systemClock) {
        this.systemClock = systemClock;
    }

    public Iterable<Q> getQueryProvider() {
        return queryProvider;
    }

    public void setQueryProvider(Iterable<Q> queryProvider) {
        this.queryProvider = queryProvider;
    }

    public Iterable<E> getEndpointProvider() {
        return endpointProvider;
    }

    public void setEndpointProvider(Iterable<E> endpointProvider) {
        this.endpointProvider = endpointProvider;
    }
    
    public void setInvokerProvider(Provider<Invoker> invokerProvider) {
        this.invokerProvider = invokerProvider;
    }
}