/*
 * [ProbeViaAWS.java]
 *
 * Summary: Find Amazon part number corresponding to an ISBN. Used in production htmlmacros. Probe all Amazon stores.
 *
 * Copyright: (c) 2012-2017 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.8+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.0 2012-03-26 initial version
 */
package com.mindprod.aws;

import com.mindprod.aws.jax.AWSECommerceService;
import com.mindprod.aws.jax.AWSECommerceServicePortType;
import com.mindprod.aws.jax.AwsHandlerResolver;
import com.mindprod.aws.jax.Item;
import com.mindprod.aws.jax.ItemLookup;
import com.mindprod.aws.jax.ItemLookupRequest;
import com.mindprod.aws.jax.Items;
import com.mindprod.aws.jax.Offer;
import com.mindprod.aws.jax.OfferListing;
import com.mindprod.aws.jax.Offers;
import com.mindprod.aws.jax.OperationRequest;
import com.mindprod.stores.BStore;
import com.mindprod.stores.OnlineStore;
import com.mindprod.stores.StockStatus;

import javax.xml.namespace.QName;
import javax.xml.ws.Holder;
import javax.xml.ws.WebServiceException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.List;

import static java.lang.System.*;

/**
 * Find Amazon part number corresponding to an ISBN. Used in production htmlmacros. Probe all Amazon stores.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 2012-03-26 initial version
 * @see FetchBookFacts
 * @since 2012-03-26
 */
public class ProbeViaAWS
    {
    /**
     * true if want extra output and stop on first error.
     */
    private static final boolean DEBUGGING = true;

    /**
     * fetch confidential amazon.com-assigned awsAccessKeyId from environment set awsaccesskeyid=xxxxx
     */
    private static final String AWS_ACCESS_KEY_ID = System.getenv( "awsaccesskeyid" );

    /**
     * fetch confidential amazon.com-assigned awsSecretAccessKey assigned by Amazon set awssecretaccesskey=xxxxx
     */
    private static final String AWS_SECRET_ACCESS_KEY = System.getenv( "awssecretaccesskey" );

    /**
     * identifies the context in which names should be interpreted in the schema.
     * Why do we need to specify this? It appears FOUR times in the wsdl file. Perhaps as a check the code
     * matches the generated Java. URLs for other stores are embedded in the WSDL file.
     */
    private static final String NAME_SPACE_URI = "http://webservices.amazon.com/AWSECommerceService/2013-08-01";

    /**
     * name of the SOAP service
     */
    private static final String QNAME = "AWSECommerceService";

    /**
     * location of JAX schmo, locally cached. for amazon.com in the USA.  Would have to be modified for other countries.
     * Original came from http://ecs.amazonaws.com/AWSECommerceService/AWSECommerceService.wsd
     * Both Amazon.ca and Amazon.com use the same WSDL.
     */
    private static final String WSDL_LOCATION = "file:///E:/com/mindprod/aws/jax/AWSECommerceService.wsdl";

    /**
     * standard boilerplate to connect to amazon.com AWS server with SOAP
     *
     * @return port to use to send requests.
     * @throws java.net.MalformedURLException if some URLs were mis-specified in the following code.
     */
    private static AWSECommerceService getService() throws MalformedURLException
        {
        // Set the service:
        AWSECommerceService service = new AWSECommerceService( new URL( WSDL_LOCATION ), new QName( NAME_SPACE_URI,
                QNAME ) );
        // AwsHandlerResolver does the timestamp, signing and Base64 encoding
        service.setHandlerResolver( new AwsHandlerResolver( AWS_SECRET_ACCESS_KEY ) );
        // get the corresponding service port. This looks up the endpoint server.
        return service;
        }

    /**
     * convert isbn13 to asin, probe just one country.
     *
     * @param isbn13 isbn13
     *
     * @return corresponding asin, or null if cannot find it.
     */
    private static String isbnToAsinViaAWSProbingOneStore( final String isbn13, final BStore bookstore )
        {
        try
            {
            final String associateTag = bookstore.getAccount(); // don't use environment as we did in experiments
            final AWSECommerceServicePortType port = bookstore.getPort( getService() );
            // new ItemLookup
            final ItemLookup itemLookup = new ItemLookup();
            // new ItemLookupRequest which is part of the ItemLookup
            final ItemLookupRequest itemLookupRequest = new ItemLookupRequest();
            // odd our lookup request to the the Lookup.
            final List<ItemLookupRequest> itemLookupRequests = itemLookup.getRequest();
            itemLookupRequests.add( itemLookupRequest );
            // Set up the values of the ItemLookupRequest
            itemLookupRequest.setSearchIndex( "Books" );
            itemLookupRequest.setIdType( "EAN" );
            itemLookupRequest.getItemId().add( isbn13 );    // there is no setItemID method
            itemLookupRequest.setMerchantId( "All" );
            itemLookupRequest.setCondition( "All" );
            // specify info to include in response
            final List<String> responseGroup = itemLookupRequest.getResponseGroup();
            responseGroup.add( "ItemAttributes" );
            // set up Holder for the response tree
            final Holder<OperationRequest> operationrequest = new Holder<>();
            final Holder<List<Items>> items = new Holder<>();
            final String marketplaceDomain = "";  // not yet supported
            final String xmlEscaping = "Single";
            final String validate = "";
            // Probe Amazon Server, WARNING! Amazon changes the parms to this method frequently.
            // Inserts awsAccessKeyID and associateTag
            // note order validate, xmlEscaping, different from itemSearch
            if ( false )
                {
                out.println( "isbn13 = " + isbn13 );
                out.println( "bookstore = " + bookstore );
                out.println( "AWS_ACCESS_KEY_ID = " + AWS_ACCESS_KEY_ID );
                out.println( "AWS_SECRET_ACCESS_KEY = " + AWS_SECRET_ACCESS_KEY );
                out.println( "associateTag =  " + associateTag );
                out.println( "port = " + port );
                }
            if ( false )
                {
                out.println( "Probing AWS for " + bookstore.getEnumName() + " to lookup ISBN " + isbn13 + " to find the ASIN" );
                }
            port.itemLookup( marketplaceDomain, AWS_ACCESS_KEY_ID, associateTag, validate, xmlEscaping,
                    itemLookupRequest, itemLookupRequests, operationrequest, items );
            // analyse results
            final List<Items> result = items.value;
            final int size = result.get( 0 ).getItem().size();
            for ( int i = 0; i < size; i++ )
                {
                final Item item = result.get( 0 ).getItem().get( i );
                final String asin = item.getASIN();
                if ( asin != null )
                    {
                    out.println( "ISBN  " + isbn13 + " -> " + asin + " lookup successful for store " + bookstore.getEnumName() );
                    return asin;
                    }
                } //end loop to process results
            // if it simply does not have in in the database
            out.println( "ISBN  " + isbn13 + " has no corresponding ASIN for store " + bookstore.getEnumName() );
            return null;
            }
        catch ( MalformedURLException e )
            {
            throw new IllegalArgumentException( "Amazon JAX bug. Generating malformed URLS" );
            }
        catch ( WebServiceException e )
            {
            err.println( "Error: Unable to find asin for " + isbn13 + " at AWS server for store " + bookstore.getEnumName() + " " + e
                    .getMessage() );
            return null;
            }
        }

    /**
     * probe the amazon AWS api to find if a given asin is in stock.
     *
     * @param asin Amazon part number
     *
     * @return StockStatus enum
     */
    public static StockStatus isASINInStockViaAWS( final String asin, final OnlineStore store )
        {
        try
            {
            store.setProbeCompletionStage( 5 );
            final String associateTag = store.getAccount();
            // this is how we select which country Amazon store to probe.
            // The following line takes quite a while
            final AWSECommerceServicePortType port = store.getPort( getService() );
            if ( port == null )
                {
                err.println( "Unable to make AWS connection to " + store.getEnumName() );
                return StockStatus.REFUSINGPROBES;
                }
            // new ItemLookup
            final ItemLookup itemLookup = new ItemLookup();
            // new ItemLookupRequest which is part of the ItemLookup
            final ItemLookupRequest itemLookupRequest = new ItemLookupRequest();
            // odd our lookup request to the the Lookup.
            final List<ItemLookupRequest> itemLookupRequests = itemLookup.getRequest();
            itemLookupRequests.add( itemLookupRequest );
            // Set up the values of the ItemLookupRequest
            // lookup of variants only works with ASIN
            itemLookupRequest.setIdType( "ASIN" );
            itemLookupRequest.getItemId().add( asin );    // there is no setItemID method
            itemLookupRequest.setMerchantId( "All" );
            itemLookupRequest.setCondition( "All" );
            // specify info to include in response
            final List<String> responseGroup = itemLookupRequest.getResponseGroup();
            responseGroup.add( "Offers" );
            // set up Holder for the response tree
            final Holder<OperationRequest> operationRequest = new Holder<>();
            final Holder<List<Items>> items = new Holder<>();
            final String marketplaceDomain = "";  // not yet supported
            final String xmlEscaping = "Single";
            final String validate = "";
            store.setProbeCompletionStage( 6 );
            // Probe Amazon Server, WARNING! Amazon changes the parms to this method frequently.
            // Inserts awsAccessKeyID and associateTag
            // note order validate, xmlEscaping, different from itemSearch
            port.itemLookup( marketplaceDomain, AWS_ACCESS_KEY_ID, associateTag, validate, xmlEscaping,
                    itemLookupRequest, itemLookupRequests, operationRequest, items );
            store.setProbeCompletionStage( 7 );
            // analyse results
            final List<Items> result = items.value;
            final int size = result.get( 0 ).getItem().size();
            for ( int i = 0; i < size; i++ )
                {
                final Item item = result.get( 0 ).getItem().get( i );
                final Offers offers = item.getOffers();
                if ( offers == null )
                    {
                    continue;
                    }
                final List<Offer> offerList = offers.getOffer();
                for ( Offer offer : offerList )
                    {
                    // getOfferListing will never be null
                    for ( OfferListing offerListing : offer.getOfferListing() )
                        {
                        final String availabilityType = offerListing.getAvailabilityAttributes().getAvailabilityType();
                        if ( false )
                            {
                            out.println( "asin = " + asin + " availabilityType = " + availabilityType );
                            }
                        // might be "now" or "unknown" (temp out of stock) or "futureDate"
                        if ( availabilityType.equals( "now" ) )
                            {
                            return StockStatus.INSTOCK;
                            }
                        // other possibilities? ???
                        }
                    }
                } //end loop to process results
            // must be carried in some sense or we would not have an ASIN to lookup.
            return StockStatus.OUTOFSTOCK;
            }
        catch ( MalformedURLException e )
            {
            throw new IllegalArgumentException( "Amazon JAX bug. Generating malformed URLS" );
            }
        }

    /**
     * convert isbn13 to asin, probe just as many countries as necessary.
     *
     * @param isbn13 isbn13
     *
     * @return corresponding asin, or null if cannot find it.
     */
    public static String isbnToASINviaAWS( final String isbn13 )
        {
        // this is quite slow if you don't get a hit on Amazon.com
        // We only do it once, and record the failure as a "none" in the cache.
        String asin = isbnToAsinViaAWSProbingOneStore( isbn13, BStore.AMAZONCOM );
        if ( asin != null )
            {
            return asin;
            }
        asin = isbnToAsinViaAWSProbingOneStore( isbn13, BStore.AMAZONCA );
        if ( asin != null )
            {
            return asin;
            }
        asin = isbnToAsinViaAWSProbingOneStore( isbn13, BStore.AMAZONUK );
        if ( asin != null )
            {
            return asin;
            }
        asin = isbnToAsinViaAWSProbingOneStore( isbn13, BStore.AMAZONDE );
        if ( asin != null )
            {
            return asin;
            }
        asin = isbnToAsinViaAWSProbingOneStore( isbn13, BStore.AMAZONFR );
        if ( asin != null )
            {
            return asin;
            }
        return isbnToAsinViaAWSProbingOneStore( isbn13, BStore.AMAZONIT );
        // don't bother with AMAZONES or AMAZONIN
        }
    }