/*
 * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: MIT-0
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package software.amazon.qldb.tutorial;

import com.amazon.ion.IonReader;
import com.amazon.ion.IonStruct;
import com.amazon.ion.IonValue;
import com.amazon.ion.system.IonReaderBuilder;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import software.amazon.qldb.Result;
import software.amazon.qldb.TransactionExecutor;
import software.amazon.qldb.tutorial.model.Owner;
import software.amazon.qldb.tutorial.model.Person;
import software.amazon.qldb.tutorial.model.SampleData;

/**
 * Find primary owner for a particular vehicle's VIN.
 * Transfer to another primary owner for a particular vehicle's VIN.
 *
 * This code expects that you have AWS credentials setup per:
 * http://docs.aws.amazon.com/java-sdk/latest/developer-guide/setup-credentials.html
 */
public final class TransferVehicleOwnership {
    public static final Logger log = LoggerFactory.getLogger(TransferVehicleOwnership.class);

    private TransferVehicleOwnership() { }

    /**
     * Query a driver's information using the given ID.
     *
     * @param txn
     *              The {@link TransactionExecutor} for lambda execute.
     * @param documentId
     *              The unique ID of a document in the Person table.
     * @return a {@link Person} object.
     * @throws IllegalStateException if failed to convert parameter into {@link IonValue}.
     */
    public static Person findPersonFromDocumentId(final TransactionExecutor txn, final String documentId) {
        try {
            log.info("Finding person for documentId: {}...", documentId);
            final String query = "SELECT p.* FROM Person AS p BY pid WHERE pid = ?";

            Result result = txn.execute(query, Constants.MAPPER.writeValueAsIonValue(documentId));
            if (result.isEmpty()) {
                throw new IllegalStateException("Unable to find person with ID: " + documentId);
            }

            return Constants.MAPPER.readValue(result.iterator().next(), Person.class);
        } catch (IOException ioe) {
            throw new IllegalStateException(ioe);
        }
    }

    /**
     * Find the primary owner for the given VIN.
     *
     * @param txn
     *              The {@link TransactionExecutor} for lambda execute.
     * @param vin
     *              Unique VIN for a vehicle.
     * @return a {@link Person} object.
     * @throws IllegalStateException if failed to convert parameter into {@link IonValue}.
     */
    public static Person findPrimaryOwnerForVehicle(final TransactionExecutor txn, final String vin) {
        try {
            log.info("Finding primary owner for vehicle with Vin: {}...", vin);
            final String query = "SELECT Owners.PrimaryOwner.PersonId FROM VehicleRegistration AS v WHERE v.VIN = ?";
            final List<IonValue> parameters = Collections.singletonList(Constants.MAPPER.writeValueAsIonValue(vin));
            Result result = txn.execute(query, parameters);
            final List<IonStruct> documents = ScanTable.toIonStructs(result);
            ScanTable.printDocuments(documents);
            if (documents.isEmpty()) {
                throw new IllegalStateException("Unable to find registrations with VIN: " + vin);
            }

            final IonReader reader = IonReaderBuilder.standard().build(documents.get(0));
            final String personId = Constants.MAPPER.readValue(reader, LinkedHashMap.class).get("PersonId").toString();
            return findPersonFromDocumentId(txn, personId);
        } catch (IOException ioe) {
            throw new IllegalStateException(ioe);
        }
    }

    /**
     * Update the primary owner for a vehicle registration with the given documentId.
     *
     * @param txn
     *              The {@link TransactionExecutor} for lambda execute.
     * @param vin
     *              Unique VIN for a vehicle.
     * @param documentId
     *              New PersonId for the primary owner.
     * @throws IllegalStateException if no vehicle registration was found using the given document ID and VIN, or if failed
     * to convert parameters into {@link IonValue}.
     */
    public static void updateVehicleRegistration(final TransactionExecutor txn, final String vin, final String documentId) {
        try {
            log.info("Updating primary owner for vehicle with Vin: {}...", vin);
            final String query = "UPDATE VehicleRegistration AS v SET v.Owners.PrimaryOwner = ? WHERE v.VIN = ?";

            final List<IonValue> parameters = new ArrayList<>();
            parameters.add(Constants.MAPPER.writeValueAsIonValue(new Owner(documentId)));
            parameters.add(Constants.MAPPER.writeValueAsIonValue(vin));

            Result result = txn.execute(query, parameters);
            ScanTable.printDocuments(result);
            if (result.isEmpty()) {
                throw new IllegalStateException("Unable to transfer vehicle, could not find registration.");
            } else {
                log.info("Successfully transferred vehicle with VIN '{}' to new owner.", vin);
            }
        } catch (IOException ioe) {
            throw new IllegalStateException(ioe);
        }
    }

    public static void main(final String... args) {
        final String vin = SampleData.VEHICLES.get(0).getVin();
        final String primaryOwnerGovId = SampleData.PEOPLE.get(0).getGovId();
        final String newPrimaryOwnerGovId = SampleData.PEOPLE.get(1).getGovId();

        ConnectToLedger.getDriver().execute(txn -> {
            final Person primaryOwner = findPrimaryOwnerForVehicle(txn, vin);
            if (!primaryOwner.getGovId().equals(primaryOwnerGovId)) {
                // Verify the primary owner.
                throw new IllegalStateException("Incorrect primary owner identified for vehicle, unable to transfer.");
            }

            final String newOwner = Person.getDocumentIdByGovId(txn, newPrimaryOwnerGovId);
            updateVehicleRegistration(txn, vin, newOwner);
        });
        log.info("Successfully transferred vehicle ownership!");
    }
}