/*
 * The MIT License
 * Copyright © 2014-2019 Ilkka Seppälä
 *
 * 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, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * 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 com.iluwatar.saga.choreography;

import java.util.function.Supplier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * Common abstraction class representing services. implementing a general contract @see {@link
 * ChoreographyChapter}
 */
public abstract class Service implements ChoreographyChapter {
  protected static final Logger LOGGER = LoggerFactory.getLogger(Service.class);

  private final ServiceDiscoveryService sd;

  public Service(ServiceDiscoveryService service) {
    this.sd = service;
  }

  @Override
  public Saga execute(Saga saga) {
    var nextSaga = saga;
    Object nextVal;
    var chapterName = saga.getCurrent().getName();
    if (chapterName.equals(getName())) {
      if (saga.isForward()) {
        nextSaga = process(saga);
        nextVal = nextSaga.getCurrentValue();
        if (nextSaga.isCurrentSuccess()) {
          nextSaga.forward();
        } else {
          nextSaga.back();
        }
      } else {
        nextSaga = rollback(saga);
        nextVal = nextSaga.getCurrentValue();
        nextSaga.back();
      }

      if (isSagaFinished(nextSaga)) {
        return nextSaga;
      }

      nextSaga.setCurrentValue(nextVal);
    }
    var finalNextSaga = nextSaga;

    return sd.find(chapterName).map(ch -> ch.execute(finalNextSaga))
        .orElseThrow(serviceNotFoundException(chapterName));
  }

  private Supplier<RuntimeException> serviceNotFoundException(String chServiceName) {
    return () -> new RuntimeException(
        String.format("the service %s has not been found", chServiceName));
  }

  @Override
  public Saga process(Saga saga) {
    var inValue = saga.getCurrentValue();
    LOGGER.info("The chapter '{}' has been started. "
            + "The data {} has been stored or calculated successfully",
        getName(), inValue);
    saga.setCurrentStatus(Saga.ChapterResult.SUCCESS);
    saga.setCurrentValue(inValue);
    return saga;
  }

  @Override
  public Saga rollback(Saga saga) {
    var inValue = saga.getCurrentValue();
    LOGGER.info("The Rollback for a chapter '{}' has been started. "
            + "The data {} has been rollbacked successfully",
        getName(), inValue);

    saga.setCurrentStatus(Saga.ChapterResult.ROLLBACK);
    saga.setCurrentValue(inValue);
    return saga;
  }

  private boolean isSagaFinished(Saga saga) {
    if (!saga.isPresent()) {
      saga.setFinished(true);
      LOGGER.info(" the saga has been finished with {} status", saga.getResult());
      return true;
    }
    return false;
  }

}
