/*-
 * ============LICENSE_START=======================================================
 * ONAP - SO
 * ================================================================================
 * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * Licensed 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.
 * ============LICENSE_END=========================================================
 */

package org.onap.so.bpmn.common;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

import org.camunda.bpm.engine.delegate.DelegateExecution;
import org.onap.so.bpmn.common.exceptions.MalformedBuildingBlockInputException;
import org.onap.so.bpmn.common.exceptions.MissingBuildingBlockInputException;
import org.onap.so.bpmn.common.exceptions.RequiredExecutionVariableExeception;
import org.onap.so.bpmn.servicedecomposition.entities.GeneralBuildingBlock;
import org.onap.so.bpmn.servicedecomposition.entities.ResourceKey;

public class DelegateExecutionImpl implements BuildingBlockExecution, Serializable {

	private final Map<String, Serializable> seedMap;
	private transient DelegateExecution execution;
	private static final String INVALID_INPUT_MISSING = "Expected variable of \"%s\" not found in execution";
	private static final String INVALID_INPUT_CLASS_CAST = "Expected variable of \"%s\" was the wrong object type in the execution";

	private static final String MISSING_MSG = "Execution variable \"gBBInput\" cannot be null when executing building blocks";
	private static final String MALFORMED_MSG = "Execution variable \"gBBInput\" must contain an element of type GeneralBuildingBlock";
	
	public DelegateExecutionImpl(Map<String, Serializable> seedMap) {
		this.seedMap = seedMap;
	}
	
	public DelegateExecutionImpl(DelegateExecution execution) {
		this.seedMap = new HashMap<>();
		execution.getVariables().forEach((key, value) -> {
			if (value instanceof Serializable) {
				seedMap.put(key, (Serializable)value);
			}
		});
		/* must occur for junit tests to work */
		this.execution = execution;
	}
	@Override
	public GeneralBuildingBlock getGeneralBuildingBlock() {
		try {
			GeneralBuildingBlock generalBuildingBlock =  (GeneralBuildingBlock) execution.getVariable("gBBInput");
			
			if (generalBuildingBlock == null) {
				throw new MissingBuildingBlockInputException(MISSING_MSG);
			}
			
			return generalBuildingBlock;
		} catch (ClassCastException e) {
			throw new MalformedBuildingBlockInputException(MALFORMED_MSG, e);
		}
	}

	@Override
	public <T> T getVariable(String key) {
		return this.get(key);
	}

	@Override
	public <T> T getRequiredVariable(String key) throws RequiredExecutionVariableExeception {
		final T result;
	
		result = this.get(key);
		if (result == null) {
			throw new RequiredExecutionVariableExeception(String.format(INVALID_INPUT_MISSING, key));

		}
		return result;
	}

	@Override
	public void setVariable(String key, Serializable value) {
		this.execution.setVariable(key, value);
	}
	
	@Override
	public Map<ResourceKey, String> getLookupMap() {
		return this.get("lookupKeyMap");
	}
	
	@Override
	public String getFlowToBeCalled() {
		return this.get("flowToBeCalled");
	}
	public DelegateExecution getDelegateExecution() {
		return this.execution;
	}
	
	public void setDelegateExecution(DelegateExecution execution) {
		this.execution = execution;
		this.seedMap.forEach((key, value) -> {
			if (!execution.hasVariable(key)) {
				execution.setVariable(key, value);
			}
		});
	}
	
	protected <T> T get(String key) {
		final Object value = this.execution.getVariable(key);
	
		return (T)value;
	}
}