/*-
 * ============LICENSE_START=======================================================
 * org.openecomp.aai
 * ================================================================================
 * 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.openecomp.aai.introspection.sideeffect;

import java.io.UnsupportedEncodingException;
import java.net.URISyntaxException;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Optional;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.tinkerpop.gremlin.structure.Vertex;

import org.openecomp.aai.db.props.AAIProperties;
import org.openecomp.aai.exceptions.AAIException;
import org.openecomp.aai.introspection.Introspector;
import org.openecomp.aai.introspection.Loader;
import org.openecomp.aai.introspection.LoaderFactory;
import org.openecomp.aai.introspection.ModelType;
import org.openecomp.aai.introspection.sideeffect.exceptions.AAIMissingRequiredPropertyException;
import org.openecomp.aai.schema.enums.PropertyMetadata;
import org.openecomp.aai.serialization.db.DBSerializer;
import org.openecomp.aai.serialization.engines.TransactionalGraphEngine;

public abstract class SideEffect {

	protected static final Pattern template = Pattern.compile("\\{(.*?)\\}");
	protected final Introspector obj;
	protected final TransactionalGraphEngine dbEngine;
	protected final DBSerializer serializer;
	protected final Loader latestLoader = LoaderFactory.createLoaderForVersion(ModelType.MOXY, AAIProperties.LATEST);
	protected final Vertex self;
	public SideEffect (Introspector obj, Vertex self, TransactionalGraphEngine dbEngine, DBSerializer serializer) {
		this.obj = obj;
		this.dbEngine = dbEngine;
		this.serializer = serializer;
		this.self = self;
	}

	protected void execute() throws UnsupportedEncodingException, URISyntaxException, AAIException {
		final Map<String, String> properties = this.findPopertiesWithMetadata(obj, this.getPropertyMetadata());
		for (Entry<String, String> entry : properties.entrySet()) {
			Optional<String> populatedUri = this.replaceTemplates(obj, entry.getValue());
			Optional<String> completeUri = this.resolveRelativePath(populatedUri);
			this.processURI(completeUri, entry);
		}
	}

	protected Map<String, String> findPopertiesWithMetadata(Introspector obj, PropertyMetadata metadata) {
		final Map<String, String> result = new HashMap<>();
		for (String prop : obj.getProperties()) {
			final Map<PropertyMetadata, String> map = obj.getPropertyMetadata(prop);
			if (map.containsKey(metadata)) {
				result.put(prop, map.get(metadata));
			}
		}
		return result;
	}
	
	protected Map<String, String> findProperties(Introspector obj, String uriString) throws AAIMissingRequiredPropertyException {
		
		final Map<String, String> result = new HashMap<>();
		final Set<String> missing = new LinkedHashSet<>();
		Matcher m = template.matcher(uriString);
		int properties = 0;
		while (m.find()) {
			String propName = m.group(1);
			String value = obj.getValue(propName);
			properties++;
			if (value != null) {
				result.put(propName, value);
			} else {
				if (replaceWithWildcard()) {
					result.put(propName, "*");
				}
				missing.add(propName);
			}
		}
		
		if (!missing.isEmpty() && (properties != missing.size())) {
			throw new AAIMissingRequiredPropertyException("Cannot complete " + this.getPropertyMetadata().toString() + " uri. Missing properties " + missing);
		}
		return result;
	}
	
	private Optional<String> replaceTemplates(Introspector obj, String uriString) throws AAIMissingRequiredPropertyException {
		String result = uriString;
		final Map<String, String> propMap = this.findProperties(obj, uriString);
		if (propMap.isEmpty()) {
			return Optional.empty();
		}
		for (Entry<String, String> entry : propMap.entrySet()) {
			result = result.replaceAll("\\{" + entry.getKey() + "\\}", entry.getValue());
		}
		//drop out wildcards if they exist
		result = result.replaceFirst("/[^/]+?(?:/\\*)+", "");
		return Optional.of(result);
	}
	
	private Optional<String> resolveRelativePath(Optional<String> populatedUri) throws UnsupportedEncodingException {
		if (!populatedUri.isPresent()) {
			return Optional.empty();
		} else {
			return Optional.of(populatedUri.get().replaceFirst("\\./", this.serializer.getURIForVertex(self) + "/"));
		}
	}
	
	protected abstract boolean replaceWithWildcard();
	protected abstract PropertyMetadata getPropertyMetadata();
	protected abstract void processURI(Optional<String> completeUri, Entry<String, String> entry) throws URISyntaxException, UnsupportedEncodingException, AAIException;
}