/**
 * ============LICENSE_START=======================================================
 * Gizmo
 * ================================================================================
 * Copyright © 2017 AT&T Intellectual Property.
 * Copyright © 2017 Amdocs
 * 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=========================================================
 *
 * ECOMP is a trademark and service mark of AT&T Intellectual Property.
 */
package org.onap.schema;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

import org.codehaus.jackson.map.ObjectMapper;
import org.onap.crud.exception.CrudException;

import java.io.IOException;
import java.util.*;
import java.util.stream.Collectors;
import javax.ws.rs.core.Response.Status;


public class RelationshipSchema {
  private static final Gson gson = new GsonBuilder().create();

  public static final String SCHEMA_SOURCE_NODE_TYPE = "from";
  public static final String SCHEMA_TARGET_NODE_TYPE = "to";
  public static final String SCHEMA_RELATIONSHIP_TYPE = "label";
  public static final String SCHEMA_RULES_ARRAY = "rules";


  private Map<String, Map<String, Class<?>>> relations = new HashMap<>();
  /**
   * Hashmap of valid relationship types along with properties.
   */
  private Map<String, Map<String, Class<?>>> relationTypes  = new HashMap<>();


  public RelationshipSchema(List<String> jsonStrings) throws CrudException, IOException {
    String edgeRules = jsonStrings.get(0);
    String props = jsonStrings.get(1);

    HashMap<String, ArrayList<LinkedHashMap<String, String>>> rules = new ObjectMapper().readValue(edgeRules, HashMap.class);
    HashMap<String, String> properties = new ObjectMapper().readValue(props, HashMap.class);
    Map<String, Class<?>> edgeProps = properties.entrySet().stream().collect(Collectors.toMap(p -> p.getKey(), p -> {
      try {
        return resolveClass(p.getValue());
      } catch (CrudException | ClassNotFoundException e) {
        e.printStackTrace();
      }
      return null;
    }));

    rules.get(SCHEMA_RULES_ARRAY).forEach(l -> {
      relationTypes.put(l.get(SCHEMA_RELATIONSHIP_TYPE), edgeProps);
      relations.put(buildRelation(l.get(SCHEMA_SOURCE_NODE_TYPE), l.get(SCHEMA_TARGET_NODE_TYPE), l.get(SCHEMA_RELATIONSHIP_TYPE)), edgeProps);
    });
  }



  public Map<String, Class<?>> lookupRelation(String key) {
    return this.relations.get(key);
  }

  public Map<String, Class<?>> lookupRelationType(String type) {
    return this.relationTypes.get(type);
  }

  public boolean isValidType(String type) {
    return relationTypes.containsKey(type);
  }


  private String buildRelation(String source, String target, String relation){
    return source + ":" + target + ":" + relation;
  }

  private Class<?> resolveClass(String type) throws CrudException, ClassNotFoundException {
    Class<?> clazz = Class.forName(type);
    validateClassTypes(clazz);
    return clazz;
  }

  private void validateClassTypes(Class<?> clazz) throws CrudException {
    if (!clazz.isAssignableFrom(Integer.class) && !clazz.isAssignableFrom(Double.class)
            && !clazz.isAssignableFrom(Boolean.class) && !clazz.isAssignableFrom(String.class)) {
      throw new CrudException("", Status.BAD_REQUEST);
    }
  }
}