/*
 * Copyright © 2016-2018 European Support Limited
 *
 * 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.
 */

package org.openecomp.core.util;

import org.openecomp.core.dao.UniqueValueDao;
import org.openecomp.core.dao.types.UniqueValueEntity;
import org.openecomp.core.utilities.CommonMethods;
import org.openecomp.sdc.common.errors.CoreException;
import org.openecomp.sdc.common.errors.ErrorCategory;
import org.openecomp.sdc.common.errors.ErrorCode;

import java.util.Optional;

public class UniqueValueUtil {

  private static final String UNIQUE_VALUE_VIOLATION = "UNIQUE_VALUE_VIOLATION";
  private static final String UNIQUE_VALUE_VIOLATION_MSG = "%s with the value '%s' already exists.";
  private static final char FORMATTED_UNIQUE_VALUE_SEPARATOR = '_';

  private final UniqueValueDao uniqueValueDao;

  public UniqueValueUtil(UniqueValueDao uniqueValueDao) {
    this.uniqueValueDao = uniqueValueDao;
  }

  /**
   * Create unique value.
   *
   * @param type              the type
   * @param uniqueCombination the unique combination
   */
  public void createUniqueValue(String type, String... uniqueCombination) {
    formatValue(uniqueCombination).ifPresent(formattedValue -> {
      validateUniqueValue(type, formattedValue, uniqueCombination);
      uniqueValueDao.create(new UniqueValueEntity(type, formattedValue));
    });
  }

  /**
   * Delete unique value.
   *
   * @param type              the type
   * @param uniqueCombination the unique combination
   */
  public void deleteUniqueValue(String type, String... uniqueCombination) {
    formatValue(uniqueCombination).ifPresent(
        formattedValue -> uniqueValueDao.delete(new UniqueValueEntity(type, formattedValue)));

  }

  /**
   * Update unique value.
   *
   * @param type          the type
   * @param oldValue      the old value
   * @param newValue      the new value
   * @param uniqueContext the unique context
   */
  public void updateUniqueValue(String type, String oldValue, String newValue,
                                String... uniqueContext) {
    if (newValue == null || oldValue == null || !newValue.equalsIgnoreCase(oldValue)) {
      createUniqueValue(type, CommonMethods.concat(uniqueContext, new String[]{newValue}));
      deleteUniqueValue(type, CommonMethods.concat(uniqueContext, new String[]{oldValue}));
    }
  }

  /**
   * Validate unique value.
   *
   * @param type              the type
   * @param uniqueCombination the unique combination
   */
  public void validateUniqueValue(String type, String... uniqueCombination) {
    formatValue(uniqueCombination)
        .ifPresent(formattedValue -> validateUniqueValue(type, formattedValue, uniqueCombination));
  }

  /**
   * Checks if a unique value is taken.
   *
   * @return true if the unique value is occupied, false otherwise
   */
  public boolean isUniqueValueOccupied(String type, String... uniqueCombination) {
    return formatValue(uniqueCombination)
        .map(formattedValue -> isUniqueValueOccupied(type, formattedValue))
        .orElse(false);
  }

  private void validateUniqueValue(String type, String formattedValue,
                                   String... uniqueCombination) {
    if (isUniqueValueOccupied(type, formattedValue)) {
      throw new CoreException(new ErrorCode.ErrorCodeBuilder()
          .withCategory(ErrorCategory.APPLICATION)
          .withId(UNIQUE_VALUE_VIOLATION)
          .withMessage(String
              .format(UNIQUE_VALUE_VIOLATION_MSG, type, getValueWithoutContext(uniqueCombination)))
          .build());
    }
  }

  private boolean isUniqueValueOccupied(String type, String formattedValue) {
    return uniqueValueDao.get(new UniqueValueEntity(type, formattedValue)) != null;
  }

  private static Optional<String> formatValue(String[] uniqueCombination) {
    if (uniqueCombination == null || uniqueCombination.length == 0
        || getValueWithoutContext(uniqueCombination) == null) {
      return Optional.empty();
    }

    uniqueCombination[uniqueCombination.length - 1] =
        getValueWithoutContext(uniqueCombination).toLowerCase();
    return Optional.of(CommonMethods
        .arrayToSeparatedString(uniqueCombination, FORMATTED_UNIQUE_VALUE_SEPARATOR));
  }

  private static String getValueWithoutContext(String... uniqueCombination) {
    return uniqueCombination[uniqueCombination.length - 1];
  }
}