/*-
 * ============LICENSE_START=======================================================
 *  Copyright (C) 2019 Nordix Foundation.
 * ================================================================================
 * 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.
 *
 * SPDX-License-Identifier: Apache-2.0
 * ============LICENSE_END=========================================================
 */

package org.onap.policy.models.base;

import java.util.LinkedList;
import java.util.List;
import lombok.Getter;

/**
 * This class records the result of a validation and holds all validation observation messages.
 */
@Getter
public class PfValidationResult {
    /**
     * The ValidationResult enumeration describes the severity of a validation result.
     */
    public enum ValidationResult {
    /** No problems or observations were detected during validation. */
    VALID,
    /**
     * Observations were made on a concept (such as blank descriptions) of a nature that will not
     * affect the use of the concept.
     */
    OBSERVATION,
    /**
     * Warnings were made on a concept (such as defined but unused concepts) of a nature that may
     * affect the use of the concept.
     */
    WARNING,
    /**
     * Errors were detected on a concept (such as referenced but undefined concepts) of a nature
     * that will affect the use of the concept.
     */
    INVALID
    }

    // The actual verification result
    private ValidationResult validationResult = ValidationResult.VALID;

    // Messages collected during the verification process
    private final List<PfValidationMessage> messageList = new LinkedList<>();

    /**
     * Check if a validation reported a valid concept, returns true if the model is usable (that is,
     * even if the model has warnings or observations).
     *
     * @return true, if the concept is reported as valid and can be used
     */
    public boolean isValid() {
        return validationResult != ValidationResult.INVALID;
    }

    /**
     * Check if a validation reported a concept with no errors or warnings, returns true if the
     * model is OK to use.
     *
     * @return true, if the concept has no warnings or errors
     */
    public boolean isOk() {
        return validationResult == ValidationResult.VALID || validationResult == ValidationResult.OBSERVATION;
    }

    /**
     * Adds a validation message to the validation result, used by validate() implementations on
     * {@link PfConcept} subclasses to report validaiton observations.
     *
     * @param validationMessage the validation message
     */
    public void addValidationMessage(final PfValidationMessage validationMessage) {
        messageList.add(validationMessage);

        // Check if the incoming message has a more sever status than the
        // current one on the overall validation result,
        // if so, the overall result goes to that level
        if (validationMessage.getValidationResult().ordinal() > validationResult.ordinal()) {
            validationResult = validationMessage.getValidationResult();
        }
    }

    /*
     * (non-Javadoc)
     *
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        final StringBuilder builder = new StringBuilder();

        switch (validationResult) {
            case VALID:

                builder.append("***validation of model successful***");
                return builder.toString();
            case OBSERVATION:

                builder.append("\n***observations noted during validation of model***\n");
                break;
            case WARNING:

                builder.append("\n***warnings issued during validation of model***\n");
                break;
            case INVALID:
                builder.append("\n***validation of model failed***\n");
                break;
            default:
                break;
        }

        for (final PfValidationMessage message : messageList) {
            builder.append(message);
            builder.append("\n");
        }

        builder.append("********************************");
        return builder.toString();
    }
}