path: root/model/src/main/java/org/onap/policy/apex/model/modelapi/ApexApiResult.java

/*-
 * ============LICENSE_START=======================================================
 *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
 *  Modifications Copyright (C) 2020,2022 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.apex.model.modelapi;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import lombok.Setter;

/**
 * The Class ApexEditorAPIResult return the result of and messages from all model API method calls on the
 * {@link ApexModel} API.
 */
@Setter
public class ApexApiResult {

    /**
     * This enumeration is used to represent the result status of a call on the {@link ApexModel} API.
     */
    public enum Result {
        /** The method call succeeded. */
        SUCCESS,
        /** The method call succeeded and all operations are now completed. */
        FINISHED,
        /** The method call for a create operation failed because the concept already exists. */
        CONCEPT_EXISTS,
        /**
         * The method call for a create operation failed because multiple concepts already exists.
         */
        MULTIPLE_CONCEPTS_EXIST,
        /** The method call on a concept failed because the referenced concept does not exist. */
        CONCEPT_DOES_NOT_EXIST,
        /** The method call failed because no action was specified on the method call. */
        NO_ACTION_SPECIFIED,
        /**
         * The method call failed because of a structural error, a missing reference, or other error on the model.
         */
        FAILED,
        /**
         * The method call failed for another reason such as the method call is not implemented yet on the concept on
         * which it was called.
         */
        OTHER_ERROR;

        /**
         * Check if a result is OK.
         *
         * @param result the result
         * @return true if the result is not OK
         */
        public static boolean isOk(final Result result) {
            return result == Result.SUCCESS || result == Result.FINISHED;
        }

        /**
         * Check if a result is not OK.
         *
         * @param result the result
         * @return true if the result is not OK
         */
        public static boolean isNok(final Result result) {
            return !isOk(result);
        }
    }

    private Result result;
    private List<String> messages = new ArrayList<>();

    /**
     * The Default Constructor creates a result for a successful operation with no messages.
     */
    public ApexApiResult() {
        result = Result.SUCCESS;
    }

    /**
     * This Constructor creates a result with the given result status with no messages.
     *
     * @param result the result status to use on this result
     */
    public ApexApiResult(final Result result) {
        this.result = result;
    }

    /**
     * This Constructor creates a result with the given result status and message.
     *
     * @param result the result status to use on this result
     * @param message the message to return with the result
     */
    public ApexApiResult(final Result result, final String message) {
        this.result = result;
        addMessage(message);
    }

    /**
     * This Constructor creates a result with the given result status and {@link Throwable} object such as an exception.
     * The message and stack trace from the {@link Throwable} object are added to the message list of this message.
     *
     * @param result the result status to use on this result
     * @param throwable the throwable object from which to add the message and stack trace
     */
    public ApexApiResult(final Result result, final Throwable throwable) {
        this.result = result;
        addThrowable(throwable);
    }

    /**
     * This Constructor creates a result with the given result status, message, and {@link Throwable} object such as an
     * exception. The message and stack trace from the {@link Throwable} object are added to the message list of this
     * message.
     *
     * @param result the result status to use on this result
     * @param message the message to return with the result
     * @param throwable the throwable object from which to add the message and stack trace
     */
    public ApexApiResult(final Result result, final String message, final Throwable throwable) {
        this.result = result;
        addMessage(message);
        addThrowable(throwable);
    }

    /**
     * This message is a utility message that checks if the result of an operation on the API was OK.
     *
     * @return true, if the result indicates the API operation succeeded
     */
    public boolean isOk() {
        return Result.isOk(result);
    }

    /**
     * This message is a utility message that checks if the result of an operation on the API was not OK.
     *
     * @return true, if the result indicates the API operation did not succeed
     */
    public boolean isNok() {
        return Result.isNok(result);
    }

    /**
     * Gets the result status of an API operation.
     *
     * @return the result status
     */
    public Result getResult() {
        return result;
    }

    /**
     * Gets the list of messages returned by an API operation.
     *
     * @return the list of messages returned by an API operation
     */
    public List<String> getMessages() {
        return messages;
    }

    /**
     * Gets all the messages returned by an API operation as a single string.
     *
     * @return the messages returned by an API operation as a single string
     */
    public String getMessage() {
        final StringBuilder builder = new StringBuilder();
        for (final String message : messages) {
            builder.append(message);
            builder.append('\n');
        }

        return builder.toString();
    }

    /**
     * Adds a message from an API operation to the bottom of the list of messages to be returned.
     *
     * @param message the message from an API operation to add to the bottom of the list of messages to be returned
     */
    public void addMessage(final String message) {
        if (message != null && message.trim().length() > 0) {
            messages.add(message);
        }
    }

    /**
     * Adds the message and stack trace from a {@link Throwable} object such as an exception from an API operation to
     * the bottom of the list of messages to be returned.
     *
     * @param throwable the {@link Throwable} object such as an exception from an API operation from which the message
     *        and stack trace are to be extracted and placed at the bottom of the list of messages to be returned
     */
    public void addThrowable(final Throwable throwable) {
        final StringWriter throwableStringWriter = new StringWriter();
        final PrintWriter throwablePrintWriter = new PrintWriter(throwableStringWriter);
        throwable.printStackTrace(throwablePrintWriter);
        messages.add(throwable.getMessage());
        messages.add(throwableStringWriter.toString());
    }

    /**
     * Gets a representation of the {@link ApexApiResult} instance as a JSON string.
     *
     * @return the result instance JSON string
     */
    public String toJson() {
        final StringBuilder builder = new StringBuilder();
        builder.append("{\n");

        builder.append("\"result\": \"");
        builder.append(result.toString());
        builder.append("\",\n");

        builder.append("\"messages\": [");
        boolean first = true;
        for (final String message : messages) {
            if (first) {
                builder.append("\n\"");
                first = false;
            } else {
                builder.append(",\n\"");
            }
            builder.append(message.replace("\"", "\\\\\""));
            builder.append("\"");
        }
        builder.append("]\n");

        builder.append("}\n");

        return builder.toString();
    }

    /**
     * {@inheritDoc}.
     */
    @Override
    public String toString() {
        final StringBuilder builder = new StringBuilder();
        builder.append("result: ");
        builder.append(result);
        builder.append('\n');
        builder.append(getMessage());
        return builder.toString();
    }
}