/*
 * Copyright 2016 Open Networking Laboratory
 *
 * 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.onosproject.yangutils.datamodel;

import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
import org.onosproject.yangutils.parser.Parsable;
import org.onosproject.yangutils.parser.ParsableDataType;

/*-
 * The "must" statement, which is optional, takes as an argument a string that
 * contains an XPath expression. It is used to formally declare a constraint
 * on valid data.
 *
 * When a datastore is validated, all "must" constraints are conceptually
 * evaluated once for each data node in the data tree, and for all leafs with
 * default values in use. If a data node does not exist in the data tree, and
 * it does not have a default value, its "must" statements are not evaluated.
 *
 * All such constraints MUST evaluate to true for the data to be valid.
 *
 *  The must's sub-statements
 *
 *                +---------------+---------+-------------+------------------+
 *                | substatement  | section | cardinality |data model mapping|
 *                +---------------+---------+-------------+------------------+
 *                | description   | 7.19.3  | 0..1        | -string          |
 *                | error-app-tag | 7.5.4.2 | 0..1        | -not supported   |
 *                | error-message | 7.5.4.1 | 0..1        | -not supported   |
 *                | reference     | 7.19.4  | 0..1        | -string          |
 *                +---------------+---------+-------------+------------------+
 */

/**
 * Maintain information defined in YANG must.
 */
public class YangMust implements YangDesc, YangReference, Parsable {

    /**
     * Constraint info.
     */
    private String constratint;

    /**
     * Description string.
     */
    private String description;

    /**
     * reference string.
     */
    private String reference;

    /**
     * Create a YANG must restriction.
     */
    public YangMust() {
    }

    /**
     * Get the constraint.
     *
     * @return the constraint.
     */
    public String getConstratint() {
        return constratint;
    }

    /**
     * Set the constraint.
     *
     * @param constratint the constraint to set
     */
    public void setConstratint(String constratint) {
        this.constratint = constratint;
    }

    /**
     * Get the description.
     *
     * @return the description.
     */
    public String getDescription() {
        return description;
    }

    /**
     * Set the description.
     *
     * @param description set the description.
     */
    public void setDescription(String description) {
        this.description = description;
    }

    /**
     * Get the textual reference.
     *
     * @return the reference.
     */
    public String getReference() {
        return reference;
    }

    /**
     * Set the textual reference.
     *
     * @param reference the reference to set.
     */
    public void setReference(String reference) {
        this.reference = reference;
    }

    /**
     * Returns the type of the parsed data.
     *
     * @return returns MUST_DATA
     */
    public ParsableDataType getParsableDataType() {
        return ParsableDataType.MUST_DATA;
    }

    /**
     * Validate the data on entering the corresponding parse tree node.
     *
     * @throws DataModelException a violation of data model rules.
     */
    public void validateDataOnEntry() throws DataModelException {
        // TODO auto-generated method stub, to be implemented by parser
    }

    /**
     * Validate the data on exiting the corresponding parse tree node.
     *
     * @throws DataModelException a violation of data model rules.
     */
    public void validateDataOnExit() throws DataModelException {
        // TODO auto-generated method stub, to be implemented by parser
    }
}