com.redhat.lightblue.query.SetExpression Maven / Gradle / Ivy

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/*
 Copyright 2013 Red Hat, Inc. and/or its affiliates.

 This file is part of lightblue.

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see .
 */
package com.redhat.lightblue.query;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.redhat.lightblue.util.Error;
import com.redhat.lightblue.util.Path;

import java.util.*;

/**
 * Expression to modify a field (set and add)
 *  * primitive_update_expression := { $set : { path : rvalue_expression , ...} } |
 *                                { $unset : path } |
 *                                { $unset :[ path, ... ] }
 *                                { $add : { path : rvalue_expression, ... } }
 * 
 */
public class SetExpression extends PrimitiveUpdateExpression {

    private static final long serialVersionUID = 1L;

    private final List fields;
    private UpdateOperator op;

    /**
     * Constructs a set expression using the given list
     */
    public SetExpression(UpdateOperator op, List list) {
        this.fields = list;
        if (op == UpdateOperator._set || op == UpdateOperator._add) {
            this.op = op;
        } else {
            throw new IllegalArgumentException(QueryConstants.ERR_UNSUPPORTED_OPERATOR + op);
        }
    }

    /**
     * Constructs a set expression using the given list
     */
    public SetExpression(UpdateOperator op, FieldAndRValue... l) {
        this.fields = Arrays.asList(l);
        if (op == UpdateOperator._set || op == UpdateOperator._add) {
            this.op = op;
        } else {
            throw new IllegalArgumentException(QueryConstants.ERR_UNSUPPORTED_OPERATOR + op);
        }
    }

    /**
     * Returns the fields to be updated, and their new values
     */
    public List getFields() {
        return fields;
    }

    /**
     * Returns the update operator
     */
    public UpdateOperator getOp() {
        return op;
    }

    @Override
    public JsonNode toJson() {
        ObjectNode node = getFactory().objectNode();
        ObjectNode values = getFactory().objectNode();
        for (FieldAndRValue x : fields) {
            values.set(x.getField().toString(),
                    x.getRValue().toJson());
        }
        node.set(op.toString(), values);
        return node;
    }

    /**
     * Parses a set expression using the given json object
     */
    public static SetExpression fromJson(ObjectNode node) {
        if (node.size() == 1) {
            UpdateOperator op = null;
            if (node.has(UpdateOperator._add.toString())) {
                op = UpdateOperator._add;
            } else if (node.has(UpdateOperator._set.toString())) {
                op = UpdateOperator._set;
            }
            if (op != null) {
                ObjectNode arg = (ObjectNode) node.get(op.toString());
                List list = new ArrayList<>();
                for (Iterator> itr = arg.fields(); itr.hasNext();) {
                    Map.Entry entry = itr.next();
                    Path field = new Path(entry.getKey());
                    RValueExpression rvalue = RValueExpression.fromJson(entry.getValue());
                    list.add(new FieldAndRValue(field, rvalue));
                }
                return new SetExpression(op, list);
            }
        }
        throw Error.get(QueryConstants.ERR_INVALID_SET_EXPRESSION, node.toString());
    }

    @Override
    public int hashCode() {
        int hash = 7;
        hash = 79 * hash + Objects.hashCode(this.fields);
        hash = 79 * hash + Objects.hashCode(this.op);
        return hash;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final SetExpression other = (SetExpression) obj;
        if (!Objects.equals(this.fields, other.fields)) {
            return false;
        }
        if (this.op != other.op) {
            return false;
        }
        return true;
    }

}