/*
 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 <http://www.gnu.org/licenses/>.
 */
package com.redhat.lightblue.assoc;

import java.io.Serializable;

import com.redhat.lightblue.metadata.CompositeMetadata;
import com.redhat.lightblue.metadata.FieldTreeNode;

import com.redhat.lightblue.query.QueryExpression;

import com.redhat.lightblue.util.Path;

/**
 * Contains information about a field in the query
 *
 * <pre>
 *    { field; 'x.y', op:'=', rvalue=<value> }
 * </pre>
 *
 * <ul>
 * <li>fieldNameInClause: x.y</li>
 * <li>fullFieldName: x.y</li>
 * <li>fieldMd: Metadata node for x.y</li>
 * <li>fieldEntity: The metadata for the entity containing x.y</li>
 * <li>entityRelativeFieldName: x.y, the relative field name of the field in the
 * entity containing it, as it appears in clause</li>
 * <li>entityRelativeFieldNameWithContext: x.y, the relative field name of the
 * field in the entity containing it, including any enclosing arrays</li>
 * <li>clause: The query clause</li>
 * <li>leaf: true (whether of not the field is used in an actual
 * comparison)</li>
 * </ul>
 *
 * <pre>
 *  { array: 'a.b', elemMatch: { field:'x.y', op:'=',rvalue:<value>} }
 * </pre>
 *
 * <ul>
 * <li>fieldNameInClause: x.y</li>
 * <li>fullFieldName: a.b.*.x.y</li>
 * <li>entityRelativeFieldName: If a.b.* is a reference field, entity relative
 * field name is x.y.<li>
 * <li>entityRelativeFieldNameWithContext: If a.b.* is a reference field, entity
 * relative field name is a.b.*.x.y.<li>
 * <li>clause: {field:'x.y', op:'=',rvalue:<value>}</li>
 * <li>leaf: For a.b, false, for a.b.*.x.y, true</li>
 * </ul>
 */
public class QueryFieldInfo implements Serializable {

    private static final long serialVersionUID = 1l;

    private final Path fieldNameInClause;
    private final Path fullFieldName;
    private final FieldTreeNode fieldMd;
    private final CompositeMetadata fieldEntity;
    private final Path entityRelativeFieldName;
    private final Path entityRelativeFieldNameWithContext;
    private final QueryExpression clause;
    private final boolean leaf;

    public QueryFieldInfo(Path fieldNameInClause,
                          Path fullFieldName,
                          FieldTreeNode fieldMd,
                          CompositeMetadata fieldEntity,
                          Path entityRelativeFieldName,
                          Path entityRelativeFieldNameWithContext,
                          QueryExpression clause,
                          boolean leaf) {
        this.fieldNameInClause = fieldNameInClause;
        this.fullFieldName = fullFieldName;
        this.fieldMd = fieldMd;
        this.fieldEntity = fieldEntity;
        this.entityRelativeFieldName = entityRelativeFieldName;
        this.entityRelativeFieldNameWithContext = entityRelativeFieldNameWithContext;
        this.clause = clause;
        this.leaf = leaf;
    }

    /**
     * Whether the field is a leaf, i.e. the field is used in a comparison and
     * not an intermediate array
     */
    public boolean isLeaf() {
        return leaf;
    }

    /**
     * Name of the field in the clause containing the field.
     */
    public Path getFieldNameInClause() {
        return fieldNameInClause;
    }

    /**
     * Full name of the field. This includes the array name if the field appears
     * in an elemMatch clause.
     */
    public Path getFullFieldName() {
        return fullFieldName;
    }

    /**
     * Field metadata
     */
    public FieldTreeNode getFieldMd() {
        return fieldMd;
    }

    /**
     * The composite metadata for the entity containing the field
     */
    public CompositeMetadata getFieldEntity() {
        return fieldEntity;
    }

    /**
     * The name of the field relative to the entity containing it
     */
    public Path getEntityRelativeFieldName() {
        return entityRelativeFieldName;
    }

    /**
     * The name of the field relative to the entity containing it, including any
     * arrays enclosing this field
     */
    public Path getEntityRelativeFieldNameWithContext() {
        return entityRelativeFieldNameWithContext;
    }

    /**
     * The clause containing the field
     */
    public QueryExpression getClause() {
        return clause;
    }

    @Override
    public String toString() {
        if (entityRelativeFieldName.equals(fullFieldName)) {
            return fullFieldName + "@" + fieldEntity.getName();
        } else {
            return entityRelativeFieldName + "@" + fieldEntity.getName() + ":" + fullFieldName;
        }
    }
}