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 * regarding copyright ownership.  The ASF licenses this file
 * to you 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
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package org.apache.sling.scripting.sightly.impl.filter;

import org.apache.sling.scripting.sightly.compiler.expression.Expression;
import org.apache.sling.scripting.sightly.compiler.expression.ExpressionNode;
import org.apache.sling.scripting.sightly.compiler.expression.nodes.MapLiteral;
import org.apache.sling.scripting.sightly.compiler.expression.nodes.RuntimeCall;

/**
 * Implementation for the format filter &amp; runtime support.
 */
public class FormatFilter extends AbstractFilter {

    public static final String FORMAT_OPTION = "format";
    public static final String TYPE_OPTION = "type";
    public static final String FORMAT_LOCALE_OPTION = "formatLocale";
    public static final String TIMEZONE_OPTION = "timezone";

    private static final class FormatFilterLoader {
        private static final FormatFilter INSTANCE = new FormatFilter();
    }

    private FormatFilter() {
    }

    public static FormatFilter getInstance() {
        return FormatFilterLoader.INSTANCE;
    }

    @Override
    public Expression apply(Expression expression, ExpressionContext expressionContext) {
        //todo: if the expression is a string constant, we can produce the transformation at
        //compile time, with no need of a runtime function
        if (!expression.containsOption(FORMAT_OPTION) || expressionContext == ExpressionContext.PLUGIN_DATA_SLY_USE || expressionContext
                == ExpressionContext.PLUGIN_DATA_SLY_TEMPLATE || expressionContext == ExpressionContext.PLUGIN_DATA_SLY_CALL) {
            return expression;
        }
        ExpressionNode translation =
                new RuntimeCall(RuntimeCall.FORMAT, expression.getRoot(),
                        new MapLiteral(getFilterOptions(expression,
                                FORMAT_OPTION,
                                TYPE_OPTION,
                                I18nFilter.LOCALE_OPTION,
                                FORMAT_LOCALE_OPTION,
                                TIMEZONE_OPTION)));
        return expression.withNode(translation);
    }
}