/*
 * Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
 * 
 * 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 freemarker.core;

import freemarker.template.TemplateException;
import freemarker.template.TemplateModel;

class BuiltInsForOutputFormatRelated {

    static class no_escBI extends AbstractConverterBI {

        @Override
        protected TemplateModel calculateResult(String lho, MarkupOutputFormat outputFormat, Environment env)
                throws TemplateException {
            return outputFormat.fromMarkup(lho);
        }
        
    }

    static class escBI extends AbstractConverterBI {

        @Override
        protected TemplateModel calculateResult(String lho, MarkupOutputFormat outputFormat, Environment env)
                throws TemplateException {
            return outputFormat.fromPlainTextByEscaping(lho);
        }
        
    }
    
    static abstract class AbstractConverterBI extends BuiltInForMarkupOutputFormatRelated {

        @Override
        protected TemplateModel calculateResult(Environment env) throws TemplateException {
            TemplateModel lhoTM = target.eval(env);
            String lhoStr = EvalUtil.coerceModelToString(lhoTM, target, null, true, env);
            MarkupOutputFormat contextOF = outputFormat;
            if (lhoStr == null) { // should indicate that lhoTM is a TemplateMarkupOutputModel
                TemplateMarkupOutputModel lhoMO;
                try {
                    lhoMO = (TemplateMarkupOutputModel) lhoTM;
                } catch (ClassCastException e) {
                    throw EvalUtil.newModelHasStoredNullException(null, lhoTM, target);
                }
                MarkupOutputFormat lhoOF = lhoMO.getOutputFormat();
                // ATTENTION: Keep this logic in sync. with ${...}'s logic!
                if (lhoOF == contextOF || contextOF.isOutputFormatMixingAllowed()) {
                    // bypass
                    return lhoTM;
                } else {
                    // ATTENTION: Keep this logic in sync. with ${...}'s logic!
                    lhoStr = lhoOF.getSourcePlainText(lhoMO);
                    if (lhoStr == null) {
                        throw new _TemplateModelException(target,
                                "The left side operand of ?", key, " is in ", new _DelayedToString(lhoOF),
                                " format, which differs from the current output format, ",
                                new _DelayedToString(contextOF), ". Conversion wasn't possible.");
                    }
                    // Here we know that lho is escaped plain text. So we re-escape it to the current format and
                    // bypass it, just as if the two output formats were the same earlier.
                    return contextOF.fromPlainTextByEscaping(lhoStr);
                }
            }
            return calculateResult(lhoStr, contextOF, env);
        }
        
        protected abstract TemplateModel calculateResult(String lho, MarkupOutputFormat outputFormat, Environment env)
                throws TemplateException;
        
    }
    
}