/*
 * Copyright © 2017 Ivar Grimstad ([email protected])
 *
 * 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.mvcspec.ozark.ext.groovy;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.Map;
import java.util.stream.Collectors;

import javax.annotation.Priority;
import javax.enterprise.context.ApplicationScoped;
import javax.inject.Inject;
import javax.mvc.engine.ViewEngine;
import javax.mvc.engine.ViewEngineContext;
import javax.mvc.engine.ViewEngineException;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;

import org.codehaus.groovy.control.CompilationFailedException;
import org.mvcspec.ozark.engine.ViewEngineBase;
import org.mvcspec.ozark.engine.ViewEngineConfig;

import groovy.lang.Writable;
import groovy.text.Template;
import groovy.text.markup.MarkupTemplateEngine;

/**
 * @author Daniel Dias
 */
@ApplicationScoped
@Priority(ViewEngine.PRIORITY_FRAMEWORK)
public class GroovyViewEngine extends ViewEngineBase {

    @Inject
    @ViewEngineConfig
    private MarkupTemplateEngine markupTemplateEngine;

    @Inject
    private ServletContext servletContext;

    public boolean supports(String view) {
        return view.endsWith(".tpl");
    }

    public void processView(ViewEngineContext context) throws ViewEngineException {

        Map<String, Object> model = new HashMap<>(context.getModels().asMap());
        model.put("request", context.getRequest(HttpServletRequest.class));
        Charset charset = resolveCharsetAndSetContentType(context);
        try (Writer writer = new OutputStreamWriter(context.getOutputStream(), charset);
            InputStream resourceAsStream = servletContext.getResourceAsStream(resolveView(context));
            InputStreamReader in = new InputStreamReader(resourceAsStream, "UTF-8");) {
            Template template = markupTemplateEngine.createTemplate(in);
            Writable output = template.make(model);
            output.writeTo(writer);
        } catch (IOException | CompilationFailedException | ClassNotFoundException e) {
            throw new ViewEngineException(e);
        }
    }
}