/*
    * Copyright 2016 The Lannister Project
    * 
    * 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 net.anyflow.lannister.http;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.UnsupportedEncodingException;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.w3c.tidy.Tidy;
  
  import io.netty.handler.codec.http.HttpResponseStatus;
  
  public class HtmlGenerator {
  
  	private static final Logger logger = LoggerFactory.getLogger(HtmlGenerator.class);
  
  	private static String html_error;
  
  	static {
  		html_error = tidy(Thread.currentThread().getContextClassLoader().getResourceAsStream("html/error.htm"));
  	}
  
  	public static String generate(Map<String, String> values, String htmlPath) throws IOException {
  		return replace(values, tidy(Thread.currentThread().getContextClassLoader().getResourceAsStream(htmlPath)));
  	}
  
  	private static String replace(Map<String, String> values, String htmlTemplate) {
  		String openMarker = "${";
  		String closeMarker = "}";
  
  		String ret = htmlTemplate;
  
  		for (Map.Entry<String, String> item : values.entrySet()) {
  			ret = ret.replace(openMarker + item.getKey() + closeMarker, item.getValue());
  		}
  
  		return ret;
  	}
  
  	public static String error(String message, HttpResponseStatus status) {
  		HashMap<String, String> values = new HashMap<String, String>();
  
  		values.put("ERROR_CODE", status.toString());
  		values.put("message", message);
  
  		return replace(values, html_error);
  	}
  
  	private static String tidy(InputStream is) {
  		Tidy tidy = new Tidy();
  
  		tidy.setQuiet(true);
  		tidy.setDocType("loose");
  		tidy.setTidyMark(false);
  		tidy.setOutputEncoding("UTF8");
  
  		java.io.ByteArrayOutputStream out = new java.io.ByteArrayOutputStream();
  		tidy.parse(is, out);
  
  		try {
  			return out.toString("UTF-8");
  		}
  		catch (UnsupportedEncodingException e) {
  
  			logger.error(e.getMessage(), e);
  			return null;
  		}
  	}
  }