package com.webserver.http;

import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

/**
 * HTTP协议规定的相关内容
 * @author soft01
 *
 */
public class HttpContext {
	/**
	 * 状态代码与对应的描述
	 * key:状态代码
	 * value：状态描述
	 */
	private static final Map<Integer,String> STATUS_MAPPING = new HashMap<Integer,String>();
	
	/**
	 * 介质类型映射时
	 * key:文件的后缀名
	 * value：Conent-Type对应的值
	 */
	private static final Map<String,String> MIME_TYPE_MAPPING = new HashMap<String,String>();
	
	/*
	 * URL 与 Servlet 之间的映射
	 * key: URL
	 * value: Servlet 的类名
	 */
	private static final Map<String,String> URL_MAPPING = new HashMap<>();
	
	static {
		//初始化
		initStatusMapping();
		initMimeTypeMapping();
		initUrlMapping();
	}
	
	/**
	 * 初始化URL 与 Servlet 之间的对应关系
	 */
	private static void initUrlMapping() {
		SAXReader reader = new SAXReader();
		try {
			Document doc = reader.read(new File("conf/web.xml"));
			Element root = doc.getRootElement();
			//算法
			List<Element> mappings = root.elements("servlet-mapping");
			List<Element> servlets = root.elements("servlet");
			System.out.println("mappings:"+mappings);
			System.out.println("servlets:"+servlets);
			for(Element mapping : mappings) {
				String url = mapping.elementTextTrim("url-pattern");
				String name = mapping.elementTextTrim("servlet-name");
				System.out.println(url+":"+name);
				//根据name 找到对应的className
				for(Element servlet : servlets) {
					String name_ = servlet.elementTextTrim("servlet-name");
					String className = servlet.elementTextTrim("servlet-class");
					System.out.println(name_+":"+className);
					if(name.equals(name_)) {
						System.out.println("找到："+url+":"+className);
						URL_MAPPING.put(url, className);
					}
				}
			}
			System.out.println("URL_MAPPING:"+URL_MAPPING);
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException();
		}
	}
	
	/**
	 * 初始化介质类型
	 */
	private static void initMimeTypeMapping() {
//		/*
//		 * xxxx.html
//		 * xxxx.js
//		 * xxxx.png
//		 * xxxx.css
//		 * jpg
//		 * gif
//		 */
//		MIME_TYPE_MAPPING.put("html", "text/html");
//		MIME_TYPE_MAPPING.put("css", "text/css");
//		MIME_TYPE_MAPPING.put("png", "image/png");
//		MIME_TYPE_MAPPING.put("gif", "image/gif");
//		MIME_TYPE_MAPPING.put("jpg", "image/jpg");
//		MIME_TYPE_MAPPING.put("js", "application/javascript");
		try {
			//1
			SAXReader reader = new SAXReader();
			//2文档
			Document doc = reader.read(new File("conf/web.xml"));
			//3获取根元素
			Element root = doc.getRootElement();
			//获取根元素名字
			String ename = root.getName();
			System.out.println("根元素："+ename);
			
			//获取根标签下的所有<mime-mapping>标签
			List<Element> list = root.elements("mime-mapping");
			System.out.println(list.size());
			
			for(Element empEle : list) {
				String name = empEle.elementText("extension");
				String value = empEle.elementText("mime-type");
//				System.out.println(name);
//				System.out.println(value);
				MIME_TYPE_MAPPING.put(name, value);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		
	}
	
	
	
	
	
	/**
	 * 初始化状态代码和状态描述
	 */
	private static void initStatusMapping() {
		/*
		 *        Status-Code    = "200"   ; OK
                      | "201"   ; Created
                      | "202"   ; Accepted
                      | "204"   ; No Content
                      | "301"   ; Moved Permanently
                      | "302"   ; Moved Temporarily
                      | "304"   ; Not Modified
                      | "400"   ; Bad Request
                      | "401"   ; Unauthorized
                      | "403"   ; Forbidden
                      | "404"   ; Not Found
                      | "500"   ; Internal Server Error
                      | "501"   ; Not Implemented
                      | "502"   ; Bad Gateway
                      | "503"   ; Service Unavailable
                      | extension-code
		 */
		STATUS_MAPPING.put(200, "OK");
		STATUS_MAPPING.put(201, "Created");
		STATUS_MAPPING.put(202, "Accepted");
		STATUS_MAPPING.put(204, "No Content");
		STATUS_MAPPING.put(301, "Moved Permanently");
		STATUS_MAPPING.put(302, "Moved Temporarily");
		STATUS_MAPPING.put(304, "Not Modified");
		STATUS_MAPPING.put(400, "Bad Request");
		STATUS_MAPPING.put(401, "Unauthorized");
		STATUS_MAPPING.put(403, "Forbidden");
		STATUS_MAPPING.put(404, "Not Found");
		STATUS_MAPPING.put(500, "Internal Server Error");
		STATUS_MAPPING.put(501, "Not Implemented");
		STATUS_MAPPING.put(502, "Bad Gateway");
		STATUS_MAPPING.put(503, "Service Unavailable");
	}
	
	/**
	 * 根据给定的状态代码获取对应的状态描述
	 * @return
	 */
	public static String getStatusReason(int code) {
		return STATUS_MAPPING.get(code);
	}
	
	/**
	 * 根据资源后缀名获取对应的Conent-Type值
	 * @param ext
	 * @return
	 */
	public static String getMimeType(String ext) {
		return MIME_TYPE_MAPPING.get(ext);
	}
	
	/**
	 * 根据URL 映射到对应的Servlet Class Name
	 * 用户请求URL
	 * @param url
	 * @return
	 */
	public static String getServletClass(String url) {
		return URL_MAPPING.get(url);
	}
	
	public static void main(String[] args) {
		String line = getStatusReason(404);
		System.out.println(line);
		
		String fileName = "jquery-1.8.8.min.js";	
		String[] str = fileName.split("\\.");
		String str1 = str[str.length-1];
//		int index = fileName.lastIndexOf(".")+1;
//		String str1 = fileName.substring(index);
		System.out.println(str1);
		
		String line2 = getMimeType(str1);
		System.out.println(line2);
		
		
	}
	
}