package com.grady.diytomcat;

import com.grady.diytomcat.handler.DiyNettyTomcatHandler;

import io.netty.bootstrap.ServerBootstrap;

import io.netty.channel.ChannelFuture;

import io.netty.channel.ChannelInitializer;

import io.netty.channel.ChannelOption;

import io.netty.channel.nio.NioEventLoopGroup;

import io.netty.channel.socket.SocketChannel;

import io.netty.channel.socket.nio.NioServerSocketChannel;

import io.netty.handler.codec.http.HttpRequestDecoder;

import io.netty.handler.codec.http.HttpResponseEncoder;

import org.dom4j.Document;

import org.dom4j.DocumentException;

import org.dom4j.Element;

import org.dom4j.io.SAXReader;

import java.io.File;

import java.io.IOException;

import java.net.MalformedURLException;

import java.util.HashMap;

import java.util.List;

public class DiyTomcat {

    private int port = 8080;

    public static final HashMap<String, DiyNettyServlet> SERVLET_MAPPING = new HashMap<>();

    public static final HashMap<String,String> URL_MAPPING = new HashMap<>();

    static {

        loadServlet();

    }

    private static void loadServlet() {

        try {

            //获取web.xml目录地址

            String path = DiyTomcat.class.getResource("/").getPath();

            SAXReader reader = new SAXReader();

            //读取web.xml文件

            Document document = reader.read(new File(path + "web.xml"));

            //获取根标签（servlet和servlet-mapping），放在一个List中

            Element rootElement = document.getRootElement();

            List<Element> elements = rootElement.elements();

            //循环将映射写进map映射里

            for(Element element : elements){

                if ("servlet".equalsIgnoreCase(element.getName())){

                    Element servletName = element.element("servlet-name");

                    Element servletClass = element.element("servlet-class");

                    //需要注意的是servletMapping映射的第二个参数，要通过反射的方式进行实例化

                    SERVLET_MAPPING.put(servletName.getText(),

                            (DiyNettyServlet) Class.forName(servletClass.getText().trim()).newInstance());

                }else if ("servlet-mapping".equalsIgnoreCase(element.getName())){

                    Element servletName = element.element("servlet-name");

                    Element urlPattern = element.element("url-pattern");

                    URL_MAPPING.put(urlPattern.getText(), servletName.getText());

                }

            }

        } catch (DocumentException e) {

            e.printStackTrace();

        } catch (MalformedURLException e) {

            e.printStackTrace();

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        } catch (IllegalAccessException e) {

            e.printStackTrace();

        } catch (InstantiationException e) {

            e.printStackTrace();

        }

    }

    public void start() throws IOException {

        // Boss线程

        NioEventLoopGroup bossGroup = new NioEventLoopGroup();

        // worker线程

        NioEventLoopGroup workerGroup = new NioEventLoopGroup();

        // 1.创建对象

        ServerBootstrap server = new ServerBootstrap();

        //2. 配置参数

        server.group(bossGroup,workerGroup)

                // 主线程处理类

                .channel(NioServerSocketChannel.class)

                // 子线程处理类 Handler

                .childHandler(new ChannelInitializer<SocketChannel>() {

                    protected void initChannel(SocketChannel socketChannel) throws Exception {

                        socketChannel.pipeline().addLast(new HttpResponseEncoder());

                        socketChannel.pipeline().addLast(new HttpRequestDecoder());

                        socketChannel.pipeline().addLast(new DiyNettyTomcatHandler());

                    }

                })

                //针对主线程的配置，最大线程数128

                .option(ChannelOption.SO_BACKLOG,128)

                // 针对子线程的配置，保持长连接

                .childOption(ChannelOption.SO_KEEPALIVE,true);

        try {

            // 3 启动服务器

            ChannelFuture f = server.bind(port).sync();

            System.out.println("DiyTomcat启动成功，监听的端口是：" + port);

            f.channel().closeFuture().sync();

        } catch (InterruptedException e) {

            e.printStackTrace();

        }

    }

}