package com.easyjf.web;

import java.io.File;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.apache.velocity.app.Velocity;
import org.apache.velocity.context.Context;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.util.SimplePool;

import com.easyjf.web.config.WebConfig;

/**
 * 
 * <p>
 * Title:EasyJWeb核心Servlet
 * </p>
 * <p>
 * Description: EasyJWeb核心Servlet，所有的.ejf訪問都將由該Servlet處理
 * 用戶必須在web.xml文件指定擴展名為.ejf的訪問都指向該類或其子類。
 * </p>
 * <p>
 * Copyright: Copyright (c) 2006
 * </p>
 * <p>
 * Company: www.easyjf.com
 * </p>
 * 
 * @author 蔡世友
 * @version 1.0
 */

public class ActionServlet extends HttpServlet {
	static final long serialVersionUID = 8880L;

	private static final Logger logger = (Logger) Logger
			.getLogger(ActionServlet.class.getName());

	public static final String DEFAULT_OUTPUT_ENCODING = "UTF-8";

	public static final String SERVLET_CONTEXT_KEY = ServletContext.class
			.getName();

	private static SimplePool writerPool = new SimplePool(60);

	private String defaultContentType;

	private boolean warnOfOutputStreamDeprecation = true;

	public void init(ServletConfig config) throws ServletException {
		super.init(config);
		Globals.CONFIG_FILE_FULL_PATH = getServletConfig().getServletContext()
				.getRealPath(Globals.CONFIG_FILE);
		Globals.APP_BASE_DIR = getServletConfig().getServletContext()
				.getRealPath("/");
		// logger.info("init");
		WebConfig.getInstance().init();
		// logger.info("do init apps");
		List apps = WebConfig.getInstance().getInitApps();
		// logger.info("apps.size:"+apps.size());
		for (int i = 0; i < apps.size(); i++) {

			try {
				Map app = (Map) apps.get(i);
				Method init = (Method) app.get("init");
				if (init != null) {
					init.invoke(app.get("classname"), null);
					// logger.info("init app:"+init.getClass().getName()+"init
					// method"+init.getName());
				}
			} catch (Exception e) {

			}
		}
		initTemplate(config);
	}

	public void destroy() {
		// TODO Auto-generated method stub
		List apps = WebConfig.getInstance().getInitApps();
		for (int i = 0; i < apps.size(); i++) {
			try {
				Map app = (Map) apps.get(i);
				Method des = (Method) app.get("destroy");
				if (des != null) {
					des.invoke(app.get("classname"), null);
					System.out.println("destroy app:"
							+ des.getClass().getName() + "destroy method"
							+ des.getName());

				}
			} catch (Exception e) {

			}
		}
		super.destroy();
	}

	/**
	 * 初始化模板
	 * 
	 * @param config
	 * @throws ServletException
	 */
	protected void initTemplate(ServletConfig config) throws ServletException {
		Velocity.setApplicationAttribute(SERVLET_CONTEXT_KEY,
				getServletContext());
		Properties p = new Properties();
		if (WebConfig.getInstance().getTemplateBasePath() == null
				|| WebConfig.getInstance().getTemplateBasePath().equals(""))
			WebConfig.getInstance().setTemplateBasePath(
					Globals.DEFAULT_TEMPLATE_PATH);
		String realTemplatePath = WebConfig.getInstance().getTemplateBasePath();
		File file = new File(WebConfig.getInstance().getTemplateBasePath());
		if (!file.exists())
			realTemplatePath = config.getServletContext().getRealPath(
					WebConfig.getInstance().getTemplateBasePath());
		p.setProperty("file.resource.loader.path", realTemplatePath);
		// System.out.println(realTemplatePath);

		try {
			Velocity.init(p);
		} catch (Exception e) {
			logger.error("ActionServlet: PANIC! unable to init() - " + e);
			throw new ServletException(e);
		}
	}

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doRequest(request, response);
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doRequest(request, response);
	}

	/**
	 * 處理用戶請求
	 * 
	 * @param request
	 * @param response
	 * @throws ServletException
	 * @throws IOException
	 */
	protected void doRequest(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		// 初始化Request
		try {
			doInitRequest(request, response);
		} catch (Exception e) {
			info(request, response, e);
			return;
		}
		Context context = null;
		try {
			setContentType(request, response);
			RequestProcessor rp = new RequestProcessor(this);
			rp.process(request, response);
		} catch (Exception e) {
			logger.error("ActionServlet出現嚴重錯誤:" + e);
			error(request, response, e);
		} finally {
			requestCleanup(request, response, context);
		}
	}

	protected boolean doInitRequest(HttpServletRequest request,
			HttpServletResponse response) throws Exception {
		Map map = new HashMap();
		map.put(ActionContext.HTTP_REQUEST, request);
		map.put(ActionContext.HTTP_RESPONSE, response);
		ActionContext.setContext(new ActionContext(map));
		if (WebConfig.getInstance().isDebug()) {// 調試模式每次都要初始化配置文件
			WebConfig.getInstance().init();// 初始化配置文件
			initTemplate(getServletConfig()); // 初始化模版
		}
		// 執行攔截操作
		Iterator interceptors = FrameworkEngine.getRequestInterceptors();
		if (interceptors != null) {
			while (interceptors.hasNext()) {
				IRequestInterceptor interceptor = (IRequestInterceptor) interceptors
						.next();
				Object result = interceptor.doIntercept();
				if (result instanceof Page) {
					response.sendRedirect(((Page) result).getUrl());
					return false;
				}
				// else if(result instanceof )
			}
		}

		return true;
	}

	// 清除request中的相關資料，此處為空
	protected void requestCleanup(HttpServletRequest request,
			HttpServletResponse response, Context context) {

	}

	protected void setContentType(HttpServletRequest request,
			HttpServletResponse response) {

		response.setContentType(defaultContentType);
	}

	/**
	 * 輸出系統框架錯誤信息提示
	 * 
	 * @param request
	 * @param response
	 * @param e
	 * @throws ServletException
	 */
	protected void error(HttpServletRequest request,
			HttpServletResponse response, Exception e) throws ServletException {
		try {
			StringBuffer html = new StringBuffer();
			String title = request.getCharacterEncoding() != null ? "EasyJWeb框架錯誤"
					: "EasyJWeb Framework error";
			html.append("<html>\n");
			html.append("<head><title>" + title + "</title></head>\n");
			html.append("<body>\n");
			html.append(title + ":\n<br>");
			Throwable cause = e;
			String why = cause.getMessage();
			html.append("<font color=red>");
			if (why != null && why.trim().length() > 0) {
				html.append(why);
				html
						.append("\n<br>詳細請查詢<a href='http://www.easyjf.com/' target='_blank'>http://www.easyjf.com</a>\n");
			}
			if (cause instanceof MethodInvocationException) {
				cause = ((MethodInvocationException) cause)
						.getWrappedThrowable();
			}
			html.append("</font>");

			StringWriter sw = new StringWriter();
			cause.printStackTrace(new PrintWriter(sw));
			html.append("<pre>\n");
			html.append(sw.toString());
			html.append("</pre>\n");
			html.append("</body>\n");
			html.append("</html>");
			if (request.getCharacterEncoding() != null)
				response.setContentType("text/html; charset="
						+ request.getCharacterEncoding());
			getResponseWriter(response).write(html.toString());
		} catch (Exception e2) {
			logger
					.error("ActionServlet: Exception while printing error screen: "
							+ e2);
			throw new ServletException(e);
		}
	}

	protected void info(HttpServletRequest request,
			HttpServletResponse response, Exception e) throws ServletException {
		try {
			StringBuffer html = new StringBuffer();
			String title = request.getCharacterEncoding() != null ? "EasyJWeb框架友情提示!:-)"
					: "EasyJWeb Framework Friendly Info!";
			html.append("<html>\n");
			html.append("<head><title>" + title + "</title></head>\n");
			html.append("<body>\n");
			html.append(title + ":\n<br>");
			Throwable cause = e;
			String why = cause.getMessage();
			html.append("<font color=red>");
			if (why != null && why.trim().length() > 0) {
				html.append(why);
				html
						.append("\n<br>詳細請查詢<a href='http://www.easyjf.com/' target='_blank'>http://www.easyjf.com</a>\n");
			}
			if (cause instanceof MethodInvocationException) {
				cause = ((MethodInvocationException) cause)
						.getWrappedThrowable();
			}
			html.append("</font>");
			html.append("</body>\n");
			html.append("</html>");
			if (request.getCharacterEncoding() != null)
				response.setContentType("text/html; charset="
						+ request.getCharacterEncoding());
			getResponseWriter(response).write(html.toString());
		} catch (Exception e2) {
			logger
					.error("ActionServlet: Exception while printing error screen: "
							+ e2);
			throw new ServletException(e);
		}
	}

	protected Writer getResponseWriter(HttpServletResponse response)
			throws UnsupportedEncodingException, IOException {
		Writer writer = null;
		try {
			writer = response.getWriter();
		} catch (IllegalStateException e) {
			if (this.warnOfOutputStreamDeprecation) {
				this.warnOfOutputStreamDeprecation = false;

			}
			String encoding = response.getCharacterEncoding();
			if (encoding == null) {
				encoding = DEFAULT_OUTPUT_ENCODING;
			}
			writer = new OutputStreamWriter(response.getOutputStream(),
					encoding);
		}
		return writer;
	}

	public static SimplePool getWriterPool() {
		return writerPool;
	}

}