package dark.web.frame.velocity.controller.bak;

/**
 * <p>Title:            支持Velocity的控制器</p>
 * <p>Description:      根據(jù)org.apache.velocity.servlet.VelocityServlet進(jìn)行修改，
 * 						從而將Velocity整合進(jìn)dwf框架</p>
 * <p>Copyright:        Copyright (c) 2005</p>
 * <p>Company:          DIS</p>
 * <p>Create Time:      2005-2-28 16:24:43</p>
 * @author             <a href="mailto:dark_he@hotmail.com">darkhe</a>
 * @version            1.0
 */

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import dark.web.frame.Controller;
import dark.web.frame.controller.FrontController;
import dark.web.frame.velocity.command.VelocityCommand;
import dark.web.frame.velocity.form.VelocityForm;
import dark.web.frame.velocity.page.UnknownVelocityPage;
import dark.web.frame.velocity.page.VelocityPage;

import org.apache.velocity.app.Velocity;
import org.apache.velocity.runtime.RuntimeSingleton;
import org.apache.velocity.util.SimplePool;

public abstract class VelocityController2
	extends FrontController
	implements Controller
{
	/**
	 * The context key for the HTTP request object.
	 */
	public static final String REQUEST = "req";

	/**
	 * The context key for the HTTP response object.
	 */
	public static final String RESPONSE = "res";

	/**
	 * The HTTP content type context key.
	 */
	public static final String CONTENT_TYPE = "default.contentType";

	/**
	 *  The default content type for the response
	 */
	public static final String DEFAULT_CONTENT_TYPE = "text/html";

	/**
	 *  Encoding for the output stream
	 */
	public static final String DEFAULT_OUTPUT_ENCODING = "ISO-8859-1";

	/**
	 * The default content type, itself defaulting to {@link
	 * #DEFAULT_CONTENT_TYPE} if not configured.
	 */
	public static String defaultContentType;

	/**
	 * This is the string that is looked for when getInitParameter is
	 * called (<code>org.apache.velocity.properties</code>).
	 */
	protected static final String INIT_PROPS_KEY =
		"org.apache.velocity.properties";

	/**
	 * Cache of writers
	 */

	public static SimplePool writerPool = new SimplePool(40);

	/**
	 * Velocity配置文件路徑，default設(shè)定為CLASSPATH根目錄下的velocity.properties
	 */
	public static final String PROPS_FILE = "/velocity.properties";

	/**
	 * 初始化Velocity引擎
	 */
	private void initVelocity()
	{
		try
		{
			InputStream is =
				VelocityController2.class.getResourceAsStream(PROPS_FILE);

			Properties p = new Properties();

			p.load(is);
			/*
			 *  now, lets get the two elements we care about, the 
			 *  template path and the log, and fix those from relative
			 *  to the webapp root, to absolute on the filesystem, which is
			 *  what velocity needs
			 */

			String path = p.getProperty("file.resource.loader.path");

			if (path != null)
			{
				path = getServletContext().getRealPath(path);
				log.info("file.resource.loader.path=" + path);

				p.setProperty("file.resource.loader.path", path);
			}

			path = p.getProperty("runtime.log");

			if (path != null)
			{
				path = getServletContext().getRealPath(path);
				log.info("runtime.log=" + path);

				p.setProperty("runtime.log", path);
			}

			Velocity.init(p);

			log.info("初始化Velocity引擎成功......");
		}
		catch (IOException e)
		{
			log.error("初始化Velocity引擎出錯", e);
		}
		catch (Exception e)
		{
			log.error("初始化Velocity引擎出錯", e);
		}

		/*
		 *  Now that Velocity is initialized, cache some config.
		 */
		defaultContentType =
			RuntimeSingleton.getString(CONTENT_TYPE, DEFAULT_CONTENT_TYPE);

	}

	/**
	 * 
	 * @param request
	 * @param response
	 * @throws ServletException
	 * @throws IOException
	 * @see dark.web.frame.Controller#doRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
	 */
	public void doRequest(
		HttpServletRequest request,
		HttpServletResponse response)
		throws ServletException, IOException
	{
		// 獲取page.postfix和command.postfix
		// 從而根據(jù)用戶的請求后綴的不同調(diào)用頁面處理程序或者命令處理程序
		String page_postfix = configuration.getString("page.postfix");
		String command_postfix = configuration.getString("command.postfix");

		if (page_postfix.equals(getRequestPostfix(request)))
			// 調(diào)用頁面處理程序		
		{

			String uri = request.getRequestURI();

			VelocityPage page = getVelocityPage((HttpServletRequest) request);

			// 初始化頁面類
			page.init(
				getServletContext(),
				getServletConfig(),
				request,
				response);

			// 設(shè)置velocity模版
			page.setTarget(uri);

			// 檢證頁面類的執(zhí)行權(quán)限
			if (page.isAuthentic())
			{
				// 執(zhí)行真實(shí)的商業(yè)邏輯
				page.process();
			}
		}
		else if (command_postfix.equals(getRequestPostfix(request)))
			// 調(diào)用命令處理程序		
		{
			// 如果要求做表單驗(yàn)證，則處理之
			if (isValidate(request))
			{

				String input = getInput(request);

				// 如果用戶沒有指定請求轉(zhuǎn)發(fā)路徑，則指定default value
				if (input.equals(""))
				{
					input = configuration.getString("default.input");

					log.warn(
						"dont't specify parameter $INPUT, use default.input:"
							+ input);
					request.setAttribute(
						"$WARM",
						"dont't specify parameter $INPUT, use default.input"
							+ input);
				}

				VelocityForm form = getVelocityForm(request);

				// 初始化表單驗(yàn)證類
				form.init(getServletContext(), request, response, getMessage());

				// 設(shè)置當(dāng)前表單驗(yàn)證的用戶請求轉(zhuǎn)發(fā)路徑
				form.setInput(input);

				// 檢證表單驗(yàn)證類的執(zhí)行權(quán)限
				if (form.isAuthentic())
				{
					// 執(zhí)行實(shí)際的驗(yàn)證操作
					form.validate(request, response);

					if (!form.isPass())
					{
						// 如果isPass()返回false，
						// 則說明驗(yàn)證出表單錯誤，
						// 立即停止程序處理
						//log.debug("表單驗(yàn)證失敗");													
						return;
					}
					//log.debug("表單驗(yàn)證成功");
					//log.debug("form.isPass()=" + form.isPass());	
				}
			}

			String target = getTarget(request);

			// 如果用戶沒有指定請求轉(zhuǎn)發(fā)路徑，則指定default value
			if (target.equals(""))
			{
				target = configuration.getString("default.target");

				log.warn(
					"don't specify paramter $TARGER, use default.target:"
						+ target);
				request.setAttribute(
					"$WARM",
					"don't specify paramter $TARGER, use default.target:"
						+ target);
			}

			VelocityCommand command = getVelocityCommand(request);

			// 初始化命令類
			command.init(
				getServletContext(),
				getServletConfig(),
				request,
				response);

			// 設(shè)置當(dāng)前命令的用戶請求轉(zhuǎn)發(fā)路徑
			command.setTarget(target);

			// 檢證命令類的執(zhí)行權(quán)限
			if (command.isAuthentic())
			{
				// 執(zhí)行真實(shí)的商業(yè)邏輯
				command.process();
			}
		}

	}

	/**
	 * @throws javax.servlet.ServletException
	 * @see javax.servlet.GenericServlet#init()
	 */
	public void init() throws ServletException
	{
		super.init();
		initVelocity();
	}

	/**
	 * @param request
	 * @return
	 */
	protected VelocityForm getVelocityForm(HttpServletRequest request)
		throws ServletException
	{
		try
		{
			return (VelocityForm) getFormClass(request).newInstance();
		}
		catch (Exception e)
		{
			throw new ServletException(e);
		}
	}

	/**	
	 * @param req
	 * @return
	 */
	protected VelocityCommand getVelocityCommand(HttpServletRequest request)
		throws ServletException
	{
		try
		{
			return (VelocityCommand) getCommandClass(request).newInstance();
		}
		catch (Exception e)
		{
			throw new ServletException(e);
		}
	}

	/**
	 * @param request
	 * @return
	 */
	protected VelocityPage getVelocityPage(HttpServletRequest request)
		throws ServletException
	{
		try
		{
			return (VelocityPage) getVelocityPageClass(request).newInstance();
		}
		catch (Exception e)
		{
			throw new ServletException(e);
		}
	}

	/**
	 * 通過類名串值到得類對象
	 * @param req
	 */
	protected Class getVelocityPageClass(HttpServletRequest request)
	{
		Class result = null;

		String cp = configuration.getString("page.package");

		String pageName = getPageName(request);
		String pageClassName = cp + "." + pageName;

		try
		{
			result = Class.forName(pageClassName);
		}
		catch (ClassNotFoundException e)
		{
			log.info(
				"class:"
					+ pageClassName
					+ " not found, return UnknownVelocityPage.class");
			result = UnknownVelocityPage.class;
		}

		return result;
	}
}