package org.springside.core.commons;

import org.apache.commons.lang.StringUtils;
import org.springframework.validation.BindingResult;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.servlet.ModelAndView;
import org.springside.core.Constants;
import org.springside.core.commons.support.IUser;
import org.springside.core.commons.support.audit.AuditableEntity;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;


/**
 * SpringSide 基于命名规则的CRUD Controller基类.
 * 结合了Multi-Action 与 Form Controller的优点，
 * 本类演示的仅仅是封装的一种可能性,大家可以根据自己的项目自由扩展或重定义.
 * 如果不需要这么紧密的封装，可用{@link BaseController}
 *
 * @author calvin
 * @see BaseController
 * @see org.springside.bookstore.admin.web.BookManageController
 */
abstract public class BaseManageController extends BaseController {
    /**
     * 以下的View变量即可以在配置文件中定义，也可以在子类静态初始化
     * <pre>
     * {
     * listView = "/admin/listBook.jsp";
     * editView = "/admin/editBook.jsp";
     * successView = "redirect:/admin/book.do";
     * }
     * </pre>
     */
    protected String listView = null;
    protected String editView = null;
    protected String showView = null;
    protected String successView = null;

    public void setListView(String listView) {
        this.listView = listView;
    }

    public void setEditView(String editView) {
        this.editView = editView;
    }

    public void setSuccessView(String successView) {
        this.successView = successView;
    }

    public void setShowView(String showView) {
        this.showView = showView;
    }

    /**
     * 设置默认函数为list()
     */
    public ModelAndView index(HttpServletRequest request, HttpServletResponse response) throws Exception {
        return list(request, response);
    }

    /**
     * 显示对象列表页面的模板方法.
     * 调用子类的 {@link  #onList(HttpServletRequest,HttpServletResponse,ModelAndView)}
     */
    public ModelAndView list(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView(listView);
        mav.addAllObjects(referenceData(request));
        onList(request, response, mav);
        return mav;
    }

    /**
     * 显示创建新对象的输入页面的模板方法.
     * 调用子类的 {@link  #onCreate(HttpServletRequest,HttpServletResponse,ModelAndView)}
     */
    public ModelAndView create(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView(editView);
        mav.addAllObjects(referenceData(request));
        onCreate(request, response, mav);
        return mav;
    }

    /**
     * 保存新增对象的模板方法.
     * 调用子类的 {@link #onSave(HttpServletRequest,HttpServletResponse,ModelAndView,boolean)}
     */
    public ModelAndView save(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView(successView);
        onSave(request, response, mav, true);
        return mav;
    }

    /**
     * 显示对象修改时的输入页面的模板方法.
     * 调用子类的 {@link  #onEdit(HttpServletRequest,HttpServletResponse,ModelAndView)}
     */
    public ModelAndView edit(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView(editView);
        mav.addAllObjects(referenceData(request));
        onEdit(request, response, mav);
        return mav;
    }

    /**
     * 显示对象详情页面的模板方法。该页面中的对象属性不能修改
     * 调用子类的 {@link #onShow(HttpServletRequest,HttpServletResponse,ModelAndView)}
     */
    public ModelAndView show(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView(showView);
        mav.addAllObjects(referenceData(request));
        onShow(request, response, mav);
        return mav;
    }

    /**
     * 保存对象更新的模板方法
     * 调用子类的 {@link  #onSave(HttpServletRequest,HttpServletResponse,ModelAndView,boolean)}
     */
    public ModelAndView update(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView(successView);
        onSave(request, response, mav, false);
        return mav;
    }

    /**
     * 查询对象的模板方法
     * 调用子类的 {@link  #onQuery(HttpServletRequest,HttpServletResponse,ModelAndView)}
     */
    public ModelAndView query(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView(listView);
        mav.addAllObjects(referenceData(request));
        onQuery(request, response, mav);
        return mav;
    }

    /**
     * 删除选择的对象的模板方法
     * 调用子类的 {@link  #onRemoveSelected(HttpServletRequest,HttpServletResponse,ModelAndView)}
     */
    public ModelAndView removeSelected(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView(successView);
        mav.addAllObjects(referenceData(request));
        onRemoveSelected(request, response, mav);
        return mav;
    }

    /*以下为回调函数列表,意义见前,在各子类中实现*/

    protected void onList(HttpServletRequest request, HttpServletResponse response, ModelAndView mav) throws Exception {
    }

    protected void onCreate(HttpServletRequest request, HttpServletResponse response, ModelAndView mav) throws Exception {
    }

    protected void onEdit(HttpServletRequest request, HttpServletResponse response, ModelAndView mav) throws Exception {
    }

    protected void onShow(HttpServletRequest request, HttpServletResponse response, ModelAndView mav) throws Exception {
    }

    protected void onQuery(HttpServletRequest request, HttpServletResponse response, ModelAndView mav) throws Exception {
    }

    protected void onSave(HttpServletRequest request, HttpServletResponse response, ModelAndView mav, boolean isNew) throws Exception {
    }

    protected void onRemoveSelected(HttpServletRequest request, HttpServletResponse response, ModelAndView mav) throws Exception {
    }


    /**
     * 将辅助显示的对象,如类别列表,状态列表 放入request的Attribute中.
     * 实际调用{@link #referenceData(HttpServletRequest, Map)},
     * 多此一层封装仅仅为了初始化module.
     */
    protected Map referenceData(HttpServletRequest request) {
        Map model = new HashMap();
        referenceData(request, model);
        return model;
    }

    /**
     * 将辅助显示的对象,如类别列表,状态列表 放入request的Attribute中.
     * 在各子类实现.
     */
    protected void referenceData(HttpServletRequest request, Map model) {
    }

    /**
     * 回调函数.校验出错时,将出错的对象及出错信息放回model.
     * 在{@link #onSave(HttpServletRequest,HttpServletResponse,ModelAndView,boolean)}中调用.
     */
    protected ModelAndView onBindError(HttpServletRequest request, BindingResult result, ModelAndView mav, String viewName) {
        mav.setViewName(viewName);
        mav.addAllObjects(result.getModel());
        mav.addAllObjects(referenceData(request));
        return mav;
    }

    /**
     * 为AuditableEntity接口重载了{@link BaseController#bindObject(javax.servlet.http.HttpServletRequest, Object)}的bindObject函数.
     * 如果对象实现了该接口:
     * 自动对createUser/modifyUser取session中的"user"属性.
     * 自动对createTime/modifyTime取当前时间.
     */
    protected BindingResult bindObject(HttpServletRequest request, Object command) throws Exception {
        BindingResult result = super.bindObject(request, command);
        if (command instanceof AuditableEntity) {
            AuditableEntity ve = (AuditableEntity) command;
            IUser user = (IUser) request.getSession().getAttribute(Constants.USER_IN_SESSION);
            if (ve.getCreateUser() == null)
                ve.setCreateUser(user);
            else
                ve.setModifyUser(user);

            if (ve.getCreateTime() == null)
                ve.setCreateTime(new Date());
            else
                ve.setModifyTime(new Date());
        }
        return result;
    }

    /**
     * 将上传文件写到服务器硬盘.
     * 一些不支持BLOB类型的数据库,必须把上传的文件写到硬盘.
     * 本函数写得并不严谨,如文件同名判断,加入时间戳作为文件名一部分等未做,just for demo
     *
     * @return 文件的相对路径
     */
    protected String uploadImageToFile(HttpServletRequest request, String uploadDir, String parameterName) throws IOException {

        String fileRelativePath = null;
        MultipartHttpServletRequest multipartRequest = null;

        try {
            multipartRequest = (MultipartHttpServletRequest) request;
        }
        catch (ClassCastException e) {
            return null; //only for testcast 中,mockservlet不能转为MultipartRequest
        }

        MultipartFile multipartFile = multipartRequest.getFile(parameterName);
        if (StringUtils.isNotEmpty(multipartFile.getOriginalFilename())) {
            String fileName = multipartFile.getOriginalFilename();
            String fileRealPath = getServletContext().getRealPath(uploadDir) + File.separator + fileName;
            File file = new File(fileRealPath);
            multipartFile.transferTo(file);
            fileRelativePath = uploadDir + "/" + fileName;
        }

        return fileRelativePath;
    }
}