/**
 * Task管理的Controller, 使用Restful风格的Urls:
 * 
 * List   page        : GET  /task/
 * Create page        : GET  /task/create
 * Create action      : POST /task/save
 * Update page        : GET  /task/update/{id}
 * Update action      : POST /task/save/{id}
 * Delete action      : POST /task/delete/{id}
 */
@Controller
@RequestMapping(value = "/task")
public class TaskController {

	@Autowired
	private TaskService taskService;

	@RequestMapping(value = { "list", "" })
	public String list(Model model) {
		Long userId = getCurrentUserId();
		List<Task> tasks = taskService.getUserTask(userId);

		model.addAttribute("tasks", tasks);
		return "task/taskList";
	}

	@RequestMapping(value = "create")
	public String createForm(Model model) {
		model.addAttribute("task", new Task());
		return "task/taskForm";
	}

	@RequestMapping(value = "save")
	public String create(@Valid @ModelAttribute("newTask") Task newTask, RedirectAttributes redirectAttributes) {
		User user = new User(getCurrentUserId());
		newTask.setUser(user);

		taskService.saveTask(newTask);
		redirectAttributes.addFlashAttribute("message", "创建任务成功");
		return "redirect:/task/";
	}

	@RequestMapping(value = "update/{id}")
	public String updateForm(@PathVariable("id") Long id, Model model) {
		model.addAttribute("task", taskService.getTask(id));
		return "task/taskForm";
	}

	@RequestMapping(value = "save/{id}")
	public String update(@Valid @ModelAttribute("task") Task task, RedirectAttributes redirectAttributes) {
		taskService.saveTask(task);
		redirectAttributes.addFlashAttribute("message", "更新任务成功");
		return "redirect:/task/";
	}

	@RequestMapping(value = "delete/{id}")
	public String delete(@PathVariable("id") Long id, RedirectAttributes redirectAttributes) {
		taskService.deleteTask(id);
		redirectAttributes.addFlashAttribute("message", "删除任务成功");
		return "redirect:/task/";
	}

	/**
	 * 使用@ModelAttribute, 实现Struts2 Preparable二次部分绑定的效果,先根据form的id从数据库查出Task对象,再把Form提交的内容绑定到该对象上。
	 * 因为仅update()方法的form中有id属性，因此本方法在该方法中执行.
	 */
	@ModelAttribute("task")
	private Task getTask(@RequestParam(value = "id", required = false) Long id) {
		if (id != null) {
			return taskService.getTask(id);
		}
		return null;
	}

	/**
	 * 不要绑定对象中的id属性.
	 */
	@InitBinder
	protected void initBinder(WebDataBinder binder) {
		binder.setDisallowedFields("id");
	}

	private Long getCurrentUserId() {
		ShiroUser user = (ShiroUser) SecurityUtils.getSubject().getPrincipal();
		return user.id;
	}
}