package ru.foror.articles.common.tapestry.common;

import java.io.IOException;

import org.apache.tapestry5.internal.services.LinkFactory;
import org.apache.tapestry5.internal.services.RequestPageCache;
import org.apache.tapestry5.internal.structure.Page;
import org.apache.tapestry5.model.ComponentModel;
import org.apache.tapestry5.services.ApplicationStateManager;
import org.apache.tapestry5.services.ComponentEventRequestHandler;
import org.apache.tapestry5.services.ComponentEventRequestParameters;
import org.apache.tapestry5.services.PageRenderRequestHandler;
import org.apache.tapestry5.services.PageRenderRequestParameters;
import org.apache.tapestry5.services.Response;

import ru.foror.articles.common.domain.LoginAccount;

/**
 * Авторизация страниц.
 * 
 * @author Alexey Pomogaev foror@mail.com
 */
public class SecurityHandler implements PageRenderRequestHandler, ComponentEventRequestHandler {
	
	private RolePermission rolePerm = new RolePermission();
	
	private IAuthHelper authHelper;
	
	private ApplicationStateManager appStateManager;
	
	private Response response;
	
	private LinkFactory linkFactory;
	
	private RequestPageCache cache;
	
	private PageRenderRequestHandler pageRenderRequestHandler;
	
	private ComponentEventRequestHandler componentEventRequestHandler;
	
	/**
	 * Конструктор при прямых запросах к страницам.
	 */
	public SecurityHandler(PageRenderRequestHandler delegate, 
			IAuthHelper authHelper, ApplicationStateManager appStateManager,
			Response response, LinkFactory linkFactory, RequestPageCache cache) {
		
		this.authHelper = authHelper;
		this.appStateManager = appStateManager;
		this.response = response;
		this.linkFactory = linkFactory;
		this.cache = cache;
		this.pageRenderRequestHandler = delegate;
	}
	
	/**
	 * Конструктор для запросов к страницам вызванных через события Tapestry.
	 */
	public SecurityHandler(ComponentEventRequestHandler delegate, 
			IAuthHelper authHelper, ApplicationStateManager appStateManager,
			Response response, LinkFactory linkFactory, RequestPageCache cache) {
		
		this.authHelper = authHelper;
		this.appStateManager = appStateManager;
		this.response = response;
		this.linkFactory = linkFactory;
		this.cache = cache;
		this.componentEventRequestHandler = delegate;
	}
	
	/**
	 * Перехват прямого запроса к странице.
	 */
	public void handle(PageRenderRequestParameters parameters) throws IOException {
		if (authorization(cache.get(parameters.getLogicalPageName()))) {
			pageRenderRequestHandler.handle(parameters);
		}
	}
	
	/**
	 * Перехват события Tapestry.
	 */
	public void handle(ComponentEventRequestParameters parameters) throws IOException {		
		if (parameters.getContainingPageName().equals(parameters.getActivePageName())) {
			if (authorization(cache.get(parameters.getContainingPageName()))) {
				componentEventRequestHandler.handle(parameters);
			}			
		} else {
			if (authorization(cache.get(parameters.getContainingPageName()))
					&& authorization(cache.get(parameters.getActivePageName()))) {
				componentEventRequestHandler.handle(parameters);
			}			
		}
	}
	
	/**
	 * Авторизация пользователя. Подробнее ${@link RolePermission}.
	 * 
	 * При провале авторизации произойдёт переадресация, стандартными средствами 
	 * сервлетов, на {@link SystemPage#PermissionLow} или {@link SystemPage#PermissionFail}.
	 */
	public boolean authorization(Page page) throws IOException {				
		if (!authHelper.isLoginAccount()) {
			authHelper.loginByCookie();
		}
		
		ComponentModel model = page.getRootComponent()
								   .getComponentResources()
								   .getComponentModel();
		
		if (rolePerm.isAnonym(model)) {
			return true;
		}
		
		if (authHelper.isLoginAccount()) {
			if (!rolePerm.isAnonymOnly(model) 
					&& rolePerm.isEnableAccess(appStateManager.get(LoginAccount.class).getRole(), model)) {
				return true;
			}
			
			response.sendRedirect(linkFactory.createPageLink(SystemPage.PermissionLow.name(), false));
			return false;
		} else if (rolePerm.isAnonymOnly(model)) {
			return true;
		}
		
		response.sendRedirect(linkFactory.createPageLink(SystemPage.PermissionFail.name(), false));
		return false;
	}
}