package cc.bnblogs.springsecurity.validate.imagecode;

import cc.bnblogs.springsecurity.Exception.ValidateCodeException;
import cc.bnblogs.springsecurity.controller.ValidateCodeController;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.web.authentication.AuthenticationFailureHandler;
import org.springframework.social.connect.web.HttpSessionSessionStrategy;
import org.springframework.social.connect.web.SessionStrategy;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.ServletRequestBindingException;
import org.springframework.web.bind.ServletRequestUtils;
import org.springframework.web.context.request.ServletWebRequest;
import org.springframework.web.filter.OncePerRequestFilter;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 本过滤器只会校验一次
 */
@Component
public class ValidateCodeFilter extends OncePerRequestFilter {

    @Autowired
    private AuthenticationFailureHandler authenticationFailureHandler;

    private SessionStrategy sessionStrategy = new HttpSessionSessionStrategy();

    @Override
    protected void doFilterInternal(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse,
                                    FilterChain filterChain) throws ServletException, IOException {
        // 判断请求的路径和方法决定是否进行验证码校验
        if (StringUtils.equalsIgnoreCase("/login", httpServletRequest.getRequestURI())
                && StringUtils.equalsIgnoreCase(httpServletRequest.getMethod(), "post")) {
            try {
                validateCode(new ServletWebRequest(httpServletRequest));
            } catch (ValidateCodeException e) {
                // 校验失败，返回对应错误信息
                authenticationFailureHandler.onAuthenticationFailure(httpServletRequest, httpServletResponse, e);
                return;
            }
        }
        // 不需要进行验证码校验，进入下一步
        filterChain.doFilter(httpServletRequest, httpServletResponse);
    }

    /**
     * 验证码校验
     * @param servletWebRequest
     * @throws ServletRequestBindingException
     */
    private void validateCode(ServletWebRequest servletWebRequest) throws ServletRequestBindingException {
        // 从Session中取出ImageCode对象
        ImageCode codeInSession = (ImageCode) sessionStrategy.getAttribute(servletWebRequest,
                ValidateCodeController.SESSION_KEY_IMAGE_CODE);
        // 获取用户输入的验证码
        String codeInRequest = ServletRequestUtils.getStringParameter(servletWebRequest.
                getRequest(), "imageCode");

        if (StringUtils.isBlank(codeInRequest)) {
            throw new ValidateCodeException("验证码不能为空!");
        }
        if (codeInSession == null) {
            throw new ValidateCodeException("验证码不存在!");
        }
        if (codeInSession.isExpire()) {
            sessionStrategy.removeAttribute(servletWebRequest, ValidateCodeController.SESSION_KEY_IMAGE_CODE);
            throw new ValidateCodeException("验证码已过期!");
        }
        if (!StringUtils.equalsIgnoreCase(codeInSession.getCode(), codeInRequest)) {
            throw new ValidateCodeException("验证码不正确!");
        }
        // 从Session中移除验证码对象
        sessionStrategy.removeAttribute(servletWebRequest, ValidateCodeController.SESSION_KEY_IMAGE_CODE);
    }
}