package com.ydtech.security.utils;

import com.ydtech.security.GrantedAuthorityImpl;
import com.ydtech.security.JwtAuthenticatioToken;
import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import org.apache.catalina.User;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.context.SecurityContextHolder;

import javax.servlet.http.HttpServletRequest;
import java.io.Serializable;
import java.util.*;

/**
 * JWT工具类
 *
 * @author Louis
 * @date Jun 29, 2019
 */
public class JwtTokenUtils implements Serializable {

    private static final long serialVersionUID = 1L;

    /**
     * 用户名称
     */
    private static final String USERNAME = Claims.SUBJECT;
    /**
     * 创建时间
     */
    private static final String CREATED = "created";
    /**
     * 权限列表
     */
    private static final String AUTHORITIES = "authorities";
    /**
     * 密钥
     */
    private static final String SECRET = "abcdefgh";
    /**
     * 有效期12小时
     */
    private static final long EXPIRE_TIME = 12 * 60 * 60 * 1000;

    /**
     * deptId
     */
    private static final String DEPTID = "deptId";

    /**
     * userId
     */
    private static final String USERID = "id";

    /**
     * 生成令牌
     *
     * @param authentication 用户
     * @return 令牌
     */
    public static String generateToken(Authentication authentication) {
        Map<String, Object> claims = new HashMap<>(3);
        claims.put(USERNAME, SecurityUtils.getUsername(authentication));
        claims.put(CREATED, new Date());
        claims.put(DEPTID, SecurityUtils.getDeptId());
        claims.put(AUTHORITIES, authentication.getAuthorities());
        claims.put(USERID, SecurityUtils.getUserId());

        return generateToken(claims);
    }

    /**
     * 从数据声明生成令牌
     *
     * @param claims 数据声明
     * @return 令牌
     */
    private static String generateToken(Map<String, Object> claims) {
        Date expirationDate = new Date(System.currentTimeMillis() + EXPIRE_TIME);
        return Jwts.builder().setClaims(claims).setExpiration(expirationDate).signWith(SignatureAlgorithm.HS512, SECRET).compact();
    }

    /**
     * 从令牌中获取用户名
     *
     * @param token 令牌
     * @return 用户名
     */
    public static String getUsernameFromToken(String token) {
        String username;
        try {
            Claims claims = getClaimsFromToken(token);
            username = claims.getSubject();
        } catch (Exception e) {
            username = null;
        }
        return username;
    }

    /**
     * 根据请求令牌获取登录认证信息
     *
     * @param request 令牌
     * @return 用户名
     */
    public static Authentication getAuthenticationeFromToken(HttpServletRequest request) {
        Authentication authentication = null;
        // 获取请求携带的令牌
        String token = JwtTokenUtils.getToken(request);
        if (token != null) {
            // 请求令牌不能为空
            if (SecurityUtils.getAuthentication() == null) {
                // 上下文中Authentication为空
                Claims claims = getClaimsFromToken(token);
                if (claims == null) {
                    return null;
                }
                String username = claims.getSubject();
                if (username == null) {
                    return null;
                }
                if (isTokenExpired(token)) {
                    return null;
                }
                Object authors = claims.get(AUTHORITIES);
                List<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>();
                if (authors != null && authors instanceof List) {
                    for (Object object : (List) authors) {
                        authorities.add(new GrantedAuthorityImpl((String) ((Map) object).get("authority")));
                    }
                }
                authentication = new JwtAuthenticatioToken(username, null, authorities, token);
            } else {
                String username = SecurityUtils.getByUsername();
                if (username == null) {
                    return null;
                }
                if (validateToken(token, username)) {
                    // 如果上下文中Authentication非空，且请求令牌合法，直接返回当前登录认证信息
                    authentication = SecurityContextHolder.getContext().getAuthentication();
                }
            }
        }
        return authentication;
    }

    /**
     * 从令牌中获取数据声明
     *
     * @param token 令牌
     * @return 数据声明
     */
    private static Claims getClaimsFromToken(String token) {
        Claims claims;
        try {
            claims = Jwts.parser().setSigningKey(SECRET).parseClaimsJws(token).getBody();
        } catch (Exception e) {
            claims = null;
        }
        return claims;
    }

    /**
     * 验证令牌
     *
     * @param token
     * @param username
     * @return
     */
    public static Boolean validateToken(String token, String username) {
        String userName = getUsernameFromToken(token);
        return (userName.equals(username) && !isTokenExpired(token));
    }

    /**
     * 刷新令牌
     *
     * @param token
     * @return
     */
    public static String refreshToken(String token) {
        String refreshedToken;
        try {
            Claims claims = getClaimsFromToken(token);
            claims.put(CREATED, new Date());
            refreshedToken = generateToken(claims);
        } catch (Exception e) {
            refreshedToken = null;
        }
        return refreshedToken;
    }

    /**
     * 判断令牌是否过期
     *
     * @param token 令牌
     * @return 是否过期
     */
    public static Boolean isTokenExpired(String token) {
        try {
            Claims claims = getClaimsFromToken(token);
            Date expiration = claims.getExpiration();
            return expiration.before(new Date());
        } catch (Exception e) {
            return false;
        }
    }

    /**
     * 获取请求token
     *
     * @param request
     * @return
     */
    public static String getToken(HttpServletRequest request) {
        String token = request.getHeader("Authorization");
        String tokenHead = "Bearer ";
        if (token == null) {
            token = request.getHeader("token");
        } else if (token.contains(tokenHead)) {
            token = token.substring(tokenHead.length());
        }
        if ("".equals(token)) {
            token = null;
        }
        return token;
    }

    /**
     * 从请求中获取用户名
     *
     * @param request
     * @return 用户名
     */
    public static String getUsernameFromRequest(HttpServletRequest request) {
        String username;
        try {
            String token = getToken(request);
            username = getUsernameFromToken(token);
        } catch (Exception e) {
            username = null;
        }
        return username;
    }

    /**
     * 从请求中获取部门id
     *
     * @param request
     * @return 部门id
     */
    public static String getDeptIdFromRequest(HttpServletRequest request) {
        String deptId;
        try {
            String token = getToken(request);
            deptId = getDeptIdFromToken(token);
        } catch (Exception e) {
            deptId = null;
        }
        return deptId;
    }

    /**
     * 从请求中获取用户id
     *
     * @param request
     * @return 用户id
     */
    public static String getUserIdFromRequest(HttpServletRequest request) {
        String userId;
        try {
            String token = getToken(request);
            userId = getUserIdFromToken(token);
        } catch (Exception e) {
            userId = null;
        }
        return userId;
    }

    /**
     * 从令牌中获取部门id
     *
     * @return
     */
    public static String getDeptIdFromToken(String token) {
        String deptId = null;
        try {
            Claims claims = getClaimsFromToken(token);
            deptId = (String) claims.get(DEPTID);
        } catch (Exception e) {
            deptId = null;
        }
        return deptId;
    }


    /**
     * 从令牌中获取用户id
     *
     * @return
     */
    public static String getUserIdFromToken(String token) {
        String userId = null;
        try {
            Claims claims = getClaimsFromToken(token);
            userId = (String) claims.get(USERID);
        } catch (Exception e) {
            userId = null;
        }
        return userId;
    }

}