package com.sandu.common.security.jwt;

import com.sandu.common.security.config.SecurityProperties;
import io.jsonwebtoken.*;
import io.jsonwebtoken.io.Decoders;
import io.jsonwebtoken.security.Keys;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.User;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;
import java.security.Key;
import java.util.Arrays;
import java.util.Collection;
import java.util.Date;
import java.util.stream.Collectors;

/**
 * @author chenjiantian
 * @date 2021/4/23 16:43
 */
@Slf4j
public class JwtTokenProvider implements InitializingBean {

    private static final String AUTHORITIES_KEY = "auth";
    private static final String CREDENTIALS_KEY = "cred";
    private final SecurityProperties properties;
    private Key key;

    public JwtTokenProvider(SecurityProperties properties) {
        this.properties = properties;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        byte[] keyBytes = Decoders.BASE64.decode(properties.getBase64Secret());
        this.key = Keys.hmacShaKeyFor(keyBytes);
    }

    /**
     * 根据认证信息生成一个token
     */
    public String createToken(Authentication authentication) {

        String authorities = authentication.getAuthorities().stream()
                .map(GrantedAuthority::getAuthority)
                .collect(Collectors.joining(","));

        long now = (new Date()).getTime();
        Date expiration = new Date(now + properties.getTokenValidityInSeconds());

        return Jwts.builder()
                .setSubject(authentication.getName())
                .claim(AUTHORITIES_KEY, authorities)
                .claim(CREDENTIALS_KEY, authentication.getCredentials())
                .setExpiration(expiration)
                .signWith(key, SignatureAlgorithm.HS512)
                .compact();
    }



    /**
     * 根据token获取认证信息
     */
    public Authentication getAuthentication(String token) {
        Claims claims = Jwts.parserBuilder()
                .setSigningKey(key)
                .build()
                .parseClaimsJws(token)
                .getBody();

        Collection<? extends GrantedAuthority> authorities =
                Arrays.stream(claims.get(AUTHORITIES_KEY).toString().split(","))
                        .map(SimpleGrantedAuthority::new)
                        .collect(Collectors.toList());

        User principal = new User(claims.getSubject(), "", authorities);

        return new UsernamePasswordAuthenticationToken(principal, claims.get(CREDENTIALS_KEY), authorities);
    }

    /**
     * 验证token有效性
     */
    public boolean validateToken(String authToken) {
        try {
            Jwts.parserBuilder().setSigningKey(key).build().parseClaimsJws(authToken);
            return true;
        } catch (io.jsonwebtoken.security.SecurityException | MalformedJwtException e) {
            log.info("Invalid JWT signature.");
            e.printStackTrace();
        } catch (ExpiredJwtException e) {
            log.info("Expired JWT token.");
            e.printStackTrace();
        } catch (UnsupportedJwtException e) {
            log.info("Unsupported JWT token.");
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            log.info("JWT token compact of handler are invalid.");
            e.printStackTrace();
        }
        return false;
    }

    /**
     * 获取请求头的token
     */
    public String getToken(HttpServletRequest request) {
        final String requestHeader = request.getHeader(properties.getHeader());
        if (requestHeader != null && requestHeader.startsWith(properties.getTokenStartWith())) {
            return requestHeader.substring(properties.getTokenStartWith().length());
        }
        return null;
    }

    public Throwable getException(String authToken) {
        try {
            Jwts.parserBuilder().setSigningKey(key).build().parseClaimsJws(authToken);
            return null;
        } catch (Exception e) {
            return e;
        }
    }

    /**
     * 获取Claims 不论是不是jwt过期
     * @param token
     * @return
     */
    public Claims getClaimsForce(String token) {
        try {
            Claims claims = Jwts.parserBuilder()
                    .setSigningKey(key)
                    .build()
                    .parseClaimsJws(token)
                    .getBody();
            return claims;
        } catch (io.jsonwebtoken.security.SecurityException | MalformedJwtException e) {
            log.info("Invalid JWT signature.");
        } catch (ExpiredJwtException e) {
            log.info("Expired JWT token.");
            return e.getClaims();
        } catch (UnsupportedJwtException e) {
            log.info("Unsupported JWT token.");
        } catch (IllegalArgumentException e) {
            log.info("JWT token compact of handler are invalid.");
        }

        return null;
    }

    /**
     * 获取subject 不论是不是jwt过期
     * @param token
     * @return
     */
    public String getSubjectForce(String token) {
        Claims claimsForce = getClaimsForce(token);
        if(claimsForce != null){
            return claimsForce.getSubject();
        }
        return null;
    }

    /**
     * 刷新token 把过期的token 刷新
     * @param oldToken
     * @return
     */
    public String refreshToken(String oldToken) {

        Claims claimsForce = getClaimsForce(oldToken);
        if(claimsForce == null){
            return null;
        }

        Collection<? extends GrantedAuthority> authorities =
                Arrays.stream(claimsForce.get(AUTHORITIES_KEY).toString().split(","))
                        .map(SimpleGrantedAuthority::new)
                        .collect(Collectors.toList());

        User principal = new User(claimsForce.getSubject(), "", authorities);

        UsernamePasswordAuthenticationToken authenticationToken = new UsernamePasswordAuthenticationToken(principal, "", authorities);

        return createToken(authenticationToken);
    }

}