package com.geosegbar.configs.security;

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneOffset;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTCreationException;
import com.auth0.jwt.exceptions.JWTVerificationException;
import com.geosegbar.entities.UserEntity;
import com.geosegbar.exceptions.JWTException;

@Service
public class TokenService {

    @Value("${api.security.token.secret}")
    private String secret;

    public String generateToken(UserEntity user) {
        try {
            Algorithm algorithm = Algorithm.HMAC256(secret);
            LocalDateTime expiryDate = LocalDateTime.now().plusHours(12);

            String token = JWT.create()
                    .withIssuer("GeoSegBar")
                    .withSubject(user.getEmail())
                    .withExpiresAt(this.generateExpirationDate())
                    .sign(algorithm);

            user.setLastToken(token);
            user.setTokenExpiryDate(expiryDate);

            return token;
        } catch (JWTCreationException exception) {
            throw new JWTException("Erro ao gerar token!");
        }
    }

    public String validateToken(String token) {
        try {
            Algorithm algorithm = Algorithm.HMAC256(secret);
            return JWT.require(algorithm)
                    .withIssuer("GeoSegBar")
                    .build()
                    .verify(token)
                    .getSubject();
        } catch (JWTVerificationException exception) {
            return null;
        }
    }

    public boolean isTokenValid(String token) {
        if (token == null) {
            return false;
        }

        try {
            Algorithm algorithm = Algorithm.HMAC256(secret);
            JWT.require(algorithm)
                    .withIssuer("GeoSegBar")
                    .build()
                    .verify(token);
            return true;
        } catch (JWTVerificationException exception) {
            return false;
        }
    }

    private Instant generateExpirationDate() {
        return LocalDateTime.now().plusHours(12).toInstant(ZoneOffset.of("-3"));
    }

}