package com.auth0.jwt;

import com.auth0.jwt.exceptions.JWTDecodeException;

import com.auth0.jwt.impl.JWTParser;

import com.auth0.jwt.interfaces.Claim;

import com.auth0.jwt.interfaces.DecodedJWT;

import com.auth0.jwt.interfaces.Header;

import com.auth0.jwt.interfaces.Payload;

import org.apache.commons.codec.binary.Base64;

import org.apache.commons.codec.binary.StringUtils;

import java.util.Date;

import java.util.List;

/**

* The JWTDecoder class holds the decode method to parse a given JWT token into it's JWT representation.

*/

@SuppressWarnings("WeakerAccess")

final class JWTDecoder extends JWT {

private final String token;

private Header header;

private Payload payload;

private String signature;

JWTDecoder(String jwt) throws JWTDecodeException {

this.token = jwt;

parseToken(jwt);

}

private void parseToken(String token) throws JWTDecodeException {

final String[] parts = TokenUtils.splitToken(token);

final JWTParser converter = new JWTParser();

String headerJson;

String payloadJson;

try {

headerJson = StringUtils.newStringUtf8(Base64.decodeBase64(parts[0]));

payloadJson = StringUtils.newStringUtf8(Base64.decodeBase64(parts[1]));

} catch (NullPointerException e) {

throw new JWTDecodeException("The UTF-8 Charset isn't initialized.", e);

}

header = converter.parseHeader(headerJson);

payload = converter.parsePayload(payloadJson);

signature = parts[2];

}

@Override

public String getAlgorithm() {

return header.getAlgorithm();

}

@Override

public String getType() {

return header.getType();

}

@Override

public String getContentType() {

return header.getContentType();

}

@Override

public String getKeyId() {

return header.getKeyId();

}

@Override

public Claim getHeaderClaim(String name) {

return header.getHeaderClaim(name);

}

@Override

public String getIssuer() {

return payload.getIssuer();

}

@Override

public String getSubject() {

return payload.getSubject();

}

@Override

public List<String> getAudience() {

return payload.getAudience();

}

@Override

public Date getExpiresAt() {

return payload.getExpiresAt();

}

@Override

public Date getNotBefore() {

return payload.getNotBefore();

}

@Override

public Date getIssuedAt() {

return payload.getIssuedAt();

}

@Override

public String getId() {

return payload.getId();

}

@Override

public Claim getClaim(String name) {

return payload.getClaim(name);

}

@Override

public String getSignature() {

return signature;

}

@Override

public String getToken() {

return token;

}

}