#ifndef QJSONWEBTOKEN_H
#define QJSONWEBTOKEN_H

#include <QJsonDocument>
#include <QJsonObject>
#include <QMessageAuthenticationCode>

/**
This class implements a subset of the [JSON Web Token](https://en.wikipedia.org/wiki/JSON_Web_Token) 
open standard [RFC 7519](https://tools.ietf.org/html/rfc7519).

Currently this implementation only supports the following algorithms:

Alg   | Parameter Value	Algorithm
----- | ------------------------------------
HS256 | HMAC using SHA-256 hash algorithm
HS384 | HMAC using SHA-384 hash algorithm
HS512 | HMAC using SHA-512 hash algorithm
*/
class QJsonWebToken
{
public:
    QJsonWebToken(); // TODO : improve with params

    QJsonWebToken(const QJsonWebToken &other);

    QJsonDocument getHeaderJDoc() const;

    QString getHeaderQStr() const;
    bool setHeaderJDoc(const QJsonDocument &jdocHeader);
    bool setHeaderQStr(const QString &strHeader);

    QJsonDocument getPayloadJDoc() const;
    QString getPayloadQStr() const;

    bool setPayloadJDoc(const QJsonDocument &jdocPayload);
    bool setPayloadQStr(const QString &strPayload);

    QByteArray getSignature();
    QByteArray getSignatureBase64();
    QString getSecret() const;
    bool setSecret(const QString &strSecret);

    void setRandomSecret();
    QString getAlgorithmStr() const;
    bool setAlgorithmStr(const QString &strAlgorithm);

    QString getToken();
    bool setToken(const QString &strToken);

    QString getRandAlphanum() const;
    void setRandAlphanum(const QString &strRandAlphanum);

    int getRandLength() const;
    void setRandLength(const int &intRandLength);

    bool isValid() const;

    static QJsonWebToken fromTokenAndSecret(const QString &strToken, const QString &srtSecret);
    static QStringList supportedAlgorithms();

    void appendClaim(const QString &strClaimType, const QString &strValue);
    void removeClaim(const QString &strClaimType);
    QString claim(const QString &strClaimType);

private:
    QJsonDocument m_jdocHeader;  // unencoded
    QJsonDocument m_jdocPayload; // unencoded
    QByteArray m_byteSignature;  // unencoded
    QString m_strHeader;         // unencoded
    QString m_strPayload;        // unencoded

    QString m_strSecret;
    QString m_strAlgorithm;

    int m_intRandLength;
    QString m_strRandAlphanum;

    // helpers
    QByteArray m_byteAllData;

    bool isAlgorithmSupported(const QString &strAlgorithm);
};

#endif // QJSONWEBTOKEN_H