/*
    SPDX-FileCopyrightText: 2018 Daniel Vrátil <dvratil@kde.org>

    SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
*/

#ifndef LIBKGAPI2_ACCOUNTMANAGER_H_
#define LIBKGAPI2_ACCOUNTMANAGER_H_

#include <QObject>
#include <QList>

#include "account.h"
#include "kgapicore_export.h"


class QUrl;

namespace KGAPI2 {

class AccountManager;
/**
 * @brief AccountPromise is a result of asynchronous operations of AccountManager
 *
 * The AccountPromise is returned by AccountManager and will emit @p finished()
 * signal when the asynchronous retrieval of the Account has finished.
 *
 * The object will delete itself once @p finished signal is emitted.
 */
class KGAPICORE_EXPORT AccountPromise : public QObject
{
    Q_OBJECT
public:
    ~AccountPromise() override;

    AccountPtr account() const;

    bool hasError() const;
    QString errorText() const;

Q_SIGNALS:
    /**
     * @brief The retrieval has finished and the Account can be retrieved.
     *
     * The object is automatically scheduled for deletion after this signal
     * is emitted.
     */
    void finished(AccountPromise *self);

private:
    AccountPromise(QObject *parent = nullptr);
    Q_DISABLE_COPY(AccountPromise)

    friend class AccountManager;
    class Private;
    QScopedPointer<Private> const d;
};

class KGAPICORE_EXPORT AccountManager : public QObject
{
    Q_OBJECT
public:
    ~AccountManager() override;

    static AccountManager *instance();

    /**
     * @brief Asynchronously returns an authenticated account for given conditions
     *
     * The returned account is guaranteed to be authenticated against at least the
     * requested @p scopes, but it may be authenticated against more scopes.
     * If an account for the given @p apiKey and @p accountName already exists
     * but is not authenticated against all the scopes the user will be presented
     * with a prompt to confirm the missing scopes.
     *
     * If no such account exists, user will be prompted with full authentication
     * process.
     *
     * The returned account is guaranteed to be authenticated, however the tokens
     * may be expired. It's up to the caller to ensure the tokens are refreshed
     * using @p refreshTokens method.
     *
     * @p apiSecret is only used to authenticate new account or missing scopes
     * and is not stored anywhere.
     *
     * @see refreshTokens, hasAccount
     */
    AccountPromise *getAccount(const QString &apiKey, const QString &apiSecret,
                               const QString &accountName,
                               const QList<QUrl> &scopes);


    /**
     * @brief Asynchronously refreshes tokens in given Account
     *
     * The returned account is guaranteed to be authenticated against at least
     * the requested @p scopes, but it may be authenticated against more scopes.
     * If an account does not exist, it will be created (see AccountManager::getAccount()).
     *
     * @p apiSecret is only used to authenticate a new account.
     *
     * @see getAccount
     */
    AccountPromise *refreshTokens(const QString &apiKey, const QString &apiSecret,
                                  const QString &accountName);

    /**
     * @brief Asynchronously checks whether the specified account exists.
     *
     * Optionally, when non-empty list of @p scopes is provided this method also
     * checks whether, if the account exists, it is authenticated against the
     * provided scopes.
     *
     * The AccountPromise will have the discovered account set if it is found,
     * otherwise it's set to null.
     */
    AccountPromise *findAccount(const QString &aipKey, const QString &accountName,
                                const QList<QUrl> &scopes = {});


    /**
     * @brief Asynchronously remove given scopes from authenticated account.
     *
     * Removes the given scopes from the account authenticated scopes, so that
     * next time the account is requested with any of the removed scopes the user
     * will be presented with a prompt to confirm access again.
     */
    void removeScopes(const QString &apiKey, const QString &accountName,
                      const QList<QUrl> &removeScopes);

protected:
    explicit AccountManager(QObject *parent = nullptr);
    Q_DISABLE_COPY(AccountManager)

    static AccountManager *sInstance;
    class Private;
    QScopedPointer<Private> const d;
};

}

#endif
