/*
  Copyright (C) 2004 Reinhold Kainhofer <reinhold@kainhofer.com>
  Copyright (C) 2010-2012 Sérgio Martins <iamsergio@gmail.com>

  This library is free software; you can redistribute it and/or modify it
  under the terms of the GNU Library General Public License as published by
  the Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  This library is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
  License for more details.

  You should have received a copy of the GNU Library General Public License
  along with this library; see the file COPYING.LIB.  If not, write to the
  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  02110-1301, USA.
*/
#ifndef AKONADI_INCIDENCECHANGER_H
#define AKONADI_INCIDENCECHANGER_H

#include "akonadi-calendar_export.h"

#include <akonadi/item.h>
#include <akonadi/collection.h>
#include <kcalcore/incidence.h>

#include <QWidget>

namespace Akonadi {

/**
 * @short IncidenceChanger is the preferred way to easily create, modify and delete incidences.
 *
 * It hides the communication with akonadi from the library user.
 *
 * It provides the following features that ItemCreateJob, ItemModifyJob and
 * ItemDeleteJob do not:
 * - Sending groupware ( iTip ) messages to attendees and organizers.
 * - Aware of recurrences, allowing to only change one occurrence.
 * - Undo/Redo
 * - Group operations which are executed in an atomic manner.
 * - Collection ACLs
 * - Error dialogs with calendaring lingo
 *
 * In the context of this API, "change", means "creation", "deletion" or incidence "modification".
 *
 * @code
 * IncidenceChanger *changer = new IncidenceChanger( parent );
 * connect( changer,
 *          SIGNAL(createFinished(int,Akonadi::Item,Akonadi::IncidenceChanger::ResultCode,QString)),
 *          SLOT(slotCreateFinished(int,Akonadi::Item,Akonadi::IncidenceChanger::ResultCode,QString)) );
 *
 * connect( changer,
 *          SIGNAL(deleteFinished(int,QVector<Akonadi::Item::Id>,Akonadi::IncidenceChanger::ResultCode,QString)),
 *          SLOT(slotDeleteFinished(int,QVector<Akonadi::Item::Id>,Akonadi::IncidenceChanger::ResultCode,QString)) );
 *
 * connect( changer,SIGNAL(modifyFinished(int,Akonadi::Item,Akonadi::IncidenceChanger::ResultCode,QString)),
 *          SLOT(slotModifyFinished(int,Akonadi::Item,Akonadi::IncidenceChanger::ResultCode,QString)) );
 *
 * changer->setDestinationPolicy( IncidenceChanger::DestinationPolicyAsk );
 *
 * KCalCore::Incidence::Ptr incidence = (...);
 * int changeId = changer->createIncidence( incidence, Akonadi::Collection() );
 *
 *
 * if ( changeId == -1 )
 * {
 *  // Invalid parameters, incidence is null.
 * }
 *
 * @endcode
 *
 * @author Sérgio Martins <iamsergio@gmail.com>
 * @since 4.11
 */

class History;

class AKONADI_CALENDAR_EXPORT IncidenceChanger : public QObject
{
    Q_OBJECT
public:
    /**
      * This enum describes result codes which are returned by createFinished(),
      * modifyfinished() and deleteFinished() signals.
      */
    enum ResultCode {
        ResultCodeSuccess = 0,
        ResultCodeJobError, ///< ItemCreateJob, ItemModifyJob or ItemDeleteJob weren't successful
        ResultCodeAlreadyDeleted, ///< That incidence was already deleted, or currently being deleted.
        ResultCodeInvalidDefaultCollection, ///< Default collection is invalid and DestinationPolicyNeverAsk was used
        ResultCodeRolledback, ///< One change belonging to an atomic operation failed. All other changes were rolled back.
        ResultCodePermissions, ///< The parent collection doesn't have ACLs for this operation
        ResultCodeUserCanceled, ///< User canceled the operation
        ResultCodeInvalidUserCollection, ///< User somehow chose an invalid collection in the collection dialog ( should not happen )
        ResultCodeModificationDiscarded, ///< A new modification came in, the old one is discarded
        ResultCodeDuplicateId ///< Duplicate Akonadi::Item::Ids must be unique in group operations
    };

    /**
      * This enum describes destination policies.
      * Destination policies control how the createIncidence() method chooses the
      * collection where the item will be created.
      */
    enum DestinationPolicy {
        DestinationPolicyDefault, ///< The default collection is used, if it's invalid, the user is prompted. @see setDefaultCollection().
        DestinationPolicyAsk,     ///< User is always asked which collection to use.
        DestinationPolicyNeverAsk ///< The default collection is used, if it's invalid, an error is returned, and the incidence isn't added.
    };

    /**
     * Enum for controlling "Do you want to e-mail attendees" type of dialogs.
     * This is only honoured if groupware communication is active.
     *
     * @see groupwareCommunication()
     * @since 4.12
     */
    enum InvitationPolicy {
        InvitationPolicySend = 0, ///< Invitation e-mails are sent without asking the user if he wants to.
        InvitationPolicyAsk,      ///< The user is asked if an e-mail should be sent. This is the default.
        InvitationPolicyDontSend  ///< E-mails aren't sent
    };

    /**
      * This enum describes change types.
      */
    enum ChangeType {
        ChangeTypeCreate,   ///> Represents an incidence creation.
        ChangeTypeModify,   ///> Represents an incidence modification.
        ChangeTypeDelete    ///> Represents an incidence deletion.
    };

    /**
      * Creates a new IncidenceChanger instance.
      * @param parent parent QObject
      */
    explicit IncidenceChanger(QObject *parent = 0);

    /**
      * Destroys this IncidenceChanger instance.
      */
    ~IncidenceChanger();

    /**
      * Creates a new incidence.
      *
      * @param incidence Incidence to create, must be valid.
      * @param collection Collection where the incidence will be created. If invalid, one according
      *                   to the DestinationPolicy will be used. You can know which collection was
      *                   used by calling lastCollectionUsed();
      * @param parent widget parent to be used in dialogs.
      *
      * @return Returns an integer which identifies this change. This identifier is useful
      *         to correlate this operation with the IncidenceChanger::createFinished() signal.
      *
      *         Returns -1 if @p incidence is invalid. The createFinished() signal
      *         won't be emitted in this case.
      */
    int createIncidence(const KCalCore::Incidence::Ptr &incidence,
                        const Akonadi::Collection &collection = Akonadi::Collection(),
                        QWidget *parent = 0);

    /**
      * Deletes an incidence. If it's recurring, all occurrences are deleted.
      *
      * @param item Item to delete. Item must be valid.
      * @param parent Parent to be used in dialogs.
      *
      * @return Returns an integer which identifies this deletion. This identifier is useful
      *         to correlate this deletion with the IncidenceChanger::deleteFinished() signal.
      *
      *         Returns -1 if item is invalid. The deleteFinished() signal won't be emitted in this
      *         case.
      */
    int deleteIncidence(const Akonadi::Item &item, QWidget *parent = 0);

    /**
      * Deletes a list of Items.
      *
      * @param items List of items do delete. They must be valid.
      * @param parent Parent to be used in dialogs.
      * @return Returns an integer which identifies this deletion. This identifier is useful
      *         to correlate this operation with the IncidenceChanger::deleteFinished() signal.
      *
      *         Returns -1 if any item is invalid or if @p items is empty. The deleteFinished() signal
      *         won't be emitted in this case.
      */
    int deleteIncidences(const Akonadi::Item::List &items, QWidget *parent = 0);

    /**
      * Modifies an incidence.
      *
      * @param item A valid item, with the new payload.
      * @param originalPayload The payload before the modification. If invalid it won't be recorded
      *                        to the undo stack and groupware functionality won't be used for this
      *                        deletion.
      * @param parent Parent to be used in dialogs.
      *
      * @return Returns an integer which identifies this modification. This identifier is useful
      *         to correlate this operation with the IncidenceChanger::modifyFinished() signal.
      *
      *         Returns -1 if the item doesn't have a valid payload. The modifyFinished() signal
      *         won't be emitted in this case.
      */
    int modifyIncidence(const Akonadi::Item &item,
                        const KCalCore::Incidence::Ptr &originalPayload = KCalCore::Incidence::Ptr(),
                        QWidget *parent = 0);

    /**
      * Some incidence operations require more than one change. Like dissociating
      * occurrences, which needs an incidence add and an incidence change.
      *
      * If you want to prevent that the same dialogs are presented multiple times
      * use this function to start a batch operation.
      *
      * If one change belonging to a batch operation fails, all other changes
      * are rolled back.
      *
      * @param operationDescription Describes what the atomic operation does.
      *        This will be what incidenceChanger->history()->descriptionForNextUndo()
      *        if you have history enabled.
      *
      * @see endAtomicOperation()
      */
    void startAtomicOperation(const QString &operationDescription = QString());

    /**
      * Tells IncidenceChanger you finished doing changes that belong to a
      * batch operation.
      *
      * @see startAtomicOperation()
      */
    void endAtomicOperation();

    /**
      * Sets the default collection.
      * @param collection The collection to be used in createIncidence() if the
      *        proper destination policy is set.
      * @see createIncidence()
      * @see destinationPolicy()
      * @see defaultCollection()
      */
    void setDefaultCollection(const Akonadi::Collection &collection);

    /**
      * Returns the defaultCollection.
      * If none is set, an invalid Collection is returned.
      * @see setDefaultCollection()
      * @see DestinationPolicy
      */
    Akonadi::Collection defaultCollection() const;

    /**
      * Sets the destination policy to use. The destination policy determines the
      * collection to use in createIncidence()
      *
      * @see createIncidence()
      * @see destinationPolicy()
      */
    void setDestinationPolicy(DestinationPolicy destinationPolicy);

    /**
      * Returns the current destination policy.
      * If none is set, DestinationPolicyDefault is returned.
      * @see setDestinationPolicy()
      * @see DestinationPolicy
      */
    DestinationPolicy destinationPolicy() const;

    /**
      * Sets if IncidenceChanger should show error dialogs.
      */
    void setShowDialogsOnError(bool enable);

    /**
      * Returns true if error dialogs are shown by IncidenceChanger.
      * The default is true.
      *
      * @see setShowDialogsOnError()
      */
    bool showDialogsOnError() const;

    /**
      * Sets if IncidenceChanger should honour collection's ACLs by disallowing changes if
      * necessary.
      */
    void setRespectsCollectionRights(bool respect);

    /**
      * Returns true if IncidenceChanger honors collection's ACLs by disallowing
      * changes if necessary.
      *
      * The default is true.
      * @see setRespectsCollectionRights()
      * @see ResultCode::ResultCodePermissions
      */
    bool respectsCollectionRights() const;

    /**
      * Enable or disable history.
      * With history enabled all changes are recored into the undo/redo stack.
      *
      * @see history()
      * @see historyEnabled()
      */
    void setHistoryEnabled(bool enable);

    /**
      * Returns true if changes are added into the undo stack.
      * Default is true.
      *
      * @see history()
      * @see historyEnabled()
      */
    bool historyEnabled() const;

    /**
      * Returns a pointer to the history object.
      * It's always valid.
      * Ownership remains with IncidenceChanger.
      */
    History* history() const;

    /**
      * For performance reasons, IncidenceChanger internaly caches the ids of the last deleted items,
      * to avoid creating useless delete jobs.
      *
      * This function exposes that functionality so it can be used in other scenarios.
      * One popular scenario is when you're using an ETM and the user is deleting items very fast,
      * ETM doesn't know about the deletions immediately, so it can happen that some items are
      * deleted more than once, resulting in an error.
      *
      * @return true if the item was deleted recently, false otherwise.
      */
    bool deletedRecently(Akonadi::Item::Id) const;

    /**
      * Enables or disabled groupware communication.
      * With groupware communication enabled, invitations and update e-mails will be sent to each
      * attendee.
      */
    void setGroupwareCommunication(bool enabled);

    /**
      * Returns if we're using groupware communication.
      * Default is false.
      * @see setGroupwareCommuniation()
      */
    bool groupwareCommunication() const;

    /**
     * Makes modifyIncidence() adjust recurrence parameters when modifying DTSTART.
     */
    void setAutoAdjustRecurrence(bool enable);

    /**
     * True if recurrence parameters are adjusted when modifying DTSTART.
     * Default is true.
     */
    bool autoAdjustRecurrence() const;

    /**
     * Sets the invitation policy.
     *
     * @since 4.12
     */
    void setInvitationPolicy(InvitationPolicy policy);

    /**
     * Returns the invitation policy.
     * The default is InvitationPolicyAsk.
     *
     * @since 4.12
     */
    InvitationPolicy invitationPolicy() const;

    /**
      * Returns the collection that the last createIncidence() used.
      * Will be invalid if no incidences were created yet.
      *
      * @see createIncidence().
      */
    Akonadi::Collection lastCollectionUsed() const;

Q_SIGNALS:
    /**
      * Emitted when IncidenceChanger creates an Incidence in akonadi.
      *
      * @param changeId the unique identifier of this change, returned by createIncidence().
      * @param item the created item, might be invalid if the @p resultCode is not ResultCodeSuccess
      * @param resultCode success/error code
      * @param errorString if @p resultCode is not ResultCodeSuccess, contains an i18n'ed error
      *        message. If you enabled error dialogs, this string was already presented to the user.
      */
    void createFinished(int changeId,
                        const Akonadi::Item &item,
                        Akonadi::IncidenceChanger::ResultCode resultCode,
                        const QString &errorString);
    /**
      * Emitted when IncidenceChanger modifies an Incidence in akonadi.
      *
      * @param changeId the unique identifier of this change, returned by modifyIncidence().
      * @param item the modified item, might be invalid if the @p resultCode is not ResultCodeSuccess
      * @param resultCode success/error code
      * @param errorString if @p resultCode is not ResultCodeSuccess, contains an i18n'ed error
      *        message. If you enabled error dialogs, this string was already presented to the user.
      */
    void modifyFinished(int changeId,
                        const Akonadi::Item &item,
                        Akonadi::IncidenceChanger::ResultCode resultCode,
                        const QString &errorString);
    /**
      * Emitted when IncidenceChanger deletes an Incidence in akonadi.
      *
      * @param changeId the unique identifier of this change, returned by deletedIncidence().
      * @param itemIdList list of deleted item ids, might be emptu if the @p resultCode is not
      *                   ResultCodeSuccess
      * @param resultCode success/error code
      * @param errorString if @p resultCode is not ResultCodeSuccess, contains an i18n'ed error
      *        message. If you enabled error dialogs, this string was already presented to the user.
      */
    void deleteFinished(int changeId,
                        const QVector<Akonadi::Item::Id> &itemIdList,
                        Akonadi::IncidenceChanger::ResultCode resultCode,
                        const QString &errorString);

private:
    //@cond PRIVATE
    friend class History;
    friend class AtomicOperation;
    // used internally by the History class
    explicit IncidenceChanger(bool enableHistory, QObject *parent = 0);
    class Private;
    Private *const d;
    //@endcond
};

}

Q_DECLARE_METATYPE(Akonadi::IncidenceChanger::DestinationPolicy)
Q_DECLARE_METATYPE(Akonadi::IncidenceChanger::ResultCode)
Q_DECLARE_METATYPE(Akonadi::IncidenceChanger::ChangeType)

#endif
