/*
 * Copyright 2003-2012, Haiku, Inc.
 * Distributed under the terms of the MIT License.
 */
#ifndef _CATALOG_DATA_H_
#define _CATALOG_DATA_H_


#include <SupportDefs.h>
#include <String.h>


class BCatalog;
class BMessage;
struct entry_ref;


/**
 * Base class for the catalog-data provided by every catalog add-on. An instance
 * of this class represents (the data of) a single catalog. Several of these
 * catalog data objects may be chained together in order to represent
 * variations of a specific language. If for instance the catalog data 'en_uk'
 * is chained to the data for 'en', a BCatalog using this catalog data chain
 * will prefer any entries in the 'en_uk' catalog, but fallback onto 'en' for
 * entries missing in the former.
 */
class BCatalogData {
public:
                                                                BCatalogData(const char* signature,
                                                                        const char* language,
                                                                        uint32 fingerprint);
        virtual                                         ~BCatalogData();

        virtual const char*                     GetString(const char* string,
                                                                        const char* context = NULL,
                                                                        const char* comment = NULL) = 0;
        virtual const char*                     GetString(uint32 id) = 0;

                        status_t                        InitCheck() const;
                        BCatalogData*           Next();

        // the following could be used to localize non-textual data (e.g.
        // icons), but these will only be implemented if there's demand for such
        // a feature:
        virtual bool                            CanHaveData() const;
        virtual status_t                        GetData(const char* name, BMessage* msg);
        virtual status_t                        GetData(uint32 id, BMessage* msg);

        // interface for catalog-editor-app and testing apps:
        virtual status_t                        SetString(const char* string,
                                                                        const char* translated,
                                                                        const char* context = NULL,
                                                                        const char* comment = NULL);
        virtual status_t                        SetString(int32 id, const char* translated);

        virtual bool                            CanWriteData() const;
        virtual status_t                        SetData(const char* name, BMessage* msg);
        virtual status_t                        SetData(uint32 id, BMessage* msg);

        virtual status_t                        ReadFromFile(const char* path = NULL);
        virtual status_t                        ReadFromAttribute(
                                                                        const entry_ref& appOrAddOnRef);
        virtual status_t                        ReadFromResource(
                                                                        const entry_ref& appOrAddOnRef);
        virtual status_t                        WriteToFile(const char* path = NULL);
        virtual status_t                        WriteToAttribute(
                                                                        const entry_ref& appOrAddOnRef);
        virtual status_t                        WriteToResource(
                                                                        const entry_ref& appOrAddOnRef);

        virtual void                            MakeEmpty();
        virtual int32                           CountItems() const;

                        void                            SetNext(BCatalogData* next);

protected:
        virtual void                            UpdateFingerprint();

protected:
        friend  class BCatalog;
        friend  status_t                        get_add_on_catalog(BCatalog*, const char*);

                        status_t                        fInitCheck;
                        BString                         fSignature;
                        BString                         fLanguageName;
                        uint32                          fFingerprint;
                        BCatalogData*           fNext;
};


inline BCatalogData*
BCatalogData::Next()
{
        return fNext;
}


// every catalog-add-on should export the following three symbols:
//
// 1. the function that instantiates a catalog for this add-on-type
extern "C"
BCatalogData* instantiate_catalog(const entry_ref& signature,
        const char* language, uint32 fingerprint);

// 2. the function that creates an empty catalog for this add-on-type
extern "C"
BCatalogData* create_catalog(const char* signature, const char* language);

// 3. the priority which will be used to order the catalog add-ons
extern uint8 gCatalogAddOnPriority;


#endif /* _CATALOG_DATA_H_ */