/*
 * LMDB Abstraction Layer.
 * Copyright (C) 2023  Yury Gubich <blue@macaw.me>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef LMDBAL_STORAGE_H
#define LMDBAL_STORAGE_H

#include "base.h"
#include "serializer.h"

namespace LMDBAL {

class iStorage {
    friend class Base;
protected:
    iStorage(const std::string& name, Base* parent);
    virtual ~iStorage();

    virtual int createTable(MDB_txn * transaction) = 0;
    virtual int drop(MDB_txn * transaction);

    bool isDBOpened() const;
    const std::string& dbName() const;

    void ensureOpened(const std::string& methodName) const;
    void throwDuplicateOrUnknown(int rc, TransactionID txn, const std::string& key) const;
    void throwNotFoundOrUnknown(int rc, TransactionID txn, const std::string& key) const;
    void throwUnknown(int rc, TransactionID txn) const;
    void throwUnknown(int rc) const;
    void throwDuplicate(const std::string& key) const;
    void throwNotFound(const std::string& key)const ;

public:
    virtual void drop();
    virtual uint32_t count() const;

    TransactionID beginReadOnlyTransaction() const;
    TransactionID beginTransaction() const;
    void commitTransaction(TransactionID id) const;
    void abortTransaction(TransactionID id) const;

protected:
    MDB_dbi dbi;
    Base* db;
    const std::string name;

    inline static const std::string dropMethodName = "drop";
    inline static const std::string countMethodName = "count";

    inline static const std::string addRecordMethodName = "addRecord";
    inline static const std::string forceRecordMethodName = "forceRecord";
    inline static const std::string changeRecordMethodName = "changeRecord";
    inline static const std::string removeRecordMethodName = "removeRecord";
    inline static const std::string checkRecordMethodName = "checkRecord";
    inline static const std::string getRecordMethodName = "getRecord";
    inline static const std::string readAllMethodName = "readAllRecord";
    inline static const std::string replaceAllMethodName = "replaceAll";
    inline static const std::string addRecordsMethodName = "addRecords";

protected:
    template <class T>
    int makeTable(MDB_txn* transaction);

    template <class T>
    static std::string toString(const T& value);
};

template <class K, class V>
class Storage : public iStorage {
    friend class Base;
protected:
    Storage(const std::string& name, Base* parent);
    ~Storage() override;

public:
    using iStorage::drop;
    virtual void addRecord(const K& key, const V& value);
    virtual bool forceRecord(const K& key, const V& value);     //returns true if there was addition, false if change
    virtual void changeRecord(const K& key, const V& value);
    virtual void removeRecord(const K& key);
    virtual bool checkRecord(const K& key) const;               //checks if there is a record with given key
    virtual V getRecord(const K& key) const;
    virtual std::map<K, V> readAll() const;
    virtual void replaceAll(const std::map<K, V>& data);
    virtual uint32_t addRecords(const std::map<K, V>& data, bool overwrite = false);

protected:
    Serializer<K>* keySerializer;
    Serializer<V>* valueSerializer;

    int createTable(MDB_txn* transaction) override;
};

}

#include "storage.hpp"

#endif //LMDBAL_STORAGE_H