/*
 * Squawk messenger. 
 * Copyright (C) 2019 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 CORE_STORAGE_H
#define CORE_STORAGE_H

#include <QString>
#include <lmdb.h>


#include "exception.h"

namespace Core {

/**
 * @todo write docs
 */
template <class K, class V>
class Storage
{
public:
    Storage(const QString& name);
    ~Storage();
    
    void open();
    void close();
    
    void addRecord(const K& key, const V& value);
    void changeRecord(const K& key, const V& value);
    void removeRecord(const K& key);
    V getRecord(const K& key) const;
    QString getName() const;
    
    
private:
    QString name;
    bool opened;
    MDB_env* environment;
    MDB_dbi base;

public:
    class Directory:
    public Utils::Exception
    {
    public:
        Directory(const std::string& p_path):Exception(), path(p_path){}

        std::string getMessage() const{return "Can't create directory for database at " + path;}
    private:
        std::string path;
    };

    class Closed:
    public Utils::Exception
    {
    public:
        Closed(const std::string& op, const std::string& acc):Exception(), operation(op), account(acc){}

        std::string getMessage() const{return "An attempt to perform operation " + operation + " on closed archive for " + account;}
    private:
        std::string operation;
        std::string account;
    };

    class NotFound:
    public Utils::Exception
    {
    public:
        NotFound(const std::string& k, const std::string& acc):Exception(), key(k), account(acc){}

        std::string getMessage() const{return "Element for id " + key + " wasn't found in database " + account;}
    private:
        std::string key;
        std::string account;
    };

    class Empty:
    public Utils::Exception
    {
    public:
        Empty(const std::string& acc):Exception(), account(acc){}

        std::string getMessage() const{return "An attempt to read ordered elements from database " + account + " but it's empty";}
    private:
        std::string account;
    };

    class Exist:
    public Utils::Exception
    {
    public:
        Exist(const std::string& acc, const std::string& p_key):Exception(), account(acc), key(p_key){}

        std::string getMessage() const{return "An attempt to insert element " + key + " to database " + account + " but it already has an element with given id";}
    private:
        std::string account;
        std::string key;
    };

    class NoAvatar:
    public Utils::Exception
    {
    public:
        NoAvatar(const std::string& el, const std::string& res):Exception(), element(el), resource(res){
            if (resource.size() == 0) {
                resource = "for himself";
            }
        }

        std::string getMessage() const{return "Element " + element + " has no avatar for " + resource ;}
    private:
        std::string element;
        std::string resource;
    };

    class Unknown:
    public Utils::Exception
    {
    public:
        Unknown(const std::string& acc, const std::string& message):Exception(), account(acc), msg(message){}

        std::string getMessage() const{return "Unknown error on database " + account + ": " + msg;}
    private:
        std::string account;
        std::string msg;
    };
};

}

MDB_val& operator << (MDB_val& data, QString& value);
MDB_val& operator >> (MDB_val& data, QString& value);

MDB_val& operator << (MDB_val& data, uint32_t& value);
MDB_val& operator >> (MDB_val& data, uint32_t& value);

namespace std {
    std::string to_string(const QString& str);
}

#include "storage.hpp"

#endif // CORE_STORAGE_H