/*
 * 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_EXCEPTIONS_H
#define LMDBAL_EXCEPTIONS_H

#include <stdexcept>
#include <string>
#include <optional>

namespace LMDBAL {

/**
 * \brief Parent abstract class for all LMDBAL exceptions
 */
class Exception : public std::exception {
public:
    Exception();
    virtual ~Exception();

    virtual std::string getMessage() const = 0; /**<\brief returns exception message*/

    const char* what() const noexcept( true ) override;
};

/**
 * \brief Thrown if LMDBAL had issues creating or opening database directory
 */
class Directory: public Exception {
public:
    /**
     * \brief Creates exception
     *
     * \param path  - path of the directory that was supposed to be used to store the database
     */
    Directory(const std::string& path);

    std::string getMessage() const;
private:
    std::string path;
};

/**
 * \brief Thrown if something in the database was called on closed state and it is not supported
 */
class Closed : public Exception {
public:
    /**
     * \brief Creates exception
     *
     * \param operation - text name of the method that was called on closed database
     * \param dbName    - name of the database
     * \param tableName - name of the storage which called that method, abscent if it's untracable or if it's thrown by the database
     */
    Closed(const std::string& operation, const std::string& dbName, const std::optional<std::string>& tableName = std::nullopt);

    std::string getMessage() const;
private:
    std::string operation;
    std::string dbName;
    std::optional<std::string> tableName;
};

/**
 * \brief Thrown if something in the database was called on opened state and it is not supported
 */
class Opened : Exception {
public:
    /**
     * \brief Creates exception
     *
     * \param action    - text name of the method that was called on opened database
     * \param dbName    - name of the database
     */
    Opened(const std::string& dbName, const std::string& action);

    std::string getMessage() const;
private:
    std::string dbName;
    std::string action;
};

/**
 * \brief Thrown if something in the database was not found
 */
class NotFound : public Exception {
public:
    /**
     * \brief Creates exception
     *
     * \param key       - record key that was not found
     * \param dbName    - name of the database
     * \param tableName - name of the storage that was looked for a record
     */
    NotFound(const std::string& key, const std::string& dbName, const std::string& tableName);

    std::string getMessage() const;
private:
    std::string key;
    std::string dbName;
    std::string tableName;
};

/**
 * \brief Thrown if there was attempt to define storages with conflicting names
 */
class StorageDuplicate : public Exception {
public:
    /**
     * \brief Creates exception
     *
     * \param dbName    - name of the database
     * \param tableName - that name that was conflicting
     */
    StorageDuplicate(const std::string& dbName, const std::string& tableName);

    std::string getMessage() const;
private:
    std::string dbName;
    std::string tableName;
};

/**
 * \brief Thrown if there was a key conflict in one of the storages
 */
class Exist : public Exception {
public:
    /**
     * \brief Creates exception
     *
     * \param key       - record key that caused the conflict
     * \param dbName    - name of the database
     * \param tableName - name of the storage that was operated with
     */
    Exist(const std::string& key, const std::string& dbName, const std::string& tableName);

    std::string getMessage() const;
private:
    std::string key;
    std::string dbName;
    std::string tableName;
};

/**
 * \brief Thrown if something unexpected happened
 */
class Unknown : public Exception {
public:
    /**
     * \brief Creates exception
     *
     * \param message   - text description of the error, most of the times contains the result of <a class="el" href="http://www.lmdb.tech/doc/group__mdb.html#ga569e66c1e3edc1a6016b86719ee3d098">mdb_strerror</a>
     * \param dbName    - name of the database
     * \param tableName - name of the storage that was operated with, abscent if the operation was with the database itself
     */
    Unknown(const std::string& dbName, const std::string& message, const std::optional<std::string>& tableName = std::nullopt);

    std::string getMessage() const;
private:
    std::string dbName;
    std::optional<std::string> tableName;
    std::string msg;
};

}

#endif //LMDBAL_EXCEPTIONS_H