// Copyright (C) 2017-2025 Internet Systems Consortium, Inc. ("ISC")

//

// This Source Code Form is subject to the terms of the Mozilla Public

// License, v. 2.0. If a copy of the MPL was not distributed with this

// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef HOOKS_CONFIG_H

#define HOOKS_CONFIG_H

#include <exceptions/exceptions.h>

#include <cc/data.h>

#include <cc/cfg_to_element.h>

#include <hooks/libinfo.h>

namespace isc {

namespace hooks {

/// @brief Exception thrown when a library failed to validate

class InvalidHooksLibraries : public Exception {

 public:

    InvalidHooksLibraries(const char* file, size_t line, const char* what) :

        isc::Exception(file, line, what) { }

};

/// @brief Wrapper class that holds hooks libraries configuration

///

/// This was moved from HooksLibrariesParser

///

/// However, this class does more than just check the list of library names.

/// It does two other things:

/// # validate libraries

/// # load libraries

/// and it provides a toElement() method to unparse a configuration.

///

/// @todo add toElement() unit tests

class HooksConfig : public isc::data::CfgToElement {

public:

    /// @brief Default constructor.

    ///

    HooksConfig() : libraries_() { }

    /// @brief Adds additional hooks libraries.

    ///

    /// @param libname full filename with path to the library.

    /// @param parameters map of parameters that configure the library.

    /// @param cfgname original value of `library` parameter from this

    /// library's configuration.

    void add(const std::string& libname,

             isc::data::ConstElementPtr parameters,

             const std::string& cfgname = "");

    /// @brief Provides access to the configured hooks libraries.

    ///

    /// @note The const reference returned is only valid as long as the

    /// object that returned it.

    const isc::hooks::HookLibsCollection& get() const {

        return libraries_;

    }

    /// @brief Removes all configured hooks libraries.

    void clear() {

        libraries_.clear();

    }

    /// @brief Compares two Hooks Config classes for equality

    ///

    /// @param other other hooksconfig to compare with

    bool equal(const HooksConfig& other) const;

    /// @brief Verifies that libraries stored in libraries_ are valid.

    ///

    /// This method is a smart wrapper around @ref

    /// isc::hooks::HooksManager::validateLibraries().

    /// It tries to validate all the libraries stored in libraries_.

    ///

    /// @param position position of the hooks-library map for error reporting

    /// @param multi_threading_enabled The flag which indicates if MT is enabled

    ///        (used to check hook libraries compatibility with MT).

    ///

    /// @throw InvalidHooksLibraries if any issue is discovered.

    void verifyLibraries(const isc::data::Element::Position& position,

                         bool multi_threading_enabled) const;

    /// @brief Commits hooks libraries configuration.

    ///

    /// This method calls necessary methods in HooksManager that will unload

    /// any libraries that may be currently loaded and will load the actual

    /// libraries. Providing that the specified libraries are valid and are

    /// different to those already loaded, this method loads the new set of

    /// libraries (and unloads the existing set).

    ///

    /// @param multi_threading_enabled The flag which indicates if MT is enabled

    ///        (used to check hook libraries compatibility with MT).

    ///

    /// @throw InvalidHooksLibraries if the call to HooksManager fails.

    void loadLibraries(bool multi_threading_enabled) const;

    /// @brief Unparse a configuration object

    ///

    /// Returns an element which must parse into the same object, i.e.

    /// @code

    /// for all valid config C parse(parse(C)->toElement()) == parse(C)

    /// @endcode

    ///

    /// @return a pointer to a configuration which can be parsed into

    /// the initial configuration object

    isc::data::ElementPtr toElement() const;

private:

    /// @brief List of hooks libraries with their configuration parameters

    isc::hooks::HookLibsCollection libraries_;

};

}  // namespace hooks

}  // namespace isc

#endif // HOOKS_CONFIG_H