/*     Copyright 2019 Diligent Graphics LLC
 *  
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF ANY PROPRIETARY RIGHTS.
 *
 *  In no event and under no legal theory, whether in tort (including negligence), 
 *  contract, or otherwise, unless required by applicable law (such as deliberate 
 *  and grossly negligent acts) or agreed to in writing, shall any Contributor be
 *  liable for any damages, including any direct, indirect, special, incidental, 
 *  or consequential damages of any character arising as a result of this License or 
 *  out of the use or inability to use the software (including but not limited to damages 
 *  for loss of goodwill, work stoppage, computer failure or malfunction, or any and 
 *  all other commercial damages or losses), even if such Contributor has been advised 
 *  of the possibility of such damages.
 */

#pragma once

/// \file
/// Definition of the Diligent::IResourceMapping interface and related data structures

#include "DeviceObject.h"

namespace Diligent
{
// {6C1AC7A6-B429-4139-9433-9E54E93E384A}
static constexpr INTERFACE_ID IID_ResourceMapping =
    {0x6c1ac7a6, 0xb429, 0x4139, {0x94, 0x33, 0x9e, 0x54, 0xe9, 0x3e, 0x38, 0x4a}};

/// Describes the resourse mapping object entry
struct ResourceMappingEntry
{
    // clang-format off

    /// Object name
    const Char* Name       = nullptr;

    /// Pointer to the object's interface
    IDeviceObject *pObject = nullptr;

    Uint32 ArrayIndex      = 0;

    /// Initializes the structure members

    /// \param [in] _Name       - Object name.
    /// \param [in] _pObject    - Pointer to the object.
    /// \param [in] _ArrayIndex - For array resources, index in the array
    ResourceMappingEntry (const Char* _Name, IDeviceObject* _pObject, Uint32 _ArrayIndex = 0)noexcept : 
        Name      { _Name     }, 
        pObject   { _pObject  },
        ArrayIndex{_ArrayIndex}
    {}

    // clang-format on

    ResourceMappingEntry() noexcept {}
};

/// Resource mapping description
struct ResourceMappingDesc
{
    /// Pointer to the array of resource mapping entries.
    /// The last element in the array must be default value
    /// created by ResourceMappingEntry::ResourceMappingEntry()
    ResourceMappingEntry* pEntries = nullptr;

    ResourceMappingDesc() noexcept {}

    explicit ResourceMappingDesc(ResourceMappingEntry* _pEntries) noexcept :
        pEntries{_pEntries}
    {}
};

/// Resouce mapping

/// This interface provides mapping between literal names and resource pointers.
/// It is created by IRenderDevice::CreateResourceMapping().
/// \remarks Resource mapping holds strong references to all objects it keeps.
class IResourceMapping : public IObject
{
public:
    /// Queries the specific interface, see IObject::QueryInterface() for details
    virtual void QueryInterface(const INTERFACE_ID& IID, IObject** ppInterface) override = 0;

    /// Adds a resource to the mapping.

    /// \param [in] Name - Resource name.
    /// \param [in] pObject - Pointer to the object.
    /// \param [in] bIsUnique - Flag indicating if a resource with the same name
    ///                         is allowed to be found in the mapping. In the latter
    ///                         case, the new resource replaces the existing one.
    ///
    /// \remarks Resource mapping increases the reference counter for referenced objects. So an
    ///          object will not be released as long as it is in the resource mapping.
    virtual void AddResource(const Char* Name, IDeviceObject* pObject, bool bIsUnique) = 0;


    /// Adds resource array to the mapping.

    /// \param [in] Name - Resource array name.
    /// \param [in] StartIndex - First index in the array, where the first element will be inserted
    /// \param [in] ppObjects - Pointer to the array of objects.
    /// \param [in] NumElements - Number of elements to add
    /// \param [in] bIsUnique - Flag indicating if a resource with the same name
    ///                         is allowed to be found in the mapping. In the latter
    ///                         case, the new resource replaces the existing one.
    ///
    /// \remarks Resource mapping increases the reference counter for referenced objects. So an
    ///          object will not be released as long as it is in the resource mapping.
    virtual void AddResourceArray(const Char* Name, Uint32 StartIndex, IDeviceObject* const* ppObjects, Uint32 NumElements, bool bIsUnique) = 0;


    /// Removes a resource from the mapping using its literal name.

    /// \param [in] Name - Name of the resource to remove.
    /// \param [in] ArrayIndex - For array resources, index in the array
    virtual void RemoveResourceByName(const Char* Name, Uint32 ArrayIndex = 0) = 0;

    /// Finds a resource in the mapping.

    /// \param [in] Name - Resource name.
    /// \param [in] ArrayIndex - for arrays, index of the array element.
    /// \param [out] ppResource - Address of the memory location where the pointer
    ///                           to the object with the given name will be written.
    ///                           If no object is found, nullptr will be written.
    /// \remarks The method increases the reference counter
    ///          of the returned object, so Release() must be called.
    virtual void GetResource(const Char* Name, IDeviceObject** ppResource, Uint32 ArrayIndex = 0) = 0;

    /// Returns the size of the resource mapping, i.e. the number of objects.
    virtual size_t GetSize() = 0;
};
} // namespace Diligent
