o3de-extras/Gems/ROS2/Code/Source/RobotImporter/Utils/SourceAssetsStorage.h

/*
 * Copyright (c) Contributors to the Open 3D Engine Project.
 * For complete copyright and license terms please see the LICENSE at the root of this distribution.
 *
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 */
#pragma once

#include <AzCore/Asset/AssetCommon.h>
#include <AzCore/Asset/AssetManager.h>
#include <AzCore/Asset/AssetManagerBus.h>
#include <AzCore/IO/FileIO.h>
#include <AzCore/Math/Crc.h>
#include <AzCore/std/containers/unordered_map.h>
#include <AzCore/std/containers/unordered_set.h>
#include <AzToolsFramework/API/EditorAssetSystemAPI.h>

namespace ROS2::Utils
{
    //! Structure contains essential information about the source and product assets in O3DE.
    //! It is designed to provide necessary information for other classes in URDF converter, eg CollidersMaker or VisualsMaker.
    struct AvailableAsset
    {
        //! Relative path to source asset eg `Assets/foo_robot/meshes/bar_link.dae`.
        AZStd::string m_sourceAssetRelativePath;

        //! Relative path to source asset eg `/home/user/project/Assets/foo_robot/meshes/bar_link.dae`.
        AZStd::string m_sourceAssetGlobalPath;

        //! Relative path to source asset eg `foo_robot/meshes/bar_link.azmodel`.
        AZStd::string m_productAssetRelativePath;

        //! Product asset ID @see AZ::Data::AssetInfo.
        AZ::Data::AssetId m_assetId;
    };

    //! The structure contains a mapping between URDF's path to O3DE asset information.
    struct UrdfAsset
    {
        //! Unresolved URDF path to mesh, eg `package://meshes/bar_link.dae`.
        AZStd::string m_urdfPath;

        //! Resolved URDF path, points to the valid mesh in the filestystem, eg `/home/user/ros_ws/src/foo_robot/meshes/bar_link.dae'
        AZStd::string m_resolvedUrdfPath;

        //! Checksum of the file located pointed by `m_resolvedUrdfPath`.
        AZ::Crc32 m_urdfFileCRC;

        //! Found O3DE asset.
        AvailableAsset m_availableAssetInfo;
    };

    /// Type that hold result of mapping from URDF path to asset info
    using UrdfAssetMap = AZStd::unordered_map<AZStd::string, Utils::UrdfAsset>;

    //! Function computes CRC32 on first kilobyte of file.
    AZ::Crc32 GetFileCRC(const AZStd::string& filename);

    //! Compute CRC for every source mesh from the assets catalog.
    //! @returns map where key is crc of source file and value is AvailableAsset.
    AZStd::unordered_map<AZ::Crc32, AvailableAsset> GetInterestingSourceAssetsCRC();

    //! Discover an association between meshes in URDF and O3DE source and product assets.
    //! The @param meshesFilenames contains the list of unresolved URDF filenames that are to be found as assets.
    //! Steps:
    //! - Functions resolves URDF filenames with `ResolveURDFPath`.
    //! - Files pointed by resolved URDF patches have their checksum computed `GetFileCRC`.
    //! - Function scans all available O3DE assets by calling `GetInterestingSourceAssetsCRC`.
    //! - Suitable mapping to the O3DE asset is found by comparing the checksum of the file pointed by the URDF path and source asset.
    //! @param meshesFilenames - list of the unresolved path from the URDF file
    //! @param urdFilename - filename of URDF file, used for resolvement
    //! @returns a URDF Asset map where the key is unresolved URDF path to AvailableAsset
    UrdfAssetMap FindAssetsForUrdf(const AZStd::unordered_set<AZStd::string>& meshesFilenames, const AZStd::string& urdFilename);

} // namespace ROS2::Utils