//
// Copyright 2019 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
//    names, trademarks, service marks, or product names of the Licensor
//    and its affiliates, except as required to comply with Section 4(c) of
//    the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
#include "pxr/pxr.h"
#include "pxr/usdImaging/usdAppUtils/camera.h"

#include "pxr/base/tf/diagnostic.h"
#include "pxr/usd/sdf/path.h"
#include "pxr/usd/usd/prim.h"
#include "pxr/usd/usd/primFlags.h"
#include "pxr/usd/usd/primRange.h"
#include "pxr/usd/usd/stage.h"
#include "pxr/usd/usdGeom/camera.h"


PXR_NAMESPACE_OPEN_SCOPE


UsdGeomCamera
UsdAppUtilsGetCameraAtPath(
        const UsdStagePtr& stage,
        const SdfPath& cameraPath)
{
    if (!stage) {
        TF_CODING_ERROR("Invalid stage");
        return UsdGeomCamera();
    }

    if (!cameraPath.IsPrimPath()) {
        // A non-prim path cannot be a camera.
        return UsdGeomCamera();
    }

    SdfPath usdCameraPath = cameraPath;

    if (!cameraPath.IsAbsolutePath()) {
        if (cameraPath.GetPathElementCount() > 1u) {
            // XXX: Perhaps we should error here? For now we coerce the camera
            // path to be absolute using the absolute root path and print a
            // warning.
            usdCameraPath =
                cameraPath.MakeAbsolutePath(SdfPath::AbsoluteRootPath());
            TF_WARN(
                "Camera path \"%s\" is not absolute. Using absolute path "
                "instead: \"%s\"",
                cameraPath.GetText(),
                usdCameraPath.GetText());
        } else {
            // Search for the camera by name.
            UsdPrimRange primRange =
                UsdPrimRange::Stage(stage, UsdTraverseInstanceProxies());

            for (const UsdPrim& usdPrim : primRange) {
                if (usdPrim.GetName() == cameraPath.GetNameToken()) {
                    const UsdGeomCamera usdCamera(usdPrim);
                    if (usdCamera) {
                        return usdCamera;
                    }
                }
            }
        }
    }

    return UsdGeomCamera::Get(stage, usdCameraPath);
}


PXR_NAMESPACE_CLOSE_SCOPE