/*
 * Copyright 2017 The Cartographer Authors
 *
 * 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
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using CartographerSharp.Sensor;
using CartographerSharp.Transform;
using  RobotNet10.Shared.Numbers;

namespace CartographerSharp.Mapping;

/// <summary>
/// Interface for pose extrapolation.
/// </summary>
public interface IPoseExtrapolator
{
    /// <summary>
    /// Returns the time of the last added pose or long.MinValue if no pose was added yet.
    /// </summary>
    long GetLastPoseTime();

    /// <summary>
    /// Returns the time of the last extrapolated pose.
    /// </summary>
    long GetLastExtrapolatedTime();

    /// <summary>
    /// Adds a pose at the given time.
    /// </summary>
    void AddPose(long time, Rigid3d pose);

    /// <summary>
    /// Adds IMU data.
    /// </summary>
    void AddImuData(ImuData imuData);

    /// <summary>
    /// Adds odometry data.
    /// </summary>
    void AddOdometryData(OdometryData odometryData);

    /// <summary>
    /// Extrapolates pose to the given time.
    /// </summary>
    Rigid3d ExtrapolatePose(long time);

    /// <summary>
    /// Extrapolates pose with low-pass filter to reduce jitter during direction changes.
    /// Match C++: ExtrapolatePose_filter
    /// </summary>
    Rigid3d ExtrapolatePoseFilter(long time);

    /// <summary>
    /// Extrapolates poses with gravity for multiple times.
    /// </summary>
    ExtrapolationResult ExtrapolatePosesWithGravity(List<long> times);

    /// <summary>
    /// Returns the current gravity alignment estimate as a rotation from
    /// the tracking frame into a gravity aligned frame.
    /// </summary>
    Quaternion EstimateGravityOrientation(long time);
}

/// <summary>
/// Result of pose extrapolation with gravity.
/// </summary>
public struct ExtrapolationResult
{
    /// <summary>
    /// The poses for the requested times at index 0 to N-1 (previous poses).
    /// </summary>
    public List<Rigid3f> PreviousPoses { get; set; }
    
    /// <summary>
    /// The pose for the requested time at index N (current pose).
    /// </summary>
    public Rigid3d CurrentPose { get; set; }
    
    /// <summary>
    /// Current velocity estimate.
    /// </summary>
    public Vector3 CurrentVelocity { get; set; }
    
    /// <summary>
    /// Gravity alignment estimate as a rotation from the tracking frame into a gravity aligned frame.
    /// </summary>
    public Quaternion GravityFromTracking { get; set; }
}