using Leap;

using System.Collections.Generic;

using System.Linq;

using UniRx;

using UniRx.Triggers;

using UnityEngine;



/// <summary>

/// Camera controller

/// </summary>

public class CameraController : MonoBehaviour

{

    /** Camera movement speed */

    private float speed = 0.025f;



    /** Leap Motion controller */

    private Controller controller;



    /** Entry point */

    void Start()

    {

        // Leap Motion controller

        controller = new Controller();



        // Get hand data from Leap Motion every frame

        var handsStream = this.UpdateAsObservable()

            .Select(_ => controller.Frame().Hands);



        // Stream that fires when the fist gesture ends

        var endRockGripStream = handsStream

            .Where(hands => !IsRockGrip(hands));



        // Camera control

        handsStream

            // Only when making a fist

            .Where(hands => IsRockGrip(hands))

            // Get palm position

            .Select(hands => ToVector3(hands[0].PalmPosition))

            // Buffer current and previous values (2 values with step 1)

            .Buffer(2, 1)

            // Calculate movement vector from the difference

            .Select(positions => positions[1] - positions[0])

            // Log the movement

            .Do(movement => Debug.Log("Movement: " + movement))

            // Clear the buffer when the fist gesture ends

            .TakeUntil(endRockGripStream).RepeatUntilDestroy(this)

            // Move the camera

            .Subscribe(movement => transform.Translate(-speed * movement));

    }



    /** Check if hand is making a fist */

    bool IsRockGrip(List<Hand> hands)

    {

        return

            // One hand detected

            hands.Count == 1 &&

            // All fingers are closed (none extended)

            hands[0].Fingers.ToArray().Count(x => x.IsExtended) == 0;

    }



    /** Convert Leap Vector to Unity Vector3 */

    Vector3 ToVector3(Vector v)

    {

        return new Vector3(v.x, v.y, -v.z);

    }

}