using System;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;

//旧版算法
public class o09AxisCS
{
    static public Vector3 AccIdentity = new Vector3(0, -1, 0);
    static public Vector3 MagIdentity = new Vector3(-1, 2, 0).normalized;
    public class State
    {
        public long TimeGap;
        public Vector3 Acc = AccIdentity;
        public Vector3 AccSmooth = AccIdentity;
        public double AccVariance = 1;

        public Vector3 Gyr;
        public Vector3 Mag = MagIdentity;
        public Vector3 MagSmooth = MagIdentity;
        public Quaternion Qua = Quaternion.identity;
        public Quaternion QuaSmooth = Quaternion.identity;
        public double Variance = 1;
    }

    o0Project.Variance HardwareVarianceGyr = new o0Project.Variance(1000);
    o0Project.Variance HardwareVarianceAcc = new o0Project.Variance(1000);
    o0Project.Variance HardwareVarianceMag = new o0Project.Variance(1000);

    public List<State> States = new List<State>();

    public Vector3 AccOld;
    public Vector3 GyrOld;
    public Vector3 MagOld;

    public float x;
    public float y;
    public float z;

    long TimeGapOld;
    o0Aien.o0WeightedAverageFilterVector3 AccFilter = new o0Aien.o0WeightedAverageFilterVector3(5);
    o0Aien.o0WeightedAverageFilterVector3 MagFilter = new o0Aien.o0WeightedAverageFilterVector3(10);
         
    public Quaternion update(Vector3 AccOld, Vector3 GyrOld, Vector3 MagOld, long TimeGapOld)
    {
        o0UIRawImageTester.UpdateAllOffset();

        var Acc = this.AccOld;
        var Gyr = (this.GyrOld + GyrOld)/2;
        var Mag = this.MagOld;
        float TimeGap = this.TimeGapOld;
        this.AccOld = AccOld;
        this.GyrOld = GyrOld;
        this.MagOld = MagOld;
        this.TimeGapOld = TimeGapOld;
        var Last = States.LastOrDefault() ?? new State();
        if (this.TimeGapOld <= 0)
            return Last.Qua;
        States.Add(new State());
        if (States.Count > 200)
            States.RemoveAt(0);
        var state = States.Last();
        state.Acc = Acc;

        state.AccSmooth = AccFilter.Update(Acc);
        
        state.Gyr = Gyr;
        state.Mag = Mag;/**/
        state.MagSmooth = MagFilter.Update(Mag);
        if (States.Count <=1)
            return Quaternion.identity;

        HardwareVarianceGyr.Update((Gyr).magnitude);//每毫秒方差2.331017E-09 度左右   0.00000002331017
        HardwareVarianceAcc.Update(Vector3.Angle(state.Acc, Last.Acc));//方差0.0012度左右
        HardwareVarianceMag.Update(Vector3.Angle(state.Mag, Last.Mag));//方差3.5度左右

        var LastQuaternion = Last.Qua;

        var newQua = new Quaternion();
        newQua.eulerAngles = Gyr * TimeGap;
        var quaGyr = LastQuaternion * newQua;

        double AccLengthToAngle = 5;//1倍引力差相当于多少度方差
        double MagLengthToAngle = 5;//1倍磁力差相当于多少度方差

        double GyrVariance = Last.Variance + Math.Pow((Gyr * TimeGap).magnitude * 0.3,3);// 指数4 = 方差2 * 欧拉角旋转误差2     移动导致累计误差
        double AccVariance = Math.Max((Gyr * TimeGap).magnitude, Vector3.Angle(state.AccSmooth, Last.AccSmooth)) * 1 + Math.Pow(Math.Abs(state.AccSmooth.magnitude - 9.8) / 9.8 * AccLengthToAngle,4);
        double MagVariance = Math.Max((Gyr * TimeGap).magnitude, Vector3.Angle(state.MagSmooth, Last.MagSmooth)) * 1 + Math.Pow(Math.Abs(state.MagSmooth.magnitude - 1) / 1 * MagLengthToAngle,4);/**/


        state.Variance = GyrVariance;
        state.Variance = state.Variance * (AccVariance+ MagVariance) / (state.Variance + (AccVariance + MagVariance));

        if (double.IsNaN(GyrVariance))
            GyrVariance = double.MinValue;
        if (double.IsNaN(AccVariance))
            AccVariance = double.MinValue;
        if (double.IsNaN(MagVariance))
            MagVariance = double.MinValue;
        if (double.IsNaN(state.Variance))
            state.Variance = double.MinValue;

        var quaAccMag = o0Project.o0.FormQuaternion(AccIdentity, MagIdentity, state.AccSmooth, state.MagSmooth, (float)(AccVariance / (AccVariance + MagVariance)));

        var quaMinRate = GyrVariance / (GyrVariance + Math.Max(AccVariance, MagVariance));
        var quaMaxRate = GyrVariance / (GyrVariance + Math.Min(AccVariance, MagVariance));
        Quaternion quaFirst = Quaternion.Slerp(quaGyr, quaAccMag, (float)quaMinRate).normalized;
        if (float.IsNaN(quaFirst.w))
            quaFirst = Last.Qua;

        var quaSecondRate = (quaMaxRate - quaMinRate) / (1 - quaMinRate);

        state.Qua = AccVariance < MagVariance ? o0Project.o0.FormQuaternion(quaFirst, AccIdentity, state.AccSmooth, (float)quaSecondRate) : o0Project.o0.FormQuaternion(quaFirst, MagIdentity, state.MagSmooth, (float)quaSecondRate);
        
        if (float.IsNaN(state.Qua.w))
            state.Qua = Last.Qua;/**/
        state.QuaSmooth = Quaternion.Slerp(Last.QuaSmooth, state.Qua, 0.3f);

        var frontV = Last.Qua * Vector3.forward;
        var upV = Last.Qua * Vector3.up;

        x = (Mathf.Atan(upV.y / upV.z) / Mathf.PI * 180 + (upV.z < 0 ? 90:270));
        y = (Mathf.Atan(frontV.z / frontV.x) / Mathf.PI * 180+(frontV.x < 0 ? 90:270));
        z = (Mathf.Atan(upV.y / upV.x) / Mathf.PI * 180 + (upV.x < 0 ? 90:270));

        return state.Qua;
    }

    public void SetIdentity()
    {
        Quaternion qua = default;
        AccIdentity = AccOld;
        MagIdentity = MagOld;
        qua = o0Project.o0.FormQuaternion(Quaternion.identity, Vector3.up,AccIdentity, 1);
        AccIdentity=qua*AccIdentity;
        MagIdentity = qua*MagIdentity;
        States.Last().Qua = Quaternion.identity;
        // States.Last().Qua = qua*States.Last().Qua;//Quaternion.identity;
        States.Last().Variance = 0.0000001;
    }

    public State getLastState() {
        return this.States.Last();
    }

    public Vector3 getGyrOld() {
        return GyrOld;
    }

    public void DeleteStatesFromTail(int count) {
        if (count <= 0 || States.Count == 0) return;
        States = States.GetRange(0, States.Count - count <= 0 ? 1 :  States.Count - count);
    }

    public void SetAccMagVariance(double value) {
        States.Last().AccVariance = value;
        States.Last().Variance = value;
    }
}