namespace Nerd_STF.Mathematics;

public struct Float2 : ICloneable, IComparable<Float2>, IEquatable<Float2>, IGroup<float>
{
    public static Float2 Down => new(0, -1);
    public static Float2 Left => new(-1, 0);
    public static Float2 Right => new(1, 0);
    public static Float2 Up => new(0, 1);

    public static Float2 One => new(1, 1);
    public static Float2 Zero => new(0, 0);

    public float Magnitude => Mathf.Sqrt(x * x + y * y);
    public Float2 Normalized => this * Mathf.InverseSqrt(x * x + y * y);

    public float x, y;

    public Float2(float all) : this(all, all) { }
    public Float2(float x, float y)
    {
        this.x = x;
        this.y = y;
    }
    public Float2(Fill<float> fill) : this(fill(0), fill(1)) { }
    public Float2(Fill<int> fill) : this(fill(0), fill(1)) { }

    public float this[int index]
    {
        get => index switch
        {
            0 => x,
            1 => y,
            _ => throw new IndexOutOfRangeException(nameof(index)),
        };
        set
        {
            switch (index)
            {
                case 0:
                    x = value;
                    break;

                case 1:
                    y = value;
                    break;

                default: throw new IndexOutOfRangeException(nameof(index));
            }
        }
    }

    public static Float2 Absolute(Float2 val) =>
        new(Mathf.Absolute(val.x), Mathf.Absolute(val.y));
    public static Float2 Average(params Float2[] vals) => Sum(vals) / vals.Length;
    public static Float2 Ceiling(Float2 val) =>
        new(Mathf.Ceiling(val.x), Mathf.Ceiling(val.y));
    public static Float2 Clamp(Float2 val, Float2 min, Float2 max) =>
        new(Mathf.Clamp(val.x, min.x, max.x),
            Mathf.Clamp(val.y, min.y, max.y));
    public static Float2 ClampMagnitude(Float2 val, float minMag, float maxMag)
    {
        if (maxMag < minMag) throw new ArgumentOutOfRangeException(nameof(maxMag),
            nameof(maxMag) + " must be greater than or equal to " + nameof(minMag));
        float mag = val.Magnitude;
        if (mag >= minMag && mag <= maxMag) return val;
        val = val.Normalized;
        if (mag < minMag) val *= minMag;
        else if (mag > maxMag) val *= maxMag;
        return val;
    }
    public static Float3 Cross(Float2 a, Float2 b, bool normalized = false) =>
        Float3.Cross(a, b, normalized);
    public static Float2 Divide(Float2 num, params Float2[] vals)
    {
        foreach (Float2 f in vals) num /= f;
        return num;
    }
    public static float Dot(Float2 a, Float2 b) => a.x * b.x + a.y * b.y;
    public static float Dot(params Float2[] vals)
    {
        if (vals.Length < 1) return 0;
        float x = 1, y = 1;
        foreach (Float2 f in vals)
        {
            x *= f.x;
            y *= f.y;
        }
        return x + y;
    }
    public static Float2 Floor(Float2 val) =>
        new(Mathf.Floor(val.x), Mathf.Floor(val.y));
    public static Float2 Lerp(Float2 a, Float2 b, float t, bool clamp = true) =>
        new(Mathf.Lerp(a.x, b.x, t, clamp), Mathf.Lerp(a.y, b.y, t, clamp));
    public static Float2 Median(params Float2[] vals)
    {
        float index = Mathf.Average(0, vals.Length - 1);
        Float2 valA = vals[Mathf.Floor(index)], valB = vals[Mathf.Ceiling(index)];
        return Average(valA, valB);
    }
    public static Float2 Max(params Float2[] vals)
    {
        if (vals.Length < 1) return Zero;
        Float2 val = vals[0];
        foreach (Float2 f in vals) val = f > val ? f : val;
        return val;
    }
    public static Float2 Min(params Float2[] vals)
    {
        if (vals.Length < 1) return Zero;
        Float2 val = vals[0];
        foreach (Float2 f in vals) val = f < val ? f : val;
        return val;
    }
    public static Float2 Product(params Float2[] vals)
    {
        if (vals.Length < 1) return Zero;
        Float2 val = One;
        foreach (Float2 f in vals) val *= f;
        return val;
    }
    public static Float2 Round(Float2 val) =>
        new(Mathf.Round(val.x), Mathf.Round(val.y));
    public static Float2 Subtract(Float2 num, params Float2[] vals)
    {
        foreach (Float2 f in vals) num -= f;
        return num;
    }
    public static Float2 Sum(params Float2[] vals)
    {
        Float2 val = Zero;
        foreach (Float2 f in vals) val += f;
        return val;
    }

    public static (float[] Xs, float[] Ys) SplitArray(params Float2[] vals)
    {
        float[] Xs = new float[vals.Length], Ys = new float[vals.Length];
        for (int i = 0; i < vals.Length; i++)
        {
            Xs[i] = vals[i].x;
            Ys[i] = vals[i].y;
        }
        return (Xs, Ys);
    }

    public int CompareTo(Float2 other) => Magnitude.CompareTo(other.Magnitude);
    public override bool Equals([NotNullWhen(true)] object? obj)
    {
        if (obj == null || obj.GetType() != typeof(Float2)) return base.Equals(obj);
        return Equals((Float2)obj);
    }
    public bool Equals(Float2 other) => x == other.x && y == other.y;
    public override int GetHashCode() => x.GetHashCode() ^ y.GetHashCode();
    public override string ToString() => ToString((string?)null);
    public string ToString(string? provider) =>
        "X: " + x.ToString(provider) + " Y: " + y.ToString(provider);
    public string ToString(IFormatProvider provider) =>
        "X: " + x.ToString(provider) + " Y: " + y.ToString(provider);

    public object Clone() => new Float2(x, y);

    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
    public IEnumerator<float> GetEnumerator()
    {
        yield return x;
        yield return y;
    }

    public float[] ToArray() => new[] { x, y };
    public Fill<float> ToFill()
    {
        Float2 @this = this;
        return i => @this[i];
    }
    public List<float> ToList() => new() { x, y };

    public Vector2d ToVector() => new(new(Mathf.ArcTan(y / x), Angle.Type.Radians), Magnitude);

    public static Float2 operator +(Float2 a, Float2 b) => new(a.x + b.x, a.y + b.y);
    public static Float2 operator -(Float2 d) => new(-d.x, -d.y);
    public static Float2 operator -(Float2 a, Float2 b) => new(a.x - b.x, a.y - b.y);
    public static Float2 operator *(Float2 a, Float2 b) => new(a.x * b.x, a.y * b.y);
    public static Float2 operator *(Float2 a, float b) => new(a.x * b, a.y * b);
    public static Float2 operator *(Float2 a, Matrix b) => (Float2)((Matrix)a * b);
    public static Float2 operator /(Float2 a, Float2 b) => new(a.x / b.x, a.y / b.y);
    public static Float2 operator /(Float2 a, float b) => new(a.x / b, a.y / b);
    public static Float2 operator /(Float2 a, Matrix b) => (Float2)((Matrix)a / b);
    public static bool operator ==(Float2 a, Float2 b) => a.Equals(b);
    public static bool operator !=(Float2 a, Float2 b) => !a.Equals(b);
    public static bool operator >(Float2 a, Float2 b) => a.CompareTo(b) > 0;
    public static bool operator <(Float2 a, Float2 b) => a.CompareTo(b) < 0;
    public static bool operator >=(Float2 a, Float2 b) => a == b || a > b;
    public static bool operator <=(Float2 a, Float2 b) => a == b || a < b;

    public static implicit operator Float2(Complex val) => new(val.u, val.i);
    public static explicit operator Float2(Quaternion val) => new(val.u, val.i);
    public static explicit operator Float2(Float3 val) => new(val.x, val.y);
    public static explicit operator Float2(Float4 val) => new(val.x, val.y);
    public static implicit operator Float2(Int2 val) => new(val.x, val.y);
    public static explicit operator Float2(Int3 val) => new(val.x, val.y);
    public static explicit operator Float2(Int4 val) => new(val.x, val.y);
    public static explicit operator Float2(Matrix m) => new(m[0, 0], m[1, 0]);
    public static explicit operator Float2(Vector2d val) => val.ToXYZ();
    public static explicit operator Float2(Vert val) => new(val.position.x, val.position.y);
    public static implicit operator Float2(Fill<float> fill) => new(fill);
    public static implicit operator Float2(Fill<int> fill) => new(fill);
}