using Cryville.Crtr.Components;
using Cryville.Crtr.Event;
using UnityEngine;

namespace Cryville.Crtr {
	class TrackHandler : ContainerHandler {
		readonly GroupHandler gh;
		readonly Chart.Track track;

		public TrackHandler(Chart.Track ev, GroupHandler gh) : base() {
			track = ev;
			this.gh = gh;
		}
		
		public override string TypeName { get { return "track"; } }

		public override void Init() {
			base.Init();
			sgos = RootTransform.GetComponentsInChildren<SectionalGameObject>();
		}
		SectionalGameObject[] sgos;
		Vector3 bpos; Quaternion brot;
		Vector3 spos;
		public override void StartPhysicalUpdate(ContainerState s) {
			base.StartPhysicalUpdate(s);
			if (CanDoGraphicalUpdate(s)) {
				TransformAwake(s);
			}
		}
		protected override void StartPreGraphicalUpdate(ContainerState s) {
			base.StartPreGraphicalUpdate(s);
			spos = Vector3.zero;
			TransformAwake(s);
			bpos = Position;
			brot = Rotation;
		}
		protected override void StartGraphicalUpdate(ContainerState s) {
			base.StartGraphicalUpdate(s);
			if (RootTransform) {
				TransformAwake(s);
				var p = Position;
				foreach (var i in sgos) {
					i.Reset();
					i.AppendPoint(p, s.QuatDir);
				}
			}
		}
		void TransformAwake(ContainerState s) {
			pwp = Vector3.zero;
			cpt = s.ScreenPoint;
			ptime = s.Time;
			Position = pwp + cpt + spos;
			Rotation = Quaternion.Euler(s.Direction);
		}

		Vector3 cpt; // Current point
		Vector3 ppt = Vector3.zero; // Previous point
		Vector3 pwp = Vector3.zero; // Previous world point
		double ptime; // Previous time
		float length;

		public override void Update(ContainerState s, StampedEvent ev) {
			base.Update(s, ev);
			if (CanDoGraphicalUpdate(s)) {
				var tpt = s.ScreenPoint;
				var tsv = s.ScrollVelocity;

				Vector3 dpt = (Vector3)tpt - ppt; // Delta 2D point
				dpt.z = (float)((s.Time - ptime) * ChartPlayer.sv * tsv); // Delta Z
				Quaternion rotq = Quaternion.Euler(s.Direction); // Rotation
				var dwp = rotq * dpt; // Delta world point
				var nl = length + dwp.magnitude; // New length
				var tdist = s.Distance;
				if (nl >= tdist) {
					s.Break();
					return;
				}
				length = nl;
				var wp = pwp + dwp; // World point
				pwp = wp;
				ppt += dpt;

				ptime = s.Time;
				Position = pwp + cpt + spos;
				Rotation = Quaternion.Euler(s.Direction);

				if (!RootTransform || s.CloneType == 3) return;
				foreach (var i in sgos)
					i.AppendPoint(Position, s.QuatDir);
			}
			else UpdatePosition(s);
		}

		void UpdatePosition(ContainerState s) {
			cpt = s.ScreenPoint;
			ppt = cpt;
			pwp = Vector3.zero;
			ptime = s.Time;
			length = 0;
			Position = pwp + cpt + spos;
			Rotation = Quaternion.Euler(s.Direction);
		}

		// TODO Fix anchor rotation
		public override void Anchor() {
			base.Anchor();
			spos = bpos - Position;
		}

		protected override void EndGraphicalUpdate(ContainerState s) {
			base.EndGraphicalUpdate(s);
			EndUpdatePosition(s);
			var p = Position;
			foreach (var i in sgos) {
				i.AppendPoint(p, s.QuatDir);
				i.Seal();
			}
		}

		void EndUpdatePosition(ContainerState s) {
			var tpt = s.ScreenPoint;
			var tsv = s.ScrollVelocity;
			
			Vector3 dpt = (Vector3)tpt - ppt;
			dpt.z = (float)((s.Time - ptime) * ChartPlayer.sv * tsv);
			Quaternion rotq = Quaternion.Euler(s.Direction);
			var dwp = rotq * dpt; // Delta world point
			var nl = length + dwp.magnitude; // New length
			var tdist = s.Distance;
			if (nl >= tdist)
				dwp *= (tdist - length) / (nl - length);
			length = nl;
			var wp = pwp + dwp; // World point
			pwp = wp;
			ppt += dpt;
			Position = pwp + cpt + spos;
			Rotation = Quaternion.Euler(s.Direction);
		}
	}
}