using System.Collections.Generic;
using CodeImp.DoomBuilder.Map;
using CodeImp.DoomBuilder.VisualModes;
using CodeImp.DoomBuilder.GZBuilder.Geometry;
using CodeImp.DoomBuilder.Geometry;
using CodeImp.DoomBuilder.Config;

namespace CodeImp.DoomBuilder.GZBuilder.Data {
	
	public static class LinksCollector {
		private struct ThingsCheckResult {
			public bool ProcessPathNodes;
			public bool ProcessInterpolationPoints;
			public bool ProcessThingsWithGoal;
			public bool ProcessCameras;
			public bool ProcessActorMovers;
		}
		
		public static List<Line3D> GetThingLinks(ICollection<VisualThing> visualThings) {
			List<Thing> things = new List<Thing>();
			foreach (VisualThing vt in visualThings) things.Add(vt.Thing);

			ThingsCheckResult result = checkThings(things);
			if (result.ProcessPathNodes || result.ProcessInterpolationPoints || result.ProcessThingsWithGoal || result.ProcessCameras)
				return getThingLinks(result, true);
			return new List<Line3D>();
		}
		
		public static List<Line3D> GetThingLinks(ICollection<Thing> things) {
			ThingsCheckResult result = checkThings(things);
			if (result.ProcessPathNodes || result.ProcessInterpolationPoints || result.ProcessThingsWithGoal || result.ProcessCameras)
				return getThingLinks(result, false);
			return new List<Line3D>();
		}

		private static ThingsCheckResult checkThings(ICollection<Thing> things) {
			ThingsCheckResult result = new ThingsCheckResult();

			foreach (Thing t in things) {
				if(t.Type == 9024) //zdoom path node
					result.ProcessPathNodes = true;
				else if(t.Type == 9070) //zdoom camera interpolation point
					result.ProcessInterpolationPoints = true;
				else if(t.Action == 229 && t.Args[1] != 0) //Thing_SetGoal
					result.ProcessThingsWithGoal = true;
				else if(t.Type == 9072 && (t.Args[0] != 0 || t.Args[1] != 0)) //camera with a path
					result.ProcessCameras = true;
				else if(t.Type == 9074 && (t.Args[0] != 0 || t.Args[1] != 0) && t.Args[3] != 0) //actor mover
					result.ProcessActorMovers = true;
			}

			if(result.ProcessActorMovers || result.ProcessCameras)
				result.ProcessInterpolationPoints = true;

			if(result.ProcessThingsWithGoal)
				result.ProcessPathNodes = true;

			return result;
		}

		private static List<Line3D> getThingLinks(ThingsCheckResult result, bool correctHeight) {
			List<Line3D> lines = new List<Line3D>();
			Dictionary<int, List<Thing>> pathNodes = new Dictionary<int, List<Thing>>();
			Dictionary<int, List<Thing>> interpolationPoints = new Dictionary<int, List<Thing>>();
			List<Thing> thingsWithGoal = new List<Thing>();
			List<Thing> cameras = new List<Thing>();
			List<Thing> actorMovers = new List<Thing>();
			Dictionary<int, List<Thing>> actorMoverTargets = new Dictionary<int, List<Thing>>();

			//collect relevant things
			foreach (Thing t in General.Map.Map.Things) {
				if(result.ProcessPathNodes && t.Type == 9024) {
					if(!pathNodes.ContainsKey(t.Tag))
						pathNodes[t.Tag] = new List<Thing>();
					pathNodes[t.Tag].Add(t);
				}
				if(result.ProcessInterpolationPoints && t.Type == 9070) {
					if(!interpolationPoints.ContainsKey(t.Tag))
						interpolationPoints[t.Tag] = new List<Thing>();
					interpolationPoints[t.Tag].Add(t);
				}
				if (result.ProcessThingsWithGoal && t.Action == 229 && t.Args[1] != 0) {
					thingsWithGoal.Add(t);
				}
				if (result.ProcessCameras && t.Type == 9072 && (t.Args[0] != 0 || t.Args[1] != 0)) {
					cameras.Add(t);
				}
				if(result.ProcessActorMovers && t.Type == 9074 && (t.Args[0] != 0 || t.Args[1] != 0) && t.Args[3] != 0) {
					actorMovers.Add(t);
				}
			}

			if(actorMovers.Count > 0) {
				List<int> targetedTags = new List<int>();

				foreach(Thing t in actorMovers) {
					targetedTags.Add(t.Args[3]);
				}

				foreach(Thing t in General.Map.Map.Things) {
					if(targetedTags.Contains(t.Tag)) {
						if(!actorMoverTargets.ContainsKey(t.Tag))
							actorMoverTargets[t.Tag] = new List<Thing>();
						actorMoverTargets[t.Tag].Add(t);
					}
				}
			}

			Vector3D start = new Vector3D();
			Vector3D end = new Vector3D();

			//process path nodes
			if (result.ProcessPathNodes) {
				foreach (KeyValuePair<int, List<Thing>> group in pathNodes) {
					foreach(Thing t in group.Value) {
						if(t.Args[0] == 0) continue; //no goal
						
						if(pathNodes.ContainsKey(t.Args[0])) {
							start = t.Position;
							if(correctHeight) start.z += getCorrectHeight(t);

							foreach(Thing tt in pathNodes[t.Args[0]]) {
								end = tt.Position;
								if(correctHeight) end.z += getCorrectHeight(tt);
								lines.Add(new Line3D(start, end));
							}
						}
					}
				}
			}

			//process things with Thing_SetGoal
			if (result.ProcessThingsWithGoal) {
				foreach (Thing t in thingsWithGoal) {
					if (pathNodes.ContainsKey(t.Args[1])) {
						if (t.Args[0] == 0 || t.Args[0] == t.Tag) {
							start = t.Position;
							if (correctHeight) start.z += getCorrectHeight(t);

							foreach(Thing tt in pathNodes[t.Args[1]]) {
								end = tt.Position;
								if(correctHeight) end.z += getCorrectHeight(tt);

								lines.Add(new Line3D(start, end, Line3DType.ACTIVATOR));
							}
						}
					}
				}
			}

			//process interpolation points
			if (result.ProcessInterpolationPoints) {
				foreach (KeyValuePair<int, List<Thing>> group in interpolationPoints) {
					foreach(Thing t in group.Value) {
						int targetTag = t.Args[3] + (t.Args[4] << 8);
						if(targetTag == 0) continue; //no goal

						if(interpolationPoints.ContainsKey(targetTag)) {
							start = t.Position;
							if(correctHeight) start.z += getCorrectHeight(t);

							foreach(Thing tt in interpolationPoints[targetTag]) {
								end = tt.Position;
								if(correctHeight) end.z += getCorrectHeight(tt);
								lines.Add(new Line3D(start, end));
							}
						}
					}
				}
			}

			//process cameras
			if (result.ProcessCameras) {
				foreach (Thing t in cameras) {
					int targetTag = t.Args[0] + (t.Args[1] << 8);
					if (targetTag == 0) continue; //no goal

					if(interpolationPoints.ContainsKey(targetTag)) {
						start = t.Position;
						if(correctHeight) start.z += getCorrectHeight(t);

						foreach(Thing tt in interpolationPoints[targetTag]) {
							end = tt.Position;
							if(correctHeight) end.z += getCorrectHeight(tt);
							lines.Add(new Line3D(start, end, Line3DType.ACTIVATOR));
						}
					}
				}
			}

			//process actor movers
			if(result.ProcessActorMovers) {
				foreach(Thing t in actorMovers) {
					int targetTag = t.Args[0] + (t.Args[1] << 8);
					if(targetTag == 0) continue; //no goal

					//add interpolation point target
					if(interpolationPoints.ContainsKey(targetTag)) {
						start = t.Position;
						if(correctHeight) start.z += getCorrectHeight(t);

						foreach(Thing tt in interpolationPoints[targetTag]) {
							end = tt.Position;
							if(correctHeight) end.z += getCorrectHeight(tt);
							lines.Add(new Line3D(start, end, Line3DType.ACTIVATOR));
						}
					}

					//add thing-to-move target
					if(actorMoverTargets.ContainsKey(t.Args[3])) {
						start = t.Position;
						if(correctHeight) start.z += getCorrectHeight(t);

						foreach(Thing tt in actorMoverTargets[t.Args[3]]) {
							end = tt.Position;
							if(correctHeight) end.z += getCorrectHeight(tt);
							lines.Add(new Line3D(start, end, Line3DType.ACTIVATOR));
						}
					}
				}
			}

			return lines;
		}

		private static float getCorrectHeight(Thing thing) {
			ThingTypeInfo tti = General.Map.Data.GetThingInfo(thing.Type);
			float height = tti.Height / 2f;
			if (thing.Sector != null) height += thing.Sector.FloorHeight;
			return height;
		}
	}
}