#nullable enable
using System;
using System.Collections.Generic;
using System.Linq;
using Sandbox;
using Sandbox.Diagnostics;
using Sandbox.Physics;

namespace Editor.Mcp
{
	internal static class PerformanceAndPhysicsDriver
	{
		private static Scene? ResolveScene()
		{
			if ( Game.ActiveScene != null ) return Game.ActiveScene;
			var session = EditorRuntime.GetStaticProperty( "Editor.SceneEditorSession", "Active" );
			if ( session != null )
			{
				return EditorRuntime.GetMember( session, "Scene" ) as Scene;
			}
			return null;
		}

		public static ToolOutcome<object> ProfilePerformance()
		{
			try
			{
				var scene = ResolveScene();

				// Memory & Garbage Collection metrics
				var memoryMetrics = new
				{
					BytesAllocatedHotLoop = PerformanceStats.BytesAllocated,
					Gen0Collections = PerformanceStats.Gen0Collections,
					Gen1Collections = PerformanceStats.Gen1Collections,
					Gen2Collections = PerformanceStats.Gen2Collections,
					GcPauseDurationMs = PerformanceStats.GcPause,
					Exceptions = PerformanceStats.Exceptions,
					ProcessMemoryUsageMB = PerformanceStats.ApproximateProcessMemoryUsage / (1024f * 1024f)
				};

				// Network Host Telemetry
				object? networkStats = null;
				if ( Networking.IsActive )
				{
					networkStats = new
					{
						Networking.IsActive,
						Networking.IsHost,
						Networking.IsClient,
						InBytesPerSecond = Networking.HostStats.InBytesPerSecond,
						OutBytesPerSecond = Networking.HostStats.OutBytesPerSecond,
						NetworkFps = Networking.HostStats.Fps,
						ConnectedClients = Connection.All?.Count ?? 0
					};
				}

				// Scene Complexity
				var sceneStats = new
				{
					TotalGameObjects = scene?.GetAllObjects( false ).Count() ?? 0,
					Rigidbodies = scene?.GetAllComponents<Rigidbody>().Count() ?? 0,
					ModelPhysicsRagdolls = scene?.GetAllComponents<ModelPhysics>().Count() ?? 0,
					ModelRenderers = scene?.GetAllComponents<ModelRenderer>().Count() ?? 0,
					PointLights = scene?.GetAllComponents<PointLight>().Count() ?? 0
				};

				return ToolOutcome<object>.Ready( new
				{
					FrameTimeMs = PerformanceStats.FrameTime,
					GpuFrametimeMs = PerformanceStats.GpuFrametime,
					GpuFrameNumber = PerformanceStats.GpuFrameNumber,
					Memory = memoryMetrics,
					Network = networkStats,
					SceneComplexity = sceneStats,
					Status = "Performance and GPU timeline telemetry captured"
				} );
			}
			catch ( Exception ex )
			{
				return ToolOutcome<object>.Failure( null, ToolStatus.Failed, "performance.profile_failed", "Performance profiling failed.", ex );
			}
		}

		public static ToolOutcome<object> AuditPhysicsAndRagdoll(
			string? target = null,
			float maxBoneStretchPercent = 15.0f,
			float maxVelocity = 5000.0f,
			bool applyStressImpulse = false,
			float impulseForce = 500.0f )
		{
			var scene = ResolveScene();
			if ( scene == null )
			{
				return ToolOutcome<object>.Failure( null, ToolStatus.Unavailable, "physics.no_scene", "No active scene loaded." );
			}

			var ragdolls = scene.GetAllComponents<ModelPhysics>().ToArray();
			var rigidbodies = scene.GetAllComponents<Rigidbody>().ToArray();

			if ( !string.IsNullOrWhiteSpace( target ) )
			{
				ragdolls = ragdolls.Where( r => string.Equals( r.GameObject.Name, target.Trim(), StringComparison.OrdinalIgnoreCase ) ).ToArray();
				rigidbodies = rigidbodies.Where( r => string.Equals( r.GameObject.Name, target.Trim(), StringComparison.OrdinalIgnoreCase ) ).ToArray();
			}

			var stretchViolations = new List<object>();
			var penetrationViolations = new List<object>();
			var velocityViolations = new List<object>();
			var inspectedJointCount = 0;
			var inspectedBodyCount = 0;

			// Optional stress test impulse injection
			if ( applyStressImpulse )
			{
				foreach ( var r in rigidbodies )
				{
					r.ApplyImpulse( Vector3.Random * impulseForce );
				}
				foreach ( var mp in ragdolls )
				{
					mp.PhysicsGroup?.ApplyImpulse( Vector3.Random * impulseForce );
				}
			}

			// 1. Audit ModelPhysics Ragdoll Joints & Bodies via PhysicsGroup
			foreach ( var mp in ragdolls )
			{
				var group = mp.PhysicsGroup;
				if ( group != null )
				{
					if ( group.Joints != null )
					{
						foreach ( var j in group.Joints )
						{
							inspectedJointCount++;
							var b1 = j.Body1;
							var b2 = j.Body2;
							if ( b1 != null && b2 != null )
							{
								var currentDist = Vector3.DistanceBetween( b1.Position, b2.Position );
								if ( currentDist > 150f ) // Natural bone separation limit
								{
									stretchViolations.Add( new
									{
										Ragdoll = mp.GameObject.Name,
										BodyA = b1.ToString(),
										BodyB = b2.ToString(),
										Distance = currentDist,
										Issue = "Joint bone stretched beyond anatomical threshold"
									} );
								}
							}
						}
					}

					if ( group.Bodies != null )
					{
						foreach ( var b in group.Bodies )
						{
							inspectedBodyCount++;
							var vel = b.Velocity.Length;
							if ( float.IsNaN( vel ) || float.IsInfinity( vel ) || vel > maxVelocity )
							{
								velocityViolations.Add( new
								{
									Ragdoll = mp.GameObject.Name,
									Velocity = vel,
									Position = b.Position,
									Issue = "Extreme or NaN velocity detected"
								} );
							}

							// Floor clipping check
							var groundTrace = scene.Trace.Ray( b.Position + Vector3.Up * 20f, b.Position - Vector3.Up * 50f )
								.WithoutTags( "trigger" )
								.Run();

							if ( groundTrace.Hit && b.Position.z < (groundTrace.EndPosition.z - 10f) )
							{
								penetrationViolations.Add( new
								{
									Ragdoll = mp.GameObject.Name,
									BonePosition = b.Position,
									GroundHeight = groundTrace.EndPosition.z,
									Issue = "Ragdoll bone clipped below terrain/floor plane"
								} );
							}
						}
					}
				}
			}

			// 2. Audit Standard Rigidbodies
			foreach ( var rb in rigidbodies )
			{
				inspectedBodyCount++;
				var vel = rb.Velocity.Length;
				if ( float.IsNaN( vel ) || float.IsInfinity( vel ) || vel > maxVelocity )
				{
					velocityViolations.Add( new
					{
						GameObject = rb.GameObject.Name,
						Velocity = vel,
						Position = rb.WorldPosition,
						Issue = "Extreme or NaN velocity detected"
					} );
				}
			}

			var passed = stretchViolations.Count == 0 && penetrationViolations.Count == 0 && velocityViolations.Count == 0;

			return ToolOutcome<object>.Ready( new
			{
				Action = "physics_ragdoll_audit",
				Passed = passed,
				InspectedRagdollCount = ragdolls.Length,
				InspectedRigidbodyCount = rigidbodies.Length,
				InspectedJointCount = inspectedJointCount,
				InspectedBodyCount = inspectedBodyCount,
				StretchViolationCount = stretchViolations.Count,
				StretchViolations = stretchViolations,
				PenetrationViolationCount = penetrationViolations.Count,
				PenetrationViolations = penetrationViolations,
				VelocityViolationCount = velocityViolations.Count,
				VelocityViolations = velocityViolations,
				Status = passed ? "All physics bodies and ragdoll joints passed stability criteria" : "Physics stability violations detected"
			} );
		}
	}
}