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


[Serializable]
public class GravityRayConfig{
	public float radius = 0.5f;
	public float length = 5.0f;
	public float tileLength = 3.0f;

	public static bool operator==(GravityRayConfig c1, GravityRayConfig c2){
		return c1.radius == c2.radius && c1.length == c2.length && c1.tileLength == c2.tileLength;
	}
	public static bool operator!=(GravityRayConfig c1, GravityRayConfig c2){
		return c1.radius != c2.radius || c1.length != c2.length ||  c1.tileLength != c2.tileLength;
	}
	public void AssignFrom(GravityRayConfig other){
		radius = other.radius;
		length = other.length;
		tileLength = other.tileLength;
	}
}


[ExecuteInEditMode]
public class GravityRayBody : MonoBehaviour {
	public GravityRayConfig config;
	private GravityRayConfig lastConfig = new GravityRayConfig();
	private const string rayObjectName = "Beam";
	public Material beamMaterial;
	GameObject ray = null;
	List<GameObject> capturedObjects = new List<GameObject>();
	public float centeringForce = 0.5f;
	public float dragForce = 0.5f;

	// Use this for initialization
	void Start () {
		RebuildRay ();
		lastConfig = config;
	}

	void RebuildRay(){
		lastConfig.AssignFrom (config);

		if (ray == null) {
			ray = AdvancedUtils.FindChild(gameObject, rayObjectName);
		}
		if (ray == null) {
			ray = AdvancedUtils.CreateMeshObject(rayObjectName);
			ray.transform.parent = transform;
			ray.transform.localPosition = Vector3.zero;
			ray.transform.localRotation = Quaternion.identity;
			ray.transform.localScale = Vector3.one;
		}



		CapsuleCollider c = gameObject.GetComponent<CapsuleCollider> ();
		if (c == null) {
			c = gameObject.AddComponent<CapsuleCollider>();
		}

		c.center = new Vector3 (0, config.length * 0.5f, 0);
		c.radius = config.radius;
		c.height = config.length;
		c.direction = 1;
		c.isTrigger = true;

		var mf = ray.GetComponent<MeshFilter> ();
		var m = mf.sharedMesh;


		Vector3[] vertices;
		Vector3[] normals;
		int[] indices;
		Vector2[] uvs;
		AdvancedUtils.GenerateCylinder (config.radius, config.length, 33, 1,2, config.length / config.tileLength,  out vertices, out indices, out uvs, out normals);

		m.vertices = vertices;
		m.SetIndices (indices, MeshTopology.Triangles, 0);
		m.normals = normals;
		m.uv = uvs;
		m.RecalculateBounds ();
		ray.renderer.sharedMaterial = beamMaterial;


	}
	
	// Update is called once per frame
	void FixedUpdate () {
		if (ray != null) {
			ray.transform.Rotate (Vector3.up, Time.deltaTime * -90.0f);
		}

		if(lastConfig != config){
			RebuildRay();
		}

		foreach (var obj in capturedObjects) {
			Vector3 a;
			Vector3 b;

			GetCylinderPoints(out a, out b);


			Vector3 n = (b - a).normalized;
			Vector3 p = AdvancedMath.LineNearestPoint(a, b, obj.transform.position);
			Vector3 centeringDir = (p - obj.transform.position).normalized;


			//Debug.Log(centeringDir);
			obj.rigidbody.velocity += centeringDir * centeringForce * Time.deltaTime;

			float forwardSpeed = Vector3.Dot(n, obj.rigidbody.velocity); 
			float diff = dragForce - forwardSpeed;
			obj.rigidbody.velocity += n *  dragForce * Time.deltaTime * 0.9f * diff;

			//obj.rigidbody.velocity =obj.rigidbody.velocity * 0.9f * Time.deltaTime + centeringDir * centeringForce * Time.deltaTime + n *  dragForce * Time.deltaTime;
		}
	}

	void GetCylinderPoints(out Vector3 a, out Vector3 b){
		a = ray.transform.position;
		b = ray.transform.position + ray.transform.up * config.length;
	}

	void OnTriggerEnter(Collider other){
		if (other.rigidbody!= null && !other.rigidbody.isKinematic && !capturedObjects.Contains (other.gameObject)) {
			capturedObjects.Add(other.gameObject);
			other.rigidbody.useGravity = false;
			other.rigidbody.velocity = Vector3.zero;
			Debug.Log("Beam captured object: " + other.name);
		}
	}

	void OnTriggerExit(Collider other){
		if (capturedObjects.Contains (other.gameObject)) {
			capturedObjects.Remove(other.gameObject);
			other.rigidbody.useGravity = true;
			Debug.Log("Beam lost object: " + other.name);
		}
	}


	void OnDrawGizmos(){
		if(lastConfig != config){
			RebuildRay();
		}

		if(ray != null){
			Vector3 a;
			Vector3 b;
			
			GetCylinderPoints(out a, out b);
			Gizmos.DrawWireSphere(a, 0.2f);
			Gizmos.DrawWireSphere(b, 0.2f);
		}
	}
}