/*********************************************************************
 * \file   LeafSearch.cs
 * \author Ryan Wang Nian Jing
 * \brief  Leaf node implementation for AI searching for player
 *         
 *
 * \copyright Copyright (c) 2022 DigiPen Institute of Technology. Reproduction
   or disclosure of this file or its contents without the prior written
   consent of DigiPen Institute of Technology is prohibited.
 *********************************************************************/

using SHADE;
using SHADE_Scripting.AIBehaviour.BehaviourTree;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

//VARIABLES HERE
public partial class LeafSearch : BehaviourTreeNode
{
  private Transform transform;
  private Vector3 eyeOffset;
  private float sightDistance;
  private GameObject? player; //To be searched for and marked
}

//FUNCTIONS HERE
public partial class LeafSearch : BehaviourTreeNode
{
  public LeafSearch(string name, Transform t, Vector3 eo, float sDist) : base(name)
  {
    transform = t;
    eyeOffset = eo;
    sightDistance = sDist;
    player = null;
  }

  //Helper, find the nearest unobstructed waypoint to return to when chase is over
  private void reevaluateWaypoint()
  {
    Debug.Log("Reevaluating Waypoints");
    List<GameObject> waypoints = (List<GameObject>)GetNodeData("waypoints");

    if (waypoints == null)
    {
      SetNodeData("currentWaypointIndex", 0);
      return;
    }

    int nearestWaypointIndex = 0;
    for (int i = 0; i < waypoints.Count; ++i)
    {
      if ((transform.GlobalPosition - waypoints[i].GetComponent<Transform>().GlobalPosition).GetSqrMagnitude() <
        (transform.GlobalPosition - waypoints[nearestWaypointIndex].GetComponent<Transform>().GlobalPosition).GetSqrMagnitude())
      {
        nearestWaypointIndex = i;
      }
    }
    SetNodeData("currentWaypointIndex", nearestWaypointIndex);
  }

  public override BehaviourTreeNodeStatus Evaluate()
  {
    //Debug.LogWarning("LeafSearch");
    onEnter(BehaviourTreeNodeStatus.RUNNING);

    //Search for player
    player = GameObject.Find("Player");

    //Automatically fail if no player is found
    if (player == null)
    {
      SetNodeData("isAlert", false);
      status = BehaviourTreeNodeStatus.FAILURE;
      onExit(BehaviourTreeNodeStatus.FAILURE);
      return status;
    }
    else
    {
      //Fail if unable to find a player
      //Get player's transform
      Transform plrT = player.GetValueOrDefault().GetComponent<Transform>();

      //DELETE THIS
      //Debug.Log("X " + MathF.Sin(transform.LocalEulerAngles.y).ToString() + " Z " + MathF.Cos(transform.LocalEulerAngles.y).ToString());
      //Debug.Log("Looking at: " + transform.LocalRotation.y.ToString() + " To player is: " + temporary.ToString());
      //Debug.Log("Look difference is: " + (transform.LocalRotation.y - differenceDirection.y).ToString());
      //Debug.Log("Dot: " + Quaternion.Dot(differenceDirection, transform.GlobalRotation));

      //Fail if too far from vision range
      if ((plrT.GlobalPosition - transform.GlobalPosition).GetMagnitude() > sightDistance)
      {
        //Debug.Log("Failure: Too far");
        if (GetNodeData("isAlert") != null && (bool)GetNodeData("isAlert") == true)
        {
          Debug.Log("AI play unalert hmm");
          reevaluateWaypoint();
        }
        SetNodeData("isAlert", false);
        status = BehaviourTreeNodeStatus.FAILURE;
        onExit(BehaviourTreeNodeStatus.FAILURE);
        return status;
      }

      //Fail if player is out of FOV
      //TODO currently a simple dot product against negative is done, this makes it essentially be a semicircle in front at which AI can see
      Vector3 difference = plrT.GlobalPosition - transform.GlobalPosition;
      difference.y = 0.0f; //Disregard Y axis
      Vector3 lookDirection = new Vector3(MathF.Sin(transform.LocalEulerAngles.y), 0.0f, MathF.Cos(transform.LocalEulerAngles.y));
      //Debug.Log("Dot: " + Vector3.Dot(difference, lookDirection));
      if (Vector3.Dot(difference, lookDirection) < 0.0f)
      {
        //Debug.Log("Failure: Out of FOV");
        if (GetNodeData("isAlert") != null && (bool)GetNodeData("isAlert") == true)
        {
          Debug.Log("AI play unalert hmm");
          reevaluateWaypoint();
        }
        SetNodeData("isAlert", false);
        status = BehaviourTreeNodeStatus.FAILURE;
        onExit(BehaviourTreeNodeStatus.FAILURE);
        return status;
      }

      //LocalRotation is between -1 and 1, which are essentially the same.
      //0 and -1/1 are 180 deg apart
      //Quaternion differenceDirection = Quaternion.FromToRotation(Vector3.Forward, plrT.GlobalPosition - transform.GlobalPosition);
      //Debug.Log("Looking at: " + transform.LocalRotation.y.ToString() + " To player is: " + differenceDirection.y.ToString());

      //Draw a ray, succeed if ray is unobstructed
      Vector3 eyePosition = transform.GlobalPosition + eyeOffset;
      Ray sightRay = new Ray(eyePosition, plrT.GlobalPosition - eyePosition);
      RaycastHit sightRayHit = Physics.Raycast(sightRay);
      //As of November 2022, RaycastHit contains only the FIRST object hit by
      //the ray in the Other GameObject data member
      //Diren may likely add ALL objects hit by the ray over December
      if (sightRayHit.Hit && sightRayHit.Other != player)
      {
        //Debug.Log("Failure: Ray hit obstacle named " + sightRayHit.Other.GetValueOrDefault().Name + " ID" + sightRayHit.Other.GetValueOrDefault().EntityId);
        if (GetNodeData("isAlert") != null && (bool)GetNodeData("isAlert") == true)
        {
          Debug.Log("AI play unalert hmm");
          reevaluateWaypoint();
        }
        SetNodeData("isAlert", false);
        status = BehaviourTreeNodeStatus.FAILURE;
        onExit(BehaviourTreeNodeStatus.FAILURE);
        return status;
      }
      else if (sightRayHit.Hit && sightRayHit.Other == player)
      {
        //Debug.Log("Ray hit player");
      }

      //All checks for now succeeded
      //Debug.Log("Success: Homeowner has sighted player");
      //Write player's transform into the blackboard
      SetNodeData("target", plrT);

      if (GetNodeData("isAlert") != null && (bool)GetNodeData("isAlert") == false)
      {
        Debug.Log("AI Play Alerted Yell here");
      }
      SetNodeData("isAlert", true);

      status = BehaviourTreeNodeStatus.SUCCESS;
      onExit(BehaviourTreeNodeStatus.SUCCESS);
      return status;
    }
  }
}