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

namespace MoreMountains.Tools
{
    [RequireComponent(typeof(LineRenderer))]
    public class MMLineRendererCircle : MonoBehaviour
    {
        /// the possible axis 
        public enum DrawAxis { X, Y, Z };
     
        [Header("Draw Axis")]
        /// the axis on which to draw the circle
        [Tooltip("the axis on which to draw the circle")]
        public DrawAxis Axis = DrawAxis.Z;
        /// the distance by which to push the circle on the draw axis
        [Tooltip("the distance by which to push the circle on the draw axis")]
        public float NormalOffset = 0;
        
        [Header("Geometry")]
        /// the amount of segments on the line renderer. More segments, more smoothness, more performance cost
        [Tooltip("the amount of segments on the line renderer. More segments, more smoothness, more performance cost")]
        [Range(0, 2000)]
        public int PositionsCount = 60;
     
        [Header("Shape")]
        /// the length of the circle's horizontal radius
        [Tooltip("the length of the circle's horizontal radius")]
        public float HorizontalRadius = 10;
        /// the length of the circle's vertical radius
        [Tooltip("the length of the circle's vertical radius")]
        public float VerticalRadius = 10;

        [Header("Debug")]
        /// if this is true, the circle will be redrawn every time you change a value in the inspector, otherwise you'll have to call the DrawCircle method (or press the debug button below)
        [Tooltip("if this is true, the circle will be redrawn every time you change a value in the inspector, otherwise you'll have to call the DrawCircle method (or press the debug button below)")]
        public bool AutoRedrawOnValuesChange = false;
        /// a test button used to call the DrawCircle method
        [MMInspectorButton("DrawCircle")]
        public bool DrawCircleButton;
        
        protected LineRenderer _line;
        protected Vector3 _newPosition;
        protected float _angle, _x, _y, _z;
     
        /// <summary>
        /// On Awake we initialize our line renderer and draw our circle
        /// </summary>
        protected virtual void Awake()
        {
            Initialization();
            DrawCircle();
        }

        /// <summary>
        /// Grabs the line renderer and sets it up
        /// </summary>
        protected virtual void Initialization()
        {
            _line = gameObject.GetComponent<LineRenderer>();
            _line.positionCount = PositionsCount + 1;
            _line.useWorldSpace = false;
        }
     
        /// <summary>
        /// Sets all point positions for our line renderer
        /// </summary>
        public virtual void DrawCircle()
        {
            _angle = 0f;
            _z = NormalOffset;
            
            switch(Axis)
            {
                case DrawAxis.X: 
                    DrawCircleX();
                    break;
                case DrawAxis.Y: 
                    DrawCircleY();
                    break;
                case DrawAxis.Z: 
                    DrawCircleZ();
                    break;
            }
        }

        /// <summary>
        /// Computes the x position of the new point
        /// </summary>
        /// <returns></returns>
        protected virtual float ComputeX()
        {
            return Mathf.Cos (Mathf.Deg2Rad * _angle) * HorizontalRadius;
        }

        /// <summary>
        /// Computes the y position of the new point
        /// </summary>
        /// <returns></returns>
        protected virtual float ComputeY()
        {
            return Mathf.Sin (Mathf.Deg2Rad * _angle) * VerticalRadius;
        }

        /// <summary>
        /// Draws a circle on the x axis
        /// </summary>
        protected virtual void DrawCircleX()
        {
            for (int i = 0; i < (PositionsCount + 1); i++)
            {
                _x = ComputeX();
                _y = ComputeY();
                
                _newPosition.x = _z;
                _newPosition.y = _y;
                _newPosition.z = _x;
                _line.SetPosition(i, _newPosition);
     
                _angle += (360f / PositionsCount);
            }
        }

        /// <summary>
        /// Draws a circle on the y axis
        /// </summary>
        protected virtual void DrawCircleY()
        {
            for (int i = 0; i < (PositionsCount + 1); i++)
            {
                _x = ComputeX();
                _y = ComputeY();
                
                _newPosition.x = _y;
                _newPosition.y = _z;
                _newPosition.z = _x;
                _line.SetPosition(i, _newPosition);
     
                _angle += (360f / PositionsCount);
            }
        }

        /// <summary>
        /// Draws a circle on the z axis
        /// </summary>
        protected virtual void DrawCircleZ()
        {
            for (int i = 0; i < (PositionsCount + 1); i++)
            {
                _x = ComputeX();
                _y = ComputeY();
                
                _newPosition.x = _x;
                _newPosition.y = _y;
                _newPosition.z = _z;
                _line.SetPosition(i, _newPosition);
     
                _angle += (360f / PositionsCount);
            }
        }

        /// <summary>
        /// On Validate we redraw our circle if needed
        /// </summary>
        protected virtual void OnValidate()
        {
            if (AutoRedrawOnValuesChange)
            {
                DrawCircle();
            }
        }
    }
}