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

public class ProbablilityTest : MonoBehaviour
{
    public MathExtras.Keyframe[] quantileKeyframes;
    public AnimationCurve quantileCurve;

    public int numSamples = 100 * 1000;
    public int numBuckets = 100;

    public Vector3 labelPos;

    private int[] _buckets;
    private int _maxBucketCount;

    //          LIFECYCLE
#if UNITY_EDITOR
    private void OnDrawGizmos()
    {
        // Guard
        if (_buckets == null)
            return;
        
        // Display histogram
        for (int i = 1; i < this._buckets.Length; i++)
        {
            Vector3 a = new Vector3((i - 1) / (float)this.numBuckets, _buckets[i - 1] / (float)_maxBucketCount, 0f);
            Vector3 b = new Vector3(i / (float)this.numBuckets, _buckets[i] / (float)_maxBucketCount, 0f);

            Debug.DrawLine(a, b, Color.red);
        }

        // Display probability
        Handles.Label(this.labelPos, $"{(_maxBucketCount / (float)this.numSamples):P2}");
    }
#endif

    //          BEHAVIORS
    public void CurveFromKeyframes()
    {
        this.quantileCurve = MathExtras.CurveFromKeyframes(this.quantileKeyframes);
    }

    public void VisualizeDistribution()
    {
        _buckets = new int[this.numBuckets];
        _maxBucketCount = 0;

        for (int i = 0; i < numSamples; i++)
        {
            // Take sample from distribution
            float rand = MathExtras.SampleDistribution(this.quantileCurve);

            // Update histogram
            int bucket = Mathf.FloorToInt(rand * this.numBuckets);

            if (bucket < 0 || bucket >= this._buckets.Length)
                continue;

            _buckets[bucket]++;
            if (_buckets[bucket] > _maxBucketCount)
                _maxBucketCount = _buckets[bucket];
        }
    }
}