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

[RequireComponent(typeof(CanvasRenderer))]
public class MenuEchoWaveRenderer : MaskableGraphic
{
    [Range(24, 120)]
    public int segments = 72;

    [Tooltip("Текущий радиус кольца в пикселях")]
    public float radius = 0f;

    [Tooltip("Толщина светящейся полосы волны")]
    public float thickness = 28f;

    [Tooltip("Яркость/прозрачность волны (0 - 1)")]
    [Range(0f, 1f)]
    public float waveAlpha = 1f;

    [Header("Цвета свечения")]
    public Color waveColor = new Color(0.00f, 0.90f, 1.0f, 1.0f);   // Неоновый циан
    public Color coreColor = new Color(0.40f, 1.00f, 0.95f, 1.0f);   // Яркое ядро

    public void SetWave(float currentRadius, float currentThickness, float currentAlpha, Color baseColor, Color highlightColor)
    {
        radius = currentRadius;
        thickness = currentThickness;
        waveAlpha = Mathf.Clamp01(currentAlpha);
        waveColor = baseColor;
        coreColor = highlightColor;
        SetVerticesDirty();
    }

    protected override void OnPopulateMesh(VertexHelper vh)
    {
        vh.Clear();
        if (radius <= 0.5f || thickness <= 0.5f || waveAlpha <= 0.001f) return;

        float halfThick = thickness * 0.5f;
        float rInner = Mathf.Max(0f, radius - halfThick);
        float rCenter = radius;
        float rOuter = radius + halfThick;

        Color edgeCol = new Color(waveColor.r, waveColor.g, waveColor.b, 0f);
        Color midCol = new Color(coreColor.r, coreColor.g, coreColor.b, coreColor.a * waveAlpha);

        float angleStep = 360f / segments;

        for (int i = 0; i < segments; i++)
        {
            float a1 = i * angleStep * Mathf.Deg2Rad;
            float a2 = (i + 1) * angleStep * Mathf.Deg2Rad;

            Vector2 dir1 = new Vector2(Mathf.Cos(a1), Mathf.Sin(a1));
            Vector2 dir2 = new Vector2(Mathf.Cos(a2), Mathf.Sin(a2));

            Vector2 pIn1 = dir1 * rInner;
            Vector2 pIn2 = dir2 * rInner;
            Vector2 pMid1 = dir1 * rCenter;
            Vector2 pMid2 = dir2 * rCenter;
            Vector2 pOut1 = dir1 * rOuter;
            Vector2 pOut2 = dir2 * rOuter;

            // 1. Полоса: от внутреннего прозрачного края к яркому центру
            int idx1 = vh.currentVertCount;
            vh.AddVert(pIn1, edgeCol, Vector2.zero);
            vh.AddVert(pMid1, midCol, Vector2.zero);
            vh.AddVert(pMid2, midCol, Vector2.zero);
            vh.AddVert(pIn2, edgeCol, Vector2.zero);
            vh.AddTriangle(idx1, idx1 + 1, idx1 + 2);
            vh.AddTriangle(idx1, idx1 + 2, idx1 + 3);

            // 2. Полоса: от яркого центра к внешнему прозрачному краю
            int idx2 = vh.currentVertCount;
            vh.AddVert(pMid1, midCol, Vector2.zero);
            vh.AddVert(pOut1, edgeCol, Vector2.zero);
            vh.AddVert(pOut2, edgeCol, Vector2.zero);
            vh.AddVert(pMid2, midCol, Vector2.zero);
            vh.AddTriangle(idx2, idx2 + 1, idx2 + 2);
            vh.AddTriangle(idx2, idx2 + 2, idx2 + 3);
        }
    }
}