using System;
using System.Collections;
using UnityEngine;

namespace AibisDream.FixSystem
{
    public class ScanLine : MonoBehaviour
    {
        #region 组件索引

        private LineRenderer _line;
        private OscilloscopeSystem _oscilloscopeSystem;

        #endregion

        #region 部分参数（后面改成从screen获取）

        private float _screenLeftX;
        private float _screenRightX;

        private float _topY;
        private float _bottomY;

        private const float ScanSpeed = 2f;

        public event Action ScanErrorEvent;

        #endregion

        private void Awake()
        {
            InitComponentRefs();
        }

        private void InitComponentRefs()
        {
            _oscilloscopeSystem = GetComponentInParent<OscilloscopeSystem>();
            
            _line = GetComponent<LineRenderer>();
            _line.enabled = false;
            _line.positionCount = 2;
        }

        public IEnumerator ScanForError(float spikeX)
        {
            _line.enabled = true;
           _oscilloscopeSystem.isScanning = true;
            // 初始化扫描线
            InitStartLine();
            // 扫描线右移
            var currentX = _screenLeftX;
            var lastX = currentX;
            while (currentX <= _screenRightX)
            {
                // 横坐标右移
                currentX += Time.deltaTime * ScanSpeed;
                SetLinePos(currentX);

                // 检查是否扫到尖峰
                if (CheckSpikeInRange(lastX, currentX, spikeX))
                {
                    // 修改线条
                    MarkLineAsError(spikeX);
                    // 触发扫描事件
                    yield return new WaitForSeconds(1f);
                    ScanErrorEvent?.Invoke();
                    break;
                }

                lastX = currentX;
                yield return null;
            }

            _oscilloscopeSystem.isScanning = false;
        }

        private void InitStartLine()
        {
            // 初始状态是一根靠左的竖线
            SetLinePos(_screenLeftX);

            _line.enabled = true;
            _line.startColor = Color.white;
            _line.endColor = Color.white;
        }

        private void SetLinePos(float posX)
        {
            var topPosition = new Vector3(posX, _topY, 0);
            var bottomPosition = new Vector3(posX, _bottomY, 0);
            _line.SetPosition(0, topPosition);
            _line.SetPosition(1, bottomPosition);
        }

        private bool CheckSpikeInRange(float x1, float x2, float spikeX)
        {
            var left = Mathf.Min(x1, x2);
            var right = Mathf.Max(x1, x2);
            return spikeX >= left && spikeX <= right;
        }

        private void MarkLineAsError(float spikeX)
        {
            SetLinePos(spikeX);
            _line.startColor = Color.red;
            _line.endColor = Color.red;
        }

        public void CloseScan()
        {
            _line.enabled = false;
        }

        public void SetScreenSize(float width, float height)
        {
            _screenLeftX = - width / 2;
            _screenRightX = width / 2;

            _topY = height / 2;
            _bottomY = - height / 2;
        }
    }
}