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

/// <summary>
/// UI兼容的图表组件
/// 使用UI Image和RectTransform在Canvas中绘制折线图，替代LineRenderer
/// </summary>
public class UIChartComponent : MonoBehaviour
{
    [Header("图表设置")]
    public RectTransform chartArea;
    public TextMeshProUGUI valueLabel;
    public TextMeshProUGUI titleLabel;
    public Color lineColor = Color.green;
    public float lineWidth = 2f;
    
    [Header("数据设置")]
    public int maxDataPoints = 50;
    public float minValue = 0f;
    public float maxValue = 100f;
    public string unit = "";
    
    [Header("UI设置")]
    public GameObject linePrefab; // 预制件：包含Image组件的GameObject
    public Transform lineParent; // 折线段的父物体
    
    private List<float> dataPoints = new List<float>();
    private List<GameObject> lineSegments = new List<GameObject>();
    
    void Awake()
    {
        InitializeChart();
    }
    
    /// <summary>
    /// 初始化图表
    /// </summary>
    private void InitializeChart()
    {
        // 如果没有设置lineParent，使用chartArea
        if (lineParent == null && chartArea != null)
        {
            lineParent = chartArea;
        }
        
        // 如果没有linePrefab，创建一个默认的
        if (linePrefab == null)
        {
            CreateDefaultLinePrefab();
        }
    }
    
    /// <summary>
    /// 创建默认的线段预制件
    /// </summary>
    private void CreateDefaultLinePrefab()
    {
        linePrefab = new GameObject("LineSegment");
        
        // 添加RectTransform
        var rectTransform = linePrefab.AddComponent<RectTransform>();
        rectTransform.anchorMin = new Vector2(0.5f, 0.5f);
        rectTransform.anchorMax = new Vector2(0.5f, 0.5f);
        rectTransform.pivot = new Vector2(0.5f, 0.5f);
        
        // 添加Image组件
        var image = linePrefab.AddComponent<Image>();
        image.color = lineColor;
        
        // 设置为预制件状态
        linePrefab.SetActive(false);
    }
    
    /// <summary>
    /// 添加数据点
    /// </summary>
    public void AddDataPoint(float value)
    {
        dataPoints.Add(value);
        
        // 保持最大数据点数量
        if (dataPoints.Count > maxDataPoints)
        {
            dataPoints.RemoveAt(0);
        }
        
        UpdateChart();
        UpdateValueLabel(value);
    }
    
    /// <summary>
    /// 更新图表显示
    /// </summary>
    private void UpdateChart()
    {
        if (chartArea == null || lineParent == null)
        {
            return;
        }

        int requiredSegmentCount = Mathf.Max(0, dataPoints.Count - 1);
        EnsureLineSegmentCount(requiredSegmentCount);

        var rect = chartArea.rect;
        var width = rect.width;
        var height = rect.height;
        
        for (int i = 0; i < lineSegments.Count; i++)
        {
            var segment = lineSegments[i];
            if (segment == null)
            {
                continue;
            }

            bool active = i < requiredSegmentCount;
            if (segment.activeSelf != active)
            {
                segment.SetActive(active);
            }

            if (!active)
            {
                continue;
            }

            Vector2 point1 = CalculatePointPosition(i, dataPoints[i], width, height);
            Vector2 point2 = CalculatePointPosition(i + 1, dataPoints[i + 1], width, height);
            UpdateLineSegment(segment, point1, point2);
        }
    }
    
    /// <summary>
    /// 计算数据点在图表中的位置
    /// </summary>
    private Vector2 CalculatePointPosition(int index, float value, float width, float height)
    {
        float x = (float)index / (maxDataPoints - 1) * width - width / 2;
        float y = Mathf.Lerp(-height / 2, height / 2, 
            Mathf.InverseLerp(minValue, maxValue, value));
        
        return new Vector2(x, y);
    }
    
    /// <summary>
    /// 创建线段
    /// </summary>
    private void EnsureLineSegmentCount(int requiredCount)
    {
        if (linePrefab == null)
        {
            return;
        }

        while (lineSegments.Count < requiredCount)
        {
            GameObject segment = Instantiate(linePrefab, lineParent);
            segment.SetActive(false);
            lineSegments.Add(segment);
        }
    }

    private void UpdateLineSegment(GameObject segment, Vector2 point1, Vector2 point2)
    {
        if (segment == null) return;

        RectTransform segmentRect = segment.GetComponent<RectTransform>();
        Image segmentImage = segment.GetComponent<Image>();
        if (segmentRect == null) return;
        
        // 计算线段的位置、长度和角度
        Vector2 direction = point2 - point1;
        float length = direction.magnitude;
        float angle = Mathf.Atan2(direction.y, direction.x) * Mathf.Rad2Deg;
        
        // 设置线段位置（中心点）
        segmentRect.anchoredPosition = (point1 + point2) / 2;
        
        // 设置线段大小（宽度为lineWidth，高度为长度）
        segmentRect.sizeDelta = new Vector2(length, lineWidth);
        
        // 设置线段旋转
        segmentRect.rotation = Quaternion.Euler(0, 0, angle);
        
        // 设置颜色
        if (segmentImage != null)
        {
            segmentImage.color = lineColor;
        }
    }
    
    /// <summary>
    /// 清除所有线段
    /// </summary>
    private void ClearLineSegments()
    {
        foreach (var segment in lineSegments)
        {
            if (segment != null)
            {
                Destroy(segment);
            }
        }
        lineSegments.Clear();
    }
    
    /// <summary>
    /// 更新数值标签
    /// </summary>
    private void UpdateValueLabel(float value)
    {
        if (valueLabel != null)
        {
            valueLabel.text = value.ToString("F1") + unit;
        }
    }
    
    /// <summary>
    /// 设置图表标题
    /// </summary>
    public void SetTitle(string title)
    {
        if (titleLabel != null)
        {
            titleLabel.text = title;
        }
    }
    
    /// <summary>
    /// 设置线条颜色
    /// </summary>
    public void SetLineColor(Color color)
    {
        lineColor = color;
        
        // 更新现有线段的颜色
        foreach (var segment in lineSegments)
        {
            if (segment != null)
            {
                var image = segment.GetComponent<Image>();
                if (image != null)
                {
                    image.color = lineColor;
                }
            }
        }
    }
    
    /// <summary>
    /// 设置值范围
    /// </summary>
    public void SetValueRange(float min, float max)
    {
        minValue = min;
        maxValue = max;
        UpdateChart(); // 重新绘制图表以应用新范围
    }
    
    /// <summary>
    /// 清空数据
    /// </summary>
    public void ClearData()
    {
        dataPoints.Clear();
        ClearLineSegments();
        
        if (valueLabel != null)
        {
            valueLabel.text = "0.0" + unit;
        }
    }
    
    /// <summary>
    /// 获取当前数据点数量
    /// </summary>
    public int GetDataPointCount()
    {
        return dataPoints.Count;
    }
    
    /// <summary>
    /// 获取最新的数据值
    /// </summary>
    public float GetLatestValue()
    {
        return dataPoints.Count > 0 ? dataPoints[dataPoints.Count - 1] : 0f;
    }
    
    void OnDestroy()
    {
        ClearLineSegments();
    }
}