using UnityEngine;
using UnityEngine.UI;
using TMPro;
using System.Linq;

public class StairDiagramController : MonoBehaviour
{
    [Header("元件綁定")]
    public RectTransform 繪圖區_panel;
    public RectTransform 對應資訊區_panel;
    public GameObject 階梯Prefab;
    public GameObject 資訊列Prefab; // 預設放一個 TMP Text 或含文字的UI列
    public GameObject 線段編號Prefab;

    [Header("參數設定")]
    [SerializeField] TMP_InputField  階梯階數_tb;
    [SerializeField] TextMeshProUGUI 總深_tb,總高_tb, 斜邊_tb, 長邊_tb, 推薦斜邊_tb, 推薦長邊_tb, 最小斜邊_tb, 最小長邊_tb;
    [SerializeField] TMP_InputField[] 高;
    [SerializeField] TMP_InputField[] 深;

    [SerializeField] Image 法規_bg,推薦_bg,最小_bg;
    [SerializeField] GameObject 簡易圖_pl,斜坡板參數_pl;
    
    int 線段編號 = 1;
    public void 返回參數(){
        簡易圖_pl.SetActive(false);
        斜坡板參數_pl.SetActive(true);
    }
    public void 生成法規圖(string 畫圖種類){
        法規_bg.color=Color.white;推薦_bg.color=Color.white;最小_bg.color=Color.white;
        if (畫圖種類 == "法規"){
            法規_bg.color = new Color32(253, 228, 151, 255);
        }
        else if (畫圖種類 == "推薦"){
            推薦_bg.color = new Color32(253, 228, 151, 255);
        }
        else if (畫圖種類 == "最小"){
            最小_bg.color = new Color32(253, 228, 151, 255);
        }
        
        int 階梯層數 = int.Parse(階梯階數_tb.text);
        float shortSide = float.Parse(總高_tb.text);
        float longSide = float.Parse(總深_tb.text);
        if (shortSide == 0f || longSide == 0f)
            return;
        簡易圖_pl.SetActive(true);
        斜坡板參數_pl.SetActive(false);
        foreach (Transform child in 繪圖區_panel)
            Destroy(child.gameObject);
        foreach (Transform child in 對應資訊區_panel)
            Destroy(child.gameObject);

        線段編號 = 1;
        float[] stepWidths = GetStepWidths(1);
        float[] stepHeights = GetStepHeights(1);
        float lastStepWidth = stepWidths[階梯層數 - 1];
        
        double angle = 0;
        if (shortSide >= 20){
            angle = 4.78;
        }else if(shortSide >=5 && shortSide < 20){
            angle = 5.74;
        }else if(shortSide >=4 && shortSide < 5){
            angle = 11.54;
        }else if(shortSide >=0 && shortSide < 3){
            angle = 30;
        }
        計算斜邊(angle, shortSide, longSide, stepWidths[階梯層數 - 1], 斜邊_tb, 長邊_tb);
        計算斜邊(9.59, shortSide, longSide, stepWidths[階梯層數 - 1], 推薦斜邊_tb, 推薦長邊_tb);
        計算斜邊(11.54, shortSide, longSide, stepWidths[階梯層數 - 1], 最小斜邊_tb, 最小長邊_tb);
        
        float hypotenuse = float.Parse(斜邊_tb.text);
        float hypotenuse2 = float.Parse(推薦斜邊_tb.text);
        float hypotenuse3 = float.Parse(最小斜邊_tb.text);

        float longuse = float.Parse(長邊_tb.text);
        float longuse2 = float.Parse(推薦長邊_tb.text);
        float longuse3 = float.Parse(最小長邊_tb.text);
       
        float otherSide = Mathf.Sqrt(hypotenuse * hypotenuse - shortSide * shortSide);
        float otherSide2 = Mathf.Sqrt(hypotenuse2 * hypotenuse2 - shortSide * shortSide);
        float otherSide3 = Mathf.Sqrt(hypotenuse3 * hypotenuse3 - shortSide * shortSide);
        float setWidthLast = GetStepWidths(1)[階梯層數 - 1];
        float 倍數 = Mathf.Round((繪圖區_panel.rect.width - 100f) / (otherSide + setWidthLast) * 100f) / 100f;

        float bottomY = 100f;
        float pointA_x = 10f;
        Vector2 pointA = new Vector2(pointA_x, bottomY);
        Vector2 pointB = new Vector2(pointA.x + otherSide * 倍數, bottomY);
        Vector2 pointC = new Vector2(pointB.x, bottomY + shortSide * 倍數);
        Vector2 pointD = new Vector2(pointB.x - otherSide2 * 倍數, bottomY);
        Vector2 pointE = new Vector2(pointB.x - otherSide3 * 倍數, bottomY);

        if(畫圖種類=="法規"){
            DrawLine(pointA, pointC, Color.blue, 畫圖種類+"斜坡板長度", hypotenuse);
            DrawLine(pointA, pointB, Color.black, "通道保留空間", longuse);
        }else if(畫圖種類=="推薦"){
            DrawLine(pointD, pointC, Color.black, 畫圖種類+"斜坡板長度", hypotenuse);
            DrawLine(pointD, pointB, Color.black, "通道保留空間", longuse2);
        }else{//最小
            DrawLine(pointE, pointC, Color.red, 畫圖種類+"斜坡板長度", hypotenuse);
            DrawLine(pointE, pointB, Color.black, "通道保留空間", longuse3);
        }
        
        float startX = pointA.x + otherSide * 倍數;
        for (int i = 0; i < 階梯層數 - 1; i++)
            startX -= stepWidths[i] * 倍數;

        float baseX;
        float baseOtherSide;

        if (畫圖種類 == "法規"){
            baseX = pointA.x;
            baseOtherSide = otherSide;
        }else if (畫圖種類 == "推薦"){
            baseX = pointD.x;
            baseOtherSide = otherSide2;
        }else{ // 最小
            baseX = pointE.x;
            baseOtherSide = otherSide3;
        }

        for (int i = 0; i < 階梯層數 - 1; i++)
        {
            float leftX = startX + stepWidths.Take(i).Sum() * 倍數;
            float stairTopY = bottomY + stepHeights.Take(i + 1).Sum() * 倍數;
            Vector2 stairTop = new Vector2(leftX, stairTopY);

            // 法規線在對應 X 的 Y 高度
            float slopeY = bottomY + (leftX - baseX) * (shortSide / baseOtherSide);
            Vector2 intersectPoint = new Vector2(leftX, slopeY);

            // ✅ 關鍵修改：統一與 VB 一樣公式
            float 垂直距離 = Mathf.Round((slopeY - stairTopY) / 倍數 * 10f) / 10f;

            Vector2 mid = (stairTop + intersectPoint) / 2 + Vector2.up * 10;
            DrawLine(stairTop, intersectPoint, Color.yellow, "間距", 垂直距離);
        }


        float stairX = startX;
        float stairY = bottomY;

        for (int i = 0; i < 階梯層數; i++){
            float w = stepWidths[i] * 倍數;
            float h = stepHeights[i] * 倍數;
            DrawStairBox(new Vector2(stairX, stairY), w, h);
            stairX += w;
            stairY += h;
        }
    }
    void DrawStairBox(Vector2 bottomLeft, float width, float height){
        GameObject box = Instantiate(階梯Prefab, 繪圖區_panel);
        RectTransform rt = box.GetComponent<RectTransform>();

        rt.anchorMin = rt.anchorMax = rt.pivot = new Vector2(0, 0); // 左下角錨點
        rt.anchoredPosition = bottomLeft;
        rt.sizeDelta = new Vector2(width, height);
    }
    void DrawLine(Vector2 start, Vector2 end, Color color, string 用途 = "", float 實際長度 = -1f){
        GameObject line = new GameObject("UILine", typeof(Image));
        line.transform.SetParent(繪圖區_panel, false);

        RectTransform rt = line.GetComponent<RectTransform>();
        Image image = line.GetComponent<Image>();
        image.color = color;

        Vector2 direction = end - start;
        float length = direction.magnitude;
        float angle = Mathf.Atan2(direction.y, direction.x) * Mathf.Rad2Deg;

        rt.sizeDelta = new Vector2(length, 10f);
        rt.pivot = new Vector2(0, 0.5f);
        rt.anchorMin = new Vector2(0, 0);
        rt.anchorMax = new Vector2(0, 0);
        rt.anchoredPosition = start;
        rt.localRotation = Quaternion.Euler(0, 0, angle);

        // 加線段編號（畫面旁邊）
       GameObject label = Instantiate(線段編號Prefab, 繪圖區_panel);
        TextMeshProUGUI text = label.GetComponent<TextMeshProUGUI>();
        text.text = $"L{線段編號}";
        RectTransform textRT = label.GetComponent<RectTransform>();
        textRT.anchorMin = textRT.anchorMax = new Vector2(0, 0);
        textRT.pivot = new Vector2(0.5f, 0.5f);
        // 計算文字偏移（避免被線擋住）
        Vector2 mid = (start + end) / 2;
        Vector2 offset = Vector2.Perpendicular((end - start).normalized) * 15f;
        textRT.anchoredPosition = mid + offset;

        label.transform.SetAsLastSibling();
        // 紀錄這條線的資訊到對應區域
        if (string.IsNullOrEmpty(用途))
            用途 = "未指定";

        if (實際長度 < 0f)
            實際長度 = Vector2.Distance(start, end); // fallback 值

        AddInfoRow($"L{線段編號}", 用途, 實際長度);
        線段編號++;
    }
    void AddInfoRow(string 編號, string 用途, float 長度){
        GameObject row = Instantiate(資訊列Prefab, 對應資訊區_panel);
        TextMeshProUGUI[] labels = row.GetComponentsInChildren<TextMeshProUGUI>();
        labels[0].text = 編號 + " | ";
        labels[1].text = $"{用途} | {Mathf.Round(長度 * 10f) / 10f} cm";
    }
    public float[] GetStepWidths(float multiplier){
        float[] widths = new float[深.Length];
        for (int i = 0; i < 深.Length; i++){
            widths[i] = GetDepthValue(深[i], multiplier);
        }
        return widths;
    }


    public float[] GetStepHeights(float multiplier)
    {
        float[] heights = new float[高.Length];
        for (int i = 0; i < 高.Length; i++){
            heights[i] = GetHeightValue(高[i], multiplier);
        }
        return heights;
    }


    private float GetDepthValue(TMP_InputField inputField, float multiplier){
        if (!string.IsNullOrWhiteSpace(inputField.text) && float.TryParse(inputField.text, out float value)){
            return value * multiplier;
        }
        return 0f;
    }


    private float GetHeightValue(TMP_InputField inputField, float multiplier){
        if (!string.IsNullOrWhiteSpace(inputField.text) && float.TryParse(inputField.text, out float value)){
            return value * multiplier;
        }
        return 0f;
    }
    void 計算斜邊(double angle, double 短邊, double 長邊, double setWidth, TextMeshProUGUI 斜邊Text, TextMeshProUGUI 長邊Text){
        double angleInRadians = angle * Mathf.Deg2Rad;
        double hypotenuse = 短邊 / Mathf.Sin((float)angleInRadians);
        double longSide = hypotenuse * Mathf.Cos((float)angleInRadians) - 長邊 + setWidth;

        斜邊Text.text = System.Math.Round(hypotenuse, 1, System.MidpointRounding.AwayFromZero).ToString();
        長邊Text.text = System.Math.Round(longSide, 1, System.MidpointRounding.AwayFromZero).ToString();
    }
}