//--------------------------------------------------------
//    [Author]:           第二世界
//    [  Date ]:           Monday, September 11, 2017
//--------------------------------------------------------
using UnityEngine;
using System.Collections;
using UnityEngine.UI;

using System.Text;

public class BossLifeBar : MonoBehaviour
{
    [SerializeField] Sprite[] m_LifeBarSprites;

    [SerializeField] Image m_BackGround;
    [SerializeField] Image m_MiddleGround;
    [SerializeField] Image m_PrefaceGround;

    [SerializeField] Slider m_SliderMiddleground;
    [SerializeField] Slider m_SliderForeground;

    [SerializeField] Text m_Surplus;

    [SerializeField] Text m_SurplusPercent;
    

    [SerializeField] float m_SmoothTime = 0.3f;
    public float smoothTime {
        get { return m_SmoothTime; }
    }

    Pattern pattern = Pattern.Reduce;
    float targetValue = 0f;
    int totalSegments = 1;
    int surplusSegments = -1;

    float refValue = 0f;
    float timer = 0f;
    float behaviourStartValue = 0f;

    float m_CurrentBehaviourValue = 0f;
    float currentBehaviourValue {
        get { return m_CurrentBehaviourValue; }
        set {
            m_CurrentBehaviourValue = value;
            UpdateSurplusSegments(currentBehaviourValue);

            float behaviourDecimalValue = GetSegmentDecimal(m_CurrentBehaviourValue);
            float trueDecimalValue = GetSegmentDecimal(targetValue);

            switch (pattern)
            {
                case Pattern.Add:
                    m_SliderForeground.value = behaviourDecimalValue;
                    m_SliderMiddleground.value = behaviourDecimalValue > trueDecimalValue ? 1f : trueDecimalValue;
                    break;
                case Pattern.Reduce:
                    m_SliderMiddleground.value = behaviourDecimalValue;
                    m_SliderForeground.value = behaviourDecimalValue < trueDecimalValue ? 0f : trueDecimalValue;
                    break;
                case Pattern.None:
                    m_SliderMiddleground.value = behaviourDecimalValue;
                    m_SliderForeground.value = behaviourDecimalValue;
                    break;
            }
        }
    }

    public void SetBaseInfo(int _lifeBarCount, ulong _hp, ulong _maxHp)
    {
        surplusSegments = -1;
        totalSegments = _lifeBarCount;

        // 使用精确值，不再人为减小
        float percentage = (_maxHp > 0) ? (float)_hp / (float)_maxHp : 0f;
        targetValue = currentBehaviourValue = percentage * totalSegments;

        // 使用统一的 GetSegmentDecimal，避免小数精度导致进度条为0
        var behaviourDecimalValue = GetSegmentDecimal(currentBehaviourValue);
        m_SliderForeground.value = m_SliderMiddleground.value = behaviourDecimalValue;

        refValue = 0f;

        // 立刻显示基准百分比（使用 percentage）
        m_SurplusPercent.text = (percentage * 100f).ToString("F2") + "%";
    }

    public void Show(ulong _hp, ulong _maxHp)
    {
        var percentage = Mathf.Clamp(_hp, 0, _maxHp) / (float)_maxHp;
        var tempValue = totalSegments * percentage; // 不再减小
        pattern = tempValue > targetValue ? Pattern.Add : tempValue < targetValue ? Pattern.Reduce : Pattern.None;

        behaviourStartValue = currentBehaviourValue;
        targetValue = tempValue;

        timer = 0f;
        refValue = 0f;

        // 立即更新百分比显示（直接使用 percentage）
        m_SurplusPercent.text = (percentage * 100f).ToString("F2") + "%";
    }

    private void LateUpdate()
    {
        if (Mathf.Abs(currentBehaviourValue - targetValue) > 0.00001f)
        {
            var newValue = Mathf.SmoothDamp(currentBehaviourValue, targetValue, ref refValue, smoothTime);
            currentBehaviourValue = newValue;
        }
    }

    static StringBuilder stringBuild = new StringBuilder();
    private void UpdateSurplusSegments(float _targetValue)
    {
        var currentSurplus = Mathf.CeilToInt(_targetValue);
        if (currentSurplus != surplusSegments)
        {
            surplusSegments = currentSurplus;
            var colorSetLength = m_LifeBarSprites.Length;
            var index = surplusSegments % colorSetLength;
            var nextIndex = index == 0 ? colorSetLength - 1 : index - 1;

            m_PrefaceGround.overrideSprite = m_LifeBarSprites[index];
            m_MiddleGround.overrideSprite = m_LifeBarSprites[index];
            m_BackGround.overrideSprite = m_LifeBarSprites[nextIndex];

            m_BackGround.SetActive(surplusSegments > 1);

            m_Surplus.text = "x" + surplusSegments.ToString();
            float pct = totalSegments > 0 ? Mathf.Clamp01(_targetValue / totalSegments) : 0f;
            // 修复格式并处理接近 100% 的情况
            if (1f - pct < 0.00005f) pct = 1f;
            m_SurplusPercent.text = (pct * 100f).ToString("F2") + "%";
        }
    }

    // int GetNumKey(int _num)
    // {
    //     var config = DamageNumConfig.Get("BossLifeBarSurplusNum");
    //     return config.nums[_num - 48];
    // }


    enum Pattern
    {
        None,
        Add,
        Reduce,
    }

    // helper: 返回段内小数部分；当恰好为整数且大于0时，返回1以表示满格（避免0导致进度条变空）
    private float GetSegmentDecimal(float value)
    {
        // 先判断是否为 0，避免被误判为"整段满格"
        if (value <= 0f) return 0f;

        // 使用一个小的容忍值来处理浮点误差，避免 near-integer 导致 0
        const float eps = 1e-5f;

        // 先做一个向下稳定的 floor，避免 2.999999 变成 2 的问题
        float stableFloor = Mathf.Floor(value + eps);
        float frac = value - stableFloor;

        // 只有在 value > 0 且接近整数时才返回 1（表示当前段满格）
        if (frac <= eps && value >= 1f - eps)
            return 1f;
        
        return Mathf.Clamp01(frac);
    }

}