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

public class PenetrateBulletCurve : BulletCurve
{
    private Vector2 start;      // 子弹起点（本地坐标）
    private Vector2 end;        // 目标点（本地坐标）
    private Vector2 outPos;     // 屏幕外延长点（本地坐标）
    private bool hitTriggered = false; // 是否已触发onHit

    public PenetrateBulletCurve(BattleObject caster, SkillConfig skillConfig, BattleEffectPlayer effectPlayer, RectTransform target, List<HB427_tagSCUseSkill.tagSCUseSkillHurt> hurtList, int bulletIndex, Action<int, List<HB427_tagSCUseSkill.tagSCUseSkillHurt>> onHit)
        : base(caster, skillConfig, effectPlayer, target, hurtList, bulletIndex, onHit) { }

    /// <summary>
    /// 初始化弹道参数
    /// </summary>
    public override void Reset()
    {
        base.Reset();
        hitTriggered = false;
        start = WorldToLocalAnchoredPosition(bulletTrans.position) + bulletOffset;
        end = WorldToLocalAnchoredPosition(target.position);
        duration = Vector2.Distance(start, end) / skillConfig.BulletFlySpeed;
        Vector2 dir = (end - start).normalized;
        float extend = 500f; // 贯穿距离，可根据需求调整
        outPos = end + dir * extend;
    }

    /// <summary>
    /// 每帧调用，驱动子弹移动和表现
    /// </summary>
    public override void Run()
    {
        if (finished) return;
        elapsed += Time.deltaTime;
        float t = Mathf.Clamp01(elapsed / duration);

        // 贯穿分两段：0~0.5到目标点，0.5~1.0继续飞出
        float mid = 0.5f;
        Vector2 pos;
        if (t < mid)
        {
            // 前半段：插值到目标点
            pos = Vector2.Lerp(start, end, t / mid);
        }
        else
        {
            // 后半段：插值到屏幕外
            pos = Vector2.Lerp(end, outPos, (t - mid) / (1f - mid));
            // 到达目标点瞬间触发onHit，只触发一次
            if (!hitTriggered)
            {
                hitTriggered = true;
                onHit?.Invoke(mBulletIndex, hurts);
            }
        }
        bulletTrans.anchoredPosition = pos;

        // 旋转：始终朝向运动方向，子弹默认90°向上
        Vector2 dir = (t < mid) ? (end - start) : (outPos - end);
        float angle = Mathf.Atan2(dir.y, dir.x) * Mathf.Rad2Deg - 90f;
        bulletTrans.localRotation = Quaternion.Euler(0, 0, angle);

        // 到达终点，结束
        if (t >= 1f)
        {
            finished = true;
        }
    }
}