using System.Collections.Generic;
using UnityEngine;

namespace BrewMonster
{
    /// <summary>
    /// Helper class to track and draw gizmos for skill GFX projectiles.
    /// Draws projectile path from host to target, auto-removes after 10 seconds.
    /// 用于跟踪和绘制技能GFX弹道辅助线的辅助类。绘制从施法者到目标的弹道路径，10秒后自动移除。
    /// </summary>
    public static class SkillGfxGizmoDrawer
    {
        /// <summary>
        /// Gizmo data for a single projectile
        /// 单个弹道的辅助线数据
        /// </summary>
        private class GizmoData
        {
            public Vector3 startPos;        // Host position / 施法者位置
            public Vector3 currentPos;      // Current projectile position / 当前弹道位置
            public Vector3 targetPos;       // Target position / 目标位置
            public float createTime;        // Time when created / 创建时间
            public long hostID;             // Host ID for identification / 施法者ID
            public long targetID;           // Target ID for identification / 目标ID
            public GfxMoveMode moveMode;    // Movement mode / 移动模式
        }

        private static readonly List<GizmoData> m_GizmoList = new List<GizmoData>();
        private const float GIZMO_LIFETIME = 10.0f; // 10 seconds / 10秒

        /// <summary>
        /// Register a projectile for gizmo drawing
        /// 注册一个弹道用于辅助线绘制
        /// </summary>
        public static void RegisterProjectile(long hostID, long targetID, Vector3 startPos, Vector3 targetPos, GfxMoveMode moveMode)
        {
            
            var gizmo = new GizmoData
            {
                startPos = startPos,
                currentPos = startPos,
                targetPos = targetPos,
                createTime = Time.time,
                hostID = hostID,
                targetID = targetID,
                moveMode = moveMode
            };
            m_GizmoList.Add(gizmo);
        }

        /// <summary>
        /// Update projectile position
        /// 更新弹道位置
        /// </summary>
        public static void UpdateProjectile(long hostID, long targetID, Vector3 currentPos, Vector3 targetPos)
        {
            for (int i = m_GizmoList.Count - 1; i >= 0; i--)
            {
                var gizmo = m_GizmoList[i];
                if (gizmo.hostID == hostID && gizmo.targetID == targetID)
                {
                    gizmo.currentPos = currentPos;
                    gizmo.targetPos = targetPos; // Update target in case it moves
                    return;
                }
            }
        }

        /// <summary>
        /// Remove projectile gizmo
        /// 移除弹道辅助线
        /// </summary>
        public static void RemoveProjectile(long hostID, long targetID)
        {
            for (int i = m_GizmoList.Count - 1; i >= 0; i--)
            {
                var gizmo = m_GizmoList[i];
                if (gizmo.hostID == hostID && gizmo.targetID == targetID)
                {
                    m_GizmoList.RemoveAt(i);
                    return;
                }
            }
        }

        /// <summary>
        /// Draw all gizmos (called from OnDrawGizmos)
        /// 绘制所有辅助线（从OnDrawGizmos调用）
        /// </summary>
        public static void DrawGizmos()
        {
            if (m_GizmoList.Count == 0)
                return; // No gizmos to draw / 没有辅助线要绘制
            
            float currentTime = Time.time;

            // Remove expired gizmos and draw active ones
            // 移除过期的辅助线并绘制活动的
            for (int i = m_GizmoList.Count - 1; i >= 0; i--)
            {
                var gizmo = m_GizmoList[i];
                float age = currentTime - gizmo.createTime;

                // Remove if expired
                // 如果过期则移除
                if (age > GIZMO_LIFETIME)
                {
                    m_GizmoList.RemoveAt(i);
                    continue;
                }

                // Calculate fade alpha (fade out in last 2 seconds)
                // 计算淡出透明度（最后2秒淡出）
                float alpha = age > (GIZMO_LIFETIME - 2.0f) 
                    ? 1.0f - ((age - (GIZMO_LIFETIME - 2.0f)) / 2.0f)
                    : 1.0f;

                // Draw projectile path
                // 绘制弹道路径
                Gizmos.color = GetColorForMoveMode(gizmo.moveMode, alpha);
                
                // Draw line from start to current position (trail)
                // 绘制从起点到当前位置的线（轨迹）
                if (Vector3.Distance(gizmo.startPos, gizmo.currentPos) > 0.01f)
                {
                    Gizmos.DrawLine(gizmo.startPos, gizmo.currentPos);
                }
                
                // Draw line from current position to target (remaining path)
                // 绘制从当前位置到目标的线（剩余路径）
                Gizmos.color = GetColorForMoveMode(gizmo.moveMode, alpha * 0.5f); // Lighter for remaining path
                if (Vector3.Distance(gizmo.currentPos, gizmo.targetPos) > 0.01f)
                {
                    Gizmos.DrawLine(gizmo.currentPos, gizmo.targetPos);
                }
                
                // Draw sphere at current position (larger for visibility)
                // 在当前位置绘制球体（更大以便可见）
                Gizmos.color = GetColorForMoveMode(gizmo.moveMode, alpha);
                Gizmos.DrawSphere(gizmo.currentPos, 0.5f); // Increased from 0.2f to 0.5f
                
                // Draw wire sphere at target (larger for visibility)
                // 在目标位置绘制线框球体（更大以便可见）
                Gizmos.color = GetColorForMoveMode(gizmo.moveMode, alpha * 0.5f);
                Gizmos.DrawWireSphere(gizmo.targetPos, 0.5f); // Increased from 0.3f to 0.5f
                
                // Draw wire sphere at start position
                // 在起始位置绘制线框球体
                Gizmos.color = GetColorForMoveMode(gizmo.moveMode, alpha * 0.3f);
                Gizmos.DrawWireSphere(gizmo.startPos, 0.3f);
            }
        }

        /// <summary>
        /// Get color for movement mode
        /// 根据移动模式获取颜色
        /// </summary>
        private static Color GetColorForMoveMode(GfxMoveMode mode, float alpha)
        {
            Color baseColor;
            switch (mode)
            {
                case GfxMoveMode.enumLinearMove:
                    baseColor = Color.yellow; // Yellow for linear
                    break;
                case GfxMoveMode.enumOnTarget:
                    baseColor = Color.red; // Red for instant hit
                    break;
                case GfxMoveMode.enumParabolicMove:
                    baseColor = Color.green; // Green for parabolic
                    break;
                case GfxMoveMode.enumMissileMove:
                    baseColor = Color.cyan; // Cyan for missile
                    break;
                default:
                    baseColor = Color.white;
                    break;
            }
            baseColor.a = alpha;
            return baseColor;
        }

        /// <summary>
        /// Clear all gizmos
        /// 清除所有辅助线
        /// </summary>
        public static void ClearAll()
        {
            m_GizmoList.Clear();
        }

        /// <summary>
        /// Get current gizmo count (for debugging)
        /// 获取当前辅助线数量（用于调试）
        /// </summary>
        public static int GetGizmoCount()
        {
            return m_GizmoList.Count;
        }
    }
}