import { _decorator, Component, Node, Vec3, Vec2, find, UITransform, RigidBody2D } from 'cc';
import { BulletTrajectory } from './BulletTrajectory';
const { ccclass, property } = _decorator;

/**
 * 子弹生命周期控制器
 * 负责管理子弹的生存时间和销毁条件
 */

export interface BulletLifecycleConfig {
    type: 'hit_destroy' | 'range_limit' | 'ricochet_counter' | 'ground_impact' | 'return_trip' | 'ground_impact_with_effect' | 'target_impact';
    maxLifetime: number;          // 最大生存时间（秒）
    penetration: number;          // 穿透次数
    ricochetCount: number;        // 弹射次数
    returnToOrigin: boolean;      // 是否返回原点
    returnDelay?: number;         // 返回延迟（秒）
    maxRange?: number;            // 最大射程
    effectDuration?: number;      // 效果持续时间（用于地面效果）
}

export interface LifecycleState {
    elapsedTime: number;          // 已存活时间
    hitCount: number;             // 命中次数
    ricochetLeft: number;         // 剩余弹射次数
    pierceLeft: number;           // 剩余穿透次数
    travelDistance: number;       // 已飞行距离
    phase: 'active' | 'returning' | 'effect' | 'destroyed';  // 生命周期阶段
    shouldDestroy: boolean;       // 是否应该销毁
    startPosition: Vec3;          // 起始位置
    returnTimer: number;          // 返回计时器
}

@ccclass('BulletLifecycle')
export class BulletLifecycle extends Component {
    private config: BulletLifecycleConfig = null;
    private state: LifecycleState = null;
    private lastPosition: Vec3 = new Vec3();
    
    /**
     * 初始化生命周期
     */
    public init(config: BulletLifecycleConfig, startPos: Vec3) {
        this.config = { ...config };
        
        this.state = {
            elapsedTime: 0,
            hitCount: 0,
            ricochetLeft: config.ricochetCount,
            pierceLeft: config.penetration,
            travelDistance: 0,
            phase: 'active',
            shouldDestroy: false,
            startPosition: startPos.clone(),
            returnTimer: config.returnDelay || 0
        };
        
        this.lastPosition = this.node.worldPosition.clone();
    }
    
    /**
     * 处理命中事件
     */
    public onHit(hitNode: Node): boolean {
        if (!this.config || !this.state) return true;
        
        this.state.hitCount++;
        
        switch (this.config.type) {
            case 'hit_destroy':
                return this.handleHitDestroy();
                
            case 'range_limit':
                return this.handleRangeLimit();
                
            case 'ricochet_counter':
                return this.handleRicochetCounter();
                
            case 'ground_impact':
            case 'ground_impact_with_effect':
                return this.handleGroundImpact(hitNode);
                
            case 'return_trip':
                return this.handleReturnTrip();
                
            case 'target_impact':
                return this.handleTargetImpact(hitNode);
                
            default:
                return true; // 默认销毁
        }
    }
    
    /**
     * 处理命中即销毁逻辑
     */
    private handleHitDestroy(): boolean {
        this.state.shouldDestroy = true;
        return true;
    }
    
    /**
     * 处理射程限制逻辑
     */
    private handleRangeLimit(): boolean {
        // 穿透逻辑
        if (this.state.pierceLeft > 0) {
            this.state.pierceLeft--;
            return false; // 不销毁，继续飞行
        } else {
            this.state.shouldDestroy = true;
            return true;
        }
    }
    
    /**
     * 处理弹射计数逻辑
     */
    private handleRicochetCounter(): boolean {
        if (this.state.ricochetLeft > 0) {
            this.state.ricochetLeft--;
            
            // 触发弹射
            const trajectory = this.getComponent(BulletTrajectory);
            if (trajectory) {
                // BulletTrajectory会处理方向改变
            }
            
            return false; // 不销毁，继续弹射
        } else {
            this.state.shouldDestroy = true;
            return true;
        }
    }
    
    /**
     * 处理地面撞击逻辑
     */
    private handleGroundImpact(hitNode: Node): boolean {
        const isGround = this.isGroundNode(hitNode);
        
        if (isGround) {
            // 进入效果阶段
            this.state.phase = 'effect';
            
            // 延迟销毁，等待效果结束
            if (this.config.effectDuration && this.config.effectDuration > 0) {
                this.scheduleOnce(() => {
                    this.state.shouldDestroy = true;
                }, this.config.effectDuration);
            } else {
                this.state.shouldDestroy = true;
            }
            
            return true;
        } else {
            // 延迟销毁，确保爆炸的 0.1 s 延迟能正常触发
            this.scheduleOnce(() => {
                this.state.shouldDestroy = true;
            }, 0.2);

            // === 立即冻结子弹运动，避免命中后继续绕圈 ===
            const trajectory = this.getComponent(BulletTrajectory);
            if (trajectory) {
                trajectory.enabled = false; // 停止后续 update
            }

            const rigidBody = this.getComponent(RigidBody2D);
            if (rigidBody) {
                rigidBody.linearVelocity = new Vec2(0, 0);
                rigidBody.angularVelocity = 0;
            }
            
            return true;
        }
    }
    
    /**
     * 处理回旋镖逻辑
     */
    private handleReturnTrip(): boolean {
        if (this.state.phase === 'active') {
            // 首次命中立即开始返程，不再依据pierceLeft
            this.startReturn();
            return false; // 不销毁
        } else if (this.state.phase === 'returning') {
            // 返回途中命中，仅造成伤害不销毁
            return false;
        }
        return false;
    }
    
    /**
     * 处理目标撞击逻辑（导弹）
     */
    private handleTargetImpact(hitNode: Node): boolean {
        const isEnemy = this.isEnemyNode(hitNode);
        
        if (isEnemy) {
            this.state.shouldDestroy = true;
            return true;
        }
        
        // 如果不是敌人，继续飞行（导弹不会被其他物体阻挡）
        return false;
    }
    
    /**
     * 判断是否为地面节点
     */
    private isGroundNode(node: Node): boolean {
        const name = node.name.toLowerCase();
        return name.includes('ground') || 
               name.includes('wall') || 
               name.includes('地面') ||
               name.includes('墙');
    }
    
    /**
     * 判断是否为敌人节点
     */
    private isEnemyNode(node: Node): boolean {
        const name = node.name.toLowerCase();
        return name.includes('enemy') || 
               name.includes('敌人') ||
               node.getComponent('EnemyInstance') !== null;
    }
    
    update(dt: number) {
        if (!this.config || !this.state) return;
        
        this.state.elapsedTime += dt;
        
        // 更新飞行距离
        this.updateTravelDistance();
        
        // 检查各种销毁条件
        this.checkDestroyConditions();
        
        // 处理特殊逻辑
        this.updateSpecialLogic(dt);
        
        // 如果需要销毁，执行销毁
        if (this.state.shouldDestroy) {
            this.destroyBullet();
        }
    }
    
    /**
     * 更新飞行距离
     */
    private updateTravelDistance() {
        const currentPos = this.node.worldPosition;
        const distance = Vec3.distance(this.lastPosition, currentPos);
        this.state.travelDistance += distance;
        this.lastPosition.set(currentPos);
    }
    
    /**
     * 检查销毁条件
     */
    private checkDestroyConditions() {
        // 检查时间限制
        if (this.state.elapsedTime >= this.config.maxLifetime) {
            this.state.shouldDestroy = true;
            return;
        }
        
        // === 射程限制逻辑优化 ===
        if (this.config.maxRange && this.state.travelDistance >= this.config.maxRange) {
            if (this.config.type === 'range_limit') {
                this.state.shouldDestroy = true;
            } else if (this.config.type === 'return_trip') {
                // 回旋镖：首次超距时开始返回；返回途中不再因射程销毁
                if (this.state.phase === 'active') {
                    this.startReturn();
                }
            }
            // 其他生命周期类型忽略射程限制
            return;
        }
        
        // 检查越界
        if (this.checkOutOfBounds()) {
            if (this.config.type === 'return_trip' && this.state.phase === 'active') {
                this.startReturn();
            } else {
                this.state.shouldDestroy = true;
            }
            return;
        }
    }
    
    /**
     * 更新特殊逻辑
     */
    private updateSpecialLogic(dt: number) {
        switch (this.config.type) {
            case 'return_trip':
                this.updateReturnTrip(dt);
                break;
        }
    }
    
    /**
     * 更新回旋镖逻辑
     */
    private updateReturnTrip(dt: number) {
        if (this.state.phase === 'active' && this.state.returnTimer > 0) {
            this.state.returnTimer -= dt;
            if (this.state.returnTimer <= 0) {
                this.startReturn();
            }
        } else if (this.state.phase === 'returning') {
            // 检查是否返回到原点
            const distanceToOrigin = Vec3.distance(this.node.worldPosition, this.state.startPosition);
            if (distanceToOrigin <= 50) { // 50单位的容差
                this.state.shouldDestroy = true;
            }
        }
    }
    
    /**
     * 开始返回
     */
    private startReturn() {
        this.state.phase = 'returning';
        
        const trajectory = this.getComponent(BulletTrajectory);
        if (trajectory) {
            trajectory.setTargetPosition(this.state.startPosition);
            trajectory.reverseDirection();
        }
    }
    
    /**
     * 检查越界
     */
    private checkOutOfBounds(): boolean {
        // 优先使用 GameArea 的可视区域（若存在）
        const gameArea = find('Canvas/GameLevelUI/GameArea');
        let bounding = null;
        if (gameArea) {
            const tr = gameArea.getComponent(UITransform);
            if (tr) {
                bounding = tr.getBoundingBoxToWorld();
            }
        }

        // fallback => Canvas 整体区域
        if (!bounding) {
            const canvas = find('Canvas');
            if (canvas) {
                const tr = canvas.getComponent(UITransform);
                if (tr) {
                    bounding = tr.getBoundingBoxToWorld();
                }
            }
        }

        // 若无法获取区域，则不做越界销毁
        if (!bounding) return false;

        // 允许一定的 margin
        const margin = 300; // 扩大容差，防止大速度时瞬移出界
        const pos = this.node.worldPosition;

        return pos.x < bounding.xMin - margin ||
               pos.x > bounding.xMax + margin ||
               pos.y < bounding.yMin - margin ||
               pos.y > bounding.yMax + margin;
    }
    
    /**
     * 销毁子弹
     */
    private destroyBullet() {
        this.node.destroy();
    }
    
    /**
     * 获取生命周期状态
     */
    public getState(): LifecycleState {
        return this.state;
    }
    
    /**
     * 检查是否应该销毁
     */
    public shouldDestroy(): boolean {
        return this.state ? this.state.shouldDestroy : true;
    }
    
    /**
     * 强制销毁
     */
    public forceDestroy() {
        this.state.shouldDestroy = true;
    }
    
    /**
     * 获取剩余生命时间
     */
    public getRemainingLifetime(): number {
        if (!this.config || !this.state) return 0;
        return Math.max(0, this.config.maxLifetime - this.state.elapsedTime);
    }
    
    /**
     * 验证配置
     */
    public static validateConfig(config: BulletLifecycleConfig): boolean {
        if (!config) return false;
        
        if (config.maxLifetime <= 0) return false;
        if (config.penetration < 0) return false;
        if (config.ricochetCount < 0) return false;
        if (config.maxRange && config.maxRange <= 0) return false;
        if (config.effectDuration && config.effectDuration < 0) return false;
        if (config.returnDelay && config.returnDelay < 0) return false;
        
        return true;
    }
}