/**
 * 文件功能：聊天室特效管理器
 *
 * 统一管理全屏 Canvas 特效的入口、防重入和资源清理。
 * 使用方式：EffectManager.play('fireworks' | 'rain' | 'lightning' | 'snow' | 'sakura' | 'meteors' | 'gold-rain' | 'hearts' | 'confetti' | 'fireflies')
 */

const EffectManager = (() => {
    // 当前正在播放的特效名称（防止同时播放两个特效）
    let _current = null;
    // 全屏 Canvas 元素引用
    let _canvas = null;
    // 待播放特效队列，避免多个进场效果互相打断
    const _queue = [];

    /**
     * 获取或创建全屏 Canvas 元素
     * 属性：fixed 定位，覆盖全屏，pointer-events:none 不阻止用户交互
     */
    function _getCanvas() {
        if (_canvas && document.body.contains(_canvas)) {
            return _canvas;
        }
        const c = document.createElement("canvas");
        c.id = "effect-canvas";
        c.style.cssText = [
            "position:fixed",
            "top:0",
            "left:0",
            "width:100vw",
            "height:100vh",
            "z-index:99999",
            "pointer-events:none",
        ].join(";");
        c.width = window.innerWidth;
        c.height = window.innerHeight;
        document.body.appendChild(c);
        _canvas = c;
        return c;
    }

    /**
     * 特效结束后清理 Canvas，重置状态，并停止音效
     */
    function _cleanup() {
        if (_canvas && document.body.contains(_canvas)) {
            document.body.removeChild(_canvas);
        }
        _canvas = null;
        _current = null;
        // 通知音效引擎停止（兜底：正常情况下音效会自行计时结束）
        if (typeof EffectSounds !== "undefined") {
            EffectSounds.stop();
        }

        if (_queue.length > 0) {
            const nextType = _queue.shift();
            if (nextType) {
                play(nextType);
            }
        }
    }

    /**
     * 播放指定特效
     *
     * @param {string} type  特效类型：fireworks / rain / lightning / snow / sakura / meteors / gold-rain / hearts / confetti / fireflies
     */
    function play(type) {
        // 防重入：同时只允许一个特效
        if (_current) {
            console.log(`[EffectManager] 特效 ${_current} 正在播放，加入队列 ${type}`);
            _queue.push(type);
            return;
        }

        const canvas = _getCanvas();
        _current = type;

        // 同步触发对应音效
        if (typeof EffectSounds !== "undefined") {
            EffectSounds.play(type);
        }

        switch (type) {
            case "fireworks":
                if (typeof FireworksEffect !== "undefined") {
                    FireworksEffect.start(canvas, _cleanup);
                }
                break;
            case "wedding-fireworks":
                // 婚礼专属：双倍礼花，粉金浪漫配色，持续 12 秒
                if (typeof FireworksEffect !== "undefined") {
                    FireworksEffect.startDouble(canvas, _cleanup);
                }
                break;
            case "rain":
                if (typeof RainEffect !== "undefined") {
                    RainEffect.start(canvas, _cleanup);
                }
                break;
            case "lightning":
                if (typeof LightningEffect !== "undefined") {
                    LightningEffect.start(canvas, _cleanup);
                }
                break;
            case "snow":
                if (typeof SnowEffect !== "undefined") {
                    SnowEffect.start(canvas, _cleanup);
                }
                break;
            case "sakura":
                if (typeof SakuraEffect !== "undefined") {
                    SakuraEffect.start(canvas, _cleanup);
                }
                break;
            case "meteors":
                if (typeof MeteorsEffect !== "undefined") {
                    MeteorsEffect.start(canvas, _cleanup);
                }
                break;
            case "gold-rain":
                if (typeof GoldRainEffect !== "undefined") {
                    GoldRainEffect.start(canvas, _cleanup);
                }
                break;
            case "hearts":
                if (typeof HeartsEffect !== "undefined") {
                    HeartsEffect.start(canvas, _cleanup);
                }
                break;
            case "confetti":
                if (typeof ConfettiEffect !== "undefined") {
                    ConfettiEffect.start(canvas, _cleanup);
                }
                break;
            case "fireflies":
                if (typeof FirefliesEffect !== "undefined") {
                    FirefliesEffect.start(canvas, _cleanup);
                }
                break;
            default:
                console.warn(`[EffectManager] 未知特效类型：${type}`);
                _cleanup();
        }
    }

    return { play };
})();