/**
 * 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。
 * 播放期间用户点击屏幕任意位置可立即结束当前全屏特效。
 * 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 = [];
    // 当前特效播放批次，用于忽略手动停止后的旧回调
    let _playToken = 0;
    // 是否已经绑定本轮点击停止监听
    let _clickStopBound = false;
    // 延迟绑定定时器，避免触发播放的同一次点击立即停止特效
    let _clickStopTimer = null;

    /**
     * 获取或创建全屏 Canvas 元素
     * 属性：fixed 定位，覆盖全屏，播放期间接收点击用于立即停止特效。
     */
    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:auto",
            "cursor:pointer",
            "touch-action:manipulation",
        ].join(";");
        c.width = window.innerWidth;
        c.height = window.innerHeight;
        document.body.appendChild(c);
        _canvas = c;
        return c;
    }

    /**
     * 绑定点击屏幕立即停止当前特效的监听。
     *
     * 延后一帧绑定，避免触发特效的同一次点击被误判为结束点击。
     */
    function _bindClickStop() {
        if (_clickStopBound) {
            return;
        }

        _clickStopTimer = window.setTimeout(() => {
            if (!_current || _clickStopBound) {
                return;
            }

            _clickStopBound = true;
            if (_canvas) {
                _canvas.addEventListener("pointerdown", _handleStopClick, {
                    capture: true,
                });
                _canvas.addEventListener("mousedown", _handleStopClick, {
                    capture: true,
                });
            }
            document.addEventListener("pointerdown", _handleStopClick, {
                capture: true,
            });
            document.addEventListener("mousedown", _handleStopClick, {
                capture: true,
            });
        }, 120);
    }

    /**
     * 解绑点击停止监听，避免特效结束后影响正常聊天操作。
     */
    function _unbindClickStop() {
        if (_clickStopTimer) {
            window.clearTimeout(_clickStopTimer);
            _clickStopTimer = null;
        }

        if (!_clickStopBound) {
            return;
        }

        if (_canvas) {
            _canvas.removeEventListener("pointerdown", _handleStopClick, {
                capture: true,
            });
            _canvas.removeEventListener("mousedown", _handleStopClick, {
                capture: true,
            });
        }
        document.removeEventListener("pointerdown", _handleStopClick, {
            capture: true,
        });
        document.removeEventListener("mousedown", _handleStopClick, {
            capture: true,
        });
        _clickStopBound = false;
    }

    /**
     * 处理屏幕点击结束特效。
     */
    function _handleStopClick(event) {
        if (event) {
            event.stopPropagation();
        }

        stop();
    }

    /**
     * 特效结束后清理 Canvas，重置状态，并停止音效。
     *
     * @param {Object} options 清理选项
     * @param {boolean} options.playNext 是否继续播放队列中的下一个特效
     * @param {number|null} options.token 当前特效播放批次
     */
    function _cleanup({ playNext = true, token = null } = {}) {
        if (token !== null && token !== _playToken) {
            return;
        }

        _playToken++;
        _unbindClickStop();

        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 (playNext && _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;
        const token = _playToken;
        const finishCurrent = () => _cleanup({ token });
        _bindClickStop();

        // 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, finishCurrent);
                }
                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, finishCurrent);
                }
                break;
            case "rain":
                if (typeof RainEffect !== "undefined") {
                    RainEffect.start(canvas, finishCurrent);
                }
                break;
            case "lightning":
                if (typeof LightningEffect !== "undefined") {
                    LightningEffect.start(canvas, finishCurrent);
                }
                break;
            case "snow":
                if (typeof SnowEffect !== "undefined") {
                    SnowEffect.start(canvas, finishCurrent);
                }
                break;
            case "sakura":
                if (typeof SakuraEffect !== "undefined") {
                    SakuraEffect.start(canvas, finishCurrent);
                }
                break;
            case "meteors":
                if (typeof MeteorsEffect !== "undefined") {
                    MeteorsEffect.start(canvas, finishCurrent);
                }
                break;
            case "gold-rain":
                if (typeof GoldRainEffect !== "undefined") {
                    GoldRainEffect.start(canvas, finishCurrent);
                }
                break;
            case "hearts":
                if (typeof HeartsEffect !== "undefined") {
                    HeartsEffect.start(canvas, finishCurrent);
                }
                break;
            case "confetti":
                if (typeof ConfettiEffect !== "undefined") {
                    ConfettiEffect.start(canvas, finishCurrent);
                }
                break;
            case "fireflies":
                if (typeof FirefliesEffect !== "undefined") {
                    FirefliesEffect.start(canvas, finishCurrent);
                }
                break;
            default:
                console.warn(`[EffectManager] 未知特效类型：${type}`);
                finishCurrent();
        }
    }

    /**
     * 用户手动停止当前全屏特效。
     *
     * 会立即移除画布、停止音效，并清空排队中的后续特效。
     */
    function stop() {
        if (!_current) {
            return;
        }

        _queue.length = 0;
        _cleanup({ playNext: false });
    }

    return { play, stop };
})();