/**
 * Error Boundary Module
 * 全局错误捕获与处理，防止未处理异常导致页面崩溃
 */

// ========== 全局错误边界 ==========

const ErrorBoundary = {
    _toastContainer: null,

    init() {
        // 捕获未处理的 Promise 拒绝
        window.addEventListener('unhandledrejection', (event) => {
            console.error('[ErrorBoundary] Unhandled promise rejection:', event.reason);
            
            // 如果是离线错误，不显示 toast
            if (event.reason && event.reason.message === 'OFFLINE') {
                return;
            }
            
            this.showToast('操作失败，请重试', 'error');
            event.preventDefault();
        });

        // 捕获全局 JS 错误
        window.addEventListener('error', (event) => {
            console.error('[ErrorBoundary] Uncaught error:', event.error || event.message);
            
            // 忽略资源加载错误（由网络问题引起）
            if (event.target && event.target !== window) {
                return;
            }
            
            this.showToast('页面出现错误，请刷新重试', 'error');
        });

        console.log('[ErrorBoundary] 全局错误边界已初始化');
    },

    /**
     * 显示 Toast 通知
     * @param {string} message - 消息内容
     * @param {'info'|'success'|'warning'|'error'} type - 消息类型
     * @param {number} duration - 显示时长（毫秒）
     */
    showToast(message, type = 'info', duration = 3000) {
        if (!this._toastContainer) {
            this._toastContainer = document.createElement('div');
            this._toastContainer.id = 'toast-container';
            this._toastContainer.style.cssText = `
                position: fixed; top: 20px; right: 20px; z-index: 10000;
                display: flex; flex-direction: column; gap: 8px; pointer-events: none;
            `;
            document.body.appendChild(this._toastContainer);
        }

        const colors = {
            info: 'var(--deep-blue, #1a73e8)',
            success: 'var(--success, #34a853)',
            warning: 'var(--warning, #fbbc04)',
            error: 'var(--danger, #ea4335)'
        };

        const toast = document.createElement('div');
        toast.className = 'toast-notification';
        toast.style.cssText = `
            background: ${colors[type] || colors.info}; color: white;
            padding: 12px 20px; border-radius: 8px; font-size: 14px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.15); pointer-events: auto;
            opacity: 0; transform: translateX(20px);
            transition: opacity 0.3s, transform 0.3s;
            max-width: 320px; word-break: break-word;
        `;
        toast.textContent = message;
        this._toastContainer.appendChild(toast);

        // Animate in
        requestAnimationFrame(() => {
            toast.style.opacity = '1';
            toast.style.transform = 'translateX(0)';
        });

        // Auto dismiss
        setTimeout(() => {
            toast.style.opacity = '0';
            toast.style.transform = 'translateX(20px)';
            setTimeout(() => toast.remove(), 300);
        }, duration);
    },

    /**
     * 安全执行异步函数，捕获错误并显示 toast
     * @param {Function} fn - 异步函数
     * @param {string} errorMsg - 错误时显示的消息
     * @returns {Promise<any>}
     */
    async wrap(fn, errorMsg = '操作失败') {
        try {
            return await fn();
        } catch (error) {
            console.error('[ErrorBoundary] Wrapped function error:', error);
            if (error.message !== 'OFFLINE') {
                this.showToast(errorMsg, 'error');
            }
            return null;
        }
    }
};

// 暴露为全局
window.ErrorBoundary = ErrorBoundary;

// 自动初始化
document.addEventListener('DOMContentLoaded', () => {
    ErrorBoundary.init();
});