const API_KEY = 'your-external-api-key';
const API_BASE = '/api/v1';
const REQUEST_TIMEOUT = 30000;

let pendingRequests = 0;
let loadingToast = null;
let loadingTimer = null;

function showNonBlockingLoading(message = '加载中...') {
    pendingRequests++;
    updateLoadingUI(message);

    if (loadingTimer) clearTimeout(loadingTimer);
    loadingTimer = setTimeout(() => {
        console.warn('Some requests may be stuck, force clearing');
    }, 60000);
}

function hideNonBlockingLoading() {
    pendingRequests = Math.max(0, pendingRequests - 1);
    updateLoadingUI(pendingRequests > 0 ? '处理中...' : null);
}

function updateLoadingUI(message) {
    if (!message) {
        if (loadingToast) {
            loadingToast.remove();
            loadingToast = null;
        }
        return;
    }

    if (!loadingToast) {
        loadingToast = document.createElement('div');
        loadingToast.id = 'loading-toast';
        loadingToast.style.cssText = `
            position: fixed;
            top: 20px;
            left: 50%;
            transform: translateX(-50%);
            background: rgba(0,0,0,0.8);
            color: white;
            padding: 12px 24px;
            border-radius: 8px;
            font-size: 14px;
            z-index: 10000;
            display: flex;
            align-items: center;
            gap: 10px;
        `;
        document.body.appendChild(loadingToast);
    }

    const spinner = '<div style="width:16px;height:16px;border:2px solid #fff;border-top-color:transparent;border-radius:50%;animation:spin 0.8s linear infinite"></div>';
    const style = '<style>@keyframes spin{to{transform:rotate(360deg)}}</style>';
    if (!document.getElementById('loading-spinner-style')) {
        document.head.insertAdjacentHTML('beforeend', style);
    }
    loadingToast.innerHTML = spinner + `<span>${message}</span><span style="font-size:12px;opacity:0.7">(${pendingRequests})</span>`;
}

async function api(endpoint, options = {}) {
    const method = options.method || 'GET';
    const isMutation = ['POST', 'PUT', 'DELETE'].includes(method);
    const startMsg = `请求${isMutation ? '修改' : '获取'}中...`;

    showNonBlockingLoading(startMsg);

    const controller = new AbortController();
    const timeoutId = setTimeout(() => {
        controller.abort();
        showToast('请求超时，请稍后重试', 'error');
    }, REQUEST_TIMEOUT);

    try {
        const headers = {
            'X-API-Key': API_KEY,
            'Content-Type': 'application/json',
            ...options.headers
        };

        const response = await fetch(API_BASE + endpoint, {
            ...options,
            headers,
            signal: controller.signal
        });

        clearTimeout(timeoutId);

        if (!response.ok) {
            const error = `HTTP ${response.status}: ${response.statusText}`;
            if (isMutation) {
                showToast('操作失败: ' + error, 'error');
            }
            return { success: false, error };
        }

        const data = await response.json();

        if (isMutation && data.success === false && data.error) {
            showToast(data.error, 'error');
        }

        return data;

    } catch (err) {
        clearTimeout(timeoutId);
        if (err.name === 'AbortError') {
            return { success: false, error: '请求超时' };
        }
        const errorMsg = err.message || '网络错误';
        if (isMutation) {
            showToast(errorMsg, 'error');
        }
        return { success: false, error: errorMsg };

    } finally {
        hideNonBlockingLoading();
    }
}

const apiClient = {
    get: (endpoint) => api(endpoint),
    post: (endpoint, data) => api(endpoint, { method: 'POST', body: JSON.stringify(data) }),
    put: (endpoint, data) => api(endpoint, { method: 'PUT', body: JSON.stringify(data) }),
    delete: (endpoint) => api(endpoint, { method: 'DELETE' }),

    nodes: {
        list: () => api('/nodes/'),
        get: (name) => api(`/nodes/${name}`),
        create: (data) => api('/nodes/', { method: 'POST', body: JSON.stringify(data) }),
        update: (name, data) => api(`/nodes/${name}`, { method: 'PUT', body: JSON.stringify(data) }),
        delete: (name) => api(`/nodes/${name}`, { method: 'DELETE' }),
        status: (name) => api(`/nodes/${name}/status`)
    },

    messages: {
        send: (data) => api('/messages/send', { method: 'POST', body: JSON.stringify(data) }),
        broadcast: (data) => api('/messages/broadcast', { method: 'POST', body: JSON.stringify(data) })
    },

    config: {
        getMonitor: () => api('/config/monitor'),
        updateMonitor: (data) => api('/config/monitor', { method: 'POST', body: JSON.stringify(data) }),
        getWebhook: () => api('/config/webhook'),
        updateWebhook: (data) => api('/config/webhook', { method: 'POST', body: JSON.stringify(data) })
    },

    logs: {
        recent: (count = 50) => api(`/logs/recent?count=${count}`)
    }
};

window.api = api;
window.apiClient = apiClient;