/**
 * HyperFlow 3.0 — API Service Layer
 * Connects the React frontend to the FastAPI backend
 * All endpoints proxied via Vite dev server → /api → http://localhost:8000
 */

const getBaseUrl = () => {
  const override = localStorage.getItem('hyperflow_backend_url');
  if (override) return override;
  const envUrl = import.meta.env.VITE_BACKEND_URL;
  if (envUrl) return envUrl;
  if (typeof window !== 'undefined') {
    const hn = window.location.hostname;
    if (hn === 'localhost' || hn === '127.0.0.1') {
      return 'http://127.0.0.1:8000';
    }
  }
  return 'https://gaurav711-hyperflow.hf.space';
};

export function setBackendUrl(url) {
  if (url) {
    localStorage.setItem('hyperflow_backend_url', url.replace(/\/$/, ''));
  } else {
    localStorage.removeItem('hyperflow_backend_url');
  }
}

export function getBackendUrl() {
  return getBaseUrl();
}

async function apiFetch(path, options = {}) {
  try {
    const base = getBaseUrl();
    const url = base ? `${base}${path}` : path;
    const headers = { 'Content-Type': 'application/json', ...options.headers };
    
    // Inject personal Swiggy token from localStorage if available
    const personalToken = localStorage.getItem('swiggy_access_token');
    if (personalToken) {
      headers['Authorization'] = `Bearer ${personalToken}`;
    }

    const res = await fetch(url, {
      headers,
      ...options,
    });
    if (!res.ok) {
      const err = await res.json().catch(() => ({ detail: res.statusText }));
      throw new Error(err.detail || 'API error');
    }
    return res.json();
  } catch (err) {
    console.warn(`[API] ${path} failed (offline fallback):`, err.message);
    return null; // caller uses null to fall back to local state
  }
}

// ─── OAuth 2.1 + PKCE ─────────────────────────────────────────────────────────

export async function fetchLoginUrl() {
  return apiFetch('/api/v1/auth/login-url');
}

export async function exchangeCode(code, state) {
  return apiFetch('/api/v1/auth/exchange', {
    method: 'POST',
    body: JSON.stringify({ code, state }),
  });
}

// ─── Dark Store / Inventory ───────────────────────────────────────────────────

export async function fetchRestockAlerts(storeId = 'store_01') {
  return apiFetch(`/api/v1/forecast/${storeId}/restock-alerts`);
}

export async function fetchForecast(storeId, skuId) {
  return apiFetch(`/api/v1/forecast/${storeId}/${skuId}`);
}

export async function fetchAvailabilityMetrics(storeId = 'store_01') {
  return apiFetch(`/api/v1/metrics/availability/${storeId}`);
}

export async function fetchProfitability(storeId) {
  return apiFetch(`/api/v1/profitability/${storeId}`);
}

export async function fetchBumpRate() {
  return apiFetch('/api/v1/metrics/bump-rate');
}

export async function fetchRobustness() {
  return apiFetch('/api/v1/metrics/robustness');
}

export async function triggerRetrain() {
  return apiFetch('/api/v1/ml/retrain', { method: 'POST' });
}

// ─── Inventory Reservation ────────────────────────────────────────────────────

export async function reserveInventory({ order_id, store_id, sku_id, qty_requested }) {
  return apiFetch('/api/v1/orders/reserve', {
    method: 'POST',
    body: JSON.stringify({ order_id, store_id, sku_id, qty_requested }),
  });
}

// ─── Restaurants & Coupons ───────────────────────────────────────────────────

export async function fetchRestaurants() {
  return apiFetch('/api/v1/restaurants');
}

export async function fetchRestaurantMenu(restaurantId) {
  return apiFetch(`/api/v1/restaurants/${restaurantId}/menu`);
}

export async function createRestaurant(data) {
  return apiFetch('/api/v1/restaurants', {
    method: 'POST',
    body: JSON.stringify(data),
  });
}

export async function fetchCoupons() {
  return apiFetch('/api/v1/coupons');
}

export async function createCoupon(data) {
  return apiFetch('/api/v1/coupons', {
    method: 'POST',
    body: JSON.stringify(data),
  });
}

// ─── Dineout ─────────────────────────────────────────────────────────────────

export async function fetchDineoutReservations() {
  return apiFetch('/api/v1/dineout/reservations');
}

export async function reserveDineout({ hotel, time, party }) {
  return apiFetch('/api/v1/dineout/reserve', {
    method: 'POST',
    body: JSON.stringify({ hotel, time, party }),
  });
}

// ─── Expense Logs ─────────────────────────────────────────────────────────────

export async function fetchExpenseLogs() {
  return apiFetch('/api/v1/user/expenses');
}

// ─── Festival Settings ────────────────────────────────────────────────────────

export async function fetchFestivalSettings() {
  return apiFetch('/api/v1/settings/festival');
}

export async function updateFestivalSettings(theme_name) {
  return apiFetch(`/api/v1/settings/festival?theme_name=${theme_name}`, {
    method: 'POST',
  });
}

// ─── WebSocket Live Metrics ───────────────────────────────────────────────────

/**
 * Opens a WebSocket connection to the live metrics stream.
 * @param {function} onMessage - callback(data: object)
 * @returns {WebSocket} - call .close() to disconnect
 */
export function connectLiveMetrics(onMessage) {
  const base = getBaseUrl();
  const wsBase = base
    ? base.replace(/^http/, 'ws')
    : `${window.location.protocol === 'https:' ? 'wss' : 'ws'}://${window.location.host}`;
  const ws = new WebSocket(`${wsBase}/ws/live-metrics`);
  ws.onmessage = (e) => {
    try {
      onMessage(JSON.parse(e.data));
    } catch {}
  };
  ws.onerror = (e) => console.warn('[WS] live-metrics error', e);
  return ws;
}

// ─── Swiggy Food MCP Direct Tool Calls ────────────────────────────────────────

export async function fetchFoodAddresses() {
  return apiFetch('/api/v1/food/addresses');
}

export async function updateFoodCart({ addressId, items, couponCode }) {
  return apiFetch('/api/v1/food/cart', {
    method: 'POST',
    body: JSON.stringify({ addressId, items, couponCode }),
  });
}

export async function placeFoodOrder({ addressId, paymentMethod }) {
  return apiFetch('/api/v1/food/orders', {
    method: 'POST',
    body: JSON.stringify({ addressId, paymentMethod }),
  });
}

export async function trackFoodOrder(orderId) {
  return apiFetch(`/api/v1/food/orders/${orderId}/track`);
}

// ─── HyperFlow 4.0 v2 Core Endpoints ──────────────────────────────────────────

export async function fetchDemandOracle(addressId = 'default_address', lat = 20.3533, lng = 85.8333) {
  return apiFetch(`/api/v2/oracle/demand?addressId=${addressId}&lat=${lat}&lng=${lng}`);
}

export async function predictRefund({ order_id, complaint_type, complaint_text, item_name, item_price }) {
  return apiFetch('/api/v2/refund/predict', {
    method: 'POST',
    body: JSON.stringify({ order_id, complaint_type, complaint_text, item_name, item_price }),
  });
}

export async function fetchDineoutSniper(latitude = 20.3533, longitude = 85.8333, cuisine = 'Buffet', date = '2026-07-25') {
  return apiFetch(`/api/v2/dineout/sniper?latitude=${latitude}&longitude=${longitude}&cuisine=${cuisine}&date=${date}`);
}

export async function analyzeDispatch(store_location = [20.3533, 85.8333], orders_count = 5) {
  return apiFetch('/api/v2/dispatch/analyze', {
    method: 'POST',
    body: JSON.stringify({ store_location, orders_count }),
  });
}

export function connectETALive(orderId, onMessage) {
  const base = getBaseUrl();
  const wsBase = base
    ? base.replace(/^http/, 'ws')
    : `${window.location.protocol === 'https:' ? 'wss' : 'ws'}://${window.location.host}`;
  const token = localStorage.getItem('swiggy_access_token') || '';
  const ws = new WebSocket(`${wsBase}/api/v2/ws/eta-live/${orderId}?token=${token}`);
  ws.onmessage = (e) => {
    try {
      onMessage(JSON.parse(e.data));
    } catch {}
  };
  ws.onerror = (e) => console.warn('[WS] eta-live error', e);
  return ws;
}