const API_BASE = import.meta.env.VITE_API_URL || "";

export async function request(path, options = {}) {
  const url = `${API_BASE}${path}`;
  const response = await fetch(url, {
    headers: {
      "Content-Type": "application/json",
      ...options.headers,
    },
    ...options,
  });
  
  if (!response.ok) {
    const errText = await response.text();
    let parsedErr;
    try {
      parsedErr = JSON.parse(errText);
    } catch {
      parsedErr = errText;
    }
    throw new Error(parsedErr?.detail || parsedErr || "Request failed");
  }
  
  return response.json();
}

export const api = {
  // Products
  getProducts: () => request("/api/products/"),
  getProductPriceHistory: (id) => request(`/api/products/${id}/price-history`),
  updateProduct: (id, data) => request(`/api/products/${id}`, { method: "PUT", body: JSON.stringify(data) }),
  getCategories: () => request("/api/products/categories"),

  // Inventory
  getInventories: () => request("/api/inventory/"),
  adjustInventoryStock: (id, change, reason) => 
    request(`/api/inventory/${id}/adjust?qty_change=${change}&reason=${encodeURIComponent(reason)}`, { method: "POST" }),
  getInventoryHistory: (id) => request(`/api/inventory/${id}/history`),
  getReplenishmentRecommendations: () => request("/api/inventory/recommendations/replenishment"),
  getTransferRecommendations: () => request("/api/inventory/recommendations/transfers"),
  getWarehouses: () => request("/api/inventory/warehouses"),
  getWarehousesStatus: () => request("/api/inventory/warehouses/status"),

  // Orders
  getOrders: () => request("/api/orders/"),
  createOrder: (data) => request("/api/orders/", { method: "POST", body: JSON.stringify(data) }),
  
  // Simulator Controls
  getSimulatorStatus: () => request("/api/orders/simulator/status"),
  controlSimulator: (is_running, speed = 1.0, demand_type = "normal", demand_multiplier = 1.0, seasonality_level = "medium", supply_level = "medium", flash_sale_active = false, competitor_discount_active = false, scenario = "Normal Demand") => 
    request("/api/orders/simulator/control", { 
      method: "POST", 
      body: JSON.stringify({ is_running, speed, demand_type, demand_multiplier, seasonality_level, supply_level, flash_sale_active, competitor_discount_active, scenario }) 
    }),
  generateBulkOrders: (count = 10000) => 
    request(`/api/orders/simulator/generate?count=${count}`, { method: "POST" }),

  // Pricing Decisions
  getPricingDecisions: () => request("/api/products/pricing-decisions/recommendations"),

  // Analytics
  getKPIs: () => request("/api/analytics/kpis"),
  getRevenueChart: (days = 30) => request(`/api/analytics/revenue-chart?days=${days}`),
  getForecastChart: (productId) => request(`/api/analytics/forecast-chart?product_id=${productId}`),

  // System Controls
  triggerPricingEngine: () => request("/api/system/trigger/pricing", { method: "POST" }),
  triggerForecastEngine: () => request("/api/system/trigger/forecast", { method: "POST" }),
  triggerAnomalyDetection: () => request("/api/system/trigger/anomaly", { method: "POST" }),
  triggerScenarioEvent: (eventType) => 
    request("/api/system/trigger/event", { method: "POST", body: JSON.stringify({ event_type: eventType }) }),
  getAnomalies: (resolved = false) => request(`/api/system/anomalies?resolved=${resolved}`),
  resolveAnomaly: (id) => request(`/api/system/anomalies/${id}/resolve`, { method: "POST" }),
  getAuditLogs: () => request("/api/system/audit-logs"),

  // SSE Stream
  subscribeToAlerts: (onEventMap) => {
    const eventSource = new EventSource(`${API_BASE}/api/system/alerts/stream`);
    
    // Connect default listeners
    Object.entries(onEventMap).forEach(([eventName, callback]) => {
      eventSource.addEventListener(eventName, (e) => {
        try {
          const data = JSON.parse(e.data);
          callback(data);
        } catch (err) {
          console.error(`Error parsing SSE data for [${eventName}]:`, err);
        }
      });
    });

    eventSource.onerror = (err) => {
      console.warn("SSE connection error, attempting auto-reconnect:", err);
    };

    return () => {
      eventSource.close();
    };
  }
};