feat(fundamentals): Add FundamentalsService and SEC EDGAR provider with caching, rate-limiting, tests, and docs updates

ts/stocks/interfaces/fundamentals.ts

@@ -0,0 +1,102 @@
+/**
+ * Interfaces for stock fundamental data (financials from SEC filings)
+ * Separate from stock price data (OHLCV) to maintain clean architecture
+ */
+
+// Request types for fundamental data
+export interface IFundamentalsCurrentRequest {
+  type: 'fundamentals-current';
+  ticker: string;
+}
+
+export interface IFundamentalsBatchRequest {
+  type: 'fundamentals-batch';
+  tickers: string[];
+}
+
+export type IFundamentalsRequest =
+  | IFundamentalsCurrentRequest
+  | IFundamentalsBatchRequest;
+
+/**
+ * Stock fundamental data from SEC filings (10-K, 10-Q)
+ * Contains financial metrics like EPS, Revenue, Assets, etc.
+ */
+export interface IStockFundamentals {
+  ticker: string;
+  cik: string;
+  companyName: string;
+  provider: string;
+  timestamp: Date;
+  fetchedAt: Date;
+
+  // Per-share metrics
+  earningsPerShareBasic?: number;
+  earningsPerShareDiluted?: number;
+  sharesOutstanding?: number;
+  weightedAverageSharesOutstanding?: number;
+
+  // Income statement (annual USD)
+  revenue?: number;
+  netIncome?: number;
+  operatingIncome?: number;
+  grossProfit?: number;
+  costOfRevenue?: number;
+
+  // Balance sheet (annual USD)
+  assets?: number;
+  liabilities?: number;
+  stockholdersEquity?: number;
+  cash?: number;
+  propertyPlantEquipment?: number;
+
+  // Calculated metrics (requires current price)
+  marketCap?: number;        // price × sharesOutstanding
+  priceToEarnings?: number;  // price / EPS
+  priceToBook?: number;      // marketCap / stockholdersEquity
+
+  // Metadata
+  fiscalYear?: string;
+  fiscalQuarter?: string;
+  filingDate?: Date;
+  form?: '10-K' | '10-Q' | string;
+}
+
+/**
+ * Provider interface for fetching fundamental data
+ * Parallel to IStockProvider but for fundamentals instead of prices
+ */
+export interface IFundamentalsProvider {
+  name: string;
+  priority: number;
+  fetchData(request: IFundamentalsRequest): Promise<IStockFundamentals | IStockFundamentals[]>;
+  isAvailable(): Promise<boolean>;
+  readonly requiresAuth: boolean;
+  readonly rateLimit?: {
+    requestsPerMinute: number;
+    requestsPerDay?: number;
+  };
+}
+
+/**
+ * Configuration for fundamentals providers
+ */
+export interface IFundamentalsProviderConfig {
+  enabled: boolean;
+  priority?: number;
+  timeout?: number;
+  retryAttempts?: number;
+  retryDelay?: number;
+  cacheTTL?: number; // Custom cache TTL for this provider
+}
+
+/**
+ * Registry for managing fundamental data providers
+ */
+export interface IFundamentalsProviderRegistry {
+  register(provider: IFundamentalsProvider, config?: IFundamentalsProviderConfig): void;
+  unregister(providerName: string): void;
+  getProvider(name: string): IFundamentalsProvider | undefined;
+  getAllProviders(): IFundamentalsProvider[];
+  getEnabledProviders(): IFundamentalsProvider[];
+}