/**
 * Claude Vision-driven OCR for expense receipts. PR1 stub: types and the
 * service contract. The actual API call wires up in PR9 with prompt
 * caching on the system text and Haiku 4.5 by default.
 */

export interface OcrLineItem {
  description: string;
  quantity?: number;
  unitPrice?: number;
  amount: number;
}

export interface OcrResult {
  vendor: string | null;
  amount: number | null;
  currency: string | null;
  /** ISO date YYYY-MM-DD. */
  date: string | null;
  lineItems: OcrLineItem[];
  /** 0..1; below 0.6 surfaces "verify mode" UI. */
  confidence: number;
}

export interface OcrContext {
  fileId: string;
  fileUrl: string;
  /** Optional MIME hint; the service still detects from bytes. */
  mimeType?: string;
}

/** Cost ceiling per call (Haiku 4.5 + cached system prompt). PR9 enforces. */
export const OCR_MAX_TOKENS = 1024;
export const OCR_LOW_CONFIDENCE_THRESHOLD = 0.6;

/** Stub — returns "pending" shape so callers can wire UI in PR1 without
 *  Anthropic credentials. */
export async function ocrReceipt(_ctx: OcrContext): Promise<OcrResult> {
  return {
    vendor: null,
    amount: null,
    currency: null,
    date: null,
    lineItems: [],
    confidence: 0,
  };
}