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jorgecuadros-platform/apps/api/src/statements/ocr/ocr.provider.ts
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rmancinasandClaude Opus 5 d6501f1d74
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feat(recibos): OCR capture for gas butano and municipal predial
Adds four parsers to the statement intake — GAS TIJUANA plus one per
municipality, because Tijuana, Rosarito and Ensenada issue three
completely different predial documents — and a text-layer fast path for
the born-digital invoices the gas company sends.

Measured against a new corpus of 14 documents / 29 pages: provider read
on 29/29, amount on 26/29, and 21/29 auto-matched against the dev
database (22/29 identified). The eight review cases are all legitimate.

Five things the corpus forced:

- Not every statement is a scan. The gas invoices are born-digital CFDIs
  whose text layer is exact; rasterising them only loses information (one
  sample turned `MEDIDOR: VM01014426` into `ar (LTR): 014420`). The new
  `OcrProvider.textPages` reads the embedded layer via `pdftotext
  -bbox-layout` — same poppler package as `pdftoppm`, so no new
  dependency — and OCR stays the fallback for real scans. Poppler's own
  `<line>` grouping follows text flow rather than the page, so words are
  regrouped by vertical position; without that, a two-column header
  leaves every label separated from the value printed beside it.

- The clave catastral is not two letters and six digits. Position three
  is a letter in 15 of the 932 stored claves, and digitising the whole
  tail mapped a real `MMB01041` to a nonexistent `MM801041`.

- Tijuana predial prints no clave at all. Its only identifier is an
  8-digit municipal account carried in a 32-digit payment barcode, which
  the legacy database never held, so it goes in `meterNumber` alongside
  gas — `accountNumber` holds `DATMEX.predial`, which is not a
  per-property key and must not be overwritten. Those pages start cold
  and are taught by the first confirm.

- On Rosarito and Ensenada the clave is the primary key, not a fallback:
  those receipts print nothing else, so a unique hit auto-matches. On a
  utility bill that merely happens to print one it stays a review hint.

- A misread `$` is the dangerous failure. An Ensenada receipt for
  $2,203.00 OCR'd as `82,203.00`, which would post a charge 37x too large
  and look ordinary in the ledger. Predial amounts now require a literal
  `$` and a page that cannot produce one goes to review.

The scoped match field is now one exported function rather than three
copies of `kind === "GAS" ? ... : ...`, since the lookup, the
blank-service fill and the confirm write-back have to agree or a
reference gets learned into a column nothing searches.

First tests in this package: 23 specs over the parsers and the text-layer
reader, every fixture a verbatim OCR excerpt from a real receipt. Adds
the jest config they need and a build tsconfig so they stay out of dist.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-01 12:52:20 -07:00

72 lines
3.0 KiB
TypeScript

/**
* The OCR seam. Everything above this interface works in terms of page text and
* word boxes, so the concrete engine is swappable without touching the parsers,
* the matcher, or the schema.
*
* The shipped implementation is self-hosted Tesseract (see tesseract.provider).
* That choice is evidence-based rather than assumed: run against 46 pages of
* real scanned CFE, CESPT and Telnor statements, it identified the provider on
* 46/46 and extracted a usable account reference on 43/46, and on a later
* corpus of 19 scanned municipal predial receipts it read the provider on
* 19/19 and an identifier on 18/19 — well past the bar for a queue whose whole
* point is that a human confirms every row. A
* managed document-extraction API (Textract, Document Intelligence, Document
* AI) fits behind this same interface if per-page accuracy ever proves
* insufficient, with no schema change — but at 300+ pages/month/company it
* would carry a real recurring cost for accuracy that is not currently the
* bottleneck.
*/
/** One OCR'd word, with where it sits on the page. */
export interface OcrWord {
text: string;
/** Pixel box in the rendered page image. */
left: number;
top: number;
width: number;
height: number;
/** Engine confidence for this word, 0..1. */
confidence: number;
}
export interface OcrPage {
/** Full page text, reading order, newline-separated. */
text: string;
/**
* Word boxes. Needed because several of the real layouts are *tables* — the
* CESPT "RECIBO" prints `No. DE CUENTA` as a column header with the value in
* the row beneath it, which line-oriented text cannot associate. Parsers fall
* back to geometry for exactly those fields.
*/
words: OcrWord[];
/** Mean word confidence across the page, 0..1. */
confidence: number;
}
export interface OcrProvider {
/** True when the engine is actually usable in this deployment. */
available(): Promise<boolean>;
/** Split a PDF into one rendered page image per page. */
renderPages(pdf: Buffer): Promise<Buffer[]>;
/** OCR a single rendered page image. */
recognize(pageImage: Buffer): Promise<OcrPage>;
/**
* Read a PDF's own text layer, one entry per page, `null` where the page has
* none worth using.
*
* Not every statement is a scan. The gas company e-mails born-digital CFDI
* invoices whose text is already exact and already positioned — running those
* through a rasteriser and a character recogniser can only lose information
* (one sample turned `MEDIDOR: VM01014426` into `ar (LTR): 014420`) while
* costing about a minute of CPU per page for the privilege. Where the layer
* exists it is strictly better input for the same parsers, so it is tried
* first and OCR remains the fallback for genuine scans.
*
* Positions are reported in the same pixel space `recognize` uses, so the
* geometric helpers in the parsers work unchanged on either source.
*/
textPages(pdf: Buffer): Promise<(OcrPage | null)[]>;
}
export const OCR_PROVIDER = Symbol("OCR_PROVIDER");