scripts/generate_complex_invoice.py

#!/usr/bin/env python3
"""Generate a DELIBERATELY HARD invoice image to stress the OCR backends:
  • rotated vertical "INVOICE" banner + sideways Terms block (orientation problems)
  • a diagonal translucent "ORIGINAL COPY" watermark overlapping text
  • scattered header fields (invoice #, dates, vendor, bill-to in offset boxes)
  • a misaligned line-item table (inconsistent column alignment)
  • totals scattered across corners (subtotal / tax / shipping / grand total / balance due)

This is the kind of layout where classic OCR (Tesseract) struggles but a vision
LLM (MiniCPM-V) reads it correctly. Writes:
  backend/evals/datasets/complex_invoice_messy.png
  backend/evals/datasets/complex_invoice_messy.gt.json   (skip_eval — showcase only)
No .txt sidecar on purpose — this document REQUIRES a real OCR engine.
"""
from __future__ import annotations

import json
from pathlib import Path

from PIL import Image, ImageDraw, ImageFont

ROOT = Path(__file__).resolve().parent.parent
OUT = ROOT / "backend" / "evals" / "datasets"
W, H = 1240, 1600

GT = {
    "doc_type": "invoice",
    "invoice_number": "INV-9X-44821",
    "issue_date": "2026-04-18",
    "due_date": "2026-05-18",
    "vendor_name": "Meridian Industrial Components Ltd",
    "bill_to_name": "Aperture Retail Group",
    "currency": "USD",
    "subtotal": 9111.50,
    "tax_amount": 751.70,
    "total": 10043.20,
    "line_items": [
        {"description": "Hydraulic pump HX-220", "quantity": 4, "unit_price": 1250.00, "line_total": 5000.00},
        {"description": "Seal kit (set of 12)", "quantity": 10, "unit_price": 85.50, "line_total": 855.00},
        {"description": "Pressure gauge 0-300psi", "quantity": 6, "unit_price": 142.75, "line_total": 856.50},
        {"description": "Installation labor", "quantity": 1, "unit_price": 2400.00, "line_total": 2400.00},
    ],
    "_meta": {"doc_type": "invoice", "channel": "scanned", "difficulty": "complex_layout", "skip_eval": True},
}


def font(sz, bold=False):
    for p in ([
        "/System/Library/Fonts/Supplemental/Arial Bold.ttf" if bold else "/System/Library/Fonts/Supplemental/Arial.ttf",
        "/System/Library/Fonts/Helvetica.ttc",
        "/Library/Fonts/Arial.ttf",
    ]):
        try:
            return ImageFont.truetype(p, sz)
        except Exception:
            continue
    return ImageFont.load_default()


def rotated(base, text, xy, angle, fnt, fill=(20, 20, 20)):
    tmp = Image.new("RGBA", (max(20, len(text) * fnt.size), fnt.size + 16), (0, 0, 0, 0))
    ImageDraw.Draw(tmp).text((2, 2), text, font=fnt, fill=fill)
    tmp = tmp.rotate(angle, expand=True)
    base.paste(tmp, xy, tmp)


def main():
    OUT.mkdir(parents=True, exist_ok=True)
    img = Image.new("RGB", (W, H), "white")
    d = ImageDraw.Draw(img)

    # --- diagonal translucent watermark overlapping content ---
    wm = Image.new("RGBA", (W, H), (0, 0, 0, 0))
    wd = ImageDraw.Draw(wm)
    wd.text((140, 120), "ORIGINAL COPY", font=font(120, True), fill=(150, 150, 150, 60))
    wm = wm.rotate(28, center=(W // 2, H // 2))
    img.paste(wm, (0, 0), wm)

    # --- left vertical INVOICE banner (rotated 90) ---
    d.rectangle([18, 60, 96, 760], fill=(28, 40, 80))
    rotated(img, "INVOICE", (24, 470), 90, font(54, True), fill=(255, 255, 255))

    # --- scattered header fields (offset boxes, inconsistent placement) ---
    d.text((900, 70), "Invoice No.", font=font(20, True), fill=(90, 90, 90))
    d.text((900, 98), GT["invoice_number"], font=font(26, True), fill=(10, 10, 10))
    d.text((690, 150), f"Issued: {GT['issue_date']}", font=font(20), fill=(10, 10, 10))
    d.text((980, 200), f"Due {GT['due_date']}", font=font(20), fill=(160, 30, 30))  # offset, different spot
    # Balance due repeated near top in red (inconsistent)
    d.text((620, 60), "BALANCE DUE  $10,043.20", font=font(26, True), fill=(190, 20, 20))

    # vendor block (top-left, after banner) and bill-to (offset right-middle)
    d.rectangle([130, 90, 560, 220], outline=(120, 120, 120), width=2)
    d.text((145, 100), "FROM / Remit to:", font=font(18, True), fill=(70, 70, 70))
    d.text((145, 128), GT["vendor_name"], font=font(22, True), fill=(10, 10, 10))
    d.text((145, 160), "Unit 7, Kvaerner Estate", font=font(18), fill=(40, 40, 40))
    d.text((145, 184), "VAT GB-882-114", font=font(18), fill=(40, 40, 40))

    d.rectangle([640, 300, 1080, 420], outline=(120, 120, 120), width=2)
    d.text((655, 310), "Bill To", font=font(18, True), fill=(70, 70, 70))
    d.text((655, 338), GT["bill_to_name"], font=font(22, True), fill=(10, 10, 10))
    d.text((655, 372), "Accounts Payable, Floor 3", font=font(18), fill=(40, 40, 40))
    d.text((655, 396), "PO ref: PO-77-3391", font=font(18), fill=(40, 40, 40))

    # --- misaligned line-item table ---
    ty = 470
    d.line([130, ty - 10, 1110, ty - 10], fill=(40, 40, 40), width=2)
    # headers placed inconsistently (not above their columns)
    d.text((150, ty), "Item / Description", font=font(20, True), fill=(20, 20, 20))
    d.text((720, ty), "Unit", font=font(20, True), fill=(20, 20, 20))
    d.text((640, ty), "Qty", font=font(20, True), fill=(20, 20, 20))
    d.text((980, ty), "Amount", font=font(20, True), fill=(20, 20, 20))
    ry = ty + 44
    for i, it in enumerate(GT["line_items"], 1):
        d.text((150, ry), f"{i}.  {it['description']}", font=font(20), fill=(15, 15, 15))
        # qty/unit/amount with inconsistent alignment (left vs right vs centered)
        d.text((648, ry), str(int(it["quantity"])), font=font(20), fill=(15, 15, 15))
        d.text((700, ry), f"${it['unit_price']:,.2f}", font=font(20), fill=(15, 15, 15))
        amt = f"${it['line_total']:,.2f}"
        d.text((1090 - d.textlength(amt, font=font(20)), ry), amt, font=font(20), fill=(15, 15, 15))
        ry += 46
    d.line([130, ry + 6, 1110, ry + 6], fill=(40, 40, 40), width=1)

    # --- totals scattered across corners ---
    d.text((180, ry + 60), "Tax @ 8.25%", font=font(20), fill=(15, 15, 15))   # bottom-left
    d.text((320, ry + 60), "$751.70", font=font(20), fill=(15, 15, 15))
    d.text((640, ry + 30), "Sub-total", font=font(20), fill=(15, 15, 15))      # middle
    d.text((780, ry + 30), "$9,111.50", font=font(20), fill=(15, 15, 15))
    d.text((640, ry + 90), "Freight/Shipping", font=font(20), fill=(15, 15, 15))
    d.text((820, ry + 90), "$180.00", font=font(20), fill=(15, 15, 15))
    # grand total in a bold box, bottom-right
    d.rectangle([800, ry + 140, 1110, ry + 210], fill=(28, 40, 80))
    d.text((820, ry + 150), "GRAND TOTAL", font=font(20, True), fill=(255, 255, 255))
    d.text((820, ry + 178), "$10,043.20  USD", font=font(24, True), fill=(255, 255, 255))

    # --- sideways Terms & Conditions block (rotated 90) on the right edge ---
    rotated(img, "Terms: Net 30 days. Late fee 1.5%/mo. Goods remain property of seller until paid.",
            (1150, 360), 90, font(18), fill=(90, 90, 90))

    # footer note (two-column-ish)
    d.text((150, H - 120), "Notes: Partial back-order on item 3 may apply.", font=font(18), fill=(60, 60, 60))
    d.text((150, H - 92), "Remittance: SWIFT MERIGB2L  /  IBAN GB22 MERI 0099 8812", font=font(18), fill=(60, 60, 60))

    out_png = OUT / "complex_invoice_messy.png"
    img.save(out_png)
    (OUT / "complex_invoice_messy.gt.json").write_text(json.dumps(GT, indent=2))
    print(f"✓ wrote {out_png} ({W}x{H})")
    print(f"✓ wrote {OUT/'complex_invoice_messy.gt.json'}")


if __name__ == "__main__":
    main()