"""OCR subsystem: protocol + fake + real Surya client + factory.

Real engines (Surya today, Azure DI / AWS Textract … deferred) plug in
behind :class:`OCRClient`. The factory :func:`make_ocr_client` picks
between :class:`FakeOCRClient` (when ``IX_TEST_MODE=fake``) and
:class:`SuryaOCRClient` (production). Unknown engine names raise so a
typo'd ``IX_OCR_ENGINE`` surfaces at startup, not later.
"""

from __future__ import annotations

from ix.config import AppConfig
from ix.contracts.response import OCRDetails, OCRResult
from ix.ocr.client import OCRClient
from ix.ocr.fake import FakeOCRClient
from ix.ocr.surya_client import SuryaOCRClient


def make_ocr_client(cfg: AppConfig) -> OCRClient:
    """Return the :class:`OCRClient` configured for the current run."""

    if cfg.test_mode == "fake":
        return FakeOCRClient(canned=OCRResult(result=OCRDetails()))
    if cfg.ocr_engine == "surya":
        return SuryaOCRClient()
    raise ValueError(f"Unknown ocr_engine: {cfg.ocr_engine!r}")


__all__ = [
    "FakeOCRClient",
    "OCRClient",
    "SuryaOCRClient",
    "make_ocr_client",
]