"""Unit tests for ExtractorFactory + detect_format + the OCR-fallback flow."""

from __future__ import annotations

import pytest

from contract_check.core.extraction import (
    UnsupportedFormatError,
    detect_format,
    extract_document,
    get_factory,
)
from tests.unit.test_extraction_adapters import PARAGRAPH, build_docx_bytes, build_pdf_bytes

# ── detect_format: suffix / mime / magic precedence ──────────────────────────


@pytest.mark.parametrize(
    ("filename", "expected"),
    [
        ("contract.pdf", "pdf"),
        ("contract.PDF", "pdf"),
        ("contract.docx", "docx"),
        ("contract.rtf", "rtf"),
        ("contract.txt", "txt"),
        ("data.csv", "txt"),
        ("scan.png", "image"),
        ("scan.jpg", "image"),
        ("scan.jpeg", "image"),
        ("scan.tiff", "image"),
    ],
)
def test_detect_by_suffix(filename: str, expected: str) -> None:
    assert detect_format(b"", filename=filename) == expected


def test_detect_by_mime_when_suffix_unknown() -> None:
    assert detect_format(b"", mime="application/pdf", filename="contract") == "pdf"
    assert detect_format(b"", mime="image/png", filename="photo") == "image"


def test_magic_beats_wrong_suffix() -> None:
    # A real PDF mislabeled .docx must route to the PDF adapter.
    pytest.importorskip("magic")
    assert detect_format(build_pdf_bytes(), mime="", filename="contract.docx") == "pdf"


def test_unsupported_format_raises() -> None:
    with pytest.raises(UnsupportedFormatError):
        detect_format(b"", filename="archive.zip")
    binary_soup = bytes(range(256)) * 4  # deliberately not decodable text
    with pytest.raises(UnsupportedFormatError):
        detect_format(binary_soup, mime="application/x-msdownload", filename="doc.exe")


def test_docx_zip_magic_does_not_shadow_suffix() -> None:
    # DOCX is a zip; python-magic reports application/zip which the factory
    # deliberately does not map — the suffix must decide.
    pytest.importorskip("magic")
    assert detect_format(build_docx_bytes(), filename="contract.docx") == "docx"


@pytest.mark.parametrize(
    ("filename", "mime"),
    [
        ("scan.png", "image/png"),
        ("scan.jpg", "image/jpeg"),
        ("scan.jpeg", "image/jpeg"),
        ("scan.tif", "image/tiff"),
        ("scan.tiff", "image/tiff"),
    ],
)
def test_image_formats_detected(filename: str, mime: str) -> None:
    assert detect_format(b"", filename=filename) == "image"
    assert detect_format(b"", mime=mime, filename="scan.bin") == "image"


# ── factory ──────────────────────────────────────────────────────────────────


def test_factory_returns_per_format_adapters() -> None:
    factory = get_factory()
    assert type(factory.get_extractor(b"", filename="a.pdf")).__name__ == "PyMuPDFExtractor"
    assert type(factory.get_extractor(b"", filename="a.docx")).__name__ == "MammothDocxExtractor"
    assert type(factory.get_extractor(b"", filename="a.rtf")).__name__ == "RtfExtractor"
    assert type(factory.get_extractor(b"", filename="a.txt")).__name__ == "TxtExtractor"
    assert type(factory.get_extractor(b"", filename="a.png")).__name__ == "TesseractOcrExtractor"
    assert type(factory.get_extractor(b"", filename="a.jpg")).__name__ == "TesseractOcrExtractor"
    assert type(factory.get_extractor(b"", filename="a.jpeg")).__name__ == "TesseractOcrExtractor"
    assert type(factory.get_extractor(b"", filename="a.tif")).__name__ == "TesseractOcrExtractor"
    assert type(factory.get_extractor(b"", filename="a.tiff")).__name__ == "TesseractOcrExtractor"


# ── extract_document: end-to-end over bytes ──────────────────────────────────


def test_extract_document_pdf() -> None:
    result = extract_document(build_pdf_bytes(), filename="c.pdf")
    assert result.metadata["format"] == "pdf"
    assert "арбитражном суде" in result.markdown


def test_extract_document_docx() -> None:
    result = extract_document(build_docx_bytes(), filename="c.docx")
    assert result.markdown.startswith("# ")
    assert result.is_structured is True


def test_extract_document_txt_cp1251() -> None:
    result = extract_document((PARAGRAPH * 10).encode("windows-1251"), filename="c.txt")
    assert "Стороны" in result.markdown
    assert result.metadata["format"] == "txt"


def test_extract_document_unsupported() -> None:
    with pytest.raises(UnsupportedFormatError):
        extract_document(b"PK\x03\x04 whatever", filename="c.zip")


def test_extract_document_pdf_scan_falls_back_to_ocr() -> None:
    # A PDF with no text layer triggers the OCR fallback inside the
    # orchestrator. Without the tesseract engine the fallback raises
    # OCRError (retryable) — with the engine, the integration suite covers
    # the happy path.
    import pymupdf

    from contract_check.core.analysis.ocr import OCRError
    from contract_check.core.extraction import ExtractionFailedError

    doc = pymupdf.open()
    doc.new_page()  # blank page: no text at all
    data = doc.tobytes()
    doc.close()
    with pytest.raises((OCRError, ExtractionFailedError)):
        extract_document(data, filename="scan.pdf")