"""Unit tests for the extraction adapters (core/extraction/adapters/*).

Real files are generated in-memory per format (pymupdf/python-docx/PIL) so no
binary fixtures live in the repo. The OCR adapter's engine-dependent happy path
is covered when tesseract is available; error-contract tests always run.
"""

from __future__ import annotations

from pathlib import Path

import pytest

from contract_check.core.extraction import (
    ExtractedDocument,
    ExtractionFailedError,
    MammothDocxExtractor,
    PyMuPDFExtractor,
    RtfExtractor,
    TesseractOcrExtractor,
    TxtExtractor,
)

# ── shared fixture builders ──────────────────────────────────────────────────

PARAGRAPH = (
    "Стороны обязуются выполнять условия договора. "
    "Сторона А обязуется передать товар в срок. "
    "Сторона Б обязуется оплатить товар в течение десяти банковских дней. "
    "Ответственность сторон ограничена суммой договора. "
    "Споры подлежат рассмотрению в арбитражном суде города Москвы. "
)


def build_pdf_bytes(*, with_table: bool = False) -> bytes:
    import pymupdf

    doc = pymupdf.open()
    page = doc.new_page()
    if with_table:
        page.insert_htmlbox(
            page.rect,
            f'<p style="font-family:DejaVu Sans;font-size:12px">{PARAGRAPH}</p>',
        )
        x0, y0, cw, ch = 50, 200, 150, 30
        data = [["Услуга", "Цена"], ["Консультация", "5000"], ["Аудит", "15000"]]
        for r in range(len(data) + 1):
            page.draw_line(pymupdf.Point(x0, y0 + r * ch), pymupdf.Point(x0 + 2 * cw, y0 + r * ch))
        for c in range(3):
            page.draw_line(pymupdf.Point(x0 + c * cw, y0), pymupdf.Point(x0 + c * cw, y0 + 3 * ch))
        for r, row in enumerate(data):
            for c, val in enumerate(row):
                rect = pymupdf.Rect(
                    x0 + c * cw + 3, y0 + r * ch + 3, x0 + (c + 1) * cw - 3, y0 + (r + 1) * ch - 3
                )
                page.insert_htmlbox(
                    rect, f'<span style="font-family:DejaVu Sans;font-size:10px">{val}</span>'
                )
    else:
        page.insert_htmlbox(
            page.rect, f'<p style="font-family:DejaVu Sans;font-size:12px">{PARAGRAPH}</p>'
        )
    data = doc.tobytes()
    doc.close()
    return data


def build_docx_bytes() -> bytes:
    import io

    from docx import Document

    doc = Document()
    doc.add_heading("Договор поставки", level=1)
    doc.add_paragraph(PARAGRAPH)
    doc.add_paragraph(PARAGRAPH)
    buf = io.BytesIO()
    doc.save(buf)
    return buf.getvalue()


# ── PDF (pymupdf) ────────────────────────────────────────────────────────────


def test_pdf_text_only() -> None:
    result = PyMuPDFExtractor().extract(build_pdf_bytes())
    assert "арбитражном суде" in result.markdown
    assert result.is_structured is False
    assert result.metadata["format"] == "pdf"
    assert result.metadata["has_tables"] is False


def test_pdf_table_becomes_markdown_pipes() -> None:
    result = PyMuPDFExtractor().extract(build_pdf_bytes(with_table=True))
    assert result.is_structured is True
    assert result.metadata["has_tables"] is True
    # Header row + separator + data rows as pipes; no cell-text duplication.
    assert "| Услуга | Цена |" in result.markdown
    assert "| Консультация | 5000 |" in result.markdown
    assert result.markdown.count("Консультация") == 1


def test_pdf_too_short_raises() -> None:
    import pymupdf

    doc = pymupdf.open()
    doc.new_page()
    data = doc.tobytes()
    doc.close()
    with pytest.raises(ExtractionFailedError, match="слишком мало"):
        PyMuPDFExtractor().extract(data)


def test_pdf_garbage_raises() -> None:
    with pytest.raises(ExtractionFailedError):
        PyMuPDFExtractor().extract(b"definitely not a pdf")


# ── DOCX (mammoth) ───────────────────────────────────────────────────────────


def test_docx_heading_preserved() -> None:
    result = MammothDocxExtractor().extract(build_docx_bytes())
    assert result.markdown.startswith("# Договор поставки")
    assert result.is_structured is True
    assert "арбитражном суде" in result.markdown


def test_docx_garbage_raises() -> None:
    with pytest.raises(ExtractionFailedError):
        MammothDocxExtractor().extract(b"not a zip")


# ── RTF (striprtf) ───────────────────────────────────────────────────────────


def test_rtf_extracted_as_plain_text() -> None:
    body = " ".join(f"Clause {i}: the parties agree to the terms herein." for i in range(30))
    data = r"{\rtf1\ansi\deff0 " + body.replace("\n", r"\par ") + "}"
    result = RtfExtractor().extract(data.encode("ascii"))
    assert "the parties agree" in result.markdown
    assert result.is_structured is False


def test_rtf_missing_header_raises() -> None:
    with pytest.raises(ExtractionFailedError, match="RTF"):
        RtfExtractor().extract(b"just some text that is long enough " * 10)


# ── TXT (chardet) ────────────────────────────────────────────────────────────


def test_txt_windows1251_detected() -> None:
    data = (PARAGRAPH * 10).encode("windows-1251")
    result = TxtExtractor().extract(data)
    assert "арбитражном суде" in result.markdown  # decoded, not mojibake
    assert result.metadata["encoding"] == "windows-1251"
    assert result.is_structured is False


def test_txt_utf8() -> None:
    result = TxtExtractor().extract((PARAGRAPH * 5).encode("utf-8"))
    assert "Стороны" in result.markdown
    assert result.metadata["encoding"] in ("utf-8", "utf-8-sig")


def test_txt_too_short_raises() -> None:
    with pytest.raises(ExtractionFailedError):
        TxtExtractor().extract("коротко".encode())


# ── OCR (tesseract) ─────────────────────────────────────────────────────────


def _tesseract_available() -> bool:
    import os
    import shutil

    if shutil.which("tesseract") is None:
        return False
    # The default adapter uses rus+eng; skip if traineddata is missing.
    tessdata = os.environ.get("TESSDATA_PREFIX", "/usr/share/tessdata")
    return os.path.exists(os.path.join(tessdata, "eng.traineddata"))


def build_png_bytes(tmp_path: Path) -> bytes:
    from PIL import Image, ImageDraw, ImageFont

    text = (
        "Contract. The parties agree to the terms herein. "
        "Party A shall deliver the goods within ten business days. "
        "Party B shall pay the invoice within thirty days. "
        "Liability is limited to the contract value. "
        "Disputes shall be resolved in arbitration in Moscow."
    )
    font_path = "/usr/share/fonts/noto/NotoSans-Regular.ttf"
    try:
        font = ImageFont.truetype(font_path, 24)
    except OSError:
        font = ImageFont.load_default()

    img = Image.new("RGB", (1200, 400), color="white")
    draw = ImageDraw.Draw(img)
    draw.text((20, 20), text, fill="black", font=font)
    path = tmp_path / "contract.png"
    img.save(path, format="PNG")
    return path.read_bytes()


@pytest.mark.skipif(not _tesseract_available(), reason="tesseract not installed")
def test_ocr_image_extracts_text(tmp_path: Path) -> None:
    data = build_png_bytes(tmp_path)
    result = TesseractOcrExtractor().extract(data)
    assert "Contract" in result.markdown
    assert result.metadata["format"] == "image"
    assert result.metadata["pages"] == 1


def test_ocr_garbage_pdf_raises() -> None:
    from contract_check.core.analysis.ocr import OCRError

    with pytest.raises((OCRError, ExtractionFailedError)):
        TesseractOcrExtractor().extract(b"%PDF-1.4 garbage")


def test_ocr_garbage_image_raises() -> None:
    from contract_check.core.analysis.ocr import OCRError

    with pytest.raises((OCRError, ExtractionFailedError)):
        TesseractOcrExtractor().extract(b"\x89PNG\r\n\x1a\n not really a png")


# ── ExtractedDocument DTO ────────────────────────────────────────────────────


def test_extracted_document_defaults() -> None:
    doc = ExtractedDocument(markdown="x")
    assert doc.is_structured is False
    assert doc.metadata == {}