"""
PDF-family extractor.

Text per page via pypdf, plus the document info dict (title/author/dates). When
options['render'] is set and pdf2image (+ system poppler) is available, page 1 is
rendered to thumb.jpg.
"""
import io
from pathlib import Path

from .base import ExtractionResult

EXTRACTOR_ID = "pdf/pypdf@1"


def _info_metadata(reader) -> dict:
    out = {}
    info = getattr(reader, "metadata", None)
    if not info:
        return out
    for src, dst in (("title", "title"), ("author", "author"),
                     ("creation_date", "created"), ("modification_date", "modified_doc")):
        try:
            val = getattr(info, src, None)
        except Exception:
            val = None
        if val:
            out[dst] = str(val)
    return out


def _render_first_page(source: Path) -> bytes:
    from pdf2image import convert_from_path  # needs system poppler
    images = convert_from_path(str(source), first_page=1, last_page=1, dpi=100)
    if not images:
        return b""
    im = images[0]
    im.thumbnail((640, 640))
    buf = io.BytesIO()
    im.convert("RGB").save(buf, format="JPEG", quality=80)
    return buf.getvalue()


def extract(source: Path, options: dict) -> ExtractionResult:
    from pypdf import PdfReader  # lazy

    warnings = []
    reader = PdfReader(str(source))
    pages = reader.pages
    blocks = []
    for i, page in enumerate(pages, 1):
        try:
            text = page.extract_text() or ""
        except Exception as e:
            text = ""
            warnings.append(f"page {i} text extraction failed: {e}")
        blocks.append(f"## Page {i}\n\n{text.strip()}")
    content = "\n\n".join(blocks) + "\n"

    metadata = _info_metadata(reader)
    metadata["pages"] = len(pages)

    thumb = None
    if options.get("render"):
        try:
            thumb = _render_first_page(source) or None
        except ImportError:
            warnings.append("--render requested but pdf2image/poppler not available")
        except Exception as e:
            warnings.append(f"page render failed: {e}")

    return ExtractionResult(content=content, metadata=metadata, thumb=thumb,
                            warnings=warnings, extractor=EXTRACTOR_ID)