"""
PDF text extraction for user-uploaded datasheets.
Uses PyMuPDF (fitz) for robust PDF parsing.
"""

from __future__ import annotations

import logging
from pathlib import Path

logger = logging.getLogger(__name__)


def extract_text_from_pdf(file_path: str | Path) -> str:
    """
    Extract all text from a PDF file.
    Returns concatenated text from all pages.
    """
    try:
        import fitz  # PyMuPDF
    except ImportError:
        logger.error("PyMuPDF not installed. Run: pip install pymupdf")
        return ""

    try:
        doc = fitz.open(str(file_path))
        pages_text = []
        for page_num, page in enumerate(doc):
            text = page.get_text()
            if text.strip():
                pages_text.append(f"--- Page {page_num + 1} ---\n{text}")
        doc.close()

        full_text = "\n".join(pages_text)
        logger.info(
            "Extracted %d chars from %d pages of %s",
            len(full_text), len(pages_text), file_path,
        )
        return full_text

    except Exception as exc:
        logger.error("PDF extraction failed for %s: %s", file_path, exc)
        return ""


def extract_text_from_bytes(file_bytes: bytes, filename: str = "upload.pdf") -> str:
    """
    Extract text from PDF bytes (for Gradio file upload handling).
    """
    try:
        import fitz
    except ImportError:
        logger.error("PyMuPDF not installed.")
        return ""

    try:
        doc = fitz.open(stream=file_bytes, filetype="pdf")
        pages_text = []
        for page_num, page in enumerate(doc):
            text = page.get_text()
            if text.strip():
                pages_text.append(f"--- Page {page_num + 1} ---\n{text}")
        doc.close()

        full_text = "\n".join(pages_text)
        logger.info(
            "Extracted %d chars from %d pages of %s",
            len(full_text), len(pages_text), filename,
        )
        return full_text

    except Exception as exc:
        logger.error("PDF bytes extraction failed: %s", exc)
        return ""