from __future__ import annotations
import os
import base64
from typing import Tuple

def load_file(path: str) -> Tuple[str, str]:
    """
    Returns (text, image_b64).
    - text: extracted text layer (empty if image-only)
    - image_b64: base64 image (empty if plain text)
    Callers decide which to use. For PDF: both may be non-empty.
    """
    if not os.path.exists(path):
        raise FileNotFoundError(f"File not found: {path}")
    ext = os.path.splitext(path)[1].lower()
    if ext in {".txt", ".md"}:
        return _read_text(path), ""
    if ext == ".pdf":
        return _pdf_text(path), _pdf_first_page_b64(path)
    if ext in {".png", ".jpg", ".jpeg", ".webp"}:
        return "", _image_b64(path)
    return _read_text(path), ""

def _read_text(path: str) -> str:
    with open(path, "r", encoding="utf-8", errors="replace") as f:
        return f.read()

def _pdf_text(path: str) -> str:
    try:
        import fitz
        doc = fitz.open(path)
        text = "\n".join(page.get_text("text") for page in doc).strip()
        doc.close()
        return text
    except Exception:
        return ""

def _pdf_first_page_b64(path: str) -> str:
    try:
        import fitz
        doc = fitz.open(path)
        pix = doc[0].get_pixmap(dpi=150)
        b64 = base64.b64encode(pix.tobytes("png")).decode("utf-8")
        doc.close()
        return b64
    except Exception:
        return ""

def _image_b64(path: str) -> str:
    with open(path, "rb") as f:
        return base64.b64encode(f.read()).decode("utf-8")