"""OmniParse AI — OCR pipeline: Tesseract (primary) + Google Vision (fallback)."""

import io, base64
from PIL import Image as PILImage
import requests
from config import GOOGLE_VISION_KEY

# Lazy imports
_pt = None; _pdf2img = None

def _get_pt():
    global _pt
    if _pt is None:
        try:
            import pytesseract as t
            _pt = t
        except ImportError: pass
    return _pt

def _get_pdf2img():
    global _pdf2img
    if _pdf2img is None:
        try:
            from pdf2image import convert_from_path as c
            _pdf2img = c
        except ImportError: pass
    return _pdf2img

def pdf_to_images(path: str, dpi: int = 200) -> list:
    c = _get_pdf2img()
    if not c: return []
    try: return c(path, dpi=dpi)
    except Exception as e: print(f"[WARN] pdf2image: {e}"); return []

def load_image(path: str):
    try: return PILImage.open(path).convert("RGB")
    except Exception as e: print(f"[WARN] open image: {e}"); return None

def ocr_tesseract(img, lang: str = "eng") -> str:
    pt = _get_pt()
    if not pt: return ""
    try: return pt.image_to_string(img.convert("L"), lang=lang)
    except Exception as e: print(f"[WARN] tesseract: {e}"); return ""

def ocr_google_vision(img) -> str:
    if not GOOGLE_VISION_KEY: return ""
    try:
        buf = io.BytesIO(); img.save(buf, format="PNG")
        b64 = base64.b64encode(buf.getvalue()).decode("utf-8")
        payload = {"requests":[{"image":{"content":b64},"features":[{"type":"TEXT_DETECTION"}]}]}
        r = requests.post(
            f"https://vision.googleapis.com/v1/images:annotate?key={GOOGLE_VISION_KEY}",
            json=payload, timeout=15)
        r.raise_for_status()
        return r.json()["responses"][0].get("fullTextAnnotation",{}).get("text","")
    except Exception as e: print(f"[WARN] vision: {e}"); return ""

def run_ocr(img) -> str:
    text = ocr_tesseract(img)
    if len(text.strip()) < 100 and GOOGLE_VISION_KEY:
        vt = ocr_google_vision(img)
        if len(vt.strip()) > len(text.strip()): text = vt
    return text