"""
OCR Pipeline Auto-Mode Helpers.

VLM shear detection, SSE event formatting, and request models.

Lizenz: Apache 2.0
DATENSCHUTZ: Alle Verarbeitung erfolgt lokal.
"""

import json
import logging
import os
import re
from typing import Any, Dict

from pydantic import BaseModel

logger = logging.getLogger(__name__)


class RunAutoRequest(BaseModel):
    from_step: int = 1          # 1=deskew, 2=dewarp, 3=columns, 4=rows, 5=words, 6=llm-review
    ocr_engine: str = "auto"    # "auto" | "rapid" | "tesseract"
    pronunciation: str = "british"
    skip_llm_review: bool = False
    dewarp_method: str = "ensemble"  # "ensemble" | "vlm" | "cv"


async def auto_sse_event(step: str, status: str, data: Dict[str, Any]) -> str:
    """Format a single SSE event line."""
    payload = {"step": step, "status": status, **data}
    return f"data: {json.dumps(payload)}\n\n"


async def detect_shear_with_vlm(image_bytes: bytes) -> Dict[str, Any]:
    """Ask qwen2.5vl:32b to estimate the vertical shear angle of a scanned page.

    The VLM is shown the image and asked: are the column/table borders tilted?
    If yes, by how many degrees? Returns a dict with shear_degrees and confidence.
    Confidence is 0.0 if Ollama is unavailable or parsing fails.
    """
    import httpx
    import base64

    ollama_base = os.getenv("OLLAMA_BASE_URL", "http://host.docker.internal:11434")
    model = os.getenv("OLLAMA_HTR_MODEL", "qwen2.5vl:32b")

    prompt = (
        "This is a scanned vocabulary worksheet. Look at the vertical borders of the table columns. "
        "Are they perfectly vertical, or do they tilt slightly? "
        "If they tilt, estimate the tilt angle in degrees (positive = top tilts right, negative = top tilts left). "
        "Reply with ONLY a JSON object like: {\"shear_degrees\": 1.2, \"confidence\": 0.8} "
        "Use confidence 0.0-1.0 based on how clearly you can see the tilt. "
        "If the columns look straight, return {\"shear_degrees\": 0.0, \"confidence\": 0.9}"
    )

    img_b64 = base64.b64encode(image_bytes).decode("utf-8")
    payload = {
        "model": model,
        "prompt": prompt,
        "images": [img_b64],
        "stream": False,
    }

    try:
        async with httpx.AsyncClient(timeout=60.0) as client:
            resp = await client.post(f"{ollama_base}/api/generate", json=payload)
            resp.raise_for_status()
            text = resp.json().get("response", "")

        # Parse JSON from response (may have surrounding text)
        match = re.search(r'\{[^}]+\}', text)
        if match:
            data = json.loads(match.group(0))
            shear = float(data.get("shear_degrees", 0.0))
            conf = float(data.get("confidence", 0.0))
            # Clamp to reasonable range
            shear = max(-3.0, min(3.0, shear))
            conf = max(0.0, min(1.0, conf))
            return {"method": "vlm_qwen2.5vl", "shear_degrees": round(shear, 3), "confidence": round(conf, 2)}
    except Exception as e:
        logger.warning(f"VLM dewarp failed: {e}")

    return {"method": "vlm_qwen2.5vl", "shear_degrees": 0.0, "confidence": 0.0}