from __future__ import annotations
import os, time, json
import urllib.request
from typing import List, Dict, Any

EMBED_URL = os.getenv("EMBED_URL", "http://127.0.0.1:8990/embed")
EMBED_MODEL = os.getenv("EMBED_MODEL", "minilm-384")
EMBED_BATCH = int(os.getenv("EMBED_BATCH", "64"))
TIMEOUT = 60

class EmbedError(RuntimeError): ...

def _post_json(url: str, payload: Dict[str, Any]) -> Dict[str, Any]:
    data = json.dumps(payload).encode("utf-8")
    req = urllib.request.Request(url, data=data, headers={"Content-Type": "application/json"})
    with urllib.request.urlopen(req, timeout=TIMEOUT) as resp:
        return json.loads(resp.read().decode("utf-8"))

def embed_texts(texts: List[str], model: str | None = None, batch_size: int | None = None) -> List[List[float]]:
    model = model or EMBED_MODEL
    batch = batch_size or EMBED_BATCH
    out: List[List[float]] = []
    i = 0
    while i < len(texts):
        chunk = texts[i:i+batch]
        # einfache Retries bei 429/500er
        for attempt in range(5):
            try:
                resp = _post_json(EMBED_URL, {"model": model, "inputs": chunk})
                vecs = resp.get("embeddings") or resp.get("vectors") or resp.get("data")
                if not isinstance(vecs, list): raise EmbedError(f"Bad embed response keys: {resp.keys()}")
                out.extend(vecs)
                break
            except Exception as e:
                if attempt == 4: raise
                time.sleep(1.5 * (attempt + 1))
                continue
        i += batch
    return out

def embed_one(text: str, model: str | None = None) -> List[float]:
    return embed_texts([text], model=model, batch_size=1)[0]