app.py

import os
import sys
from flask import Flask, request, jsonify
from huggingface_hub import InferenceClient

app = Flask(__name__)

API_KEY = (os.getenv("API_KEY") or "").strip()
# Multilingual zero-shot model (handles Hindi + English well)
ZSL_MODEL_ID = os.getenv("ZSL_MODEL_ID", "joeddav/xlm-roberta-large-xnli").strip()

LABELS = [
    "health_wellness",
    "spiritual_guidance",
    "generate_image",
    "realtime_query",
    "other_query",
]
ALLOWED = set(LABELS)

def log(msg, **kv):
    line = " | ".join([msg] + [f"{k}={v}" for k, v in kv.items()])
    print(line, file=sys.stderr, flush=True)


# Init HF client once
client = InferenceClient(token=API_KEY) if API_KEY else None

@app.get("/")
def root():
    return jsonify({"ok": True, "model": ZSL_MODEL_ID})

@app.post("/generate_text")
def generate_text():
    if not API_KEY:
        log("DECISION_ERR", reason="missing_api_key")
        return jsonify({"error": "Missing API_KEY"}), 400
    if client is None:
        log("DECISION_ERR", reason="client_not_initialized")
        return jsonify({"error": "Client not initialized"}), 500

    data = request.get_json(silent=True) or {}
    prompt = (data.get("prompt") or "").strip()
    instructions = (data.get("instructions") or "").strip()  # not required here

    if not prompt:
        log("DECISION_BAD_REQ", has_prompt=False)
        return jsonify({"error": "Missing required fields"}), 400

    # Fast-path: explicit image command
    if prompt.startswith("/image "):
        log("DECISION_FAST", token="generate_image")
        return jsonify({"response": "generate_image"}), 200

    try:
        log("DECISION_CALL_ZSL", model=ZSL_MODEL_ID, prompt_len=len(prompt))
        zs = client.zero_shot_classification(
            prompt,
            LABELS,
            model=ZSL_MODEL_ID,
            hypothesis_template="This text is about {}.",
            multi_label=False,  # single best label
        )
    
        # Normalize shapes:
        # - Newer hub often returns a dict
        # - Some providers return a list[dict] (one per input)
        if isinstance(zs, list):
            zs = zs[0] if zs else {}
    
        if not isinstance(zs, dict):
            raise ValueError(f"Unexpected ZSL response type: {type(zs)}")
    
        labels = zs.get("labels") or zs.get("candidate_labels") or []
        scores = zs.get("scores") or []
        if not labels and "label" in zs:
            labels = [zs["label"]]
            scores = [zs.get("score", 0.0)]
    
        best = labels[0] if labels else "other_query"
        score = float(scores[0]) if scores else 0.0
        token = best if best in ALLOWED else "other_query"
    
        log("DECISION_OK", token=token, top_label=best, score=round(score, 4))
        return jsonify({"response": token}), 200
    
    except Exception as e:
        log("DECISION_FAIL", error=str(e))
        return jsonify({"response": "other_query", "error": str(e)}), 200


if __name__ == "__main__":
    port = int(os.getenv("PORT", 7860))
    log("BOOT", port=port, zsl_model=ZSL_MODEL_ID, api_key_set=bool(API_KEY))
    app.run(host="0.0.0.0", port=port)