app.py

from fastapi import FastAPI
from pydantic import BaseModel
import joblib
import logging
import json
import numpy as np
from huggingface_hub import hf_hub_download
from transformers import pipeline

logging.basicConfig(level=logging.INFO, format="%(asctime)s - %(levelname)s - %(message)s")

app = FastAPI()

models = None
en_emotion_map = None   # Will store the json mapping

def load_models():
    global models, en_emotion_map
    if models is not None:
        return

    logging.info("Loading models...")

    # ====================== NEW ENGLISH MODEL ======================
    en_repo = "E-motionAssistant/English_LR_Model_New"

    en_vectorizer = joblib.load(hf_hub_download(en_repo, "tfidf_vectorizer.joblib"))
    en_classifier = joblib.load(hf_hub_download(en_repo, "logreg_model.joblib"))
    en_label_encoder = joblib.load(hf_hub_download(en_repo, "label_encoder.joblib"))

    # Load emotion_map.json
    try:
        map_path = hf_hub_download(en_repo, "emotion_map.json")
        with open(map_path, "r", encoding="utf-8") as f:
            en_emotion_map = json.load(f)
        logging.info("✅ emotion_map.json loaded successfully for English")
    except Exception as e:
        logging.warning(f"Failed to load emotion_map.json: {e}")
        en_emotion_map = None

    # ====================== Sinhala Model ======================
    si_vectorizer = joblib.load(hf_hub_download("E-motionAssistant/Sinhala_Text_Emotion_Model_LR", "tfidf_vectorizer.joblib"))
    si_classifier = joblib.load(hf_hub_download("E-motionAssistant/Sinhala_Text_Emotion_Model_LR", "logreg_model.joblib"))
    si_label_encoder = joblib.load(hf_hub_download("E-motionAssistant/Sinhala_Text_Emotion_Model_LR", "label_encoder.joblib"))

    # ====================== Tamil Model ======================
    tamil_pipe = pipeline("text-classification", 
                          model="E-motionAssistant/Tamil_Emotion_Recognition_Model", 
                          device=-1)

    models = (en_vectorizer, en_classifier, en_label_encoder,
              si_vectorizer, si_classifier, si_label_encoder, tamil_pipe)

    logging.info("✅ All models loaded successfully.")

@app.on_event("startup")
def startup_event():
    load_models()

class PredictRequest(BaseModel):
    text: str
    language: str

@app.get("/")
def root():
    return {"status": "ok", "message": "Emotion Detector API is running"}

@app.post("/predict")
def predict(req: PredictRequest):
    if not req.text.strip():
        return {"error": "Text cannot be empty"}

    en_vec, en_clf, en_le, si_vec, si_clf, si_le, tamil_pipe = models

    try:
        lang = req.language.lower()

        if lang == "english":
            X = en_vec.transform([req.text])
            pred = int(en_clf.predict(X)[0])               # convert to int

            # Use emotion_map.json (preferred for new model)
            if en_emotion_map is not None:
                emotion = en_emotion_map.get(str(pred), f"unknown_{pred}")
            else:
                # fallback
                emotion = en_le.inverse_transform([pred])[0]

            return {"emotion": emotion, "language": "English"}

        elif lang == "sinhala":
            X = si_vec.transform([req.text])
            pred = si_clf.predict(X)[0]
            emotion = si_le.inverse_transform([pred])[0]
            return {"emotion": str(emotion), "language": "Sinhala"}

        elif lang == "tamil":
            res = tamil_pipe(req.text)[0]
            return {
                "emotion": res["label"],
                "confidence": round(float(res["score"]), 3),
                "language": "Tamil"
            }
        else:
            return {"error": f"Unsupported language: {req.language}"}

    except Exception as e:
        logging.error(f"Prediction error: {type(e).__name__} - {e}")
        return {"error": "Prediction failed. Please try again."}