"""
Run this LOCALLY to build assets/ from your real dataset.
1) Put your CSV/Parquet with at least 'tagline' (and optional 'description') columns.
2) Adjust INPUT_PATH below.
3) python prepare_assets.py
Then commit assets/ into your Space repo (or upload to a Dataset repo).
"""
import os, json, numpy as np, pandas as pd
from sentence_transformers import SentenceTransformer
import faiss

from logic.cleaning import clean_dataframe

# ---- CHANGE THIS ----
INPUT_PATH = "/mnt/data/hf-slogan-space/data/raw_slogans.csv"   # e.g., export from your notebook
ASSETS_DIR = "assets"
MODEL_NAME = "sentence-transformers/all-MiniLM-L6-v2"
NORMALIZE = True  # set False if you prefer L2

def main():
    os.makedirs(ASSETS_DIR, exist_ok=True)

    # Load
    if INPUT_PATH.endswith(".csv"):
        df = pd.read_csv(INPUT_PATH)
    elif INPUT_PATH.endswith(".parquet"):
        df = pd.read_parquet(INPUT_PATH)
    else:
        raise ValueError("Use CSV or Parquet for INPUT_PATH")

    # Clean using your real rules
    df_clean = clean_dataframe(df)
    df_clean.to_parquet(os.path.join(ASSETS_DIR, "slogans_clean.parquet"), index=False)

    # Choose text field
    if "description" in df_clean.columns:
        texts = df_clean["description"].fillna(df_clean["tagline"]).astype(str).tolist()
        text_col, fallback_col = "description", "tagline"
    else:
        texts = df_clean["tagline"].astype(str).tolist()
        text_col, fallback_col = "tagline", "tagline"

    # Encode
    encoder = SentenceTransformer(MODEL_NAME)
    emb = encoder.encode(texts, batch_size=64, convert_to_numpy=True, normalize_embeddings=NORMALIZE)

    # Save embeddings numpy (optional; not required at runtime)
    np.save(os.path.join(ASSETS_DIR, "embeddings.npy"), emb)

    # Build FAISS index
    dim = emb.shape[1]
    if NORMALIZE:
        index = faiss.IndexFlatIP(dim)   # cosine if normalized
    else:
        index = faiss.IndexFlatL2(dim)
    index.add(emb)
    faiss.write_index(index, os.path.join(ASSETS_DIR, "faiss.index"))

    meta = {
        "model_name": MODEL_NAME,
        "dim": int(dim),
        "normalized": NORMALIZE,
        "metric": "ip" if NORMALIZE else "l2",
        "row_count": int(len(df_clean)),
        "text_col": text_col,
        "fallback_col": fallback_col,
    }
    with open(os.path.join(ASSETS_DIR, "meta.json"), "w") as f:
        json.dump(meta, f, indent=2)

    print("✅ Assets built in", ASSETS_DIR)
    print(meta)

if __name__ == "__main__":
    main()