# app.py – encoder-only demo for bert-beatrix-2048
# -----------------------------------------------
# launch:  python app.py
import spaces
import torch
import gradio as gr
from huggingface_hub import snapshot_download
from bert_handler import create_handler_from_checkpoint

# ------------------------------------------------------------------
# 1.  Download *once* and load locally  -----------------------------
# ------------------------------------------------------------------
LOCAL_CKPT = snapshot_download(
    repo_id="AbstractPhil/bert-beatrix-2048",
    revision="main",
    local_dir="bert-beatrix-2048",
    local_dir_use_symlinks=False
)

handler, full_model, tokenizer = create_handler_from_checkpoint(LOCAL_CKPT)
full_model = full_model.eval().cuda()

# --- pull encoder & embeddings only --------------------------------
encoder     = full_model.bert.encoder
embeddings  = full_model.bert.embeddings
emb_ln      = full_model.bert.emb_ln
emb_drop    = full_model.bert.emb_drop

# ------------------------------------------------------------------
# 2.  Symbolic token list  ------------------------------------------
# ------------------------------------------------------------------
SYMBOLIC_ROLES = [
    "<subject>", "<subject1>", "<subject2>", "<pose>", "<emotion>",
    "<surface>", "<lighting>", "<material>", "<accessory>", "<footwear>",
    "<upper_body_clothing>", "<hair_style>", "<hair_length>", "<headwear>",
    "<texture>", "<pattern>", "<grid>", "<zone>", "<offset>",
    "<object_left>", "<object_right>", "<relation>", "<intent>", "<style>",
    "<fabric>", "<jewelry>"
]

# Sanity-check: every role must be known by the tokenizer
missing = [t for t in SYMBOLIC_ROLES
           if tokenizer.convert_tokens_to_ids(t) == tokenizer.unk_token_id]
if missing:
    raise RuntimeError(f"Tokenizer is missing special tokens: {missing}")

# ------------------------------------------------------------------
# 3.  Encoder-only inference util  ----------------------------------
# ------------------------------------------------------------------
@spaces.GPU
def encode_and_trace(text: str, selected_roles: list[str]):
    with torch.no_grad():
        batch = tokenizer(text, return_tensors="pt").to("cuda")
        ids, mask = batch.input_ids, batch.attention_mask

        x = emb_drop(emb_ln(embeddings(ids)))

        ext_mask = full_model.bert.get_extended_attention_mask(mask, x.shape[:-1])
        enc = encoder(x, attention_mask=ext_mask)               # (1, S, H)

        want = {tokenizer.convert_tokens_to_ids(t) for t in selected_roles}
        keep = torch.tensor([tid in want for tid in ids[0]], device=enc.device)

        found = [tokenizer.convert_ids_to_tokens([tid])[0] for tid in ids[0] if tid in want]
        if keep.any():
            vec = enc[0][keep].mean(0)
            norm = f"{vec.norm().item():.4f}"
        else:
            norm = "0.0000"

        return {
            "Symbolic Tokens": ", ".join(found) or "(none)",
            "Mean Norm": norm,
            "Token Count": int(keep.sum().item()),
        }

# ------------------------------------------------------------------
# 4.  Gradio UI  -----------------------------------------------------
# ------------------------------------------------------------------
def build_interface():
    with gr.Blocks(title="🧠 Symbolic Encoder Inspector") as demo:
        gr.Markdown("## 🧠 Symbolic Encoder Inspector")
        with gr.Row():
            with gr.Column():
                txt = gr.Textbox(label="Input with Symbolic Tokens", lines=3)
                chk = gr.CheckboxGroup(choices=SYMBOLIC_ROLES, label="Trace these roles")
                btn = gr.Button("Encode & Trace")
            with gr.Column():
                out_tok  = gr.Textbox(label="Symbolic Tokens Found")
                out_norm = gr.Textbox(label="Mean Norm")
                out_cnt  = gr.Textbox(label="Token Count")
        btn.click(encode_and_trace, [txt, chk], [out_tok, out_norm, out_cnt])
    return demo

if __name__ == "__main__":
    build_interface().launch()