app.py

import json, numpy as np, gradio as gr
from setfit import SetFitModel
from huggingface_hub import hf_hub_download
from evidence import extract_evidence
import os, shutil, pathlib

# Optional: only clear cache if you set CLEAR_HF_CACHE=1 in the Space secrets
if os.getenv("CLEAR_HF_CACHE") == "1":
    CACHE_DIR = os.path.expanduser("~/.cache/huggingface")
    shutil.rmtree(CACHE_DIR, ignore_errors=True)
    pathlib.Path(CACHE_DIR).mkdir(parents=True, exist_ok=True)

MODEL_ID = "DelaliScratchwerk/text-period-setfit"

# thresholds (your tuned values)
TOP_K = 3
UNCERTAINTY_THRESHOLD = 0.516
MARGIN_THRESHOLD = 0.387

# labels (Hub -> local fallback)
try:
    labels_path = hf_hub_download(MODEL_ID, "labels.json")
    LABELS = json.load(open(labels_path))
except Exception:
    LABELS = json.load(open("labels.json"))

model = SetFitModel.from_pretrained(MODEL_ID)

def format_evidence(ev: dict) -> str:
    parts = []
    if ev.get("years"):
        parts.append("**Years found:** " + ", ".join(ev["years"]))
    if ev.get("keyword_hits"):
        for bucket, keys in ev["keyword_hits"].items():
            if keys:
                parts.append(f"**{bucket}:** " + ", ".join(keys))
    return "\n\n".join(parts) if parts else "_No explicit time clues found._"

def predict(txt: str):
    txt = (txt or "").strip()
    if not txt:
        return "—", "Paste some text.", {}

    probs = np.asarray(model.predict_proba([txt])[0], dtype=float).ravel()
    if probs.size == 0:
        return "—", "Model returned no probabilities.", {}

    if probs.size != len(LABELS):
        return "—", f"Label mismatch: model has {probs.size} classes, labels.json has {len(LABELS)}", {}

    order = np.argsort(probs)[::-1]
    top1 = probs[order[0]]
    top2 = probs[order[1]] if probs.size > 1 else 0.0
    ev = extract_evidence(txt)

    # uncertain mode
    if top1 < UNCERTAINTY_THRESHOLD or (top1 - top2) < MARGIN_THRESHOLD:
        topk = [{"label": LABELS[i], "score": float(probs[i])} for i in order[:TOP_K]]
        md = "**Uncertain** — top candidates:\n" + "\n".join(
            f"- **{d['label']}**: {d['score']:.3f}" for d in topk
        )
        return "uncertain", md + "\n\n" + format_evidence(ev), {LABELS[i]: float(probs[i]) for i in order}

    # confident
    best = LABELS[order[0]]
    md = "**Reasoning hints**\n\n" + format_evidence(ev)
    return best, md, {LABELS[i]: float(probs[i]) for i in order}

with gr.Blocks(title="Text → Time Period (SetFit)") as demo:
    gr.Markdown("# Text → Time Period (SetFit)")
    with gr.Row():
        text = gr.Textbox(lines=8, label="Paste text")
        with gr.Column():
            pred = gr.Label(label="Predicted")
            reason = gr.Markdown(label="Evidence")
    scores = gr.JSON(label="Scores")

    btn = gr.Button("Submit", variant="primary")
    # Stable API route name; HTTP endpoint will be /api/predict
    btn.click(
        predict,
        inputs=text,
        outputs=[pred, reason, scores],
        api_name="predict"
    )

    gr.Examples(
        examples=[
            "Schools went remote during the pandemic; everyone wore N95s and used Zoom.",
            "Sputnik launched and kicked off the space race.",
            "MySpace was the most popular social network for a while.",
            "Creators blew up on TikTok; companies rolled out ChatGPT-powered tools.",
        ],
        inputs=text
    )

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