src/streamlit_app.py

"""
MTG Draft Assistant Streamlit App
---------------------------------
A booster-draft helper written with Streamlit and deployable on Hugging Face Spaces.

Changes in this revision
~~~~~~~~~~~~~~~~~~~~~~~~
* **supported_sets.txt** – one set code per line.
* Sidebar now shows a **single-choice list** (radio buttons) sourced from that
  file instead of a free-text box, so users can only draft sets you actually
  support.
* Fallback to the old text input if the text-file is missing or empty.

Replace the three stub functions (`load_model`, `suggest_pick`,
`generate_booster`) with your real model-/API-calls when you are ready.
"""

from __future__ import annotations

import os
import random
from pathlib import Path
from typing import Dict, List

import requests
import streamlit as st

# -----------------------------------------------------------------------------
# 0. Constants & helpers
# -----------------------------------------------------------------------------

SUPPORTED_SETS_PATH = Path("helper_files/supported_sets.txt")

@st.cache_data(show_spinner="Reading supported sets …")
def get_supported_sets(path: Path = SUPPORTED_SETS_PATH) -> List[str]:
    """Return a list of legal set codes read from *supported_sets.txt*.

    The file should contain **one set tag per line**, e.g.::

        WOE
        LCI
        MKM

    If the file is missing we fall back to an empty list so the UI
    degrades gracefully.
    """
    if path.is_file():
        return [ln.strip() for ln in path.read_text().splitlines() if ln.strip()]
    return []

# -----------------------------------------------------------------------------
# 1. Model loading (stub)
# -----------------------------------------------------------------------------

@st.cache_resource(show_spinner="Loading draft model …")
def load_model():
    """Load and return the trained drafting model.

    Adapt to your own pipeline; see previous revision for an example that pulls
    an artefact from *huggingface_hub*.  Returning *None* leaves us in demo
    mode and will pick random cards.
    """
    return None

model = load_model()

# -----------------------------------------------------------------------------
# 2. Draft-logic helpers (stubs)
# -----------------------------------------------------------------------------

def suggest_pick(pack: List[Dict], picks: List[Dict]) -> Dict:
    """Return the card the model recommends from *pack*."""
    if model is None:
        return random.choice(pack)
    return model.predict(pack=pack, picks=picks)  # type: ignore[attr-defined]


def fetch_card_image(card_name: str) -> str:
    """Fetch card art URL from Scryfall (normal size)."""
    r = requests.get(
        "https://api.scryfall.com/cards/named", params={"exact": card_name, "format": "json"}
    )
    r.raise_for_status()
    data = r.json()
    if "image_uris" in data:
        return data["image_uris"]["normal"]
    return data["card_faces"][0]["image_uris"]["normal"]


def generate_booster(set_code: str) -> List[Dict]:
    """Return a pseudo-random 15-card booster using Scryfall search."""
    url = f"https://api.scryfall.com/cards/search?q=set%3A{set_code}+is%3Abooster+unique%3Aprints"
    cards: List[Dict] = []
    while url:
        resp = requests.get(url)
        resp.raise_for_status()
        payload = resp.json()
        cards += payload["data"]
        url = payload.get("next_page") if payload.get("has_more") else None
    return random.sample(cards, 15)

# -----------------------------------------------------------------------------
# 3. Streamlit UI
# -----------------------------------------------------------------------------

st.set_page_config(page_title="MTG Draft Assistant", page_icon="🃏")

st.title("🃏 MTG Draft Assistant")

# ---------------- Sidebar -----------------------------------------------------

with st.sidebar:
    st.header("Draft setup")

    supported_sets = get_supported_sets()

    if supported_sets:
        set_code = st.radio("Choose a set to draft", supported_sets, index=0)
    else:
        st.warning(
            "*supported_sets.txt* not found or empty. Using free-text input instead.",
            icon="⚠️",
        )
        set_code = st.text_input("Set code", value="WOE")

    if st.button("Start new draft", type="primary"):
        st.session_state["pack"] = generate_booster(set_code)
        st.session_state["picks"] = []

# ---------------- Session state guards ---------------------------------------

st.session_state.setdefault("pack", [])
st.session_state.setdefault("picks", [])

if not st.session_state["pack"]:
    st.info("Choose **Start new draft** in the sidebar to open pack 1.")
    st.stop()

pack: List[Dict] = st.session_state["pack"]
picks: List[Dict] = st.session_state["picks"]

st.subheader(f"Pack {len(picks) // 15 + 1} — Pick {len(picks) % 15 + 1}")
suggested = suggest_pick(pack, picks)

st.success(f"**Model suggests:** {suggested['name']}")

# Display current pack as a 5-column grid of card images
cols = st.columns(5)
for idx, card in enumerate(pack):
    col = cols[idx % 5]
    col.image(fetch_card_image(card["name"]), use_column_width=True)
    if col.button(f"Pick {card['name']}", key=f"pick-{idx}"):
        picks.append(card)
        pack.remove(card)
        if not pack:  # end of pack ⇒ open a fresh booster
            st.session_state["pack"] = generate_booster(set_code)
        st.experimental_rerun()

with st.expander("Current picks", expanded=False):
    st.write("\n".join([c["name"] for c in picks]))