src/streamlit_app.py

import streamlit as st
import chess
import chess.svg

st.set_page_config(page_title="Chess Game", layout="wide")

# ================= CSS (compact layout) =================
st.markdown("""
<style>
.block-container {
    padding-top: 1rem;
    padding-bottom: 1rem;
}

/* Reduce spacing between columns */
div[data-testid="column"] {
    padding: 0 !important;
}

div[data-testid="stHorizontalBlock"] {
    gap: 5px !important;
}
</style>
""", unsafe_allow_html=True)

st.title("♟️ Chess Game")

# ================= INIT =================
if "board" not in st.session_state:
    st.session_state.board = chess.Board()
    st.session_state.selected = None
    st.session_state.message = ""

board = st.session_state.board

# ================= HANDLE CLICK =================
def select_square(square):
    if st.session_state.selected is None:
        piece = board.piece_at(square)
        if piece and piece.color == board.turn:
            st.session_state.selected = square
    else:
        move = chess.Move(st.session_state.selected, square)

        if move in board.legal_moves:
            board.push(move)
            st.session_state.message = "✅ Move played"
        else:
            st.session_state.message = "❌ Illegal move"

        st.session_state.selected = None

# ================= LAYOUT =================
col_board, col_controls = st.columns([2.3, 1])

# ================= BOARD =================
with col_board:
    st.subheader(f"Turn: {'White' if board.turn else 'Black'}")

    selected_square = st.session_state.selected

    svg_board = chess.svg.board(
        board=board,
        size=720,  # 🔥 big board for better UX
        lastmove=board.peek() if board.move_stack else None,
        squares=[selected_square] if selected_square else []
    )

    st.image(svg_board)

# ================= CONTROLS =================
with col_controls:
    st.subheader("🎮 Controls")

    for row in range(7, -1, -1):
        cols = st.columns(8)
        for col in range(8):
            square = chess.square(col, row)
            name = chess.square_name(square)

            if cols[col].button(name, key=name):
                select_square(square)

    if st.session_state.message:
        st.success(st.session_state.message)
        st.session_state.message = ""

    st.markdown("---")

    if st.button("↩️ Undo"):
        if board.move_stack:
            board.pop()

    if st.button("🔄 Reset"):
        st.session_state.board = chess.Board()
        st.session_state.selected = None

# ================= STATUS =================
st.subheader("Game Status")

if board.is_checkmate():
    st.error("♟️ Checkmate!")
elif board.is_stalemate():
    st.warning("Stalemate!")
elif board.is_check():
    st.warning("Check!")
else:
    st.success("Game in progress...")