"""Main Streamlit app — sidebar routing."""
import streamlit as st

# Page config must be called first
st.set_page_config(
    page_title="AI 학습 플랫폼 | 타이타닉 ML/DL",
    page_icon="🤖",
    layout="wide",
    initial_sidebar_state="expanded",
)

# Import pages
from views import home, ml_lab, dl_lab, roadmap, career

PAGES = {
    "홈 (EDA)": home,
    "ML 실습": ml_lab,
    "딥러닝 실습": dl_lab,
    "학습 로드맵": roadmap,
    "AI 직무 분석": career,
}

ICONS = {
    "홈 (EDA)": "🏠",
    "ML 실습": "🔬",
    "딥러닝 실습": "🧠",
    "학습 로드맵": "🗺️",
    "AI 직무 분석": "💼",
}

# ── Session state for active page ──
if "page" not in st.session_state:
    st.session_state.page = "홈 (EDA)"

page_keys = list(PAGES.keys())
active_idx = page_keys.index(st.session_state.page) + 1  # 1-based for CSS nth-of-type

# ── CSS: hide auto nav, style sidebar buttons ──
st.markdown(f"""
<style>
[data-testid="stSidebarNav"] {{
    display: none;
}}
section[data-testid="stSidebar"] .stButton button {{
    width: 100%;
    text-align: left;
    background-color: transparent;
    border: none;
    border-radius: 6px;
    padding: 8px 14px;
    font-size: 14px;
    cursor: pointer;
    transition: background-color 0.15s;
}}
section[data-testid="stSidebar"] .stButton button:hover {{
    background-color: rgba(255, 255, 255, 0.08);
}}
section[data-testid="stSidebar"] .stButton:nth-of-type({active_idx}) button {{
    background-color: rgba(99, 155, 255, 0.22) !important;
    border-left: 3px solid #639BFF !important;
    font-weight: 600;
}}
</style>
""", unsafe_allow_html=True)

# ── Sidebar navigation ──
st.sidebar.title("AI 학습 플랫폼")
st.sidebar.markdown("타이타닉으로 배우는 ML/DL")
st.sidebar.markdown("---")

for page_name in page_keys:
    if st.sidebar.button(f"{ICONS[page_name]}  {page_name}", key=f"nav_{page_name}"):
        st.session_state.page = page_name
        st.rerun()

st.sidebar.markdown("---")
st.sidebar.markdown("""
**데이터**: Seaborn Titanic
**프레임워크**: sklearn + PyTorch
**배포**: Hugging Face Spaces
""")

# ── Route to selected page ──
PAGES[st.session_state.page].show()