from pathlib import Path
import duckdb
import pandas as pd
import streamlit as st


def get_db_path() -> Path:
    """Resolve local DuckDB file path across reports and data/DB locations."""
    repo_root = Path(__file__).resolve().parent.parent.parent
    candidates = [
        repo_root / "dbt_nba" / "reports" / "sources" / "nba" / "dbt_nba.duckdb",
        repo_root / "data" / "DB" / "dbt_nba.duckdb",
        Path("dbt_nba/reports/sources/nba/dbt_nba.duckdb"),
        Path("data/DB/dbt_nba.duckdb"),
    ]
    for path in candidates:
        if path.exists():
            return path.resolve()
    return candidates[0]


@st.cache_resource
def get_connection():
    """Persistent read-only DuckDB connection."""
    db_path = get_db_path()
    if not db_path.exists():
        st.error(
            f"Database file not found at `{db_path}`. "
            "Run `./scripts/run_app.sh --sync` or `./scripts/pipeline.sh` to initialize."
        )
        st.stop()
    return duckdb.connect(str(db_path), read_only=True)


@st.cache_data(ttl=3600)
def query(sql: str, params: list | None = None) -> pd.DataFrame:
    """Execute SQL (optionally parameterized) and return cached DataFrame."""
    conn = get_connection()
    if params:
        return conn.execute(sql, params).df()
    return conn.execute(sql).df()


@st.cache_data(ttl=3600)
def get_seasons() -> pd.DataFrame:
    """Return available seasons ordered most recent first."""
    return query(
        "SELECT season_start_year, season_display "
        "FROM main_marts.dim_seasons "
        "ORDER BY season_start_year DESC"
    )


def get_selected_season() -> tuple[int, str]:
    """Return (season_start_year, season_display) from session state."""
    seasons = get_seasons()
    season_options = seasons["season_start_year"].tolist()
    season_labels = dict(zip(seasons["season_start_year"], seasons["season_display"]))
    if "season" not in st.session_state or st.session_state["season"] not in season_labels:
        st.session_state["season"] = season_options[0]
    season = st.session_state["season"]
    return season, season_labels[season]