"""CLI for alpha combination."""

import os
import click

from pipeline.combo.combine import combine_alphas, COMBO_METHODS


@click.group(name="combo")
def combo():
    """Combine multiple alphas into a single combined weight."""


@combo.command("combine")
@click.option(
    "--alpha-paths", required=True,
    help="Comma-separated paths to alpha parquet files",
)
@click.option("--combo-name", required=True, help="Name for this combo")
@click.option(
    "--method", default="equal_weight",
    type=click.Choice(list(COMBO_METHODS.keys())),
    help="Combination method",
)
@click.option("--output-dir", default="combos", help="Directory to save combo parquet")
def combine(alpha_paths, combo_name, method, output_dir):
    """Combine multiple alphas and save as parquet."""
    paths = [p.strip() for p in alpha_paths.split(",") if p.strip()]
    if len(paths) < 2:
        click.echo("Error: --alpha-paths requires at least 2 comma-separated paths", err=True)
        return

    result = combine_alphas(
        alpha_paths=paths,
        combo_name=combo_name,
        method=method,
    )

    os.makedirs(output_dir, exist_ok=True)
    out_path = f"{output_dir}/{combo_name}.pq"
    result.to_parquet(out_path, index=False)
    click.echo(f"Saved combo: {out_path}  ({len(result):,} rows)")
    click.echo(
        f"Weight stats — min: {result['weight'].min():.4f}, "
        f"max: {result['weight'].max():.4f}, "
        f"mean: {result['weight'].mean():.4f}"
    )