from pysbmy.density import get_density_pm_snapshot
from pysbmy.snapshot import read_snapshot
import argparse


def convert_snapshot_to_density(snapshot_path, output_path, N=None, corner=(0.0, 0.0, 0.0)):
    """
    Convert a snapshot to a density field.

    Parameters
    ----------
    snapshot_path : str
        Path to the snapshot file.
    output_path : str
        Path to the output density file.
    N : int
        Size of the density field grid (N x N x N).
    corner : tuple of float
        Corner of the box (x, y, z).
    """
    # Read the snapshot
    print("Reading snapshot...")
    snap = read_snapshot(snapshot_path)

    if N is None:
        N = snap.Np0

    # Calculate density
    print("Calculating density...")
    F = get_density_pm_snapshot(snap, N, N, N, corner[0], corner[1], corner[2])

    # Write density to file
    print("Writing density...")
    F.write(output_path)
    print("Density written to", output_path)
    print("Done.")


def console_main():
    parser = argparse.ArgumentParser(description="Convert snapshot to density.")
    parser.add_argument(
        "-S",
        "--snapshot",
        type=str,
        required=True,
        help="Path to the snapshot file.",
    )
    parser.add_argument(
        "-o",
        "--output",
        type=str,
        required=True,
        help="Path to the output density file.",
    )
    parser.add_argument(
        "-N",
        "--N",
        type=int,
        default=None,
        help="Size of the density field grid (N x N x N).",
    )
    parser.add_argument(
        "-c",
        "--corner",
        type=float,
        nargs=3,
        default=[0.0, 0.0, 0.0],
        help="Corner of the box (x, y, z).",
    )

    args = parser.parse_args()

    convert_snapshot_to_density(
        snapshot_path=args.snapshot,
        output_path=args.output,
        N=args.N,
        corner=args.corner,
    )


if __name__ == "__main__":
    console_main()