#!/usr/bin/env python3
"""script for the NEO 1 month dataset to split the data in train (or train+missing) and val set. Creates symlinks."""
from pathlib import Path
import os
from argparse import ArgumentParser, Namespace
from loggez import loggez_logger as logger

TRAIN_SET_CUTOFF = "2014-08"
TEST_SET_CUTOFF = "2017-02"

def _get_data(data_dir: Path):
    representations = [x.name for x in data_dir.iterdir() if x.is_dir()]
    data, date_to_representations = {}, {}
    for representation in representations:
        data[representation] = [f.stem for f in (data_dir / representation).iterdir() if f.suffix == ".npz"]
        assert len(data[representation]) > 0, f"No files found for representation '{representation}'"
        for item in data[representation]:
            date_to_representations.setdefault(item, []).append(representation)
    return {k: v for k, v in sorted(date_to_representations.items(), key=lambda item: item[0])}

def _total(data: dict[str, list[str]]) -> int:
    return sum(len(v) for v in data.values())

def get_args() -> Namespace:
    """cli args"""
    parser = ArgumentParser()
    parser.add_argument("data_dir", type=lambda p: Path(p).absolute())
    parser.add_argument("--output_path", "-o", required=True, type=lambda p: Path(p).absolute())
    parser.add_argument("--mode", choices=["train_set", "test_set", "train_set_plus_missing"], required=True)
    args =  parser.parse_args()
    assert args.data_dir.exists(), f"'{args.data_dir}' doesn't exist"
    assert not (pth := (args.output_path / args.mode)).exists(), f"'{pth}' already exists, remove first"
    return args

def main(args: Namespace):
    """main fn"""
    data = _get_data(args.data_dir)
    logger.info(f"Read raw data from '{args.data_dir}' across {len(data)} modalities (total npz: {_total(data)})")

    if args.mode == "train_set":
        max_values = max([len(v) for v in data.values()])
        data_filtered = {k: v for k, v in data.items() if k <= TRAIN_SET_CUTOFF and len(v) == max_values}
    elif args.mode == "train_set_plus_missing":
        max_values = max([len(v) for v in data.values()])
        data_filtered = {k: v for k, v in data.items() if k <= TRAIN_SET_CUTOFF}
    else: # test_set
        max_values = max([len(v) for v in data.values()])
        data_filtered = {k: v for k, v in data.items() if k > TRAIN_SET_CUTOFF and k <= TEST_SET_CUTOFF
                         and len(v) == max_values}
    logger.info(f"Filtered data using mode='{args.mode}' (total npz: {_total(data_filtered)})")

    out_dir: Path = args.output_path / args.mode
    out_dir.mkdir(exist_ok=False, parents=True)

    for date_stem, modalities in data_filtered.items(): # {date_stem: [modalities]}
        for modality in modalities:
            in_file: Path = args.data_dir / modality / f"{date_stem}.npz"
            out_file: Path = out_dir / modality / f"{date_stem}.npz"
            out_file.parent.mkdir(parents=True, exist_ok=True)
            os.symlink(os.path.relpath(in_file, out_file.parent), out_file)

    logger.info(f"Created symlinks at: '{out_dir}'")

if __name__ == "__main__":
    main(get_args())