#!/usr/bin/env python3
import argparse
import logging
from pathlib import Path
import sys
from typing import Iterable
from typing import Union

import numpy as np

from espnet.utils.cli_utils import get_commandline_args


def aggregate_stats_dirs(
    input_dir: Iterable[Union[str, Path]],
    output_dir: Union[str, Path],
    log_level: str,
    skip_sum_stats: bool,
):
    logging.basicConfig(
        level=log_level,
        format="%(asctime)s (%(module)s:%(lineno)d) (levelname)s: %(message)s",
    )

    input_dirs = [Path(p) for p in input_dir]
    output_dir = Path(output_dir)

    for mode in ["train", "valid"]:
        with (input_dirs[0] / mode / "batch_keys").open("r", encoding="utf-8") as f:
            batch_keys = [line.strip() for line in f if line.strip() != ""]
        with (input_dirs[0] / mode / "stats_keys").open("r", encoding="utf-8") as f:
            stats_keys = [line.strip() for line in f if line.strip() != ""]
        (output_dir / mode).mkdir(parents=True, exist_ok=True)

        for key in batch_keys:
            with (output_dir / mode / f"{key}_shape").open(
                "w", encoding="utf-8"
            ) as fout:
                for idir in input_dirs:
                    with (idir / mode / f"{key}_shape").open(
                        "r", encoding="utf-8"
                    ) as fin:
                        # Read to the last in order to sort keys
                        # because the order can be changed if num_workers>=1
                        lines = fin.readlines()
                        lines = sorted(lines, key=lambda x: x.split()[0])
                        for line in lines:
                            fout.write(line)

        for key in stats_keys:
            if not skip_sum_stats:
                sum_stats = None
                for idir in input_dirs:
                    stats = np.load(idir / mode / f"{key}_stats.npz")
                    if sum_stats is None:
                        sum_stats = dict(**stats)
                    else:
                        for k in stats:
                            sum_stats[k] += stats[k]

                np.savez(output_dir / mode / f"{key}_stats.npz", **sum_stats)

            # if --write_collected_feats=true
            p = Path(mode) / "collect_feats" / f"{key}.scp"
            scp = input_dirs[0] / p
            if scp.exists():
                (output_dir / p).parent.mkdir(parents=True, exist_ok=True)
                with (output_dir / p).open("w", encoding="utf-8") as fout:
                    for idir in input_dirs:
                        with (idir / p).open("r", encoding="utf-8") as fin:
                            for line in fin:
                                fout.write(line)


def get_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(
        description="Aggregate statistics directories into one directory",
        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
    )
    parser.add_argument(
        "--log_level",
        type=lambda x: x.upper(),
        default="INFO",
        choices=("CRITICAL", "ERROR", "WARNING", "INFO", "DEBUG", "NOTSET"),
        help="The verbose level of logging",
    )
    parser.add_argument(
        "--skip_sum_stats",
        default=False,
        action="store_true",
        help="Skip computing the sum of statistics.",
    )

    parser.add_argument("--input_dir", action="append", help="Input directories")
    parser.add_argument("--output_dir", required=True, help="Output directory")
    return parser


def main(cmd=None):
    print(get_commandline_args(), file=sys.stderr)
    parser = get_parser()
    args = parser.parse_args(cmd)
    kwargs = vars(args)
    aggregate_stats_dirs(**kwargs)


if __name__ == "__main__":
    main()
