import argparse
import glob
import os
import sys
from datetime import datetime

from sevenn import __version__

description = 'create `sevenn_data/dataset.pt` from ase readable'

source_help = 'source data to build graph, knows *'
cutoff_help = 'cutoff radius of edges in Angstrom'
filename_help = (
    'Name of the dataset, default is graph.pt. '
    + 'The dataset will be written under "sevenn_data", '
    + 'for example, {out}/sevenn_data/graph.pt.'
)
legacy_help = 'build legacy .sevenn_data'


def add_parser(subparsers):
    ag = subparsers.add_parser('graph_build', help=description)
    add_args(ag)


def add_args(parser):
    ag = parser
    ag.add_argument('source', help=source_help, type=str)
    ag.add_argument('cutoff', help=cutoff_help, type=float)
    ag.add_argument(
        '-n',
        '--num_cores',
        help='number of cores to build graph in parallel',
        default=1,
        type=int,
    )
    ag.add_argument(
        '-o',
        '--out',
        help='Existing path to write outputs.',
        type=str,
        default='./',
    )
    ag.add_argument(
        '-f',
        '--filename',
        help=filename_help,
        type=str,
        default='graph.pt',
    )
    ag.add_argument(
        '--legacy',
        help=legacy_help,
        action='store_true',
    )
    ag.add_argument(
        '-s',
        '--screen',
        help='print log to the screen',
        action='store_true',
    )
    ag.add_argument(
        '--kwargs',
        nargs=argparse.REMAINDER,
        help='will be passed to ase.io.read, or can be used to specify EFS key',
    )


def run(args):
    import sevenn.scripts.graph_build as graph_build
    from sevenn.logger import Logger

    source = glob.glob(args.source)
    cutoff = args.cutoff
    num_cores = args.num_cores
    filename = args.filename
    out = args.out
    legacy = args.legacy
    fmt_kwargs = {}
    if args.kwargs:
        for kwarg in args.kwargs:
            k, v = kwarg.split('=')
            fmt_kwargs[k] = v

    if len(source) == 0:
        print('Source has zero len, nothing to read')
        sys.exit(0)

    if not os.path.isdir(out):
        raise NotADirectoryError(f'No such directory: {out}')

    to_be_written = os.path.join(out, 'sevenn_data', filename)
    if os.path.isfile(to_be_written):
        raise FileExistsError(f'File already exist: {to_be_written}')

    metadata = {
        'sevenn_version': __version__,
        'when': datetime.now().strftime('%Y-%m-%d'),
        'cutoff': cutoff,
    }

    with Logger(filename=None, screen=args.screen) as logger:
        logger.writeline(description)

        if not legacy:
            graph_build.build_sevennet_graph_dataset(
                source,
                cutoff,
                num_cores,
                out,
                filename,
                metadata,
                **fmt_kwargs,
            )
        else:
            out = os.path.join(out, filename.split('.')[0])
            graph_build.build_script(  # build .sevenn_data
                source,
                cutoff,
                num_cores,
                out,
                metadata,
                **fmt_kwargs,
            )


def main(args=None):
    ag = argparse.ArgumentParser(description=description)
    add_args(ag)
    run(ag.parse_args())