import argparse

import csv

import json

import os

from pathlib import PosixPath

from pyproject_save_files import BuildrootPath

def read_record(record_path):

    """

    A generator yielding individual RECORD triplets.

    https://www.python.org/dev/peps/pep-0376/#record

    The triplet is str-path, hash, size -- the last two optional.

    We will later care only for the paths anyway.

    Example:

        >>> g = read_record(PosixPath('./test_RECORD'))

        >>> next(g)

        ['../../../bin/__pycache__/tldr.cpython-....pyc', '', '']

        >>> next(g)

        ['../../../bin/tldr', 'sha256=...', '12766']

        >>> next(g)

        ['../../../bin/tldr.py', 'sha256=...', '12766']

    """

    with open(record_path, newline="", encoding="utf-8") as f:

        yield from csv.reader(

            f, delimiter=",", quotechar='"', lineterminator=os.linesep

        )

def parse_record(record_path, record_content):

    """

    Returns a list with BuildrootPaths parsed from record_content

    params:

    record_path: RECORD BuildrootPath

    record_content: list of RECORD triplets

                    first item is a str-path relative to directory where dist-info directory is

                    (it can also be absolute according to the standard, but not from pip)

    Examples:

        >>> parse_record(BuildrootPath('/usr/lib/python3.7/site-packages/requests-2.22.0.dist-info/RECORD'),

        ...                            [('requests/sessions.py', 'sha256=xxx', '666')])

        ['/usr/lib/python3.7/site-packages/requests/sessions.py']

        >>> parse_record(BuildrootPath('/usr/lib/python3.7/site-packages/tldr-0.5.dist-info/RECORD'),

        ...                            [('../../../bin/tldr', 'sha256=yyy', '777')])

        ['/usr/bin/tldr']

    """

    sitedir = record_path.parent.parent  # trough the dist-info directory

    # / with absolute right operand will remove the left operand

    # any .. parts are resolved via normpath

    return [str((sitedir / row[0]).normpath()) for row in record_content]

def save_parsed_record(record_path, parsed_record, output_file):

    content = {}

    if output_file.is_file():

        content = json.loads(output_file.read_text())

    content[str(record_path)] = parsed_record

    output_file.write_text(json.dumps(content))

def main(cli_args):

    record_path = BuildrootPath.from_real(cli_args.record, root=cli_args.buildroot)

    parsed_record = parse_record(record_path, read_record(cli_args.record))

    save_parsed_record(record_path, parsed_record, cli_args.output)

def argparser():

    parser = argparse.ArgumentParser()

    r = parser.add_argument_group("required arguments")

    r.add_argument("--buildroot", type=PosixPath, required=True)

    r.add_argument("--record", type=PosixPath, required=True)

    r.add_argument("--output", type=PosixPath, required=True)

    return parser

if __name__ == "__main__":

    cli_args = argparser().parse_args()

    main(cli_args)