not_my_homework

#!/usr/bin/env python3
"""
Specialized Html2Json converter.
Does only work with the given format.

Html2Json reads by default from stdin
If a terminal is detected, the filename be
the  first argument.
"""

import json
import sys
from argparse import ArgumentParser
from collections import deque
from pathlib import Path
from typing import Union

from bs4 import BeautifulSoup


example_html = """<table>
  <tbody>
    <tr></tr>
    <tr>
      <th>1 abc</th>
      <td>good</td>
      <td><a href="/good">John (Nick)</a></td>
      <td>Lincoln</td>
    </tr>
    <tr>
        <th>20 xyz</th>
        <td>bad</td>
        <td><a href="/bad">Emma</a></td>
        <td>Smith</td>
      </tr>
      <tr></tr>
      ...
  </tbody>
</table>"""


def html2json(html: str, debug: bool = False):
    """
    Converts html to a json str.
    """
    collections = {'collections': []}
    result = collections['collections']
    # result has the same reference of the list object
    # inside the list
    fields = 'size identity state name nick'.split()
    skip_fields = 'state nick'.split()
    bs = BeautifulSoup(html, features='html.parser')
    for tr in bs.find_all('tr'):
        state = deque()
        for th_td in tr.children:
            if hasattr(th_td, 'text'):
                state.append(th_td.text)
        if not state:
            continue
        if debug:
            print(state, file=sys.stderr)
        size, identity = state.popleft().strip().split()
        size = int(size)
        state.extendleft((size, identity))
        dataset = {
            field: value for (field, value) in
            zip(fields, state)
            if field not in skip_fields
        }
        result.append(dataset)
    return json.dumps(collections, indent=4)


def main(
    inputfile: Union[None, Path],
    debug: bool, *,
    example: bool
    ) -> str:
    """
    Convert the html inputfile to a json string
    and return it.

    If sys.stdin is a pipe, then prefering this as source.
    """
    if example:
        return html2json(example_html, debug)
    if inputfile and sys.stdin.isatty():
        html_source = inputfile.read_text()
    elif not inputfile and not sys.stdin.isatty():
        html_source = sys.stdin.read()
        # reads until the pipe is closed by
        # the previous process: cat for example
    else:
        # should be impossible
        # prefering in this case the stdin
        html_source = sys.stdin.read()
    return html2json(html_source, debug)


if __name__ == '__main__':
    parser = ArgumentParser(description=__doc__)
    parser.add_argument('-f', dest='inputfile', default=None, type=Path, help='A path to the inputfile, if stdin is not used.')
    parser.add_argument('-d', dest='debug', action='store_true', help='Debug')
    parser.add_argument('-e', dest='example', action='store_true', help='Example with example data')
    args = parser.parse_args()
    json_str = main(**vars(args))
    print(json_str)