#!/usr/bin/env python3
"""Rebuild the four-team tied table from six verified historical results."""
import argparse
import json
from pathlib import Path


def calculate(source):
    names = ['Romania', 'Belgium', 'Slovakia', 'Ukraine']
    table = {name: {'team': name, 'played': 0, 'won': 0, 'drawn': 0, 'lost': 0, 'gf': 0, 'ga': 0, 'points': 0} for name in names}
    seen = set()
    for match in source['matches']:
        h, a, hg, ag = (match[k] for k in ('home', 'away', 'home_goals', 'away_goals'))
        pair = frozenset((h, a))
        if len(pair) != 2 or pair in seen or h not in table or a not in table:
            raise ValueError('Expected one match per distinct pair.')
        if any(type(n) is not int or n < 0 for n in (hg, ag)):
            raise ValueError('Invalid goals.')
        seen.add(pair)
        for team, gf, ga in ((h, hg, ag), (a, ag, hg)):
            row = table[team]
            row['played'] += 1
            row['gf'] += gf
            row['ga'] += ga
            outcome = 'won' if gf > ga else 'drawn' if gf == ga else 'lost'
            row[outcome] += 1
            row['points'] += 3 if gf > ga else 1 if gf == ga else 0
    if len(seen) != 6 or {r['points'] for r in table.values()} != {4}:
        raise ValueError('This exercise requires all four teams tied after six matches.')
    for row in table.values():
        row['gd'] = row['gf'] - row['ga']
    # All four teams are in the tie: their mini-table is the whole group.
    # This case separates every row at GD/GF, so no recursive tie rule is needed.
    rows = sorted(table.values(), key=lambda r: (r['gd'], r['gf']), reverse=True)
    if len({(r['gd'], r['gf']) for r in rows}) != 4:
        raise ValueError('This narrow example does not implement later tie rules.')
    assert [r['team'] for r in rows] == names
    assert sum(r['gf'] for r in rows) == sum(r['ga'] for r in rows) == 11
    return rows


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('input_json', type=Path)
    args = parser.parse_args()
    print(json.dumps(calculate(json.loads(args.input_json.read_text())), ensure_ascii=False, indent=2))