from pathlib import Path
import json

def main():
    REQUIRED_LTTER = 'b'
    LEGAL_LETTERS = 'aiybgrø'

    content = Path('lemma.json').read_text(encoding='utf-8')
    all_words = json.loads(content)

    legal_words = []
    for word in all_words:
        w = word[0]
        if is_legal(w, REQUIRED_LTTER, LEGAL_LETTERS):
            legal_words.append(w)

    print(legal_words)

def is_legal(word, required_letter, legal_letters):
    # Regel 1: minst 4 tegn
    if len(word) < 4:
        return False

    # Regel 2: ordet må ha 'b' i seg
    if required_letter not in word:
        return False

    # Regel 3: Alle bokstavene må være lovlig
    # enten a, i, y, b, g, r, eller ø
    for letter in word:
        if letter not in legal_letters:
            return False
        
    return True  

if __name__ == '__main__':
    main()