import subprocess
import spacy
import pyinflect
from typing import Tuple, Union

class Parser:
    def __init__(
        self
    ) -> None:
        
        self.parser = self.__init_parser("en_core_web_md")

    def __init_parser(
        self,
        model: str
    ) -> spacy.language:

        parser = None
        try:
            parser = spacy.load(model)
        except:
            print(f"* Downloading {model} model...")
            _ = subprocess.Popen(
                f"python -m spacy download {model}", 
                stdout=subprocess.PIPE, 
                shell=True
            ).communicate()

            parser = spacy.load(model)
        
        return parser
    
    def __v2participle(
        self,
        tk_verb: spacy.tokens.token.Token
    ) -> Union[str, None]:

        return tk_verb._.inflect('VBN')
    
    def __v2past(
        self,
        tk_verb: spacy.tokens.token.Token
    ) -> Union[str, None]:

        return tk_verb._.inflect('VBD')

    def __v2infinitive(
        self,
        tk_verb: spacy.tokens.token.Token
    ) -> Union[str, None]:

        return tk_verb._.inflect('VB')

    def __tokenizer(
        self,
        verb: str
    ) -> spacy.tokens.token.Token:

        return self.parser(verb)[0]

    def ___format_error(
        self,
        error: str
    ) -> str:

        template = """
            <center>
                <div class="alert alert-warning" role="alert">
                    <h6><b>{}</b></h6>
                </div>
            </center>
        """
        return template.format(error)

    def get_verbs(
        self,
        verb: str
    ) -> Tuple[str,str,str]:

        verb = verb.strip().lower()
        error, infinitive, past, participle = "", "", "", ""

        if verb == "":
            error = self.___format_error(
                f"Error: The Verb field can not be empty!"
            )
            return error, infinitive, past, participle

        tk_verb = self.__tokenizer(verb)
        infinitive = self.__v2infinitive(tk_verb)
        past = self.__v2past(tk_verb)
        participle = self.__v2participle(tk_verb)

        if infinitive is None or past is None or participle is None:
            error = self.___format_error(
                f"Error: The verb '<b>{verb}</b>' has not been found or not spelled correctly!"
            )
            return error, infinitive, past, participle

        return error, infinitive, past, participle