Look up band info in Metal Archives

#!/usr/bin/env python3

# -*- coding: utf-8 -*-

from itertools import chain

import re

from typing import Sequence

from flask import Flask

from flask_ask import Ask, statement

import jinja2

import metallum

app = Flask(__name__)

ask = Ask(app, '/')

@ask.intent('BandLookup')

def hello(bandName):

    if bandName == 'darkthrone':

        genre = 'Black Metal'

    elif bandName == 'joy division':

        genre = 'Post Punk'

def starts_with_vowel(s: str) -> bool:

    return s and s[0].lower() in {'a', 'e', 'i', 'o', 'u'}

def format_genres(genres: Sequence[str]) -> str:

    cleaned_genres = []

    for i, genre in enumerate(genres):

        cleaned_genres.append(genre.replace(' (early)', '')

                              .replace(' (mid)', '')

                              .replace(' (later)', ''))

        if i == len(genres) - 1:

            # Don’t append comma or “and” after the last genre.

            pass

        elif i == len(genres) - 2:

            # Append “and” after the last genre.

            cleaned_genres.append('and')

        else:

        genre = None

            cleaned_genres.append(',')

    if len(cleaned_genres) == 1:

        return cleaned_genres[0]

    else:

        cleaned_genres[-2] = 'and'

        return ' '.join(cleaned_genres)

BAND_TEMPLATE = jinja2.Template(

    '''{% if band.genres | length == 1 %}

    {{ band.name }} is {{ 'an' if starts_with_vowel(band.genres[0]) else 'a' }} {{ band.genres[0] }} band from {{ band.country }}.

    {% else %}

    {{ band.name }} is a band from {{ band.country }} who have played {{ format_genres(band.genres) }}

    {% endif %}

    They formed in {{ band.formed_in }} and

    {% if band.status == 'Active' %}

    are still active.

    {% else %}

    are not active, any more.

    {% endif %}

    '''

)

BAND_RESULTS_TEMPLATE = jinja2.Template(

    '''There are {{ band_results | length }} bands called {{ band_results[0].name }}:

    {% for result in band_results %}

    A band from {{ result.country }} playing {{ format_genres(result.genres) }}.

    {% endfor %}

    '''

)

DEFAULT_ENVIRONMENT = {'format_genres': format_genres,

                       'starts_with_vowel': starts_with_vowel}

    if genre:

        speech_text = '{} is a {} band.'.format(bandName, genre)

def render_template(template, **env):

    final_env = {k: v for k, v in chain(DEFAULT_ENVIRONMENT.items(),

                                        env.items())}

    return template.render(**final_env)

def describe_band(band: metallum.Band) -> str:

    rendered = render_template(BAND_TEMPLATE, band=band)

    with_cleaned_whitespace = re.sub(r'\s+', ' ', rendered).strip()

    return with_cleaned_whitespace

def name_bands(band_results: Sequence[metallum.BandResult]) -> str:

    rendered = render_template(BAND_RESULTS_TEMPLATE,

                               band_results=band_results)

    with_cleaned_whitespace = re.sub(r'\s+', ' ', rendered).strip()

    return with_cleaned_whitespace

def say_number_of_bands(band_results: Sequence[metallum.BandResult]) -> str:

    return ('There are {} bands called {}.'

            .format(len(band_results), band_results[0].name))

def band_lookup(band_name: str) -> str:

    search_results = metallum.band_search(band_name)

    if len(search_results) == 0:

        response = ('I don’t know anything about the band {}, sorry.'

                    .format(band_name))

    elif len(search_results) == 1:

        band = search_results[0].get()

        response = describe_band(band)

    elif len(search_results) < 5:

        response = name_bands(search_results)

    else:

        speech_text = 'I don’t know anything about {}, sorry.'.format(

            bandName)

        response = say_number_of_bands(search_results)

    return response

@ask.intent('BandLookup')

def band_lookup_endpoint(bandName: str) -> statement:

    response = band_lookup(bandName)

    return statement(response).simple_card('BandLookup', response)

    return statement(speech_text).simple_card('Hello', speech_text)

if __name__ == '__main__':

    app.run()