#!/usr/bin/env python3

from contextlib import contextmanager
from datetime import datetime
import locale
from pathlib import Path
import re
from sys import argv

from helpers import guess_language, read_concerts, relative_path


# TODO: change some jargon:
# - event => concert
# - canceled => warning


def split_concerts(concerts, threshold):
    cutoff = len(concerts)

    for i, c in enumerate(concerts):
        if c.time > threshold:
            cutoff = i
            break

    return reversed(concerts[:cutoff]), concerts[cutoff:]


LOCALIZED_TEXT = {
    'en': {
        'past': 'Past concerts',
        'next': 'Next concerts',
        'alt': 'Illustration:',
        'hint': 'Click on a concert to obtain more information.',
    },
    'fr': {
        'past': 'Concerts passés',
        'next': 'Prochains concerts',
        'alt': 'Illustration :',
        'hint': "Cliquez sur un concert pour obtenir plus d'informations.",
    }
}

THUMBNAILS_TEMPLATE = '''\
  <h1>{heading}</h1>
  <div class="events {time}">
{thumbnails}
  </div>\
'''

THUMBNAIL_TEMPLATE = '''\
    <div class="{eventclasses}">
      <a class="thumbnail" href="#{eventid}">
        <img src="{pic_file}" alt="{pic_alt}">
        <p class="summary">
          {summary}
        </p>
      </a>
      <div class="credits">
        <span>
          {credits}
        </span>
      </div>
    </div>\
'''


@contextmanager
def tmplocale(lang):
    old_lang, encoding = locale.getlocale()
    try:
        locale.setlocale(locale.LC_TIME, (lang, encoding))
        yield
    finally:
        locale.setlocale(locale.LC_TIME, (old_lang, encoding))


def format_credits(illustration):
    credits = illustration.source_name

    if illustration.source_link is not None:
        credits = (f'<a href="{illustration.source_link}" target="_blank">'
                   f'{illustration.source_name}'
                   '</a>')

    if illustration.license_info is not None:
        credits += ' / ' + illustration.license_info.format()

    return credits


def format_thumbnail(concert, imgdir, lang):
    eventclasses = ('event',)
    with tmplocale(lang):
        day = f'{concert.time.day} {concert.time.strftime("%B %Y")}'
    summary = f'{concert.place}<br>{day}'

    if concert.warning is not None:
        eventclasses += ('canceled',)
        summary = (f'<span class="canceled">{concert.warning}</span>\n'
                   f'          {summary}')

    alt_prefix = LOCALIZED_TEXT[lang]['alt']

    return THUMBNAIL_TEMPLATE.format_map({
        'eventclasses': ' '.join(eventclasses),
        'eventid': f'concert-{concert.time.strftime("%F")}',
        'pic_file': Path(imgdir, 'concerts', concert.illustration.file),
        'pic_alt': f'{alt_prefix} {concert.illustration.alt_text}',
        'summary': summary,
        'credits': format_credits(concert.illustration)
    })


def print_thumbnails_section(concerts, imgdir, section, lang):
    if not concerts:
        return

    thumbnails = '\n'.join(
        format_thumbnail(c, imgdir, lang) for c in concerts
    )

    print(THUMBNAILS_TEMPLATE.format(heading=LOCALIZED_TEXT[lang][section],
                                     time=section,
                                     thumbnails=thumbnails))


def print_thumbnails(concerts, imgdir, lang):
    today = datetime.fromordinal(
        datetime.today().date().toordinal()
    )
    past_concerts, next_concerts = split_concerts(concerts, today)

    print('<div id="event-list">')
    print_thumbnails_section(next_concerts, imgdir, 'next', lang)
    print_thumbnails_section(past_concerts, imgdir, 'past', lang)
    print('</div>')


DETAILS_TEMPLATE = '''\
  <div class="{concertclasses}" id="{concertid}">
{details}
  </div>\
'''


DATE_FORMATTERS = {
    'en': {
        'date': lambda d: d.strftime('%A %B %-d, %Y'),
        'time': lambda d: d.strftime('%I:%M %P'),
    },
    'fr': {
        'date': lambda d: d.strftime('%A %-d %B %Y').capitalize(),
        'time': lambda d: d.strftime('%Hh%M'),
    },
}


def detail_block(tag, classes, content):
    opener = f'<{tag} class="{" ".join(classes)}">'
    closer = f'</{tag}>'

    if isinstance(content, str):
        return f'    {opener}{content}{closer}'

    return '\n'.join((
        '    '+opener,
        *('      '+line for line in content),
        '    '+closer,
    ))


def break_lines(lines):
    return tuple(line+'<br>' for line in lines[:-1]) + (lines[-1],)


TOUCHUPS = (
    (re.compile('([0-9])(st|nd|rd|th|er|ère|nde|ème)'), r'\1<sup>\2</sup>'),
    (re.compile('(https://[^ ]+)'), r'<a href="\1" target="_blank">\1</a>'),
    (re.compile('([^ ]+@[^ ]+)'), r'<a href="mailto:\1">\1</a>'),
)


def touchup_plaintext(plaintext):
    text = plaintext
    for regexp, repl in TOUCHUPS:
        text = regexp.sub(repl, text)
    return text


def print_concert_details(concert, lang):
    concert_id = f'concert-{concert.time.strftime("%F")}'
    classes = ('details',)
    blocks = []

    if concert.warning is not None:
        classes += ('canceled',)
        blocks.append(
            detail_block('p', ('canceled',), concert.warning)
        )

    with tmplocale(lang):
        day = DATE_FORMATTERS[lang]['date'](concert.time)
    hour = DATE_FORMATTERS[lang]['time'](concert.time)

    address_lines = break_lines(concert.address.splitlines())
    piece_list = tuple(
        f'<li>{touchup_plaintext(line)}</li>'
        for line in concert.pieces.splitlines()
    )

    blocks.extend((
        detail_block('p', ('detail', 'date'), day),
        detail_block('p', ('detail', 'time'), hour),
        detail_block('p', ('detail', 'place'), address_lines),
        detail_block('ol', ('detail', 'program'), piece_list),
    ))

    instructions = [
        f'    <p>{touchup_plaintext(line)}</p>'
        for line in concert.instructions.splitlines()
    ]

    print(f'  <div class="{" ".join(classes)}" id="{concert_id}">')
    print('\n'.join(blocks+instructions))
    print('  </div>')


def print_details(concerts, lang):
    print('<div id="event-details">')
    print(f'  <p class="hint">{LOCALIZED_TEXT[lang]["hint"]}</p>')

    for c in concerts:
        print_concert_details(c, lang)

    print('</div>')


def main(concerts_src):
    imgdir = relative_path(to='images', ref=concerts_src)
    lang = guess_language(concerts_src)

    concerts = read_concerts(concerts_src)
    print_thumbnails(concerts, imgdir, lang)
    print_details(concerts, lang)


if __name__ == '__main__':
    main(argv[1])