new-codigoparallevar/scripts/blog.py

#!/usr/bin/env python3

MARKDOWN_EXTENSION = '.md'
EXTENSIONS = [
    MARKDOWN_EXTENSION,
]

MARKDOWN_EXTRA_FEATURES = [
    # See more in: https://python-markdown.github.io/extensions/
    'markdown.extensions.fenced_code',
    'markdown.extensions.codehilite',
    'markdown.extensions.extra',
]

import copy
import json
import logging
import sys
import os
import datetime
import shutil
import traceback
import time
import re
from typing import List

from bs4 import BeautifulSoup as bs4
import bs4 as BeautifulSoup
import jinja2
import inotify.adapters
import yaml
import markdown
from unidecode import unidecode

SUMMARIZE_MAX_TOKENS = 1000
ITEMS_IN_RSS = 50

NIKOLA_DATE_RE = re.compile(r'^([0-2]\d|30|31)\.(0\d|1[012])\.(\d{4}), (\d{1,2}):(\d{2})$')

COMPLETE_DATE_RE = re.compile(r'^(\d{4})-(0\d|1[012])-([0-2]\d|30|31) '
                            + r'(\d{2}):(\d{2})(:\d{2})( .+)?$')
SLUG_HYPHENATE_RE = re.compile(r'[\s\-]+')
SLUG_REMOVE_RE = re.compile(r'[^\s\-a-zA-Z0-9]*')

ROOT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

STATIC_PATH = os.path.join(ROOT_DIR, 'static')
ARTICLE_TEMPLATE_NAME = 'article.tmpl.html'
BLOG_INDEX_TEMPLATE_NAME = 'blog_index.tmpl.html'
CATEGORY_LIST_TEMPLATE_NAME = 'category_list.tmpl.html'
ARTICLE_LIST_TEMPLATE_NAME = 'article_list.tmpl.html'
RSS_TEMPLATE_NAME = 'rss.tmpl.xml'
BLOG_INDEX_PAGE_SIZE = 10

STATIC_RESOURCES = (
    ('style.css', 'css/style.css'),
    ('light-syntax.css', 'css/light-syntax.css'),
    ('dark-syntax.css', 'css/dark-syntax.css', ('@media (prefers-color-scheme: dark) {\n', '\n}')),
)

JINJA_ENV = jinja2.Environment(
    loader=jinja2.FileSystemLoader(STATIC_PATH),
    autoescape=jinja2.select_autoescape()
)

WATCH = True
if os.getenv('WATCH_AND_REBUILD', '1') == '0':
    WATCH = False

def update_statics():
    global ARTICLE_TEMPLATE
    ARTICLE_TEMPLATE = JINJA_ENV.get_template(ARTICLE_TEMPLATE_NAME)
    global BLOG_INDEX_TEMPLATE
    BLOG_INDEX_TEMPLATE = JINJA_ENV.get_template(BLOG_INDEX_TEMPLATE_NAME)
    global CATEGORY_LIST_TEMPLATE
    CATEGORY_LIST_TEMPLATE = JINJA_ENV.get_template(CATEGORY_LIST_TEMPLATE_NAME)
    global ARTICLE_LIST_TEMPLATE
    ARTICLE_LIST_TEMPLATE = JINJA_ENV.get_template(ARTICLE_LIST_TEMPLATE_NAME)
    global RSS_TEMPLATE
    RSS_TEMPLATE = JINJA_ENV.get_template(RSS_TEMPLATE_NAME)

update_statics()

MONITORED_EVENT_TYPES = (
    'IN_CREATE',
    # 'IN_MODIFY',
    'IN_CLOSE_WRITE',
    'IN_DELETE',
    'IN_MOVED_FROM',
    'IN_MOVED_TO',
    'IN_DELETE_SELF',
    'IN_MOVE_SELF',
)
LANG_PRIORITY = ('en', 'es', 'gl')


def parse_nikola_date(match):
    return datetime.datetime(year=int(match.group(3)),
                             month=int(match.group(2)),
                             day=int(match.group(1)),
                             hour=int(match.group(4)),
                             minute=int(match.group(5)),
                             # Note this final assumption is not good
                             #   and might get you in trouble if trying
                             #   to sort closely-published posts
                             #   when others are in complete-date format
                             tzinfo=datetime.timezone.utc,
                             )


def parse_complete_date(match):
    return datetime.datetime.strptime(match.group(0), '%Y-%m-%d %H:%M:%S %Z%z')

def split_tags(tags: str) -> List[str]:
    if isinstance(tags, str):
        return [tag.strip() for tag in tags.split(',')]
    elif isinstance(tags, list):
        return tags
    else:
        raise NotImplementedError("Unknown tag type: {}".format(type(tags)))

def slugify(title):
    """
    Made for compatibility with Nikola's slugify within CodigoParaLlevar blog.
    """
    slug = unidecode(title).lower()
    slug = SLUG_REMOVE_RE.sub('', slug)
    slug = SLUG_HYPHENATE_RE.sub('-', slug)
    slug = slug.strip('-')

    return slug.strip()


def read_markdown(path):
    with open(path, 'rt') as f:
        data = f.read()
    if data.startswith('---'):
        start = data.index('\n')
        if '---\n' not in data[start:]:
            raise Exception('Front matter not finished on: {}'.format(path))
        front_matter_str, content = data[start:].split('---\n', 1)
        front_matter = yaml.load(front_matter_str, Loader=yaml.SafeLoader)
    else:
        raise Exception('Front matter is needed for proper rendering. Not found on: {}'.format(
            path
        ))
    doc = markdown.markdown(content, extensions=MARKDOWN_EXTRA_FEATURES)
    return doc, front_matter


def get_out_path(front_matter):
    if 'date' in front_matter:
        if m := NIKOLA_DATE_RE.match(front_matter['date']):
            front_matter['date'] = parse_nikola_date(m)
        elif m := COMPLETE_DATE_RE.match(front_matter['date']):
            front_matter['date'] = parse_complete_date(m)
        else:
            raise NotImplementedError('Unknown date format: {}'.format(
                front_matter['date']))
    else:
        raise Exception('No date found on: {}'.format(
            path
        ))

    if 'slug' not in front_matter:
        if 'title' not in front_matter:
            raise Exception('No title found on: {}'.format(
                path
            ))

        front_matter['slug'] = slugify(front_matter['title'])

    out_path = os.path.join(str(front_matter['date'].year), front_matter['slug'])
    if front_matter.get('lang', LANG_PRIORITY[0]) != LANG_PRIORITY[0]:
        out_path = os.path.join(front_matter['lang'], str(front_matter['date'].year), front_matter['slug'])
    return out_path


def load_all(top_dir_relative):
    top = os.path.abspath(top_dir_relative)

    docs = {}

    count = 0
    for root, dirs, files in os.walk(top):
        for name in files:
            if all([not name.endswith(ext) for ext in EXTENSIONS]):
                # The logic is negative... but it works
                continue

            if name.endswith(MARKDOWN_EXTENSION):
                path = os.path.join(root, name)
                doc, front_matter = read_markdown(path)
                out_path = get_out_path(front_matter)
                docs[path] = (doc, front_matter, out_path)
                print('\rLoading posts... {}'.format(count), end='', flush=True)
                count += 1
            else:
                raise NotImplementedError('Unknown filetype: {}'.format(name))

    print(" [DONE]")
    return docs


def load_doc(filepath):
    doc, front_matter = read_markdown(filepath)
    out_path = get_out_path(front_matter)
    return (doc, front_matter, out_path)


def render_article(doc, front_matter, f, out_path):
    extsep = '/' if '/' in out_path else '\\'
    subdirs = len(out_path.split(extsep))
    base_path = os.path.join(*(['..'] * subdirs))
    result = ARTICLE_TEMPLATE.render(
        content=doc,
        title=front_matter['title'],
        post_publication_date=front_matter['date'],
        post_tags=split_tags(front_matter['tags']),
        base_path=base_path,
    )
    f.write(result)

def summarize(doc):
    tree = bs4(doc, features='lxml')

    html = list(tree.children)[0]
    body = list(html.children)[0]

    comments = tree.find_all(string=lambda text: isinstance(text, BeautifulSoup.Comment))

    teaser_end = None
    for comment in comments:
        if 'TEASER_END' in comment:
            teaser_end = comment
            break

    if 'gnucash' in doc:
        assert teaser_end is not None

    def recur_select_to_summarize(source, dest, num_tokens):
        for item in source.children:
            if num_tokens + len(item.text) < SUMMARIZE_MAX_TOKENS:
                # All source fits
                num_tokens += len(item.text)
                dest.append(item)

            else:
                if not isinstance(item, BeautifulSoup.NavigableString):
                    # Let's take as much source as we can and then stop
                    subsect = bs4()
                    recur_select_to_summarize(item, subsect, num_tokens)

                    if len(list(subsect.children)) > 0:
                        dest.append(subsect)
                break

    def cut_after_element(reference):
        while reference.next_sibling is None:
            if reference.parent is None:
                logging.warning("Reached root when looking for cutting point for teaser. Doc: {}".format(doc[:100]))
                return
            reference = reference.parent

        nxt = reference.next_sibling
        while nxt is not None:
            was = nxt
            if reference.next_sibling is not None:
                # Move to the "right"
                nxt = reference.next_sibling

            else:
                # Move "up and right"
                nxt = reference.parent
                if nxt is not None:
                    nxt = nxt.next_sibling
            was.extract()

    if teaser_end is None:
        result = bs4()

        recur_select_to_summarize(body, result, 0)
    else:
        summary = copy.copy(body)
        comments = summary.find_all(string=lambda text: isinstance(text, BeautifulSoup.Comment))

        teaser_end = None
        for comment in comments:
            if 'TEASER_END' in comment:
                teaser_end = comment
                break
        assert teaser_end is not None, 'Error finding teaser end on copy'

        cut_after_element(teaser_end)
        result = bs4()
        for child in summary.children:
            result.append(child)

    # Update summary links and hrefs
    for v in result.find_all('video') + result.find_all('image'):
        if 'src' in v.attrs and ':' not in v['src']:
            v['src'] = '/blog/' + v['src'].lstrip('/')

    for v in result.find_all('a'):
        if 'href' in v.attrs and ':' not in v['href']:
            v['href'] = '/blog/' + v['href'].lstrip('/')

    return result

def render_index(docs, dest_top):
    # Collect all languages accepted for all docs
    docs_by_slug = {}
    for (doc, front_matter, out_path) in docs.values():
        if front_matter['slug'] not in docs_by_slug:
            docs_by_slug[front_matter['slug']] = {}
        docs_by_slug[front_matter['slug']][front_matter.get('lang', LANG_PRIORITY[0])] = (doc, front_matter, out_path)

    # Remove duplicated for langs with less priority
    selected_docs = []
    for (doc, front_matter, out_path) in docs.values():
        langs = docs_by_slug[front_matter['slug']]
        lang_priority = LANG_PRIORITY.index(front_matter.get('lang', LANG_PRIORITY[0]))
        min_lang_priority = min([
            LANG_PRIORITY.index(lang)
            for lang in langs.keys()
        ])
        if lang_priority == min_lang_priority:
            selected_docs.append((doc, front_matter, out_path, langs))

    docs = sorted(selected_docs, key=lambda x: x[1]['date'], reverse=True)

    index_ranges = range(0, len(docs), BLOG_INDEX_PAGE_SIZE)

    for off in index_ranges:
        page = docs[off: off + BLOG_INDEX_PAGE_SIZE]

        posts = [
            {
                "doc": doc,
                "title": front_matter['title'],
                "post_publication_date": front_matter['date'],
                "post_tags": split_tags(front_matter['tags']),
                "summary": summarize(doc),
                "link": out_path.rstrip('/') + '/',
            }
            for (doc, front_matter, out_path, _alternatives) in page
        ]

        prev_index_num = None
        next_index_num = off // BLOG_INDEX_PAGE_SIZE + 1
        if off > 0:
            prev_index_num = off // BLOG_INDEX_PAGE_SIZE - 1
        if next_index_num >= len(index_ranges):
            next_index_num = None

        result = BLOG_INDEX_TEMPLATE.render(
            posts=posts,
            prev_index_num=prev_index_num,
            next_index_num=next_index_num,
        )

        if off == 0:
            fname = 'index.html'
        else:
            fname = 'index-{}.html'.format(off // BLOG_INDEX_PAGE_SIZE)
        with open(os.path.join(dest_top, fname), 'wt') as f:
            f.write(result)

def render_categories(docs, dest_top):
    categories = {}
    for (doc, front_matter, out_path) in docs.values():
        for tag in split_tags(front_matter['tags']):
            if tag not in categories:
                categories[tag] = []
            categories[tag].append((doc, front_matter, out_path))

    print("Found {} tags".format(len(categories), categories))
    for tag, docs in categories.items():
        docs = sorted(docs, key=lambda x: x[1]['date'], reverse=True)

        posts = [
            {
                # "doc": doc,
                "title": front_matter['title'],
                "post_publication_date": front_matter['date'],
                "post_tags": split_tags(front_matter['tags']),
                # "summary": summarize(doc),
                "link": out_path.rstrip('/') + '/',
            }
            for (doc, front_matter, out_path) in docs
        ]

        result = CATEGORY_LIST_TEMPLATE.render(
            posts=posts,
        )
        path = os.path.join(dest_top, "tags", tag.replace('/', '_'), "index.html")
        os.makedirs(os.path.dirname(path), exist_ok=True)
        with open(path, 'wt') as f:
            f.write(result)

def render_archive(docs, dest_top):
    docs = sorted(docs.values(), key=lambda x: x[1]['date'], reverse=True)

    posts = [
        {
            # "doc": doc,
            "title": front_matter['title'],
            "post_publication_date": front_matter['date'],
            "post_tags": split_tags(front_matter['tags']),
            # "summary": summarize(doc),
            "link": out_path.rstrip('/') + '/',
        }
        for (doc, front_matter, out_path) in docs
    ]

    result = ARTICLE_LIST_TEMPLATE.render(
        posts=posts,
    )
    path = os.path.join(dest_top, "articles", "index.html")
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with open(path, 'wt') as f:
        f.write(result)

def render_rss(docs, dest_top):
    # Collect all languages accepted for all docs
    docs_by_slug = {}
    for (doc, front_matter, out_path) in docs.values():
        if front_matter['slug'] not in docs_by_slug:
            docs_by_slug[front_matter['slug']] = {}
        docs_by_slug[front_matter['slug']][front_matter.get('lang', LANG_PRIORITY[0])] = (doc, front_matter, out_path)

    # Remove duplicated for langs with less priority
    selected_docs = []
    for (doc, front_matter, out_path) in docs.values():
        langs = docs_by_slug[front_matter['slug']]
        lang_priority = LANG_PRIORITY.index(front_matter.get('lang', LANG_PRIORITY[0]))
        min_lang_priority = min([
            LANG_PRIORITY.index(lang)
            for lang in langs.keys()
        ])
        if lang_priority == min_lang_priority:
            selected_docs.append((doc, front_matter, out_path, langs))

    docs = sorted(selected_docs, key=lambda x: x[1]['date'], reverse=True)

    posts = [
        {
            # "doc": doc,
            "title": front_matter['title'],
            "post_publication_date": front_matter['date'],
            "post_tags": split_tags(front_matter['tags']),
            "summary": summarize(doc),
            "link": out_path.rstrip('/') + '/',
        }
        for (doc, front_matter, out_path, langs) in docs[:ITEMS_IN_RSS]
    ]

    result = RSS_TEMPLATE.render(
        posts=posts,
        last_build_date=datetime.datetime.utcnow(),
    )
    path = os.path.join(dest_top, "rss.xml")
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with open(path, 'wt') as f:
        f.write(result)


def regen_all(source_top, dest_top, docs=None):
    if docs is None:
        docs = load_all(source_top)

    # Render posts
    for (doc, front_matter, out_path) in docs.values():
        doc_full_path = os.path.join(dest_top, out_path)
        os.makedirs(os.path.dirname(doc_full_path), exist_ok=True)
        # print("==", doc_full_path)
        full_out_path = doc_full_path + '/index.html'
        os.makedirs(os.path.dirname(full_out_path), exist_ok=True)
        with open(full_out_path, 'wt') as f:
            try:
                render_article(doc, front_matter, f, out_path)
            except:
                logging.error(traceback.format_exc())
                logging.error("Rendering failed 😿")
                continue

    # Render statics
    for static in STATIC_RESOURCES:
        src_path = static[0]
        dest_path = static[1]

        if len(static) > 2:
            before, after = static[2]
        else:
            before, after = '', ''
        target_dest = os.path.join(dest_top, dest_path)
        os.makedirs(os.path.dirname(target_dest), exist_ok=True)
        with open(os.path.join(STATIC_PATH, src_path), 'rt') as src:
            data = before + src.read() + after

        with open(target_dest, 'wt') as f:
            f.write(data)

    # Render index
    render_index(docs, dest_top)

    # Render categories
    render_categories(docs, dest_top)

    # Render archive
    render_archive(docs, dest_top)

    # Render RSS
    render_rss(docs, dest_top)

    return docs


def main(source_top, dest_top):
    notifier = inotify.adapters.InotifyTrees([source_top, STATIC_PATH])

    ## Initial load
    t0 = time.time()
    logging.info("Initial load...")
    docs = regen_all(source_top, dest_top)
    logging.info("Initial load completed in {:.2f}s".format(time.time() - t0))

    if not WATCH:
        logging.info("Build completed in {:.2f}s".format(time.time() - t0))
        return 0

    ## Updating
    for event in notifier.event_gen(yield_nones=False):
        (ev, types, directory, file) = event
        if not any([type in MONITORED_EVENT_TYPES for type in types]):
            continue
        filepath = os.path.join(directory, file)
        if filepath.startswith(STATIC_PATH):
            t0 = time.time()
            try:
                update_statics()
            except:
                logging.error(traceback.format_exc())
                logging.error("Loading new templates failed 😿")
                continue

            is_static_resource = False
            for static  in STATIC_RESOURCES:
                src_path = static[0]
                dest_path = static[1]
                if file == os.path.basename(src_path):
                    is_static_resource = True

                if len(static) > 2:
                    before, after = static[2]
                else:
                    before, after = '', ''
                target_dest = os.path.join(dest_top, dest_path)
                os.makedirs(os.path.dirname(target_dest), exist_ok=True)
                with open(os.path.join(STATIC_PATH, src_path), 'rt') as src:
                    data = before + src.read() + after

                with open(target_dest, 'wt') as f:
                    f.write(data)

            if is_static_resource:
                logging.info("Updated static resources in {:.2f}s".format(time.time() - t0))
            else:
                docs = regen_all(source_top, dest_top, docs)
                logging.info("Updated all in {:.2f}s".format(time.time() - t0))

        else:
            try:
                print("Reloading: {}".format(filepath))
                (doc, front_matter, out_path) = load_doc(filepath)
            except:
                logging.error(traceback.format_exc())
                logging.error("Skipping update 😿")
                continue

            t0 = time.time()
            docs[filepath] = (doc, front_matter, out_path)
            doc_full_path = os.path.join(dest_top, out_path)
            print("Updated: {}.html".format(doc_full_path))
            os.makedirs(os.path.dirname(doc_full_path), exist_ok=True)
            # print("==", doc_full_path)
            with open(doc_full_path + '/index.html', 'wt') as f:
                try:
                    render_article(doc, front_matter, f, out_path)
                except:
                    logging.error(traceback.format_exc())
                    logging.error("Rendering failed 😿")
                    continue

            logging.info("Updated all in {:.2f}s".format(time.time() - t0))


if __name__ == "__main__":
    if len(sys.argv) != 3:
        print("Usage: {} SOURCE_TOP DEST_TOP".format(sys.argv[0]))
        exit(0)

    logging.basicConfig(level=logging.INFO, format="%(levelname)-8s %(message)s")
    main(sys.argv[1], sys.argv[2])