#!/usr/bin/env python3
"""
build_listings.py  --  keep the homepage "Latest news" in sync with the News hub.

Problem it solves: the landing page's "Latest news" block used to be a separate
hard-coded copy, so editing the News page never updated the homepage.

Source of truth = each language's News hub (`<lang>/news/index.html`), which is
edited by hand (it may include curated teaser cards without a detail page).
This script copies the first 3 News-hub cards into the homepage's "Latest news"
block, converting them to the homepage card format and fixing relative paths.

Run after editing any News page:

    python tools/build_listings.py

Idempotent and safe to re-run. The homepage block is wrapped in
<!-- AUTO-LATEST-NEWS:START/END --> markers.
"""
import io, os, re

ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
LANGS = ("en", "mk", "si")
N_LATEST = 3

CARD_RE = re.compile(r'<article class="newshub-card".*?</article>', re.DOTALL)
EXCERPT_RE = re.compile(r'\s*<p class="newshub-excerpt">.*?</p>', re.DOTALL)
# homepage .news-articles content, anchored by the trailing "See all" button
LANDING_RE = re.compile(
    r'(<div class="news-articles">)(.*?)(</div>\s*<a href="[^"]*" class="btn btn-secondary">)',
    re.DOTALL,
)


def hub_to_landing(card):
    """Convert one News-hub card to the homepage news-card format."""
    card = EXCERPT_RE.sub("", card)  # homepage cards have no excerpt
    card = (card
            .replace('class="newshub-card"', 'class="news-card"')
            .replace('class="newshub-media"', 'class="news-card-media"')
            .replace('class="newshub-body"', 'class="card-content"')
            .replace('class="newshub-date"', 'class="author"'))
    # homepage is one directory shallower than the News hub
    card = card.replace('href="../../', 'href="../').replace('src="../../', 'src="../')
    return card.strip()


def sync_lang(lang):
    hub_path = os.path.join(ROOT, lang, "news", "index.html")
    home_path = os.path.join(ROOT, lang, "index.html")
    if not (os.path.exists(hub_path) and os.path.exists(home_path)):
        print(f"  [{lang}] skipped (missing news hub or homepage)")
        return 0

    hub = io.open(hub_path, encoding="utf-8").read()
    cards = CARD_RE.findall(hub)[:N_LATEST]
    if not cards:
        print(f"  [{lang}] no News-hub cards found")
        return 0

    inner = "\n".join("                " + hub_to_landing(c) for c in cards)
    block = ("\n                <!-- AUTO-LATEST-NEWS:START (generated from "
             f"{lang}/news/ by tools/build_listings.py — edit the News page, not here) -->\n"
             f"{inner}\n"
             "                <!-- AUTO-LATEST-NEWS:END -->\n            ")

    home = io.open(home_path, encoding="utf-8").read()
    if not LANDING_RE.search(home):
        print(f"  [{lang}] could not find the homepage 'Latest news' block")
        return 0
    home = LANDING_RE.sub(lambda m: m.group(1) + block + m.group(3), home, count=1)
    io.open(home_path, "w", encoding="utf-8", newline="").write(home)
    print(f"  [{lang}] homepage 'Latest news' <- {len(cards)} cards from the News hub")
    return len(cards)


if __name__ == "__main__":
    print("Syncing homepage 'Latest news' from each News hub:")
    total = sum(sync_lang(l) for l in LANGS)
    print(f"Done ({total} cards written).")