import re
from datetime import datetime, timezone


def normalize_posted_text(text: str | None) -> datetime | None:
    """Parse relative posted-date strings into UTC datetimes.

    Returns None if the text cannot be parsed.
    """
    if not text:
        return None

    t = text.strip().lower()
    now = datetime.now(timezone.utc)

    # Exact matches
    if t in ("today", "just posted", "posted today", "new", "1d", "0d"):
        return now.replace(hour=0, minute=0, second=0, microsecond=0)

    # "X hours ago" / "X hour ago"
    m = re.search(r"(\d+)\s*hours?\s*ago", t)
    if m:
        from datetime import timedelta
        return now - timedelta(hours=int(m.group(1)))

    # "1 day ago" / "2 days ago"
    m = re.search(r"(\d+)\s*days?\s*ago", t)
    if m:
        from datetime import timedelta
        days = int(m.group(1))
        if days <= 1:
            return now.replace(hour=0, minute=0, second=0, microsecond=0)
        return now - timedelta(days=days)

    # "yesterday"
    if "yesterday" in t:
        from datetime import timedelta
        return now - timedelta(days=1)

    # "X minutes ago"
    m = re.search(r"(\d+)\s*minutes?\s*ago", t)
    if m:
        from datetime import timedelta
        return now - timedelta(minutes=int(m.group(1)))

    # ISO date
    m = re.match(r"(\d{4}-\d{2}-\d{2})", t)
    if m:
        try:
            return datetime.strptime(m.group(1), "%Y-%m-%d").replace(tzinfo=timezone.utc)
        except ValueError:
            pass

    return None


def is_recent(text: str | None, max_days: int = 1) -> bool:
    """Return True if posted_text represents a posting within max_days days."""
    dt = normalize_posted_text(text)
    if dt is None:
        return False
    from datetime import timedelta
    cutoff = datetime.now(timezone.utc) - timedelta(days=max_days)
    return dt >= cutoff