"""
AlphaPulse Bot — Utility Functions
"""

import re
import hashlib
import logging
from datetime import datetime
from zoneinfo import ZoneInfo

from config import BASE_HASHTAGS, TOPIC_TAGS, KNOWN_TICKERS, NEWS_TYPE_SIGNALS

logger = logging.getLogger(__name__)

VANCOUVER = ZoneInfo('America/Vancouver')


def now_van() -> datetime:
    """Current Vancouver time (PST/PDT auto)."""
    return datetime.now(VANCOUVER)


def stable_id(source: str, url: str) -> str:
    """MD5-based ID — stable across Python restarts."""
    return hashlib.md5(f"{source}:{url}".encode()).hexdigest()


def build_hashtags(title: str = '', source: str = '') -> str:
    """Build dynamic hashtags from news title + base set.
    Extracts $TICKERs and appends topic tags based on keywords.
    """
    text_lower = (title + ' ' + source).lower()
    tags = set(BASE_HASHTAGS.split())

    # Extract known tickers mentioned in title
    words = re.findall(r'\b([A-Za-z]{2,6})\b', title)
    for w in words:
        if w.lower() in KNOWN_TICKERS:
            tags.add(f'${w.upper()}')

    # Add topic-based tags
    for keyword, tag in TOPIC_TAGS.items():
        if keyword in text_lower:
            tags.add(tag)

    return ' '.join(sorted(tags, key=lambda t: (not t.startswith('#crypto'), t)))


def detect_news_format(title: str) -> str | None:
    """Auto-detect best AI format from news title keywords.
    Returns format name or None (-> use weighted random).
    """
    title_lower = title.lower()
    for fmt, keywords in NEWS_TYPE_SIGNALS.items():
        if any(kw in title_lower for kw in keywords):
            return fmt
    return None