"""
sentiment.py — Nieuws sentiment engine
Bron: CryptoPanic API (gratis tier beschikbaar)
Scoring: gewogen op votes + recency, -1.0 tot +1.0
Geen zware ML modellen — rule-based op CryptoPanic's eigen
bullish/bearish labels + vote ratio. Snel en betrouwbaar.
"""
import os
import httpx
import asyncio
import logging
from datetime import datetime, timedelta
from dataclasses import dataclass, field

logger = logging.getLogger(__name__)

CRYPTOPANIC_BASE = "https://cryptopanic.com/api/v1"


@dataclass
class NewsItem:
    title:       str
    published:   datetime
    source:      str
    url:         str
    currencies:  list[str]
    sentiment:   str    # "positive" | "negative" | "neutral"
    votes_pos:   int
    votes_neg:   int
    score:       float  # berekend gewogen score


@dataclass
class SentimentResult:
    symbol:        str           # bijv. "BTC"
    score:         float         # -1.0 tot +1.0
    label:         str           # "positief" | "negatief" | "neutraal"
    confidence:    float         # 0.0 tot 1.0
    news_count:    int
    recent_news:   list[NewsItem] = field(default_factory=list)
    last_updated:  datetime = field(default_factory=datetime.utcnow)


def _calculate_item_score(item: dict) -> float:
    """
    Bereken score per nieuwsitem op basis van:
    - CryptoPanic kind label (bullish/bearish)
    - Vote verhouding
    - Recency (items ouder dan 12u wegen minder)
    """
    votes   = item.get("votes", {})
    pos     = votes.get("positive", 0)
    neg     = votes.get("negative", 0)
    total   = pos + neg

    # Vote-gebaseerde score
    if total > 0:
        vote_score = (pos - neg) / total  # -1 tot +1
    else:
        vote_score = 0.0

    # CryptoPanic kind label
    kind = item.get("kind", "news")
    if kind == "bullish":
        label_score = 0.6
    elif kind == "bearish":
        label_score = -0.6
    else:
        label_score = 0.0

    # Recency weight
    try:
        published = datetime.fromisoformat(
            item["published_at"].replace("Z", "+00:00")
        ).replace(tzinfo=None)
        age_hours = (datetime.utcnow() - published).total_seconds() / 3600
        recency   = max(0.2, 1.0 - (age_hours / 24))  # 24u = 0.2 gewicht
    except Exception:
        recency = 0.5

    # Gewogen combinatie
    score = (vote_score * 0.4 + label_score * 0.6) * recency
    return round(score, 3)


async def fetch_sentiment(symbol: str) -> SentimentResult:
    """
    Haal sentiment op voor een specifiek crypto symbol.
    symbol = coin code zonder /EUR, bijv. "BTC", "ETH"
    """
    api_key = os.getenv("CRYPTOPANIC_API_KEY", "")

    if not api_key:
        logger.warning("CRYPTOPANIC_API_KEY niet ingesteld — dummy sentiment")
        return _dummy_sentiment(symbol)

    url    = f"{CRYPTOPANIC_BASE}/posts/"
    params = {
        "auth_token":  api_key,
        "currencies":  symbol,
        "filter":      "hot",
        "public":      "true",
    }

    try:
        async with httpx.AsyncClient(timeout=10) as client:
            resp = await client.get(url, params=params)
            resp.raise_for_status()
            data = resp.json()

        results   = data.get("results", [])
        news_items = []
        scores     = []

        for item in results[:20]:  # Maximaal 20 recente items
            item_score = _calculate_item_score(item)
            scores.append(item_score)

            currencies = [
                c.get("code", "") for c in item.get("currencies", [])
            ]

            votes = item.get("votes", {})
            news_items.append(NewsItem(
                title=item.get("title", ""),
                published=datetime.fromisoformat(
                    item["published_at"].replace("Z", "+00:00")
                ).replace(tzinfo=None),
                source=item.get("source", {}).get("title", ""),
                url=item.get("url", ""),
                currencies=currencies,
                sentiment="positive" if item_score > 0.1 else (
                    "negative" if item_score < -0.1 else "neutral"
                ),
                votes_pos=votes.get("positive", 0),
                votes_neg=votes.get("negative", 0),
                score=item_score,
            ))

        if not scores:
            return _dummy_sentiment(symbol)

        avg_score   = sum(scores) / len(scores)
        confidence  = min(1.0, len(scores) / 10)  # 10+ items = max confidence

        if avg_score > 0.15:
            label = "positief"
        elif avg_score < -0.15:
            label = "negatief"
        else:
            label = "neutraal"

        return SentimentResult(
            symbol=symbol,
            score=round(avg_score, 3),
            label=label,
            confidence=round(confidence, 2),
            news_count=len(scores),
            recent_news=news_items[:5],  # Top 5 voor dashboard
        )

    except Exception as e:
        logger.error(f"Sentiment fetch mislukt voor {symbol}: {e}")
        return _dummy_sentiment(symbol)


def _dummy_sentiment(symbol: str) -> SentimentResult:
    """Fallback als API niet beschikbaar is."""
    return SentimentResult(
        symbol=symbol,
        score=0.0,
        label="neutraal",
        confidence=0.0,
        news_count=0,
        recent_news=[],
    )


async def fetch_all_sentiments(symbols: list[str]) -> dict[str, SentimentResult]:
    """Haal sentiment op voor meerdere coins parallel."""
    tasks   = [fetch_sentiment(s) for s in symbols]
    results = await asyncio.gather(*tasks, return_exceptions=True)

    output = {}
    for symbol, result in zip(symbols, results):
        if isinstance(result, SentimentResult):
            output[symbol] = result
        else:
            output[symbol] = _dummy_sentiment(symbol)

    return output