import math
import logging
from typing import Optional

import config
from signals.cluster_detector import detect_cluster
from db.db import insert_signal

logger = logging.getLogger(__name__)


def _role_weight(role: str) -> float:
    role_lower = (role or "").lower()
    for key, weight in config.ROLE_WEIGHTS.items():
        if key in role_lower:
            return weight
    return config.DEFAULT_ROLE_WEIGHT


def _score(total_value: float, role: str, cluster_size: int) -> float:
    if not total_value or total_value <= 0:
        return 0.0
    base = _role_weight(role)
    cluster_mult = 1.0 + 0.5 * (cluster_size - 1)
    return base * math.log(total_value) * cluster_mult


def process_filing(filing: dict, as_of_date: Optional[str] = None) -> Optional[dict]:
    if filing.get("flag") != "A":
        return None

    # Only open market purchases (P) or non-coded buys; exclude option exercises (X), grants (A), etc.
    tx_code = filing.get("tx_code", "")
    if tx_code and tx_code not in ("P", ""):
        logger.debug(f"Skipping non-open-market tx_code={tx_code}: {filing['accession_number']}")
        return None

    if filing.get("is_10b51"):
        logger.debug(f"Skipping 10b5-1 filing: {filing['accession_number']}")
        return None

    total_value = filing.get("total_value") or 0
    if total_value < config.MIN_TRANSACTION_VALUE:
        logger.debug(f"Below min value: {filing['accession_number']} (${total_value:,.0f})")
        return None

    ticker = filing.get("ticker", "")
    if not ticker or ticker.upper() in ("NONE", "N/A", "NA"):
        return None

    cluster_info = detect_cluster(ticker, as_of_date=as_of_date)
    cluster_size = cluster_info["cluster_size"]
    total_cluster_value = cluster_info["total_cluster_value"]

    if cluster_size < config.MIN_CLUSTER_SIZE:
        return None

    score = _score(total_value, filing.get("role", ""), cluster_size)

    signal = {
        "ticker": ticker,
        "trigger_date": filing.get("transaction_date", ""),
        "cluster_size": cluster_size,
        "total_cluster_value": total_cluster_value,
        "score": round(score, 2),
        "filing": filing,
        "cluster_buys": cluster_info["buys"],
    }

    signal_id = insert_signal(signal)
    signal["id"] = signal_id
    logger.info(f"Signal generated: {ticker} score={score:.2f} cluster={cluster_size}")
    return signal