import logging
from datetime import datetime, timezone

from eth_account import Account
from eth_account.messages import encode_defunct
from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.database import get_db
from app.models import Subscription
from app.schemas import SubscribeRequest, SubscribeResponse

router = APIRouter()
logger = logging.getLogger(__name__)

SIGN_MESSAGE = "Sign in to TrumpSignal"


from typing import Optional

def _recover_signer(signature: str) -> Optional[str]:
    """Recover signer address from an EIP-191 personal_sign signature."""
    try:
        message = encode_defunct(text=SIGN_MESSAGE)
        recovered = Account.recover_message(message, signature=signature)
        return recovered.lower()
    except Exception as exc:
        logger.warning("Signature recovery failed: %s", exc)
        return None


@router.post("/subscribe", response_model=SubscribeResponse)
async def subscribe(body: SubscribeRequest, db: AsyncSession = Depends(get_db)):
    wallet = body.wallet.lower().strip()

    # Verify EIP-191 signature
    recovered = _recover_signer(body.signature)
    if recovered is None or recovered != wallet:
        raise HTTPException(
            status_code=401,
            detail="Signature verification failed: recovered address does not match wallet",
        )

    # Upsert subscription
    result = await db.execute(
        select(Subscription).where(Subscription.wallet_address == wallet)
    )
    sub = result.scalar_one_or_none()
    now = datetime.now(timezone.utc).replace(tzinfo=None)

    if sub is None:
        sub = Subscription(
            wallet_address=wallet,
            active=True,
            subscribed_at=now,
        )
        db.add(sub)
    else:
        sub.active = True
        if sub.subscribed_at is None:
            sub.subscribed_at = now

    await db.commit()
    logger.info("Subscription activated for wallet %s", wallet)
    return SubscribeResponse(status="ok", wallet=wallet)