from fastapi import APIRouter, Depends, Header, HTTPException, status
from pydantic import BaseModel
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.audit.log import write_audit_log
from app.config import settings
from app.db.models import User
from app.db.session import get_session
from app.rounds.config import get_round_config
from app.wallet.hd import derive_user_wif

router = APIRouter(prefix="/admin", tags=["admin"])


async def require_admin(x_admin_token: str = Header(default="")) -> None:
    if not settings.admin_token or x_admin_token != settings.admin_token:
        raise HTTPException(status.HTTP_403_FORBIDDEN, "invalid admin token")


class RoundConfigResponse(BaseModel):
    fee_address: str
    bet_amount_sats: int


class RoundConfigUpdate(BaseModel):
    fee_address: str | None = None
    bet_amount_sats: int | None = None


@router.get("/config", response_model=RoundConfigResponse, dependencies=[Depends(require_admin)])
async def read_config(session: AsyncSession = Depends(get_session)) -> RoundConfigResponse:
    config = await get_round_config(session)
    await session.commit()
    return RoundConfigResponse(fee_address=config.fee_address, bet_amount_sats=config.bet_amount_sats)


@router.put("/config", response_model=RoundConfigResponse, dependencies=[Depends(require_admin)])
async def update_config(
    body: RoundConfigUpdate, session: AsyncSession = Depends(get_session)
) -> RoundConfigResponse:
    config = await get_round_config(session)
    if body.fee_address is not None:
        config.fee_address = body.fee_address
    if body.bet_amount_sats is not None:
        config.bet_amount_sats = body.bet_amount_sats
    await session.commit()
    return RoundConfigResponse(fee_address=config.fee_address, bet_amount_sats=config.bet_amount_sats)


class AdminUserResponse(BaseModel):
    id: int
    username: str
    address: str
    balance_sats: int
    created_at: str


@router.get("/users", response_model=list[AdminUserResponse], dependencies=[Depends(require_admin)])
async def list_users(session: AsyncSession = Depends(get_session)) -> list[AdminUserResponse]:
    users = (await session.scalars(select(User).order_by(User.id))).all()
    return [
        AdminUserResponse(
            id=u.id,
            username=u.username,
            address=u.address,
            balance_sats=u.cached_balance_sats,
            created_at=u.created_at.isoformat(),
        )
        for u in users
    ]


class AdminPrivkeyResponse(BaseModel):
    address: str
    wif: str


@router.get(
    "/users/{user_id}/privkey", response_model=AdminPrivkeyResponse, dependencies=[Depends(require_admin)]
)
async def user_privkey(user_id: int, session: AsyncSession = Depends(get_session)) -> AdminPrivkeyResponse:
    """Exports a user's raw private key for manual intervention (e.g. sweeping
    funds back if something's stuck). Every access is audit-logged since this is
    the most sensitive data the platform holds."""
    user = await session.get(User, user_id)
    if user is None:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "user not found")

    wif = derive_user_wif(user.derivation_index)
    await write_audit_log(session, "admin_privkey_accessed", {"user_id": user_id}, user_id=user_id)
    await session.commit()
    return AdminPrivkeyResponse(address=user.address, wif=wif)