from __future__ import annotations

import logging

from fastapi import APIRouter, Depends, HTTPException, Query, Request, status
from sqlalchemy import String, cast, func, select
from sqlalchemy.ext.asyncio import AsyncSession

from app.config import Settings
from app.core.ip_utils import extract_client_ip
from app.dependencies import get_binding_service, get_db_session, get_settings, require_admin
from app.models.token_binding import STATUS_ACTIVE, STATUS_BANNED, TokenBinding
from app.schemas.binding import (
    BindingActionRequest,
    BindingIPUpdateRequest,
    BindingItem,
    BindingListResponse,
)
from app.services.binding_service import BindingService

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/admin/api/bindings", tags=["bindings"], dependencies=[Depends(require_admin)])


def to_binding_item(binding: TokenBinding, binding_service: BindingService) -> BindingItem:
    return BindingItem(
        id=binding.id,
        token_display=binding.token_display,
        bound_ip=str(binding.bound_ip),
        binding_mode=binding.binding_mode,
        allowed_ips=[str(item) for item in binding.allowed_ips],
        status=binding.status,
        status_label=binding_service.status_label(binding.status),
        first_used_at=binding.first_used_at,
        last_used_at=binding.last_used_at,
        created_at=binding.created_at,
    )


def apply_binding_filters(
    statement,
    token_suffix: str | None,
    ip: str | None,
    status_filter: int | None,
):
    if token_suffix:
        statement = statement.where(TokenBinding.token_display.ilike(f"%{token_suffix}%"))
    if ip:
        statement = statement.where(cast(TokenBinding.bound_ip, String).ilike(f"%{ip}%"))
    if status_filter in {STATUS_ACTIVE, STATUS_BANNED}:
        statement = statement.where(TokenBinding.status == status_filter)
    return statement


async def get_binding_or_404(session: AsyncSession, binding_id: int) -> TokenBinding:
    binding = await session.get(TokenBinding, binding_id)
    if binding is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Binding was not found.")
    return binding


def log_admin_action(request: Request, settings: Settings, action: str, binding_id: int) -> None:
    logger.info(
        "Admin binding action.",
        extra={
            "client_ip": extract_client_ip(request, settings),
            "action": action,
            "binding_id": binding_id,
        },
    )


async def commit_binding_cache(binding: TokenBinding, binding_service: BindingService) -> None:
    await binding_service.sync_binding_cache(
        binding.token_hash,
        str(binding.bound_ip),
        binding.binding_mode,
        [str(item) for item in binding.allowed_ips],
        binding.status,
    )


async def update_binding_status(
    session: AsyncSession,
    binding: TokenBinding,
    status_code: int,
    binding_service: BindingService,
) -> None:
    binding.status = status_code
    await session.commit()
    await commit_binding_cache(binding, binding_service)


@router.get("", response_model=BindingListResponse)
async def list_bindings(
    page: int = Query(default=1, ge=1),
    page_size: int = Query(default=20, ge=1, le=200),
    token_suffix: str | None = Query(default=None),
    ip: str | None = Query(default=None),
    status_filter: int | None = Query(default=None, alias="status"),
    session: AsyncSession = Depends(get_db_session),
    binding_service: BindingService = Depends(get_binding_service),
) -> BindingListResponse:
    statement = apply_binding_filters(select(TokenBinding), token_suffix, ip, status_filter)

    total_result = await session.execute(select(func.count()).select_from(statement.subquery()))
    total = int(total_result.scalar_one())
    bindings = (
        await session.scalars(
            statement.order_by(TokenBinding.last_used_at.desc()).offset((page - 1) * page_size).limit(page_size)
        )
    ).all()

    return BindingListResponse(
        items=[to_binding_item(item, binding_service) for item in bindings],
        total=total,
        page=page,
        page_size=page_size,
    )


@router.post("/unbind")
async def unbind_token(
    payload: BindingActionRequest,
    request: Request,
    settings: Settings = Depends(get_settings),
    session: AsyncSession = Depends(get_db_session),
    binding_service: BindingService = Depends(get_binding_service),
):
    binding = await get_binding_or_404(session, payload.id)
    token_hash = binding.token_hash
    await session.delete(binding)
    await session.commit()
    await binding_service.invalidate_binding_cache(token_hash)
    log_admin_action(request, settings, "unbind", payload.id)
    return {"success": True}


@router.put("/ip")
async def update_bound_ip(
    payload: BindingIPUpdateRequest,
    request: Request,
    settings: Settings = Depends(get_settings),
    session: AsyncSession = Depends(get_db_session),
    binding_service: BindingService = Depends(get_binding_service),
):
    binding = await get_binding_or_404(session, payload.id)
    binding.binding_mode = payload.binding_mode
    binding.allowed_ips = payload.allowed_ips
    binding.bound_ip = binding_service.build_bound_ip_display(payload.binding_mode, payload.allowed_ips)
    await session.commit()
    await commit_binding_cache(binding, binding_service)
    log_admin_action(request, settings, "update_ip", payload.id)
    return {"success": True}


@router.post("/ban")
async def ban_token(
    payload: BindingActionRequest,
    request: Request,
    settings: Settings = Depends(get_settings),
    session: AsyncSession = Depends(get_db_session),
    binding_service: BindingService = Depends(get_binding_service),
):
    binding = await get_binding_or_404(session, payload.id)
    await update_binding_status(session, binding, STATUS_BANNED, binding_service)
    log_admin_action(request, settings, "ban", payload.id)
    return {"success": True}


@router.post("/unban")
async def unban_token(
    payload: BindingActionRequest,
    request: Request,
    settings: Settings = Depends(get_settings),
    session: AsyncSession = Depends(get_db_session),
    binding_service: BindingService = Depends(get_binding_service),
):
    binding = await get_binding_or_404(session, payload.id)
    await update_binding_status(session, binding, STATUS_ACTIVE, binding_service)
    log_admin_action(request, settings, "unban", payload.id)
    return {"success": True}