import secrets
import logging
import httpx

from fastapi import APIRouter, Request, Depends

logger = logging.getLogger(__name__)
from fastapi.responses import RedirectResponse
from fastapi.templating import Jinja2Templates
from sqlalchemy.orm import Session

from web.auth import get_current_user
from web.config import settings
from web.database import get_db
from web.models import User, EvotorConnection

router = APIRouter(prefix="/evotor")
templates = Jinja2Templates(directory="web/templates")

EVOTOR_AUTHORIZE_URL = "https://oauth.evotor.ru/oauth/authorize"
EVOTOR_TOKEN_URL = "https://oauth.evotor.ru/oauth/token"
EVOTOR_STORES_URL = "https://api.evotor.ru/stores"


def _redirect_uri() -> str:
    return f"{settings.BASE_URL}/evotor/callback"


@router.get("")
def evotor_page(
    request: Request,
    db: Session = Depends(get_db),
    user: User | None = Depends(get_current_user),
):
    if not user:
        return RedirectResponse("/login", 303)

    connection = db.query(EvotorConnection).filter(EvotorConnection.user_id == user.id).first()
    error = request.query_params.get("error")
    return templates.TemplateResponse("evotor.html", {
        "request": request,
        "user": user,
        "connection": connection,
        "error": error,
    })


@router.get("/connect")
def evotor_connect(request: Request, user: User | None = Depends(get_current_user)):
    if not user:
        return RedirectResponse("/login", 303)

    state = secrets.token_urlsafe(32)
    request.session["evotor_oauth_state"] = state

    params = (
        f"?client_id={settings.EVOTOR_CLIENT_ID}"
        f"&response_type=code"
        f"&redirect_uri={_redirect_uri()}"
        f"&scope={settings.EVOTOR_SCOPES.replace(' ', '%20')}"
        f"&state={state}"
    )
    return RedirectResponse(EVOTOR_AUTHORIZE_URL + params, 302)


@router.get("/callback")
async def evotor_callback(
    request: Request,
    db: Session = Depends(get_db),
    user: User | None = Depends(get_current_user),
):
    if not user:
        return RedirectResponse("/login", 303)

    code = request.query_params.get("code")
    state = request.query_params.get("state")
    saved_state = request.session.pop("evotor_oauth_state", None)

    if not code or not state or state != saved_state:
        return RedirectResponse("/evotor?error=invalid_state", 303)

    # Exchange code for access token
    try:
        async with httpx.AsyncClient() as client:
            token_response = await client.post(
                EVOTOR_TOKEN_URL,
                data={
                    "grant_type": "authorization_code",
                    "code": code,
                    "redirect_uri": _redirect_uri(),
                    "client_id": settings.EVOTOR_CLIENT_ID,
                    "client_secret": settings.EVOTOR_CLIENT_SECRET,
                },
                timeout=15,
            )
            token_response.raise_for_status()
            token_data = token_response.json()
    except httpx.HTTPStatusError as e:
        logger.error("Evotor token exchange HTTP error %s: %s", e.response.status_code, e.response.text)
        return RedirectResponse("/evotor?error=token_exchange", 303)
    except Exception as e:
        logger.error("Evotor token exchange failed: %s", e, exc_info=True)
        return RedirectResponse("/evotor?error=token_exchange", 303)

    access_token = token_data.get("access_token")
    refresh_token = token_data.get("refresh_token")
    expires_in = token_data.get("expires_in")
    if not access_token:
        return RedirectResponse("/evotor?error=no_token", 303)

    # Fetch first store to save store info
    store_id = None
    store_name = None
    try:
        async with httpx.AsyncClient() as client:
            stores_response = await client.get(
                EVOTOR_STORES_URL,
                headers={"Authorization": f"Bearer {access_token}"},
                timeout=15,
            )
            if stores_response.status_code == 200:
                stores = stores_response.json()
                items = stores.get("items", stores) if isinstance(stores, dict) else stores
                if items:
                    store_id = items[0].get("uuid") or items[0].get("id")
                    store_name = items[0].get("name")
    except Exception:
        pass  # Store info is optional; token is still saved

    # Save or update connection
    from datetime import datetime, timedelta
    now = datetime.utcnow()
    token_expires_at = now + timedelta(seconds=expires_in) if expires_in else None

    connection = db.query(EvotorConnection).filter(EvotorConnection.user_id == user.id).first()
    if connection:
        connection.access_token = access_token
        connection.refresh_token = refresh_token
        connection.token_expires_at = token_expires_at
        connection.store_id = store_id
        connection.store_name = store_name
        connection.is_online = True
        connection.last_checked_at = now
    else:
        connection = EvotorConnection(
            user_id=user.id,
            access_token=access_token,
            refresh_token=refresh_token,
            token_expires_at=token_expires_at,
            store_id=store_id,
            store_name=store_name,
            is_online=True,
            last_checked_at=now,
        )
        db.add(connection)
    db.commit()

    return RedirectResponse("/connections", 303)


@router.post("/disconnect")
async def evotor_disconnect(
    request: Request,
    db: Session = Depends(get_db),
    user: User | None = Depends(get_current_user),
):
    if not user:
        return RedirectResponse("/login", 303)

    connection = db.query(EvotorConnection).filter(EvotorConnection.user_id == user.id).first()
    if connection:
        db.delete(connection)
        db.commit()

    return RedirectResponse("/connections", 303)