import secrets
from datetime import datetime, timedelta, timezone
from urllib.parse import urlencode

import httpx
from fastapi import APIRouter, Depends, Request
from fastapi.responses import HTMLResponse, JSONResponse, RedirectResponse
from sqlalchemy.orm import Session

from web.auth.session import get_current_user
from web.config import settings
from web.database import get_db
from web.models.connections import EvotorConnection, VkConnection
from web.templates_env import templates

VK_SCOPE = 335876  # photos(4) + wall(8192) + groups(262144) + offline(65536)

router = APIRouter()


def _render(request: Request, template: str, ctx: dict) -> HTMLResponse:
    ctx["request"] = request
    ctx.setdefault("jivosite_widget_id", settings.JIVOSITE_WIDGET_ID)
    return templates.TemplateResponse(ctx.pop("request"), template, ctx)


def _now() -> datetime:
    return datetime.now(timezone.utc).replace(tzinfo=None)


@router.get("/connections")
async def connections_get(request: Request, db: Session = Depends(get_db)):
    try:
        user = get_current_user(request, db)
    except Exception:
        return RedirectResponse("/login", 303)

    evotor = db.query(EvotorConnection).filter_by(user_id=user.id).first()
    vk = db.query(VkConnection).filter_by(user_id=user.id).first()
    return _render(request, "connections.html", {"user": user, "evotor": evotor, "vk": vk})


@router.post("/connections/evotor")
async def connections_evotor_post(request: Request, db: Session = Depends(get_db)):
    try:
        user = get_current_user(request, db)
    except Exception:
        return RedirectResponse("/login", 303)

    form = await request.form()
    access_token = str(form.get("access_token", "")).strip()
    evotor_user_id = str(form.get("evotor_user_id", "")).strip() or None

    if not access_token:
        evotor = db.query(EvotorConnection).filter_by(user_id=user.id).first()
        return _render(request, "connections.html", {
            "user": user,
            "evotor": evotor,
            "errors": ["API-токен обязателен"],
        })

    now = _now()
    conn = db.query(EvotorConnection).filter_by(user_id=user.id).first()
    if conn:
        conn.access_token = access_token
        if evotor_user_id:
            conn.evotor_user_id = evotor_user_id
        conn.updated_at = now
    else:
        conn = EvotorConnection(
            user_id=user.id,
            evotor_user_id=evotor_user_id,
            access_token=access_token,
            api_token=secrets.token_urlsafe(32),
            connected_at=now,
            updated_at=now,
        )
        db.add(conn)

    if evotor_user_id and not user.evotor_user_id:
        user.evotor_user_id = evotor_user_id

    db.commit()
    return RedirectResponse("/connections?success=1", 303)


@router.post("/connections/evotor/disconnect")
async def connections_evotor_disconnect(request: Request, db: Session = Depends(get_db)):
    try:
        user = get_current_user(request, db)
    except Exception:
        return RedirectResponse("/login", 303)

    conn = db.query(EvotorConnection).filter_by(user_id=user.id).first()
    if conn:
        db.delete(conn)
        db.commit()
    return RedirectResponse("/connections", 303)


@router.post("/connections/vk")
async def connections_vk_post(request: Request, db: Session = Depends(get_db)):
    try:
        user = get_current_user(request, db)
    except Exception:
        return RedirectResponse("/login", 303)

    form = await request.form()
    access_token = str(form.get("access_token", "")).strip()
    vk_group_id = str(form.get("vk_group_id", "")).strip() or None

    if not access_token:
        evotor = db.query(EvotorConnection).filter_by(user_id=user.id).first()
        vk = db.query(VkConnection).filter_by(user_id=user.id).first()
        return _render(request, "connections.html", {
            "user": user,
            "evotor": evotor,
            "vk": vk,
            "errors": ["Токен VK обязателен"],
        })

    now = _now()
    conn = db.query(VkConnection).filter_by(user_id=user.id).first()
    if conn:
        conn.access_token = access_token
        if vk_group_id:
            conn.vk_user_id = vk_group_id
        conn.updated_at = now
    else:
        conn = VkConnection(
            user_id=user.id,
            access_token=access_token,
            vk_user_id=vk_group_id,
            connected_at=now,
            updated_at=now,
        )
        db.add(conn)

    db.commit()
    return RedirectResponse("/connections?success=1", 303)


@router.get("/vk-auth")
async def vk_auth(request: Request):
    try:
        get_current_user(request, next(get_db()))
    except Exception:
        return RedirectResponse("/login", 303)

    if not settings.VK_CLIENT_ID:
        return RedirectResponse("/connections?error=vk_not_configured", 303)

    state = secrets.token_urlsafe(16)
    request.session["vk_oauth_state"] = state

    redirect_uri = f"{settings.BASE_URL}/vk-callback"
    params = urlencode({
        "client_id": settings.VK_CLIENT_ID,
        "redirect_uri": redirect_uri,
        "scope": VK_SCOPE,
        "response_type": "token",
        "display": "page",
        "state": state,
        "revoke": "1",
    })
    return RedirectResponse(f"https://oauth.vk.com/authorize?{params}", 302)


@router.get("/vk-callback")
async def vk_callback_page(request: Request):
    """Serves the callback page that reads the token from the URL fragment and POSTs it."""
    return HTMLResponse("""<!DOCTYPE html>
<html lang="ru">
<head><meta charset="utf-8"><title>VK авторизация…</title>
<style>
  body { font-family: sans-serif; display: flex; align-items: center; justify-content: center;
         min-height: 100vh; margin: 0; background: #f4f4f4; }
  .box { background: #fff; padding: 2rem; border-radius: 8px; box-shadow: 0 2px 8px rgba(0,0,0,.1);
         text-align: center; max-width: 360px; }
  .spinner { width: 36px; height: 36px; border: 4px solid #e0e0e0;
             border-top-color: #0077ff; border-radius: 50%;
             animation: spin .8s linear infinite; margin: 0 auto 1rem; }
  @keyframes spin { to { transform: rotate(360deg); } }
  .error { color: #c0392b; }
</style>
</head>
<body>
<div class="box" id="box">
  <div class="spinner"></div>
  <p>Завершаем авторизацию…</p>
</div>
<script>
(function() {
  const hash = window.location.hash.slice(1);
  const params = new URLSearchParams(hash);
  const token = params.get('access_token');
  const state = params.get('state');
  const userId = params.get('user_id');
  const expiresIn = params.get('expires_in');

  if (!token) {
    document.getElementById('box').innerHTML =
      '<p class="error">Токен не получен. <a href="/connections">Вернуться назад</a></p>';
    return;
  }

  fetch('/vk-callback/save', {
    method: 'POST',
    headers: {'Content-Type': 'application/json'},
    body: JSON.stringify({ access_token: token, state: state,
                           user_id: userId, expires_in: expiresIn })
  })
  .then(r => r.json())
  .then(data => {
    if (data.ok) {
      window.location.href = '/connections?success=1';
    } else {
      document.getElementById('box').innerHTML =
        '<p class="error">' + (data.message || 'Ошибка сохранения') +
        ' <a href="/connections">Вернуться назад</a></p>';
    }
  })
  .catch(() => {
    document.getElementById('box').innerHTML =
      '<p class="error">Ошибка сети. <a href="/connections">Вернуться назад</a></p>';
  });
})();
</script>
</body>
</html>""")


@router.post("/vk-callback/save")
async def vk_callback_save(request: Request, db: Session = Depends(get_db)):
    try:
        user = get_current_user(request, db)
    except Exception:
        return JSONResponse({"ok": False, "message": "Сессия истекла, войдите снова"}, status_code=401)

    body = await request.json()
    access_token = (body.get("access_token") or "").strip()
    state = body.get("state") or ""
    vk_user_id = str(body.get("user_id") or "").strip() or None
    expires_in = body.get("expires_in")

    expected_state = request.session.pop("vk_oauth_state", None)
    if not expected_state or state != expected_state:
        return JSONResponse({"ok": False, "message": "Недействительный state, попробуйте снова"})

    if not access_token:
        return JSONResponse({"ok": False, "message": "Токен не получен"})

    token_expires_at = None
    if expires_in and str(expires_in) != "0":
        try:
            token_expires_at = _now() + timedelta(seconds=int(expires_in))
        except (ValueError, TypeError):
            pass

    now = _now()
    conn = db.query(VkConnection).filter_by(user_id=user.id).first()
    if conn:
        conn.access_token = access_token
        conn.token_expires_at = token_expires_at
        if vk_user_id:
            conn.vk_user_id = vk_user_id
        conn.updated_at = now
    else:
        conn = VkConnection(
            user_id=user.id,
            access_token=access_token,
            token_expires_at=token_expires_at,
            vk_user_id=vk_user_id,
            connected_at=now,
            updated_at=now,
        )
        db.add(conn)

    db.commit()
    return JSONResponse({"ok": True})


@router.post("/connections/vk/disconnect")
async def connections_vk_disconnect(request: Request, db: Session = Depends(get_db)):
    try:
        user = get_current_user(request, db)
    except Exception:
        return RedirectResponse("/login", 303)

    conn = db.query(VkConnection).filter_by(user_id=user.id).first()
    if conn:
        db.delete(conn)
        db.commit()
    return RedirectResponse("/connections", 303)


@router.post("/connections/evotor/test")
async def connections_evotor_test(request: Request, db: Session = Depends(get_db)):
    try:
        user = get_current_user(request, db)
    except Exception:
        return JSONResponse({"ok": False, "message": "Не авторизован"}, status_code=401)

    conn = db.query(EvotorConnection).filter_by(user_id=user.id).first()
    if not conn:
        return JSONResponse({"ok": False, "message": "Подключение не настроено"})

    try:
        r = httpx.get(
            "https://api.evotor.ru/stores",
            headers={
                "Authorization": f"Bearer {conn.access_token}",
                "Accept": "application/vnd.evotor.v2+json",
            },
            timeout=10,
        )
        if r.status_code == 200:
            data = r.json()
            items = data.get("items", data) if isinstance(data, dict) else data
            count = len(items) if isinstance(items, list) else "?"
            return JSONResponse({"ok": True, "message": f"Успешно. Найдено магазинов: {count}"})
        elif r.status_code == 401:
            return JSONResponse({"ok": False, "message": "Токен недействителен (401)"})
        else:
            return JSONResponse({"ok": False, "message": f"Ошибка API: HTTP {r.status_code}"})
    except httpx.TimeoutException:
        return JSONResponse({"ok": False, "message": "Таймаут запроса к Эвотор"})
    except Exception as e:
        return JSONResponse({"ok": False, "message": f"Ошибка: {e}"})


@router.post("/connections/vk/test")
async def connections_vk_test(request: Request, db: Session = Depends(get_db)):
    try:
        user = get_current_user(request, db)
    except Exception:
        return JSONResponse({"ok": False, "message": "Не авторизован"}, status_code=401)

    conn = db.query(VkConnection).filter_by(user_id=user.id).first()
    if not conn:
        return JSONResponse({"ok": False, "message": "Подключение не настроено"})

    try:
        if not conn.vk_user_id:
            return JSONResponse({"ok": False, "message": "Укажите ID сообщества для проверки подключения."})

        r = httpx.get(
            "https://api.vk.com/method/groups.getById",
            params={
                "group_id": conn.vk_user_id,
                "fields": "market",
                "access_token": conn.access_token,
                "v": settings.VK_API_VERSION,
            },
            timeout=10,
        )
        data = r.json()
        if "error" in data:
            code = data["error"].get("error_code")
            msg = data["error"].get("error_msg", "Неизвестная ошибка")
            return JSONResponse({"ok": False, "message": f"Ошибка VK API ({code}): {msg}"})

        groups = data.get("response", {}).get("groups", [])
        if not groups:
            return JSONResponse({"ok": False, "message": "Сообщество не найдено"})
        group = groups[0]
        name = group.get("name", "—")
        market = group.get("market", {})
        market_status = "включён" if market.get("enabled") else "выключен"
        return JSONResponse({"ok": True, "message": f"Успешно. Сообщество: «{name}», Маркет {market_status}"})
    except httpx.TimeoutException:
        return JSONResponse({"ok": False, "message": "Таймаут запроса к VK"})
    except Exception as e:
        return JSONResponse({"ok": False, "message": f"Ошибка: {e}"})