import json
import os
import tempfile
from pathlib import Path

from google.auth.transport.requests import Request
from google.oauth2.credentials import Credentials
from google_auth_oauthlib.flow import Flow
from googleapiclient.discovery import build

SCOPES = [
    "https://www.googleapis.com/auth/spreadsheets",
    "https://www.googleapis.com/auth/drive.file",
]

TOKEN_FILENAME = "google_token.json"
DATA_DIR = Path("/data")
FALLBACK_DATA_DIR = Path(tempfile.gettempdir()) / "tcc2_agent"


class GoogleOAuthError(RuntimeError):
    pass


class GoogleAuthRequiredError(GoogleOAuthError):
    pass


def _resolve_data_dir():
    preferred_dir = os.environ.get("GOOGLE_TOKEN_DIR", "").strip()
    candidates = [Path(preferred_dir)] if preferred_dir else []
    candidates.extend([DATA_DIR, FALLBACK_DATA_DIR])

    for directory in candidates:
        try:
            directory.mkdir(parents=True, exist_ok=True)
            return directory
        except OSError:
            continue

    raise GoogleOAuthError(
        "Nao foi possivel criar um diretorio para armazenar o token OAuth."
    )


def get_token_path():
    return _resolve_data_dir() / TOKEN_FILENAME


def _client_config():
    client_id = os.environ.get("GOOGLE_CLIENT_ID", "").strip()
    client_secret = os.environ.get("GOOGLE_CLIENT_SECRET", "").strip()
    redirect_uri = os.environ.get("GOOGLE_REDIRECT_URI", "").strip()

    missing = [
        name
        for name, value in {
            "GOOGLE_CLIENT_ID": client_id,
            "GOOGLE_CLIENT_SECRET": client_secret,
            "GOOGLE_REDIRECT_URI": redirect_uri,
        }.items()
        if not value
    ]

    if missing:
        raise GoogleOAuthError("Variaveis OAuth ausentes: " + ", ".join(missing))

    return {
        "web": {
            "client_id": client_id,
            "client_secret": client_secret,
            "auth_uri": "https://accounts.google.com/o/oauth2/auth",
            "token_uri": "https://oauth2.googleapis.com/token",
            "redirect_uris": [redirect_uri],
        }
    }


def build_flow(state=None):
    flow = Flow.from_client_config(_client_config(), scopes=SCOPES, state=state)
    flow.redirect_uri = os.environ.get("GOOGLE_REDIRECT_URI")
    return flow


def get_authorization_url():
    flow = build_flow()

    authorization_url, state = flow.authorization_url(
        access_type="offline",
        prompt="consent",
        include_granted_scopes="true",
    )

    return authorization_url, state  # importante retornar state


def save_credentials(credentials):
    if not credentials.refresh_token:
        raise GoogleOAuthError(
            "Refresh token nao recebido. Revogue o acesso e autorize novamente."
        )

    token_path = get_token_path()
    token_path.write_text(credentials.to_json(), encoding="utf-8")


def load_credentials():
    token_path = get_token_path()

    if not token_path.exists():
        return None

    try:
        payload = json.loads(token_path.read_text(encoding="utf-8"))
        credentials = Credentials.from_authorized_user_info(payload, SCOPES)
    except Exception:
        return None

    if credentials.expired and credentials.refresh_token:
        try:
            credentials.refresh(Request())
            save_credentials(credentials)
        except Exception:
            return None

    if not credentials.valid:
        return None

    return credentials


def get_sheets_service():
    credentials = load_credentials()

    if credentials is None:
        raise GoogleAuthRequiredError(
            "Google Sheets nao autorizado. Acesse /auth/google primeiro."
        )

    return build("sheets", "v4", credentials=credentials, cache_discovery=False)


def append_feedback_to_sheet(feedback_data):
    spreadsheet_id = os.environ.get("GOOGLE_SPREADSHEET_ID", "").strip()

    if not spreadsheet_id:
        raise GoogleOAuthError("GOOGLE_SPREADSHEET_ID nao configurado.")

    service = get_sheets_service()

    fields = [
        "timestamp",
        "search_id",
        "query",
        "rank",
        "product_id",
        "product_name",
        "categoria_inferida",
        "categoria_produto",
        "rating",
        "is_helpful",
        "feedback",
        "motivo",
        "score_final",
        "score_semantico",
        "bonus_lexical",
        "penalidade_feedback",
        "user_message",
        "note",
    ]

    row = [[str(feedback_data.get(field, "") or "") for field in fields]]

    try:
        return service.spreadsheets().values().append(
            spreadsheetId=spreadsheet_id,
            range="Feedback!A1:R1",
            valueInputOption="USER_ENTERED",
            insertDataOption="INSERT_ROWS",
            body={"values": row},
        ).execute()
    except Exception as e:
        raise GoogleOAuthError(f"Erro ao enviar para Google Sheets: {e}")