import logging
import uuid
import jwt

from datetime import UTC, datetime, timedelta
from typing import Optional, Union, List, Dict


from open_webui.apps.webui.models.users import Users
from open_webui.apps.webui.models.groups import Groups

from open_webui.constants import ERROR_MESSAGES
from open_webui.env import WEBUI_SECRET_KEY


from fastapi import Depends, HTTPException, Request, Response, status
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
from passlib.context import CryptContext

logging.getLogger("passlib").setLevel(logging.ERROR)


SESSION_SECRET = WEBUI_SECRET_KEY
ALGORITHM = "HS256"

##############
# Auth Utils
##############

bearer_security = HTTPBearer(auto_error=False)
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")


def verify_password(plain_password, hashed_password):
    return (
        pwd_context.verify(plain_password, hashed_password) if hashed_password else None
    )


def get_password_hash(password):
    return pwd_context.hash(password)


def create_token(data: dict, expires_delta: Union[timedelta, None] = None) -> str:
    payload = data.copy()

    if expires_delta:
        expire = datetime.now(UTC) + expires_delta
        payload.update({"exp": expire})

    encoded_jwt = jwt.encode(payload, SESSION_SECRET, algorithm=ALGORITHM)
    return encoded_jwt


def decode_token(token: str) -> Optional[dict]:
    try:
        decoded = jwt.decode(token, SESSION_SECRET, algorithms=[ALGORITHM])
        return decoded
    except Exception:
        return None


def extract_token_from_auth_header(auth_header: str):
    return auth_header[len("Bearer ") :]


def create_api_key():
    key = str(uuid.uuid4()).replace("-", "")
    return f"sk-{key}"


def get_http_authorization_cred(auth_header: str):
    try:
        scheme, credentials = auth_header.split(" ")
        return HTTPAuthorizationCredentials(scheme=scheme, credentials=credentials)
    except Exception:
        raise ValueError(ERROR_MESSAGES.INVALID_TOKEN)


def get_current_user(
    request: Request,
    auth_token: HTTPAuthorizationCredentials = Depends(bearer_security),
):
    token = None

    if auth_token is not None:
        token = auth_token.credentials

    if token is None and "token" in request.cookies:
        token = request.cookies.get("token")

    if token is None:
        raise HTTPException(status_code=403, detail="Not authenticated")

    # auth by api key
    if token.startswith("sk-"):
        return get_current_user_by_api_key(token)

    # auth by jwt token

    try:
        data = decode_token(token)
    except Exception as e:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid token",
        )

    if data is not None and "id" in data:
        user = Users.get_user_by_id(data["id"])
        if user is None:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail=ERROR_MESSAGES.INVALID_TOKEN,
            )
        else:
            Users.update_user_last_active_by_id(user.id)
        return user
    else:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail=ERROR_MESSAGES.UNAUTHORIZED,
        )


def get_current_user_by_api_key(api_key: str):
    user = Users.get_user_by_api_key(api_key)

    if user is None:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail=ERROR_MESSAGES.INVALID_TOKEN,
        )
    else:
        Users.update_user_last_active_by_id(user.id)

    return user


def get_verified_user(user=Depends(get_current_user)):
    if user.role not in {"user", "admin"}:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail=ERROR_MESSAGES.ACCESS_PROHIBITED,
        )
    return user


def get_admin_user(user=Depends(get_current_user)):
    if user.role != "admin":
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail=ERROR_MESSAGES.ACCESS_PROHIBITED,
        )
    return user


def has_permission(
    user_id: str,
    permission_key: str,
    default_permissions: Dict[str, bool] = {},
) -> bool:
    """
    Check if a user has a specific permission by checking the group permissions
    and falls back to default permissions if not found in any group.

    Permission keys can be hierarchical and separated by dots ('.').
    """

    def get_permission(permissions: Dict[str, bool], keys: List[str]) -> bool:
        """Traverse permissions dict using a list of keys (from dot-split permission_key)."""
        for key in keys:
            if key not in permissions:
                return False  # If any part of the hierarchy is missing, deny access
            permissions = permissions[key]  # Go one level deeper

        return bool(permissions)  # Return the boolean at the final level

    permission_hierarchy = permission_key.split(".")

    # Retrieve user group permissions
    user_groups = Groups.get_groups_by_member_id(user_id)

    for group in user_groups:
        group_permissions = group.permissions
        if get_permission(group_permissions, permission_hierarchy):
            return True

    # Check default permissions afterwards if the group permissions don't allow it
    return get_permission(default_permissions, permission_hierarchy)


def has_access(
    user_id: str,
    action: str = "write",
    access_control: Optional[dict] = None,
) -> bool:
    if access_control is None:
        return action == "read"

    user_groups = Groups.get_groups_by_member_id(user_id)
    user_group_ids = [group.id for group in user_groups]
    permission_access = access_control.get(action, {})
    permitted_group_ids = permission_access.get("group_ids", [])
    permitted_user_ids = permission_access.get("user_ids", [])

    return user_id in permitted_user_ids or any(
        group_id in permitted_group_ids for group_id in user_group_ids
    )