import logging
import uuid
import jwt
import base64
import hmac
import hashlib
import requests
import os


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

from open_webui.models.users import Users

from open_webui.constants import ERROR_MESSAGES
from open_webui.env import (
    WEBUI_SECRET_KEY,
    TRUSTED_SIGNATURE_KEY,
    STATIC_DIR,
    SRC_LOG_LEVELS,
)

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


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

log = logging.getLogger(__name__)
log.setLevel(SRC_LOG_LEVELS["OAUTH"])

SESSION_SECRET = WEBUI_SECRET_KEY
ALGORITHM = "HS256"

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


def verify_signature(payload: str, signature: str) -> bool:
    """
    Verifies the HMAC signature of the received payload.
    """
    try:
        expected_signature = base64.b64encode(
            hmac.new(TRUSTED_SIGNATURE_KEY, payload.encode(), hashlib.sha256).digest()
        ).decode()

        # Compare securely to prevent timing attacks
        return hmac.compare_digest(expected_signature, signature)

    except Exception:
        return False


def override_static(path: str, content: str):
    # Ensure path is safe
    if "/" in path or ".." in path:
        log.error(f"Invalid path: {path}")
        return

    file_path = os.path.join(STATIC_DIR, path)
    os.makedirs(os.path.dirname(file_path), exist_ok=True)

    with open(file_path, "wb") as f:
        f.write(base64.b64decode(content))  # Convert Base64 back to raw binary


def get_license_data(app, key):
    if key:
        try:
            res = requests.post(
                "https://api.openwebui.com/api/v1/license/",
                json={"key": key, "version": "1"},
                timeout=5,
            )

            if getattr(res, "ok", False):
                payload = getattr(res, "json", lambda: {})()
                for k, v in payload.items():
                    if k == "resources":
                        for p, c in v.items():
                            globals().get("override_static", lambda a, b: None)(p, c)
                    elif k == "count":
                        setattr(app.state, "USER_COUNT", v)
                    elif k == "name":
                        setattr(app.state, "WEBUI_NAME", v)
                    elif k == "metadata":
                        setattr(app.state, "LICENSE_METADATA", v)
                return True
            else:
                log.error(
                    f"License: retrieval issue: {getattr(res, 'text', 'unknown error')}"
                )
        except Exception as ex:
            log.exception(f"License: Uncaught Exception: {ex}")
    return False


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,
    background_tasks: BackgroundTasks,
    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-"):
        if not request.state.enable_api_key:
            raise HTTPException(
                status.HTTP_403_FORBIDDEN, detail=ERROR_MESSAGES.API_KEY_NOT_ALLOWED
            )

        if request.app.state.config.ENABLE_API_KEY_ENDPOINT_RESTRICTIONS:
            allowed_paths = [
                path.strip()
                for path in str(
                    request.app.state.config.API_KEY_ALLOWED_ENDPOINTS
                ).split(",")
            ]

            if request.url.path not in allowed_paths:
                raise HTTPException(
                    status.HTTP_403_FORBIDDEN, detail=ERROR_MESSAGES.API_KEY_NOT_ALLOWED
                )

        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:
            # Refresh the user's last active timestamp asynchronously
            # to prevent blocking the request
            if background_tasks:
                background_tasks.add_task(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
