dify/api/libs/helper.py

import json
import logging
import random
import re
import string
import subprocess
import time
import uuid
from collections.abc import Generator
from datetime import datetime
from hashlib import sha256
from typing import Any, Optional, Union
from zoneinfo import available_timezones

from flask import Response, current_app, stream_with_context
from flask_restful import fields

from core.app.features.rate_limiting.rate_limit import RateLimitGenerator
from extensions.ext_redis import redis_client
from models.account import Account


def run(script):
    return subprocess.getstatusoutput('source /root/.bashrc && ' + script)


class TimestampField(fields.Raw):
    def format(self, value) -> int:
        return int(value.timestamp())


def email(email):
    # Define a regex pattern for email addresses
    pattern = r"^[\w\.!#$%&'*+\-/=?^_`{|}~]+@([\w-]+\.)+[\w-]{2,}$"
    # Check if the email matches the pattern
    if re.match(pattern, email) is not None:
        return email

    error = ('{email} is not a valid email.'
             .format(email=email))
    raise ValueError(error)


def uuid_value(value):
    if value == '':
        return str(value)

    try:
        uuid_obj = uuid.UUID(value)
        return str(uuid_obj)
    except ValueError:
        error = ('{value} is not a valid uuid.'
                 .format(value=value))
        raise ValueError(error)

def alphanumeric(value: str):
    # check if the value is alphanumeric and underlined
    if re.match(r'^[a-zA-Z0-9_]+$', value):
        return value

    raise ValueError(f'{value} is not a valid alphanumeric value')

def timestamp_value(timestamp):
    try:
        int_timestamp = int(timestamp)
        if int_timestamp < 0:
            raise ValueError
        return int_timestamp
    except ValueError:
        error = ('{timestamp} is not a valid timestamp.'
                 .format(timestamp=timestamp))
        raise ValueError(error)


class str_len:
    """ Restrict input to an integer in a range (inclusive) """

    def __init__(self, max_length, argument='argument'):
        self.max_length = max_length
        self.argument = argument

    def __call__(self, value):
        length = len(value)
        if length > self.max_length:
            error = ('Invalid {arg}: {val}. {arg} cannot exceed length {length}'
                     .format(arg=self.argument, val=value, length=self.max_length))
            raise ValueError(error)

        return value


class float_range:
    """ Restrict input to an float in a range (inclusive) """
    def __init__(self, low, high, argument='argument'):
        self.low = low
        self.high = high
        self.argument = argument

    def __call__(self, value):
        value = _get_float(value)
        if value < self.low or value > self.high:
            error = ('Invalid {arg}: {val}. {arg} must be within the range {lo} - {hi}'
                     .format(arg=self.argument, val=value, lo=self.low, hi=self.high))
            raise ValueError(error)

        return value


class datetime_string:
    def __init__(self, format, argument='argument'):
        self.format = format
        self.argument = argument

    def __call__(self, value):
        try:
            datetime.strptime(value, self.format)
        except ValueError:
            error = ('Invalid {arg}: {val}. {arg} must be conform to the format {format}'
                     .format(arg=self.argument, val=value, format=self.format))
            raise ValueError(error)

        return value


def _get_float(value):
    try:
        return float(value)
    except (TypeError, ValueError):
        raise ValueError('{} is not a valid float'.format(value))

def timezone(timezone_string):
    if timezone_string and timezone_string in available_timezones():
        return timezone_string

    error = ('{timezone_string} is not a valid timezone.'
             .format(timezone_string=timezone_string))
    raise ValueError(error)


def generate_string(n):
    letters_digits = string.ascii_letters + string.digits
    result = ""
    for i in range(n):
        result += random.choice(letters_digits)

    return result


def get_remote_ip(request) -> str:
    if request.headers.get('CF-Connecting-IP'):
        return request.headers.get('Cf-Connecting-Ip')
    elif request.headers.getlist("X-Forwarded-For"):
        return request.headers.getlist("X-Forwarded-For")[0]
    else:
        return request.remote_addr


def generate_text_hash(text: str) -> str:
    hash_text = str(text) + 'None'
    return sha256(hash_text.encode()).hexdigest()


def compact_generate_response(response: Union[dict, RateLimitGenerator]) -> Response:
    if isinstance(response, dict):
        return Response(response=json.dumps(response), status=200, mimetype='application/json')
    else:
        def generate() -> Generator:
            yield from response

        return Response(stream_with_context(generate()), status=200,
                        mimetype='text/event-stream')


class TokenManager:

    @classmethod
    def generate_token(cls, account: Account, token_type: str, additional_data: dict = None) -> str:
        old_token = cls._get_current_token_for_account(account.id, token_type)
        if old_token:
            if isinstance(old_token, bytes):
                old_token = old_token.decode('utf-8')
            cls.revoke_token(old_token, token_type)

        token = str(uuid.uuid4())
        token_data = {
            'account_id': account.id,
            'email': account.email,
            'token_type': token_type
        }
        if additional_data:
            token_data.update(additional_data)

        expiry_hours = current_app.config[f'{token_type.upper()}_TOKEN_EXPIRY_HOURS']
        token_key = cls._get_token_key(token, token_type)
        redis_client.setex(
            token_key,
            expiry_hours * 60 * 60,
            json.dumps(token_data)
        )

        cls._set_current_token_for_account(account.id, token, token_type, expiry_hours)
        return token

    @classmethod
    def _get_token_key(cls, token: str, token_type: str) -> str:
        return f'{token_type}:token:{token}'

    @classmethod
    def revoke_token(cls, token: str, token_type: str):
        token_key = cls._get_token_key(token, token_type)
        redis_client.delete(token_key)

    @classmethod
    def get_token_data(cls, token: str, token_type: str) -> Optional[dict[str, Any]]:
        key = cls._get_token_key(token, token_type)
        token_data_json = redis_client.get(key)
        if token_data_json is None:
            logging.warning(f"{token_type} token {token} not found with key {key}")
            return None
        token_data = json.loads(token_data_json)
        return token_data

    @classmethod
    def _get_current_token_for_account(cls, account_id: str, token_type: str) -> Optional[str]:
        key = cls._get_account_token_key(account_id, token_type)
        current_token = redis_client.get(key)
        return current_token

    @classmethod
    def _set_current_token_for_account(cls, account_id: str, token: str, token_type: str, expiry_hours: int):
        key = cls._get_account_token_key(account_id, token_type)
        redis_client.setex(key, expiry_hours * 60 * 60, token)

    @classmethod
    def _get_account_token_key(cls, account_id: str, token_type: str) -> str:
        return f'{token_type}:account:{account_id}'


class RateLimiter:
    def __init__(self, prefix: str, max_attempts: int, time_window: int):
        self.prefix = prefix
        self.max_attempts = max_attempts
        self.time_window = time_window

    def _get_key(self, email: str) -> str:
        return f"{self.prefix}:{email}"

    def is_rate_limited(self, email: str) -> bool:
        key = self._get_key(email)
        current_time = int(time.time())
        window_start_time = current_time - self.time_window

        redis_client.zremrangebyscore(key, '-inf', window_start_time)
        attempts = redis_client.zcard(key)

        if attempts and int(attempts) >= self.max_attempts:
            return True
        return False

    def increment_rate_limit(self, email: str):
        key = self._get_key(email)
        current_time = int(time.time())

        redis_client.zadd(key, {current_time: current_time})
        redis_client.expire(key, self.time_window * 2)