utils.py

""" Handy utility functions. """

from __future__ import annotations

import asyncio
import copy
import dataclasses
import functools
import importlib
import inspect
import json
import json.decoder
import os
import pkgutil
import re
import threading
import time
import traceback
import typing
import urllib.parse
import warnings
from abc import ABC, abstractmethod
from collections import OrderedDict
from contextlib import contextmanager
from io import BytesIO
from numbers import Number
from pathlib import Path
from types import AsyncGeneratorType, GeneratorType
from typing import (
    TYPE_CHECKING,
    Any,
    Callable,
    Generic,
    Iterable,
    Iterator,
    Optional,
    TypeVar,
)

import anyio
import httpx
from typing_extensions import ParamSpec

import gradio
from gradio.context import Context
from gradio.strings import en

if TYPE_CHECKING:  # Only import for type checking (is False at runtime).
    from gradio.blocks import BlockContext, Blocks
    from gradio.components import Component
    from gradio.routes import App, Request

JSON_PATH = os.path.join(os.path.dirname(gradio.__file__), "launches.json")

P = ParamSpec("P")
T = TypeVar("T")


def get_package_version() -> str:
    try:
        package_json_data = (
            pkgutil.get_data(__name__, "package.json").decode("utf-8").strip()  # type: ignore
        )
        package_data = json.loads(package_json_data)
        version = package_data.get("version", "")
        return version
    except Exception:
        return ""


def safe_get_lock() -> asyncio.Lock:
    """Get asyncio.Lock() without fear of getting an Exception.

    Needed because in reload mode we import the Blocks object outside
    the main thread.
    """
    try:
        asyncio.get_event_loop()
        return asyncio.Lock()
    except RuntimeError:
        return None  # type: ignore


class BaseReloader(ABC):
    @property
    @abstractmethod
    def running_app(self) -> App:
        pass

    def queue_changed(self, demo: Blocks):
        return (
            hasattr(self.running_app.blocks, "_queue") and not hasattr(demo, "_queue")
        ) or (
            not hasattr(self.running_app.blocks, "_queue") and hasattr(demo, "_queue")
        )

    def swap_blocks(self, demo: Blocks):
        assert self.running_app.blocks
        # Copy over the blocks to get new components and events but
        # not a new queue
        self.running_app.blocks._queue.block_fns = demo.fns
        demo._queue = self.running_app.blocks._queue
        self.running_app.blocks = demo
        demo._queue.reload()


class SourceFileReloader(BaseReloader):
    def __init__(
        self,
        app: App,
        watch_dirs: list[str],
        watch_module_name: str,
        stop_event: threading.Event,
        change_event: threading.Event,
        demo_name: str = "demo",
    ) -> None:
        super().__init__()
        self.app = app
        self.watch_dirs = watch_dirs
        self.watch_module_name = watch_module_name
        self.stop_event = stop_event
        self.change_event = change_event
        self.demo_name = demo_name

    @property
    def running_app(self) -> App:
        return self.app

    def should_watch(self) -> bool:
        return not self.stop_event.is_set()

    def stop(self) -> None:
        self.stop_event.set()

    def alert_change(self):
        self.change_event.set()

    def swap_blocks(self, demo: Blocks):
        super().swap_blocks(demo)
        self.alert_change()


def watchfn(reloader: SourceFileReloader):
    """Watch python files in a given module.

    get_changes is taken from uvicorn's default file watcher.
    """

    # The thread running watchfn will be the thread reloading
    # the app. So we need to modify this thread_data attr here
    # so that subsequent calls to reload don't launch the app
    from gradio.cli.commands.reload import reload_thread

    reload_thread.running_reload = True

    def get_changes() -> Path | None:
        for file in iter_py_files():
            try:
                mtime = file.stat().st_mtime
            except OSError:  # pragma: nocover
                continue

            old_time = mtimes.get(file)
            if old_time is None:
                mtimes[file] = mtime
                continue
            elif mtime > old_time:
                return file
        return None

    def iter_py_files() -> Iterator[Path]:
        for reload_dir in reload_dirs:
            for path in list(reload_dir.rglob("*.py")):
                yield path.resolve()
            for path in list(reload_dir.rglob("*.css")):
                yield path.resolve()

    module = None
    reload_dirs = [Path(dir_) for dir_ in reloader.watch_dirs]
    import sys

    for dir_ in reload_dirs:
        sys.path.insert(0, str(dir_))

    mtimes = {}
    while reloader.should_watch():
        changed = get_changes()
        if changed:
            print(f"Changes detected in: {changed}")
            # To simulate a fresh reload, delete all module references from sys.modules
            # for the modules in the package the change came from.
            dir_ = next(d for d in reload_dirs if is_in_or_equal(changed, d))
            modules = list(sys.modules)
            for k in modules:
                v = sys.modules[k]
                sourcefile = getattr(v, "__file__", None)
                # Do not reload `reload.py` to keep thread data
                if (
                    sourcefile
                    and dir_ == Path(inspect.getfile(gradio)).parent
                    and sourcefile.endswith("reload.py")
                ):
                    continue
                if sourcefile and is_in_or_equal(sourcefile, dir_):
                    del sys.modules[k]
            try:
                module = importlib.import_module(reloader.watch_module_name)
                module = importlib.reload(module)
            except Exception:
                print(
                    f"Reloading {reloader.watch_module_name} failed with the following exception: "
                )
                traceback.print_exc()
                mtimes = {}
                continue

            demo = getattr(module, reloader.demo_name)
            if reloader.queue_changed(demo):
                print(
                    "Reloading failed. The new demo has a queue and the old one doesn't (or vice versa). "
                    "Please launch your demo again"
                )
            else:
                reloader.swap_blocks(demo)
            mtimes = {}
        time.sleep(0.05)


def colab_check() -> bool:
    """
    Check if interface is launching from Google Colab
    :return is_colab (bool): True or False
    """
    is_colab = False
    try:  # Check if running interactively using ipython.
        from IPython.core.getipython import get_ipython

        from_ipynb = get_ipython()
        if "google.colab" in str(from_ipynb):
            is_colab = True
    except (ImportError, NameError):
        pass
    return is_colab


def kaggle_check() -> bool:
    return bool(
        os.environ.get("KAGGLE_KERNEL_RUN_TYPE") or os.environ.get("GFOOTBALL_DATA_DIR")
    )


def sagemaker_check() -> bool:
    try:
        import boto3  # type: ignore

        client = boto3.client("sts")
        response = client.get_caller_identity()
        return "sagemaker" in response["Arn"].lower()
    except Exception:
        return False


def ipython_check() -> bool:
    """
    Check if interface is launching from iPython (not colab)
    :return is_ipython (bool): True or False
    """
    is_ipython = False
    try:  # Check if running interactively using ipython.
        from IPython.core.getipython import get_ipython

        if get_ipython() is not None:
            is_ipython = True
    except (ImportError, NameError):
        pass
    return is_ipython


def get_space() -> str | None:
    if os.getenv("SYSTEM") == "spaces":
        return os.getenv("SPACE_ID")
    return None


def is_zero_gpu_space() -> bool:
    return os.getenv("SPACES_ZERO_GPU") == "true"


def readme_to_html(article: str) -> str:
    try:
        response = httpx.get(article, timeout=3)
        if response.status_code == httpx.codes.OK:  # pylint: disable=no-member
            article = response.text
    except (httpx.InvalidURL, httpx.RequestError):
        pass
    return article


def launch_counter() -> None:
    try:
        if not os.path.exists(JSON_PATH):
            launches = {"launches": 1}
            with open(JSON_PATH, "w+") as j:
                json.dump(launches, j)
        else:
            with open(JSON_PATH) as j:
                launches = json.load(j)
            launches["launches"] += 1
            if launches["launches"] in [25, 50, 150, 500, 1000]:
                print(en["BETA_INVITE"])
            with open(JSON_PATH, "w") as j:
                j.write(json.dumps(launches))
    except Exception:
        pass


def get_default_args(func: Callable) -> list[Any]:
    signature = inspect.signature(func)
    return [
        v.default if v.default is not inspect.Parameter.empty else None
        for v in signature.parameters.values()
    ]


def assert_configs_are_equivalent_besides_ids(
    config1: dict, config2: dict, root_keys: tuple = ("mode",)
):
    """Allows you to test if two different Blocks configs produce the same demo.

    Parameters:
    config1 (dict): nested dict with config from the first Blocks instance
    config2 (dict): nested dict with config from the second Blocks instance
    root_keys (Tuple): an interable consisting of which keys to test for equivalence at
        the root level of the config. By default, only "mode" is tested,
        so keys like "version" are ignored.
    """
    config1 = copy.deepcopy(config1)
    config2 = copy.deepcopy(config2)
    config1 = json.loads(json.dumps(config1))  # convert tuples to lists
    config2 = json.loads(json.dumps(config2))

    for key in root_keys:
        if config1[key] != config2[key]:
            raise ValueError(f"Configs have different: {key}")

    if len(config1["components"]) != len(config2["components"]):
        raise ValueError("# of components are different")

    def assert_same_components(config1_id, config2_id):
        c1 = list(filter(lambda c: c["id"] == config1_id, config1["components"]))
        if len(c1) == 0:
            raise ValueError(f"Could not find component with id {config1_id}")
        c1 = c1[0]
        c2 = list(filter(lambda c: c["id"] == config2_id, config2["components"]))
        if len(c2) == 0:
            raise ValueError(f"Could not find component with id {config2_id}")
        c2 = c2[0]
        c1 = copy.deepcopy(c1)
        c1.pop("id")
        c2 = copy.deepcopy(c2)
        c2.pop("id")
        if c1 != c2:
            raise ValueError(f"{c1} does not match {c2}")

    def same_children_recursive(children1, chidren2):
        for child1, child2 in zip(children1, chidren2):
            assert_same_components(child1["id"], child2["id"])
            if "children" in child1 or "children" in child2:
                same_children_recursive(child1["children"], child2["children"])

    children1 = config1["layout"]["children"]
    children2 = config2["layout"]["children"]
    same_children_recursive(children1, children2)

    for d1, d2 in zip(config1["dependencies"], config2["dependencies"]):
        for t1, t2 in zip(d1.pop("targets"), d2.pop("targets")):
            assert_same_components(t1[0], t2[0])
        for i1, i2 in zip(d1.pop("inputs"), d2.pop("inputs")):
            assert_same_components(i1, i2)
        for o1, o2 in zip(d1.pop("outputs"), d2.pop("outputs")):
            assert_same_components(o1, o2)

        if d1 != d2:
            raise ValueError(f"{d1} does not match {d2}")

    return True


def delete_none(_dict: dict, skip_value: bool = False) -> dict:
    """
    Delete keys whose values are None from a dictionary
    """
    for key, value in list(_dict.items()):
        if skip_value and key == "value":
            continue
        elif value is None:
            del _dict[key]
    return _dict


def resolve_singleton(_list: list[Any] | Any) -> Any:
    if len(_list) == 1:
        return _list[0]
    else:
        return _list


def component_or_layout_class(cls_name: str) -> type[Component] | type[BlockContext]:
    """
    Returns the component, template, or layout class with the given class name, or
    raises a ValueError if not found.

    Parameters:
    cls_name (str): lower-case string class name of a component
    Returns:
    cls: the component class
    """
    import gradio.blocks
    import gradio.components
    import gradio.layouts
    import gradio.templates

    components = [
        (name, cls)
        for name, cls in gradio.components.__dict__.items()
        if isinstance(cls, type)
    ]
    templates = [
        (name, cls)
        for name, cls in gradio.templates.__dict__.items()
        if isinstance(cls, type)
    ]
    layouts = [
        (name, cls)
        for name, cls in gradio.layouts.__dict__.items()
        if isinstance(cls, type)
    ]
    for name, cls in components + templates + layouts:
        if name.lower() == cls_name.replace("_", "") and (
            issubclass(cls, gradio.components.Component)
            or issubclass(cls, gradio.blocks.BlockContext)
        ):
            return cls
    raise ValueError(f"No such component or layout: {cls_name}")


def run_coro_in_background(func: Callable, *args, **kwargs):
    """
    Runs coroutines in background.

    Warning, be careful to not use this function in other than FastAPI scope, because the event_loop has not started yet.
    You can use it in any scope reached by FastAPI app.

    correct scope examples: endpoints in routes, Blocks.process_api
    incorrect scope examples: Blocks.launch

    Use startup_events in routes.py if you need to run a coro in background in Blocks.launch().


    Example:
        utils.run_coro_in_background(fn, *args, **kwargs)

    Args:
        func:
        *args:
        **kwargs:

    Returns:

    """
    event_loop = asyncio.get_event_loop()
    return event_loop.create_task(func(*args, **kwargs))


def run_sync_iterator_async(iterator):
    """Helper for yielding StopAsyncIteration from sync iterators."""
    try:
        return next(iterator)
    except StopIteration:
        # raise a ValueError here because co-routines can't raise StopIteration themselves
        raise StopAsyncIteration() from None


class SyncToAsyncIterator:
    """Treat a synchronous iterator as async one."""

    def __init__(self, iterator, limiter) -> None:
        self.iterator = iterator
        self.limiter = limiter

    def __aiter__(self):
        return self

    async def __anext__(self):
        return await anyio.to_thread.run_sync(
            run_sync_iterator_async, self.iterator, limiter=self.limiter
        )


async def async_iteration(iterator):
    # anext not introduced until 3.10 :(
    return await iterator.__anext__()


@contextmanager
def set_directory(path: Path | str):
    """Context manager that sets the working directory to the given path."""
    origin = Path().absolute()
    try:
        os.chdir(path)
        yield
    finally:
        os.chdir(origin)


@contextmanager
def no_raise_exception():
    """Context manager that suppresses exceptions."""
    try:
        yield
    except Exception:
        pass


def sanitize_value_for_csv(value: str | Number) -> str | Number:
    """
    Sanitizes a value that is being written to a CSV file to prevent CSV injection attacks.
    Reference: https://owasp.org/www-community/attacks/CSV_Injection
    """
    if isinstance(value, Number):
        return value
    unsafe_prefixes = ["=", "+", "-", "@", "\t", "\n"]
    unsafe_sequences = [",=", ",+", ",-", ",@", ",\t", ",\n"]
    if any(value.startswith(prefix) for prefix in unsafe_prefixes) or any(
        sequence in value for sequence in unsafe_sequences
    ):
        value = f"'{value}"
    return value


def sanitize_list_for_csv(values: list[Any]) -> list[Any]:
    """
    Sanitizes a list of values (or a list of list of values) that is being written to a
    CSV file to prevent CSV injection attacks.
    """
    sanitized_values = []
    for value in values:
        if isinstance(value, list):
            sanitized_value = [sanitize_value_for_csv(v) for v in value]
            sanitized_values.append(sanitized_value)
        else:
            sanitized_value = sanitize_value_for_csv(value)
            sanitized_values.append(sanitized_value)
    return sanitized_values


def append_unique_suffix(name: str, list_of_names: list[str]):
    """Appends a numerical suffix to `name` so that it does not appear in `list_of_names`."""
    set_of_names: set[str] = set(list_of_names)  # for O(1) lookup
    if name not in set_of_names:
        return name
    else:
        suffix_counter = 1
        new_name = f"{name}_{suffix_counter}"
        while new_name in set_of_names:
            suffix_counter += 1
            new_name = f"{name}_{suffix_counter}"
        return new_name


def validate_url(possible_url: str) -> bool:
    headers = {"User-Agent": "gradio (https://gradio.app/; gradio-team@huggingface.co)"}
    try:
        head_request = httpx.head(possible_url, headers=headers, follow_redirects=True)
        # some URLs, such as AWS S3 presigned URLs, return a 405 or a 403 for HEAD requests
        if head_request.status_code in (403, 405):
            return httpx.get(
                possible_url, headers=headers, follow_redirects=True
            ).is_success
        return head_request.is_success
    except Exception:
        return False


def is_update(val):
    return isinstance(val, dict) and "update" in val.get("__type__", "")


def get_continuous_fn(fn: Callable, every: float) -> Callable:
    # For Wasm-compatibility, we need to use asyncio.sleep() instead of time.sleep(),
    # so we need to make the function async.
    async def continuous_coro(*args):
        while True:
            output = fn(*args)
            if isinstance(output, GeneratorType):
                for item in output:
                    yield item
            elif isinstance(output, AsyncGeneratorType):
                async for item in output:
                    yield item
            elif inspect.isawaitable(output):
                yield await output
            else:
                yield output
            await asyncio.sleep(every)

    return continuous_coro


def function_wrapper(
    f: Callable,
    before_fn: Callable | None = None,
    before_args: Iterable | None = None,
    after_fn: Callable | None = None,
    after_args: Iterable | None = None,
):
    before_args = [] if before_args is None else before_args
    after_args = [] if after_args is None else after_args
    if inspect.isasyncgenfunction(f):

        @functools.wraps(f)
        async def asyncgen_wrapper(*args, **kwargs):
            iterator = f(*args, **kwargs)
            while True:
                if before_fn:
                    before_fn(*before_args)
                try:
                    response = await iterator.__anext__()
                except StopAsyncIteration:
                    if after_fn:
                        after_fn(*after_args)
                    break
                if after_fn:
                    after_fn(*after_args)
                yield response

        return asyncgen_wrapper

    elif asyncio.iscoroutinefunction(f):

        @functools.wraps(f)
        async def async_wrapper(*args, **kwargs):
            if before_fn:
                before_fn(*before_args)
            response = await f(*args, **kwargs)
            if after_fn:
                after_fn(*after_args)
            return response

        return async_wrapper

    elif inspect.isgeneratorfunction(f):

        @functools.wraps(f)
        def gen_wrapper(*args, **kwargs):
            iterator = f(*args, **kwargs)
            while True:
                if before_fn:
                    before_fn(*before_args)
                try:
                    response = next(iterator)
                except StopIteration:
                    if after_fn:
                        after_fn(*after_args)
                    break
                if after_fn:
                    after_fn(*after_args)
                yield response

        return gen_wrapper

    else:

        @functools.wraps(f)
        def wrapper(*args, **kwargs):
            if before_fn:
                before_fn(*before_args)
            response = f(*args, **kwargs)
            if after_fn:
                after_fn(*after_args)
            return response

        return wrapper


def get_function_with_locals(
    fn: Callable,
    blocks: Blocks,
    event_id: str | None,
    in_event_listener: bool,
    request: Request | None,
):
    def before_fn(blocks, event_id):
        from gradio.context import LocalContext

        LocalContext.blocks.set(blocks)
        LocalContext.in_event_listener.set(in_event_listener)
        LocalContext.event_id.set(event_id)
        LocalContext.request.set(request)

    def after_fn():
        from gradio.context import LocalContext

        LocalContext.in_event_listener.set(False)
        LocalContext.request.set(None)

    return function_wrapper(
        fn,
        before_fn=before_fn,
        before_args=(blocks, event_id),
        after_fn=after_fn,
    )


async def cancel_tasks(task_ids: set[str]):
    matching_tasks = [
        task for task in asyncio.all_tasks() if task.get_name() in task_ids
    ]
    for task in matching_tasks:
        task.cancel()
    await asyncio.gather(*matching_tasks, return_exceptions=True)


def set_task_name(task, session_hash: str, fn_index: int, batch: bool):
    if not batch:
        task.set_name(f"{session_hash}_{fn_index}")


def get_cancel_function(
    dependencies: list[dict[str, Any]],
) -> tuple[Callable, list[int]]:
    fn_to_comp = {}
    for dep in dependencies:
        if Context.root_block:
            fn_index = next(
                i for i, d in enumerate(Context.root_block.dependencies) if d == dep
            )
            fn_to_comp[fn_index] = [
                Context.root_block.blocks[o] for o in dep["outputs"]
            ]

    async def cancel(session_hash: str) -> None:
        task_ids = {f"{session_hash}_{fn}" for fn in fn_to_comp}
        await cancel_tasks(task_ids)

    return (
        cancel,
        list(fn_to_comp.keys()),
    )


def get_type_hints(fn):
    # Importing gradio with the canonical abbreviation. Used in typing._eval_type.
    import gradio as gr  # noqa: F401
    from gradio import OAuthProfile, OAuthToken, Request  # noqa: F401

    if inspect.isfunction(fn) or inspect.ismethod(fn):
        pass
    elif callable(fn):
        fn = fn.__call__
    else:
        return {}

    try:
        return typing.get_type_hints(fn)
    except TypeError:
        # On Python 3.9 or earlier, get_type_hints throws a TypeError if the function
        # has a type annotation that include "|". We resort to parsing the signature
        # manually using inspect.signature.
        type_hints = {}
        sig = inspect.signature(fn)
        for name, param in sig.parameters.items():
            if param.annotation is inspect.Parameter.empty:
                continue
            if param.annotation == "gr.OAuthProfile | None":
                # Special case: we want to inject the OAuthProfile value even on Python 3.9
                type_hints[name] = Optional[OAuthProfile]
            if param.annotation == "gr.OAuthToken | None":
                # Special case: we want to inject the OAuthToken value even on Python 3.9
                type_hints[name] = Optional[OAuthToken]
            if "|" in str(param.annotation):
                continue
            # To convert the string annotation to a class, we use the
            # internal typing._eval_type function. This is not ideal, but
            # it's the only way to do it without eval-ing the string.
            # Since the API is internal, it may change in the future.
            try:
                type_hints[name] = typing._eval_type(  # type: ignore
                    typing.ForwardRef(param.annotation), globals(), locals()
                )
            except (NameError, TypeError):
                pass
        return type_hints


def is_special_typed_parameter(name, parameter_types):
    from gradio.helpers import EventData
    from gradio.oauth import OAuthProfile, OAuthToken
    from gradio.routes import Request

    """Checks if parameter has a type hint designating it as a gr.Request, gr.EventData, gr.OAuthProfile or gr.OAuthToken."""
    hint = parameter_types.get(name)
    if not hint:
        return False
    is_request = hint == Request
    is_oauth_arg = hint in (
        OAuthProfile,
        Optional[OAuthProfile],
        OAuthToken,
        Optional[OAuthToken],
    )
    is_event_data = inspect.isclass(hint) and issubclass(hint, EventData)
    return is_request or is_event_data or is_oauth_arg


def check_function_inputs_match(fn: Callable, inputs: list, inputs_as_dict: bool):
    """
    Checks if the input component set matches the function
    Returns: None if valid or if the function does not have a signature (e.g. is a built in),
    or a string error message if mismatch
    """
    try:
        signature = inspect.signature(fn)
    except ValueError:
        return None
    parameter_types = get_type_hints(fn)
    min_args = 0
    max_args = 0
    infinity = -1
    for name, param in signature.parameters.items():
        has_default = param.default != param.empty
        if param.kind in [param.POSITIONAL_ONLY, param.POSITIONAL_OR_KEYWORD]:
            if not is_special_typed_parameter(name, parameter_types):
                if not has_default:
                    min_args += 1
                max_args += 1
        elif param.kind == param.VAR_POSITIONAL:
            max_args = infinity
        elif param.kind == param.KEYWORD_ONLY and not has_default:
            return f"Keyword-only args must have default values for function {fn}"
    arg_count = 1 if inputs_as_dict else len(inputs)
    if min_args == max_args and max_args != arg_count:
        warnings.warn(
            f"Expected {max_args} arguments for function {fn}, received {arg_count}."
        )
    if arg_count < min_args:
        warnings.warn(
            f"Expected at least {min_args} arguments for function {fn}, received {arg_count}."
        )
    if max_args != infinity and arg_count > max_args:
        warnings.warn(
            f"Expected maximum {max_args} arguments for function {fn}, received {arg_count}."
        )


class TupleNoPrint(tuple):
    # To remove printing function return in notebook
    def __repr__(self):
        return ""

    def __str__(self):
        return ""


class MatplotlibBackendMananger:
    def __enter__(self):
        import matplotlib

        self._original_backend = matplotlib.get_backend()
        matplotlib.use("agg")

    def __exit__(self, exc_type, exc_val, exc_tb):
        import matplotlib

        matplotlib.use(self._original_backend)


def tex2svg(formula, *_args):
    with MatplotlibBackendMananger():
        import matplotlib.pyplot as plt

        fontsize = 20
        dpi = 300
        plt.rc("mathtext", fontset="cm")
        fig = plt.figure(figsize=(0.01, 0.01))
        fig.text(0, 0, rf"${formula}$", fontsize=fontsize)
        output = BytesIO()
        fig.savefig(  # type: ignore
            output,
            dpi=dpi,
            transparent=True,
            format="svg",
            bbox_inches="tight",
            pad_inches=0.0,
        )
        plt.close(fig)
        output.seek(0)
        xml_code = output.read().decode("utf-8")
        svg_start = xml_code.index("<svg ")
        svg_code = xml_code[svg_start:]
        svg_code = re.sub(r"<metadata>.*<\/metadata>", "", svg_code, flags=re.DOTALL)
        svg_code = re.sub(r' width="[^"]+"', "", svg_code)
        height_match = re.search(r'height="([\d.]+)pt"', svg_code)
        if height_match:
            height = float(height_match.group(1))
            new_height = height / fontsize  # conversion from pt to em
            svg_code = re.sub(
                r'height="[\d.]+pt"', f'height="{new_height}em"', svg_code
            )
        copy_code = f"<span style='font-size: 0px'>{formula}</span>"
    return f"{copy_code}{svg_code}"


def abspath(path: str | Path) -> Path:
    """Returns absolute path of a str or Path path, but does not resolve symlinks."""
    path = Path(path)

    if path.is_absolute():
        return path

    # recursively check if there is a symlink within the path
    is_symlink = path.is_symlink() or any(
        parent.is_symlink() for parent in path.parents
    )

    if is_symlink or path == path.resolve():  # in case path couldn't be resolved
        return Path.cwd() / path
    else:
        return path.resolve()


def is_in_or_equal(path_1: str | Path, path_2: str | Path):
    """
    True if path_1 is a descendant (i.e. located within) path_2 or if the paths are the
    same, returns False otherwise.
    Parameters:
        path_1: str or Path (should be a file)
        path_2: str or Path (can be a file or directory)
    """
    path_1, path_2 = abspath(path_1), abspath(path_2)
    try:
        if ".." in str(path_1.relative_to(path_2)):  # prevent path traversal
            return False
    except ValueError:
        return False
    return True


HTML_TAG_RE = re.compile("<.*?>")


def remove_html_tags(raw_html: str | None) -> str:
    return re.sub(HTML_TAG_RE, "", raw_html or "")


def find_user_stack_level() -> int:
    """
    Find the first stack frame not inside Gradio.
    """
    frame = inspect.currentframe()
    n = 0
    while frame:
        fname = inspect.getfile(frame)
        if "/gradio/" not in fname.replace(os.sep, "/"):
            break
        frame = frame.f_back
        n += 1
    return n


class NamedString(str):
    """
    Subclass of str that includes a .name attribute equal to the value of the string itself. This class is used when returning
    a value from the `.preprocess()` methods of the File and UploadButton components. Before Gradio 4.0, these methods returned a file
    object which was then converted to a string filepath using the `.name` attribute. In Gradio 4.0, these methods now return a str
    filepath directly, but to maintain backwards compatibility, we use this class instead of a regular str.
    """

    def __init__(self, *args):
        super().__init__()
        self.name = str(self) if args else ""


def default_input_labels():
    """
    A generator that provides default input labels for components when the user's function
    does not have named parameters. The labels are of the form "input 0", "input 1", etc.
    """
    n = 0
    while True:
        yield f"input {n}"
        n += 1


def get_extension_from_file_path_or_url(file_path_or_url: str) -> str:
    """
    Returns the file extension (without the dot) from a file path or URL. If the file path or URL does not have a file extension, returns an empty string.
    For example, "https://example.com/avatar/xxxx.mp4?se=2023-11-16T06:51:23Z&sp=r" would return "mp4".
    """
    parsed_url = urllib.parse.urlparse(file_path_or_url)
    file_extension = os.path.splitext(os.path.basename(parsed_url.path))[1]
    return file_extension[1:] if file_extension else ""


def convert_to_dict_if_dataclass(value):
    if dataclasses.is_dataclass(value):
        return dataclasses.asdict(value)
    return value


K = TypeVar("K")
V = TypeVar("V")


class LRUCache(OrderedDict, Generic[K, V]):
    def __init__(self, max_size: int = 100):
        super().__init__()
        self.max_size: int = max_size

    def __setitem__(self, key: K, value: V) -> None:
        if key in self:
            self.move_to_end(key)
        elif len(self) >= self.max_size:
            self.popitem(last=False)
        super().__setitem__(key, value)


def get_cache_folder() -> Path:
    return Path(os.environ.get("GRADIO_EXAMPLES_CACHE", "gradio_cached_examples"))


def diff(old, new):
    def compare_objects(obj1, obj2, path=None):
        if path is None:
            path = []
        edits = []

        if obj1 == obj2:
            return edits

        if type(obj1) != type(obj2):
            edits.append(("replace", path, obj2))
            return edits

        if isinstance(obj1, str) and obj2.startswith(obj1):
            edits.append(("append", path, obj2[len(obj1) :]))
            return edits

        if isinstance(obj1, list):
            common_length = min(len(obj1), len(obj2))
            for i in range(common_length):
                edits.extend(compare_objects(obj1[i], obj2[i], path + [i]))
            for i in range(common_length, len(obj1)):
                edits.append(("delete", path + [i], None))
            for i in range(common_length, len(obj2)):
                edits.append(("add", path + [i], obj2[i]))
            return edits

        if isinstance(obj1, dict):
            for key in obj1:
                if key in obj2:
                    edits.extend(compare_objects(obj1[key], obj2[key], path + [key]))
                else:
                    edits.append(("delete", path + [key], None))
            for key in obj2:
                if key not in obj1:
                    edits.append(("add", path + [key], obj2[key]))
            return edits

        edits.append(("replace", path, obj2))
        return edits

    return compare_objects(old, new)