Source code for tesseract_streamlit.runner

"""Runner utilities for ``tesseract-streamlit``.

Provides functions for serving Tesseracts, launching Streamlit,
and managing temporary app files.
"""

import contextlib
import subprocess
import sys
import time
import uuid
from collections.abc import Iterator
from pathlib import Path

import platformdirs
import requests




def get_app_path() -> Path:
    """Return a unique path in the user cache dir for the generated app."""
    cache_dir = platformdirs.user_cache_path(
        appname="tesseract-streamlit",
        appauthor="pasteur-labs",
    )
    cache_dir.mkdir(parents=True, exist_ok=True)
    return cache_dir / f"app_{uuid.uuid4().hex[:8]}.py"





def wait_for_tesseract(
    url: str, timeout: float = 60.0, poll_interval: float = 0.5
) -> None:
    """Block until the Tesseract at *url* responds, or raise on timeout."""
    deadline = time.monotonic() + timeout
    while time.monotonic() < deadline:
        try:
            resp = requests.get(f"{url}/openapi.json", timeout=2)
            if resp.status_code == 200:
                return
        except requests.ConnectionError:
            pass
        time.sleep(poll_interval)
    raise TimeoutError(f"Tesseract at {url} did not become ready within {timeout}s")





@contextlib.contextmanager
def serve_tesseract(image_name: str) -> Iterator[str]:
    """Serve a Tesseract from a container image.

    Yields:
        The URL of the served Tesseract.
    """
    import tesseract_core
    from tesseract_core.sdk import engine

    port = engine.get_free_port()
    with tesseract_core.Tesseract.from_image(image_name, port=str(port)):
        yield f"http://localhost:{port}"





def run_streamlit(app_path: Path) -> int:
    """Launch ``streamlit run`` and block until it exits.

    Returns:
        The process exit code.
    """
    result = subprocess.run(
        [sys.executable, "-m", "streamlit", "run", str(app_path)],
        check=False,
    )
    return result.returncode