"""Small append-only progress events shared with the external launcher."""
import json
import os
from pathlib import Path


def report(state, **details):
    target = os.environ.get("WORKSHOP_PROGRESS")
    if not target:
        return
    try:
        with Path(target).open("a", encoding="utf-8") as stream:
            stream.write(json.dumps(dict(state=state, **details), ensure_ascii=False) + "\n")
    except OSError:
        # Progress reporting must not interrupt a render or hide its result.
        pass