def METHOD_NAME(manager_: Manager, q: str, url_prefix: Optional[str] = None) -> Mapping[str, Any]:
    r"""Run the autocomplete algorithm.
    :param manager_: A manager
    :param q: The query string
    :param url_prefix:
        The explicit URL prefix. If not used, relative paths are generated. Introduced to
        solve https://github.com/biopragmatics/bioregistry/issues/596.
    :return: A dictionary with the autocomplete results.
    Before completion is of prefix:
    >>> from bioregistry import manager
    >>> _autocomplete(manager, 'cheb')
    {'query': 'cheb', 'results': [('chebi', ''), ('chebi', 'chebiid'), ('goche', 'gochebi')], 'success': True, 'reason': 'searched prefix', 'url': None}
    If only prefix is complete:
    >>> _autocomplete(manager, 'chebi')
    {'query': 'chebi', 'results': [('chebi', ''), ('chebi', 'chebiid'), ('goche', 'gochebi')], 'success': True, 'reason': 'matched prefix', 'url': '/chebi'}
    Not matching the pattern:
    >>> _autocomplete(manager, 'chebi:NOPE')
    {'query': 'chebi:NOPE', 'prefix': 'chebi', 'pattern': '^\\d+$', 'identifier': 'NOPE', 'success': False, 'reason': 'failed validation', 'url': None}
    Matching the pattern:
    >>> _autocomplete(manager, 'chebi:1234')
    {'query': 'chebi:1234', 'prefix': 'chebi', 'pattern': '^\\d+$', 'identifier': '1234', 'success': True, 'reason': 'passed validation', 'url': '/chebi:1234'}
    """  # noqa: E501
    if url_prefix is None:
        url_prefix = ""
    url_prefix = url_prefix.rstrip().rstrip("/")
    if ":" not in q:
        url: Optional[str]
        if q in manager_.registry:
            reason = "matched prefix"
            url = f"{url_prefix}/{q}"
        else:
            reason = "searched prefix"
            url = None
        return dict(
            query=q,
            results=_search(manager_, q),
            success=True,
            reason=reason,
            url=url,
        )
    prefix, identifier = q.split(":", 1)
    resource = manager_.get_resource(prefix)
    if resource is None:
        return dict(
            query=q,
            prefix=prefix,
            identifier=identifier,
            success=False,
            reason="bad prefix",
        )
    pattern = manager_.get_pattern(prefix)
    if pattern is None:
        success = True
        reason = "no pattern"
        norm_id = resource.standardize_identifier(identifier)
        url = f"{url_prefix}/{resource.get_curie(norm_id)}"
    elif resource.is_standardizable_identifier(identifier):
        success = True
        reason = "passed validation"
        norm_id = resource.standardize_identifier(identifier)
        url = f"{url_prefix}/{resource.get_curie(norm_id)}"
    else:
        success = False
        reason = "failed validation"
        url = None
    return dict(
        query=q,
        prefix=prefix,
        pattern=pattern,
        identifier=identifier,
        success=success,
        reason=reason,
        url=url,
    )