"""

if not isinstance(text, str) or not text:

return (None, None)

cleaned_fields = []

# Remove wrapping parentheses, if any

if text.startswith("(") and text.endswith(")"):

text = text[1:-1]

two_part_tokens = re.findall(r'\[[^\]]+\]\.\[[^\]]+\]', text)

text_without_two_part = text

for token in two_part_tokens:

text_without_two_part = text_without_two_part.replace(token, '', 1)

single_part_tokens = re.findall(r'\[[^\]]+\]', text_without_two_part)

raw_fields = two_part_tokens + single_part_tokens

for field in raw_fields:

if '].[' in field:

parts = field.split('].[', 1)

first_part = parts[0] + ']'

second_part = '[' + parts[1]

inner = second_part[1:-1]

if ':' in inner:

colon_parts = inner.split(':', 1)

if len(colon_parts) > 1 and colon_parts[0] in ['none', 'sum', 'attr', 'avg', 'min', 'max', 'count', 'usr']:

inner = colon_parts[1]

if ':' in inner:

inner = inner.rsplit(':', 1)[0]

cleaned_field = first_part + '.[' + inner + ']'

cleaned_fields.append(cleaned_field)

else:

inner = field[1:-1]

if ':' in inner:

colon_parts = inner.split(':', 1)

if len(colon_parts) > 1 and colon_parts[0] in ['none', 'sum', 'attr', 'avg', 'min', 'max', 'count', 'usr']:

inner = colon_parts[1]

if ':' in inner:

inner = inner.rsplit(':', 1)[0]

cleaned_fields.append(f'[{inner}]')

# NEW: guard no matches

if not cleaned_fields:

return (None, None)

result = re.split(r'(?<=\])\.(?=\[)', cleaned_fields[0])

datasource_name = result[0][1:-1] if len(result) > 1 else None

field_name = result[1] if len(result) > 1 else cleaned_fields[0]