"""

Regular expression patterns for COBOL Copybook parsing.

"""

import re

from typing import ClassVar

class CobolPatterns:

"""Regular expression patterns for parsing COBOL Copybook statements."""

# Base pattern for COBOL field definitions

ROW_PATTERN_BASE: ClassVar[str] = r'^(?P<level>\d{2})\s+(?P<name>\S+)'

# Optional patterns for different COBOL clauses

ROW_PATTERN_OCCURS: ClassVar[str] = r'\s+OCCURS (?P<occurs>\d+) TIMES'

ROW_PATTERN_INDEXED_BY: ClassVar[str] = (

r"\s+INDEXED BY\s(?P<indexed_by>\S+)"

)

ROW_PATTERN_REDEFINES: ClassVar[str] = r"\s+REDEFINES\s(?P<redefines>\S+)"

ROW_PATTERN_PIC: ClassVar[str] = r'\s+PIC\s+(?P<pic>\S+)'

ROW_PATTERN_END: ClassVar[str] = r'\.$'

# Optional pattern format

OPT_PATTERN_FORMAT: ClassVar[str] = "({})?"

# Compiled regex pattern for complete COBOL field definition

ROW_PATTERN: ClassVar[re.Pattern] = re.compile(

ROW_PATTERN_BASE +

OPT_PATTERN_FORMAT.format(ROW_PATTERN_REDEFINES) +

OPT_PATTERN_FORMAT.format(ROW_PATTERN_OCCURS) +

OPT_PATTERN_FORMAT.format(ROW_PATTERN_INDEXED_BY) +

OPT_PATTERN_FORMAT.format(ROW_PATTERN_PIC) +

ROW_PATTERN_END

)

# PIC clause patterns

PIC_PATTERN_REPEATS: ClassVar[re.Pattern] = re.compile(r'(.)\((\d+)\)')

PIC_PATTERN_FLOAT: ClassVar[re.Pattern] = re.compile(r'S?[9Z]*[.V][9Z]+')

PIC_PATTERN_INTEGER: ClassVar[re.Pattern] = re.compile(r'S?[9Z]+')