micromamba_root/Lib/site-packages/backrefs/_bre_parse.py

"""
Backrefs Re parser.

Licensed under MIT
Copyright (c) 2011 - 2020 Isaac Muse <isaacmuse@gmail.com>
"""
from __future__ import annotations
import re as _re
import sys
import copyreg as _copyreg
from . import util as _util
import unicodedata as _unicodedata
from . import uniprops as _uniprops
from typing import Generic, AnyStr, Match, Any, Pattern, cast

if sys.version_info >= (3, 11):
    import re._parser as _parser  # type: ignore[import]
else:
    import sre_parse as _parser

__all__ = ("ReplaceTemplate",)

_ASCII_LETTERS = frozenset(
    (
        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
        'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
        'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
    )
)
_DIGIT = frozenset(('0', '1', '2', '3', '4', '5', '6', '7', '8', '9'))
_OCTAL = frozenset(('0', '1', '2', '3', '4', '5', '6', '7'))
_HEX = frozenset(('a', 'b', 'c', 'd', 'e', 'f', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'))
_LETTERS_UNDERSCORE = _ASCII_LETTERS | frozenset(('_',))
_WORD = _LETTERS_UNDERSCORE | _DIGIT
_STANDARD_ESCAPES = frozenset(('a', 'b', 'f', 'n', 'r', 't', 'v'))
_CURLY_BRACKETS = frozenset(('{', '}'))
_PROPERTY_STRIP = frozenset((' ', '-', '_'))
_PROPERTY = _WORD | _DIGIT | _PROPERTY_STRIP
_GLOBAL_FLAGS = frozenset(('a', 'i', 'L', 'm', 's', 'u', 'x'))
_SCOPED_FLAGS = frozenset(('i', 'm', 's', 'x'))
_SCOPED_END = frozenset((':', ')'))

_CURLY_BRACKETS_ORD = frozenset((0x7b, 0x7d))

_COMPATIBILITY_PROPERTIES = frozenset(
    (
        'alpha', 'lower', 'upper', 'punct', 'digit', 'xdigit', 'alnum',
        'space', 'blank', 'cntrl', 'graph', 'print', 'word'
    )
)

# Case upper or lower
_UPPER = 1
_LOWER = 2

# Format Constants
_BACK_SLASH_TRANSLATION = {
    "\\a": '\a',
    "\\b": '\b',
    "\\f": '\f',
    "\\r": '\r',
    "\\t": '\t',
    "\\n": '\n',
    "\\v": '\v',
    "\\\\": '\\'
}

_FMT_CONV_TYPE = ('a', 'r', 's')


class LoopException(Exception):
    """Loop exception."""


class GlobalRetryException(Exception):
    """Global retry exception."""


class _SearchParser(Generic[AnyStr]):
    """Search Template."""

    _new_refs = ("c", "C", "e", "E", "h", "l", "L", "m", "M", "N", "p", "P", "Q", "R", "X")
    _re_start_wb = r"\b(?=\w)"
    _re_end_wb = r"\b(?<=\w)"
    _line_break = r'(?:\r\n|(?!\r\n)[\n\v\f\r\x85\u2028\u2029])'
    _bytes_line_break = r'(?>\r\n|[\n\v\f\r\x85])' if _util.PY311 else r'(?:\r\n|(?!\r\n)[\n\v\f\r\x85])'
    _grapheme_cluster = r'(?:{}{}*(?!{}))'

    verbose: bool
    unicode: bool
    global_flag_swap: dict[str, bool]
    temp_global_flag_swap: dict[str, bool]
    ascii: bool  # noqa: A003
    is_bytes: bool
    search: AnyStr

    def __init__(self, search: AnyStr, re_verbose: bool = False, re_unicode: bool | None = None) -> None:
        """Initialize."""

        if isinstance(search, bytes):
            self.is_bytes = True
        else:
            self.is_bytes = False

        if self.is_bytes:
            self._re_line_break = self._bytes_line_break
        else:
            self._re_line_break = self._line_break
        self.search = search
        self.re_verbose = re_verbose
        self.re_unicode = re_unicode

    def process_quotes(self, text: str) -> str:
        """Process quotes."""

        escaped = False
        in_quotes = False
        current = []
        quoted = []  # type: list[str]
        i = _util.StringIter(text)

        for t in i:
            if not escaped and t == "\\":
                escaped = True
            elif escaped:
                escaped = False
                if t == "E":
                    if in_quotes:
                        current.append(_re.escape("".join(quoted)))
                        quoted = []
                        in_quotes = False
                elif t == "Q" and not in_quotes:
                    in_quotes = True
                elif in_quotes:
                    quoted.extend(["\\", t])
                else:
                    current.extend(["\\", t])
            elif in_quotes:
                quoted.extend(t)
            else:
                current.append(t)

        if in_quotes and escaped:
            quoted.append("\\")
        elif escaped:
            current.append("\\")

        if quoted:
            current.append(_re.escape("".join(quoted)))

        return "".join(current)

    def verbose_comment(self, t: str, i: _util.StringIter) -> list[str]:
        """Handle verbose comments."""

        current = []
        escaped = False

        try:
            while t != "\n":
                if not escaped and t == "\\":
                    escaped = True
                    current.append(t)
                elif escaped:
                    escaped = False
                    if t in self._new_refs:
                        current.append("\\")
                    current.append(t)
                else:
                    current.append(t)
                t = next(i)
        except StopIteration:
            pass

        if t == "\n":
            current.append(t)
        return current

    def flags(self, text: str, scoped: bool = False) -> None:
        """Analyze flags."""

        flags = text.split('-')
        enable = flags[0]
        disable = flags[1] if len(flags) > 1 else ''

        global_retry = False
        if ('a' in enable or 'L' in enable) and self.unicode:
            self.unicode = False
            if not scoped:
                self.temp_global_flag_swap["unicode"] = True
                global_retry = True
        elif 'u' in enable and not self.unicode and not self.is_bytes:
            self.unicode = True
            if not scoped:
                self.temp_global_flag_swap["unicode"] = True
                global_retry = True
        if 'x' in disable and self.verbose:
            self.verbose = False
        elif 'x' in enable and not self.verbose:
            self.verbose = True
            if not scoped:
                self.temp_global_flag_swap["verbose"] = True
                global_retry = True
        if global_retry:
            raise GlobalRetryException('Global Retry')

    def get_unicode_property(self, i: _util.StringIter, brackets: bool = False) -> tuple[str, str]:
        """Get Unicode property."""

        index = i.index
        prop = []
        value = []
        try:
            c = next(i)
            if c.upper() in _ASCII_LETTERS:
                prop.append(c)
            elif (not brackets and c != '{') or (brackets and c != ':'):
                raise SyntaxError(f"Unicode property missing '{{' at {i.index - 1}!")
            else:
                c = next(i)
                if c == '^':
                    prop.append(c)
                    c = next(i)

                while c not in (':', '=', '}'):
                    if c not in _PROPERTY:
                        raise SyntaxError(f'Invalid Unicode property character at {i.index - 1}!')
                    if c not in _PROPERTY_STRIP:
                        prop.append(c)
                    c = next(i)

                if c in (':', '='):
                    skip = False
                    if brackets:
                        is_colon = c == ':'
                        c = next(i)
                        if is_colon and c == ']':
                            # That's the end of the property
                            skip = True
                        end = ':'
                    else:
                        c = next(i)
                        end = '}'

                    # Get the property value
                    if not skip:
                        while c != end:
                            if c not in _PROPERTY:
                                raise SyntaxError(f'Invalid Unicode property character at {i.index - 1}!')
                            if c not in _PROPERTY_STRIP:
                                value.append(c)
                            c = next(i)
                        if brackets and c == ':':
                            c = next(i)
                            if c != ']':
                                raise SyntaxError(f'Invalid Unicode property character at {i.index - 1}!')
                        if not value:
                            raise SyntaxError('Invalid Unicode property!')

        except StopIteration as e:
            if brackets:
                raise SyntaxError(f"Missing or unmatched ':]' at {index}!") from e
            else:
                raise SyntaxError(f"Missing or unmatched '{{' at {index}!") from e

        p = ''.join(prop).lower()
        v = ''.join(value).lower()

        # Ensure when using POSIX form, that any property considered a compatibility property uses the POSIX form.
        # POSIX form is not guaranteed to be different from standard form and sometimes is just an alias for standard.
        if brackets and p in _COMPATIBILITY_PROPERTIES:
            p = 'posix' + p

        return p, v

    def get_named_unicode(self, i: _util.StringIter) -> str:
        """Get Unicode name."""

        index = i.index
        value = []
        try:
            if next(i) != '{':
                raise ValueError(f"Named Unicode missing '{{' {i.index - 1}!")
            c = next(i)
            while c != '}':
                value.append(c)
                c = next(i)
        except Exception as e:
            raise SyntaxError(f"Unmatched '{{' at {index}!") from e

        return ''.join(value)

    def reference(self, t: str, i: _util.StringIter, in_group: bool = False) -> list[str]:
        """Handle references."""

        current = []

        if not in_group and t == "m":
            current.append(self._re_start_wb)
        elif not in_group and t == "M":
            current.append(self._re_end_wb)
        elif not in_group and t == "R":
            current.append(self._re_line_break)
        elif not in_group and t == "X":
            no_mark = self.unicode_props("^m", None, in_group=False)[0]
            mark = self.unicode_props("m", None, in_group=False)[0]
            current.extend(self._grapheme_cluster.format(no_mark, mark, mark))
        elif t == 'p':
            prop = self.get_unicode_property(i)
            current.extend(self.unicode_props(prop[0], prop[1], in_group=in_group))
            if in_group:
                self.found_property = True
        elif t == 'P':
            prop = self.get_unicode_property(i)
            current.extend(self.unicode_props(prop[0], prop[1], in_group=in_group, negate=True))
            if in_group:
                self.found_property = True
        elif t == "N":
            text = self.get_named_unicode(i)
            current.extend(self.unicode_name(text, in_group))
            if in_group:
                self.found_named_unicode = True
        else:
            current.extend(["\\", t])
        return current

    def get_comments(self, i: _util.StringIter) -> str | None:
        """Get comments."""

        index = i.index
        value = ['(']
        escaped = False
        try:
            c = next(i)
            if c != '?':
                i.rewind(1)
                return None
            value.append(c)
            c = next(i)
            if c != '#':
                i.rewind(2)
                return None
            value.append(c)
            c = next(i)
            while c != ')' or escaped is True:
                if escaped:
                    escaped = False
                elif c == '\\':
                    escaped = True
                value.append(c)
                c = next(i)
            value.append(c)
        except StopIteration as e:
            raise SyntaxError(f"Unmatched '(' at {index - 1}!") from e

        return ''.join(value)

    def get_flags(self, i: _util.StringIter) -> tuple[str | None, bool]:
        """
        Get flags.

        In Re, flags are quite predictable when global or scoped.
        Global can never be disabled with minus, and never have a `:` after them.
        The global flag set is also very specific, but can be used as enablers in scoped.

        The returned scoped status will indicate whether flags are generally considered
        scoped flags or global flags.
        """

        index = i.index
        value = ['(']
        toggle = False
        smells_scoped = False
        try:
            c = next(i)
            if c != '?':
                i.rewind(1)
                return None, False
            value.append(c)
            c = next(i)
            while c not in _SCOPED_END:
                if toggle:
                    if c not in _SCOPED_FLAGS:
                        raise ValueError('Bad scope')
                elif c == '-':
                    smells_scoped = True
                    toggle = True
                elif c not in _GLOBAL_FLAGS:
                    raise ValueError("Bad flag")
                value.append(c)
                c = next(i)
            if smells_scoped and c != ':':
                raise ValueError("Bad flag")
            elif c == ':':
                smells_scoped = True
            value.append(c)
        except Exception:
            i.rewind(i.index - index)
            value = []

        return ''.join(value) if value else None, smells_scoped

    def subgroup(self, t: str, i: _util.StringIter) -> list[str]:
        """Handle parenthesis."""

        current = []  # type: list[str]

        # (?#comment)
        comments = self.get_comments(i)
        if comments:
            return [comments]

        verbose = self.verbose
        unicode_flag = self.unicode

        # (?flags:pattern) or (?flags)
        flags, scoped = self.get_flags(i)
        if flags:  # pragma: no cover
            t = flags
            self.flags(flags[2:-1], scoped=scoped)
            if not scoped:
                return [flags]

        current = []
        try:
            while t != ')':
                if not current:
                    current.append(t)
                else:
                    current.extend(self.normal(t, i))

                t = next(i)
        except StopIteration:
            pass

        # Restore flags after group
        self.verbose = verbose
        self.unicode = unicode_flag

        if t == ")":
            current.append(t)
        return current

    def char_groups(self, t: str, i: _util.StringIter) -> list[str]:
        """Handle character groups."""

        current = []
        pos = i.index - 1
        found = False
        escaped = False
        first = 0
        found_property = False
        self.found_property = False
        self.found_named_unicode = False

        try:
            while True:
                # Prevent POSIX/Unicode class from being part of a range.
                if self.found_property and t == '-':
                    current.append(_re.escape(t))
                    pos += 1
                    t = next(i)
                    self.found_property = False
                    continue
                else:
                    self.found_property = False

                if not escaped and t == "\\":
                    escaped = True
                elif escaped:
                    escaped = False
                    idx = len(current) - 1
                    current.extend(self.reference(t, i, True))
                    if self.found_property:
                        # Prevent Unicode class from being part of a range.
                        if idx >= 0 and current[idx] == '-':
                            current[idx] = _re.escape('-')
                        found_property = True
                elif t == "[" and not found:
                    found = True
                    first = pos
                    current.append(t)
                elif t == "[":
                    index = i.index
                    try:
                        prop = self.get_unicode_property(i, True)  # type: tuple[str, str] | None
                    except Exception:
                        prop = None
                        i.rewind(i.index - index)
                    if prop is not None:
                        value = self.unicode_props(prop[0], prop[1], in_group=True)
                        if current[-1] == '-':
                            current[-1] = _re.escape('-')
                        current.extend(value)
                        found_property = True
                        pos = i.index - 2
                    else:
                        current.append(t)
                elif t == "^" and found and (pos == first + 1):
                    first = pos
                    current.append(t)
                elif t == "]" and found and (pos != first + 1):
                    found = False
                    current.append(t)
                    break
                else:
                    current.append(t)
                pos += 1
                t = next(i)
        except StopIteration:
            pass

        if escaped:
            current.append(t)

        # Handle properties that return an empty string.
        # This will occur when a property's values exceed
        # either the Unicode char limit on a narrow system,
        # or the ASCII limit in a byte string pattern.
        if found_property or self.found_named_unicode:
            temp = "".join(current)
            if temp == '[]':
                # We specified some properties, but they are all
                # out of reach.  Therefore we can match nothing.
                current = [f'[^{_uniprops.ASCII_RANGE if self.is_bytes else _uniprops.UNICODE_RANGE}]']
            elif temp == '[^]':
                current = [f'[{_uniprops.ASCII_RANGE if self.is_bytes else _uniprops.UNICODE_RANGE}]']
            else:
                current = [temp]

        return current

    def normal(self, t: str, i: _util.StringIter) -> list[str]:
        """Handle normal chars."""

        current = []

        if t == "\\":
            try:
                t = next(i)
                current.extend(self.reference(t, i))
            except StopIteration:
                current.append(t)
        elif t == "(":
            current.extend(self.subgroup(t, i))
        elif self.verbose and t == "#":
            current.extend(self.verbose_comment(t, i))
        elif t == "[":
            current.extend(self.char_groups(t, i))
        else:
            current.append(t)
        return current

    def unicode_name(self, name: str, in_group: bool = False) -> list[str]:
        """Insert Unicode value by its name."""

        value = ord(_unicodedata.lookup(name))
        if self.is_bytes and value > 0xFF:
            if not in_group:
                return [f'[^{_uniprops.ASCII_RANGE if self.is_bytes else _uniprops.UNICODE_RANGE}]']
            else:
                return ['']
        return [f'\\{value:03o}' if value <= 0xFF else chr(value)]

    def unicode_props(
        self,
        props: str,
        prop_value: str | None,
        in_group: bool = False,
        negate: bool = False
    ) -> list[str]:
        """
        Insert Unicode properties.

        Unicode properties are very forgiving.
        Case doesn't matter and `[ -_]` will be stripped out.
        """

        if props.startswith("^"):
            if negate:
                props = props[1:]
        elif negate:
            props = '^' + props
        if not prop_value and prop_value is not None:
            prop_value = None

        if self.is_bytes:
            mode = _uniprops.MODE_ASCII
        elif not self.unicode:
            mode = _uniprops.MODE_NORMAL
        else:
            mode = _uniprops.MODE_UNICODE

        v = _uniprops.get_unicode_property(props, prop_value, mode)
        if not in_group:
            if not v:
                v = f'^{_uniprops.ASCII_RANGE if self.is_bytes else _uniprops.UNICODE_RANGE}'
            v = f"[{v}]"
        properties = [v]

        return properties

    def main_group(self, i: _util.StringIter) -> list[str]:
        """The main group: group 0."""

        current = []
        try:
            while True:
                t = next(i)
                current.extend(self.normal(t, i))
        except StopIteration:
            pass
        return current

    def _parse(self, search: str) -> str:
        """Begin parsing."""

        self.verbose = bool(self.re_verbose)
        self.unicode = bool(self.re_unicode)
        self.global_flag_swap = {
            "unicode": False,
            "verbose": False
        }
        self.temp_global_flag_swap = {
            "unicode": False,
            "verbose": False
        }
        self.ascii = self.re_unicode is not None and not self.re_unicode
        if not self.unicode and not self.ascii:
            self.unicode = True

        new_pattern = []
        i = _util.StringIter(self.process_quotes(search))

        retry = True
        while retry:
            retry = False
            try:
                new_pattern = self.main_group(i)
            except GlobalRetryException as e:
                # Prevent a loop of retry over and over for a pattern like ((?u)(?a))
                # or (?-x:(?x))
                if self.temp_global_flag_swap['unicode']:
                    if self.global_flag_swap['unicode']:
                        raise LoopException('Global unicode flag recursion.') from e
                    else:
                        self.global_flag_swap["unicode"] = True
                if self.temp_global_flag_swap['verbose']:
                    if self.global_flag_swap['verbose']:
                        raise LoopException('Global verbose flag recursion.') from e
                    else:
                        self.global_flag_swap['verbose'] = True
                self.temp_global_flag_swap = {
                    "unicode": False,
                    "verbose": False
                }
                i.rewind(i.index)
                retry = True
        return "".join(new_pattern)

    def parse(self) -> AnyStr:
        """Apply search template."""

        if isinstance(self.search, bytes):
            return self._parse(self.search.decode('latin-1')).encode('latin-1')
        else:
            return self._parse(self.search)


class _ReplaceParser(Generic[AnyStr]):
    """Pre-replace template."""

    def __init__(self, pattern: Pattern[AnyStr], template: AnyStr, use_format: bool = False) -> None:
        """Initialize."""

        self.pattern = pattern  # type: Pattern[AnyStr]
        self._original = template  # type: AnyStr
        self._template = template  # type: AnyStr
        self.use_format = use_format
        self.end_found = False
        self.group_slots = []  # type: list[tuple[int, tuple[int | None, int | None, Any]]]
        self.literal_slots = []  # type: list[str]
        self.result = []  # type: list[str]
        self.span_stack = []  # type: list[int]
        self.single_stack = []  # type: list[int]
        self.literals = []  # type: list[AnyStr | None]
        self.groups = []  # type: list[tuple[int, int]]
        self.slot = 0
        self.manual = False
        self.auto = False
        self.auto_index = 0
        self.is_bytes = isinstance(self._original, bytes)

    def parse_format_index(self, text: str) -> int | str:
        """Parse format index."""

        base = 10
        prefix = text[1:3] if text[0] == "-" else text[:2]
        if prefix[0:1] == "0":
            char = prefix[-1]
            if char == "b":
                base = 2
            elif char == "o":
                base = 8
            elif char == "x":
                base = 16
        try:
            idx = int(text, base)  # type: int | str
        except Exception:
            idx = text
        return idx

    def get_format(self, c: str, i: _util.StringIter) -> tuple[str, list[tuple[int, Any]]]:
        """Get format group."""

        index = i.index
        field = ''
        value = []  # type: list[tuple[int, Any]]

        try:
            if c == '}':
                value.append((_util.FMT_FIELD, ''))
                value.append((_util.FMT_INDEX, -1))
            else:
                # Field
                temp = []  # type: list[str]
                if c in _LETTERS_UNDERSCORE:
                    # Handle name
                    temp.append(c)
                    c = self.format_next(i)
                    while c in _WORD:
                        temp.append(c)
                        c = self.format_next(i)
                elif c in _DIGIT:
                    # Handle group number
                    temp.append(c)
                    c = self.format_next(i)
                    while c in _DIGIT:
                        temp.append(c)
                        c = self.format_next(i)

                # Try and covert to integer index
                field = ''.join(temp).strip()
                try:
                    value = [(_util.FMT_FIELD, str(int(field, 10)))]
                except ValueError:
                    value = [(_util.FMT_FIELD, field)]
                    pass

                if c != '[':
                    value.append((_util.FMT_INDEX, None))

                # Attributes and indexes
                while c in ('[', '.'):
                    if c == '[':
                        findex = []
                        sindex = i.index - 1
                        c = self.format_next(i)
                        try:
                            while c != ']':
                                findex.append(c)
                                c = self.format_next(i)
                        except StopIteration as e:
                            raise SyntaxError(f"Unmatched '[' at {sindex - 1}") from e
                        idx = self.parse_format_index(''.join(findex))
                        value.append((_util.FMT_INDEX, idx))
                        c = self.format_next(i)
                    else:
                        findex = []
                        c = self.format_next(i)
                        while c in _WORD:
                            findex.append(c)
                            c = self.format_next(i)
                        value.append((_util.FMT_ATTR, ''.join(findex)))

                # Conversion
                if c == '!':
                    c = self.format_next(i)
                    if c not in _FMT_CONV_TYPE:
                        raise SyntaxError(f"Invalid conversion type at {i.index - 1}!")
                    value.append((_util.FMT_CONV, c))
                    c = self.format_next(i)

                # Format spec
                if c == ':':
                    fill = None  # type: str | None
                    width = []
                    align = None
                    convert = None
                    c = self.format_next(i)

                    if c in ('<', '>', '^'):
                        # Get fill and alignment
                        align = c
                        c = self.format_next(i)
                        if c in ('<', '>', '^'):
                            fill = align
                            align = c
                            c = self.format_next(i)
                    elif c in _DIGIT:
                        # Get Width
                        fill = c
                        c = self.format_next(i)
                        if c in ('<', '>', '^'):
                            align = c
                            c = self.format_next(i)
                        else:
                            width.append(fill)
                            fill = None
                    else:
                        fill = c
                        c = self.format_next(i)
                        if fill == 's' and c == '}':
                            convert = fill
                            fill = None
                        if fill is not None:
                            if c not in ('<', '>', '^'):
                                raise SyntaxError(f'Invalid format spec char at {i.index - 1}!')
                            align = c
                            c = self.format_next(i)

                    while c in _DIGIT:
                        width.append(c)
                        c = self.format_next(i)

                    if not align and len(width) and width[0] == '0':
                        raise ValueError("'=' alignment is not supported!")
                    if align and not fill and len(width) and width[0] == '0':
                        fill = '0'

                    if c == 's':
                        convert = c
                        c = self.format_next(i)

                    if not fill:
                        fill = ' '

                    value.append(
                        (
                            _util.FMT_SPEC,
                            (
                                fill.encode('latin-1') if self.is_bytes else fill,
                                align,
                                (int(''.join(width)) if width else 0),
                                convert
                            )
                        )
                    )

            if c != '}':
                raise SyntaxError(f"Unmatched '{{' at {index - 1}")
        except StopIteration as e:
            raise SyntaxError(f"Unmatched '{{' at {index - 1}!") from e

        return field, value

    def handle_format(self, t: str, i: _util.StringIter) -> None:
        """Handle format."""

        if t == '{':
            t = self.format_next(i)
            if t == '{':
                self.get_single_stack()
                self.result.append(t)
            else:
                field, text = self.get_format(t, i)
                self.handle_format_group(field, text)
        else:
            t = self.format_next(i)
            if t == '}':
                self.get_single_stack()
                self.result.append(t)
            else:
                raise SyntaxError(f"Unmatched '}}' at {i.index - 2}!")

    def get_octal(self, c: str, i: _util.StringIter) -> str | None:
        """Get octal."""

        index = i.index
        value = []
        zero_count = 0
        try:
            if c == '0':
                for _ in range(3):
                    if c != '0':
                        break
                    value.append(c)
                    c = next(i)
            zero_count = len(value)
            if zero_count < 3:
                for _ in range(3 - zero_count):
                    if c not in _OCTAL:
                        break
                    value.append(c)
                    c = next(i)
            i.rewind(1)
        except StopIteration:
            pass

        octal_count = len(value)
        if not (self.use_format and octal_count) and not (zero_count and octal_count < 3) and octal_count != 3:
            i.rewind(i.index - index)
            value = []

        return ''.join(value) if value else None

    def parse_octal(self, text: str, i: _util.StringIter) -> None:
        """Parse octal value."""

        value = int(text, 8)
        if value > 0xFF and self.is_bytes:
            # Re fails on octal greater than `0o377` or `0xFF`
            raise ValueError("octal escape value outside of range 0-0o377!")
        else:
            single = self.get_single_stack()
            if self.span_stack:
                text = self.convert_case(chr(value), self.span_stack[-1])
                value = ord(self.convert_case(text, single)) if single is not None else ord(text)
            elif single:
                value = ord(self.convert_case(chr(value), single))
            if self.use_format and value in _CURLY_BRACKETS_ORD:
                self.handle_format(chr(value), i)
            elif value <= 0xFF:
                self.result.append(f'\\{value:03o}')
            else:
                self.result.append(chr(value))

    def get_named_unicode(self, i: _util.StringIter) -> str:
        """Get named Unicode."""

        index = i.index
        value = []
        try:
            if next(i) != '{':
                raise SyntaxError(f"Named Unicode missing '{{' at {i.index - 1}!")
            c = next(i)
            while c != '}':
                value.append(c)
                c = next(i)
        except StopIteration as e:
            raise SyntaxError(f"Unmatched '}}' at {index}!") from e

        return ''.join(value)

    def parse_named_unicode(self, i: _util.StringIter) -> None:
        """Parse named Unicode."""

        value = ord(_unicodedata.lookup(self.get_named_unicode(i)))
        single = self.get_single_stack()
        if self.span_stack:
            text = self.convert_case(chr(value), self.span_stack[-1])
            value = ord(self.convert_case(text, single)) if single is not None else ord(text)
        elif single:
            value = ord(self.convert_case(chr(value), single))
        if self.use_format and value in _CURLY_BRACKETS_ORD:
            self.handle_format(chr(value), i)
        elif value <= 0xFF:
            self.result.append(f'\\{value:03o}')
        else:
            self.result.append(chr(value))

    def get_wide_unicode(self, i: _util.StringIter) -> str:
        """Get narrow Unicode."""

        value = []
        for _ in range(3):
            c = next(i)
            if c == '0':
                value.append(c)
            else:  # pragma: no cover
                raise SyntaxError(f'Invalid wide Unicode character at {i.index - 1}!')

        c = next(i)
        if c in ('0', '1'):
            value.append(c)
        else:  # pragma: no cover
            raise SyntaxError(f'Invalid wide Unicode character at {i.index - 1}!')

        for _ in range(4):
            c = next(i)
            if c.lower() in _HEX:
                value.append(c)
            else:  # pragma: no cover
                raise SyntaxError(f'Invalid wide Unicode character at {i.index - 1}!')
        return ''.join(value)

    def get_narrow_unicode(self, i: _util.StringIter) -> str:
        """Get narrow Unicode."""

        value = []
        for _ in range(4):
            c = next(i)
            if c.lower() in _HEX:
                value.append(c)
            else:  # pragma: no cover
                raise SyntaxError(f'Invalid Unicode character at {i.index - 1}!')
        return ''.join(value)

    def parse_unicode(self, i: _util.StringIter, wide: bool = False) -> None:
        """Parse Unicode."""

        text = self.get_wide_unicode(i) if wide else self.get_narrow_unicode(i)
        value = int(text, 16)
        single = self.get_single_stack()
        if self.span_stack:
            text = self.convert_case(chr(value), self.span_stack[-1])
            value = ord(self.convert_case(text, single)) if single is not None else ord(text)
        elif single:
            value = ord(self.convert_case(chr(value), single))
        if self.use_format and value in _CURLY_BRACKETS_ORD:
            self.handle_format(chr(value), i)
        elif value <= 0xFF:
            self.result.append(f'\\{value:03o}')
        else:
            self.result.append(chr(value))

    def get_byte(self, i: _util.StringIter) -> str:
        """Get byte."""

        value = []
        for _x in range(2):
            c = next(i)
            if c.lower() in _HEX:
                value.append(c)
            else:  # pragma: no cover
                raise SyntaxError(f'Invalid byte character at {i.index - 1}!')
        return ''.join(value)

    def parse_bytes(self, i: _util.StringIter) -> None:
        """Parse byte."""

        value = int(self.get_byte(i), 16)
        single = self.get_single_stack()
        if self.span_stack:
            text = self.convert_case(chr(value), self.span_stack[-1])
            value = ord(self.convert_case(text, single)) if single is not None else ord(text)
        elif single:
            value = ord(self.convert_case(chr(value), single))
        if self.use_format and value in _CURLY_BRACKETS_ORD:
            self.handle_format(chr(value), i)
        else:
            self.result.append(f'\\{value:03o}')

    def get_named_group(self, t: str, i: _util.StringIter) -> str:
        """Get group number."""

        index = i.index
        value = [t]
        try:
            c = next(i)
            if c != "<":
                raise SyntaxError(f"Group missing '<' at {i.index - 1}!")
            value.append(c)
            c = next(i)
            if c in _DIGIT:
                value.append(c)
                c = next(i)
                while c != '>':
                    if c in _DIGIT:
                        value.append(c)
                    c = next(i)
                value.append(c)
            elif c in _LETTERS_UNDERSCORE:
                value.append(c)
                c = next(i)
                while c != '>':
                    if c in _WORD:
                        value.append(c)
                    c = next(i)
                value.append(c)
            else:
                raise SyntaxError(f"Invalid group character at {i.index - 1}!")
        except StopIteration as e:
            raise SyntaxError(f"Unmatched '<' at {index}!") from e

        return ''.join(value)

    def get_group(self, t: str, i: _util.StringIter) -> str | None:
        """Get group number."""

        value = []
        try:
            if t in _DIGIT and t != '0':
                value.append(t)
                t = next(i)
                if t in _DIGIT:
                    value.append(t)
                else:
                    i.rewind(1)
        except StopIteration:
            pass
        return ''.join(value) if value else None

    def format_next(self, i: _util.StringIter) -> str:
        """Get next format char."""

        c = next(i)
        return self.format_references(next(i), i) if c == '\\' else c

    def format_references(self, t: str, i: _util.StringIter) -> str:
        """Handle format references."""

        octal = self.get_octal(t, i)
        if octal:
            o = int(octal, 8)
            if o > 0xFF and self.is_bytes:
                # Re fails on octal greater than `0o377` or `0xFF`
                raise ValueError("octal escape value outside of range 0-0o377!")
            value = chr(o)
        elif t in _STANDARD_ESCAPES or t == '\\':
            value = _BACK_SLASH_TRANSLATION['\\' + t]
        elif not self.is_bytes and t == "U":
            value = chr(int(self.get_wide_unicode(i), 16))
        elif not self.is_bytes and t == "u":
            value = chr(int(self.get_narrow_unicode(i), 16))
        elif not self.is_bytes and t == "N":
            value = _unicodedata.lookup(self.get_named_unicode(i))
        elif t == "x":
            value = chr(int(self.get_byte(i), 16))
        else:
            i.rewind(1)
            value = '\\'
        return value

    def reference(self, t: str, i: _util.StringIter) -> None:
        """Handle references."""
        octal = self.get_octal(t, i)
        if t in _OCTAL and octal:
            self.parse_octal(octal, i)
        elif (t in _DIGIT or t == 'g') and not self.use_format:
            group = self.get_group(t, i)
            if not group:
                group = self.get_named_group(t, i)
            self.handle_group('\\' + group)
        elif t in _STANDARD_ESCAPES:
            self.get_single_stack()
            self.result.append('\\' + t)
        elif t == "l":
            self.single_case(i, _LOWER)
        elif t == "L":
            self.span_case(i, _LOWER)
        elif t == "c":
            self.single_case(i, _UPPER)
        elif t == "C":
            self.span_case(i, _UPPER)
        elif t == "E":
            self.end_found = True
        elif not self.is_bytes and t == "U":
            self.parse_unicode(i, True)
        elif not self.is_bytes and t == "u":
            self.parse_unicode(i)
        elif not self.is_bytes and t == "N":
            self.parse_named_unicode(i)
        elif t == "x":
            self.parse_bytes(i)
        elif self.use_format and t in _CURLY_BRACKETS:
            self.result.append('\\\\')
            self.handle_format(t, i)
        elif self.use_format and t == 'g':
            self.result.append('\\\\')
            self.result.append(t)
        else:
            value = '\\' + t
            self.get_single_stack()
            if self.span_stack:
                value = self.convert_case(value, self.span_stack[-1])
            self.result.append(value)

    def _parse_template(self, template: str) -> str:
        """Parse template."""

        self.result = [""]

        i = _util.StringIter(template)

        try:
            while True:
                t = next(i)
                if self.use_format and t in _CURLY_BRACKETS:
                    self.handle_format(t, i)
                elif t == '\\':
                    try:
                        t = next(i)
                        self.reference(t, i)
                    except StopIteration:
                        self.result.append(t)
                        raise
                else:
                    self.result.append(t)
        except StopIteration:
            pass

        if len(self.result) > 1:
            self.literal_slots.append("".join(self.result))
            del self.result[:]
            self.result.append("")
            self.slot += 1

        return "".join(self.literal_slots)

    def parse_template(self) -> None:
        """Parse template."""

        if isinstance(self._original, bytes):
            self._template = self._parse_template(self._original.decode('latin-1')).encode('latin-1')
        else:
            self._template = self._parse_template(self._original)

        if _util.PY312:
            count = 0
            for part in _parser.parse_template(self._template, self.pattern):
                if isinstance(part, int):
                    self.groups.append((count, part))
                    self.literals.append(None)
                elif part:
                    self.literals.append(cast(AnyStr, part))
                else:
                    continue
                count += 1
        else:
            self.groups, self.literals = _parser.parse_template(self._template, self.pattern)

    def span_case(self, i: _util.StringIter, case: int) -> None:
        """Uppercase or lowercase the next range of characters until end marker is found."""

        # A new \L, \C or \E should pop the last in the stack.
        if self.span_stack:
            self.span_stack.pop()
        if self.single_stack:
            self.single_stack.pop()
        self.span_stack.append(case)
        count = len(self.span_stack)
        self.end_found = False
        try:
            while not self.end_found:
                t = next(i)
                if self.use_format and t in _CURLY_BRACKETS:
                    self.handle_format(t, i)
                elif t == '\\':
                    try:
                        t = next(i)
                        self.reference(t, i)
                    except StopIteration:
                        self.result.append(t)
                        raise
                else:
                    self.result.append(self.convert_case(t, case))
                if self.end_found or count > len(self.span_stack):
                    self.end_found = False
                    break
        except StopIteration:
            pass
        if count == len(self.span_stack):
            self.span_stack.pop()

    def convert_case(self, value: str, case: int) -> str:
        """Convert case."""

        if self.is_bytes:
            cased = []
            for c in value:
                if c in _ASCII_LETTERS:
                    cased.append(c.lower() if case == _LOWER else c.upper())
                else:
                    cased.append(c)
            return "".join(cased)
        else:
            return value.lower() if case == _LOWER else value.upper()

    def single_case(self, i: _util.StringIter, case: int) -> None:
        """Uppercase or lowercase the next character."""

        # Pop a previous case if we have consecutive ones.
        if self.single_stack:
            self.single_stack.pop()
        self.single_stack.append(case)
        try:
            t = next(i)
            if self.use_format and t in _CURLY_BRACKETS:
                self.handle_format(t, i)
            elif t == '\\':
                try:
                    t = next(i)
                    self.reference(t, i)
                except StopIteration:
                    self.result.append(t)
                    raise
            elif self.single_stack:
                this_case = self.get_single_stack()
                if this_case is not None:
                    self.result.append(self.convert_case(t, this_case))
        except StopIteration:
            pass

    def get_single_stack(self) -> int | None:
        """Get the correct single stack item to use."""

        single = None
        while self.single_stack:
            single = self.single_stack.pop()
        return single

    def handle_format_group(self, field: str, text: list[tuple[int, Any]]) -> None:
        """Handle format group."""

        # Handle auto incrementing group indexes
        if field == '':
            if self.auto:
                field = str(self.auto_index)
                text[0] = (_util.FMT_FIELD, field)
                self.auto_index += 1
            elif not self.manual and not self.auto:
                self.auto = True
                field = str(self.auto_index)
                text[0] = (_util.FMT_FIELD, field)
                self.auto_index += 1
            else:
                raise ValueError("Cannot switch to auto format during manual format!")
        elif not self.manual and not self.auto:
            self.manual = True
        elif not self.manual:
            raise ValueError("Cannot switch to manual format during auto format!")

        self.handle_group(field, tuple(text), True)

    def handle_group(
        self,
        text: str,
        capture: tuple[tuple[int, Any], ...] | None = None,
        is_format: bool = False
    ) -> None:
        """Handle groups."""

        if len(self.result) > 1:
            self.literal_slots.append("".join(self.result))
            if is_format:
                self.literal_slots.extend(["\\g<", text, ">"])
            else:
                self.literal_slots.append(text)
            del self.result[:]
            self.result.append("")
            self.slot += 1
        elif is_format:
            self.literal_slots.extend(["\\g<", text, ">"])
        else:
            self.literal_slots.append(text)

        self.group_slots.append(
            (
                self.slot,
                (
                    (self.span_stack[-1] if self.span_stack else None),
                    self.get_single_stack(),
                    (() if self.is_bytes else '') if capture is None else capture
                )
            )
        )
        self.slot += 1

    def get_base_template(self) -> AnyStr:
        """Return the unmodified template before expansion."""

        return self._original

    def parse(self) -> ReplaceTemplate[AnyStr]:
        """Parse template."""

        if not isinstance(self.pattern.pattern, type(self._original)):
            raise TypeError('Pattern string type must match replace template string type!')

        self.parse_template()

        return ReplaceTemplate(
            tuple(self.groups),
            tuple(self.group_slots),
            tuple(self.literals),
            hash(self.pattern),
            self.use_format,
            self.is_bytes
        )


class ReplaceTemplate(_util.Immutable, Generic[AnyStr]):
    """Replacement template expander."""

    __slots__ = ("groups", "group_slots", "literals", "pattern_hash", "use_format", "_hash", "_bytes")

    groups: tuple[tuple[int, int], ...]
    group_slots: tuple[tuple[int, tuple[int | None, int | None, Any]], ...]
    literals: tuple[AnyStr | None, ...]
    pattern_hash: int
    use_format: bool
    _hash: int
    _bytes: bool

    def __init__(
        self,
        groups: tuple[tuple[int, int], ...],
        group_slots: tuple[tuple[int, tuple[int | None, int | None, Any]], ...],
        literals: tuple[AnyStr | None, ...],
        pattern_hash: int,
        use_format: bool,
        is_bytes: bool
    ) -> None:
        """Initialize."""

        super().__init__(
            use_format=use_format,
            groups=groups,
            group_slots=group_slots,
            literals=literals,
            pattern_hash=pattern_hash,
            _bytes=is_bytes,
            _hash=hash(
                (
                    type(self),
                    groups, group_slots, literals,
                    pattern_hash, use_format, is_bytes
                )
            )
        )

    def __call__(self, m: Match[AnyStr] | None) -> AnyStr:
        """Call."""

        return self.expand(m)

    def __hash__(self) -> int:
        """Hash."""

        return self._hash

    def __eq__(self, other: Any) -> bool:
        """Equal."""

        return (
            isinstance(other, ReplaceTemplate) and
            self.groups == other.groups and
            self.group_slots == other.group_slots and
            self.literals == other.literals and
            self.pattern_hash == other.pattern_hash and
            self.use_format == other.use_format and
            self._bytes == other._bytes
        )

    def __ne__(self, other: Any) -> bool:
        """Equal."""

        return (
            not isinstance(other, ReplaceTemplate) or
            self.groups != other.groups or
            self.group_slots != other.group_slots or
            self.literals != other.literals or
            self.pattern_hash != other.pattern_hash or
            self.use_format != other.use_format or
            self._bytes != self._bytes
        )

    def __repr__(self) -> str:  # pragma: no cover
        """Representation."""

        return "{}.{}({!r}, {!r}, {!r}, {!r}, {!r})".format(
            self.__module__, self.__class__.__name__,
            self.groups, self.group_slots, self.literals,
            self.pattern_hash, self.use_format
        )

    def _get_group_index(self, index: int) -> int:
        """Find and return the appropriate group index."""

        g_index = 0
        for group in self.groups:
            if group[0] == index:
                g_index = group[1]
                break
        return g_index

    def _get_group_attributes(self, index: int) -> tuple[int | None, int | None, Any]:
        """Find and return the appropriate group case."""

        g_case = (None, None, -1)  # type: tuple[int | None, int | None, Any]
        for group in self.group_slots:
            if group[0] == index:
                g_case = group[1]
                break
        return g_case

    def expand(self, m: Match[AnyStr] | None) -> AnyStr:
        """Using the template, expand the string."""

        if m is None:
            raise ValueError("Match is None!")

        sep = m.string[:0]
        if not isinstance(sep, bytes if self._bytes else str):
            raise TypeError('Match string type does not match expander string type!')
        text = []
        # Expand string
        for x in range(0, len(self.literals)):
            index = x
            l = self.literals[x]
            if l is None:
                g_index = self._get_group_index(index)
                span_case, single_case, capture = self._get_group_attributes(index)
                if not self.use_format:
                    # Non format replace
                    try:
                        l = m.group(g_index)
                        if l is None:
                            l = sep
                    except IndexError as e:  # pragma: no cover
                        raise IndexError(f"'{g_index}' is out of range!") from e
                else:
                    # String format replace
                    try:
                        obj = m.group(g_index)
                    except IndexError as e:  # pragma: no cover
                        raise IndexError(f"'{g_index}' is out of range!") from e
                    l = _util.format_captures(
                        [] if obj is None else [obj],
                        capture,
                        _util._to_bstr if isinstance(sep, bytes) else _util._to_str,
                        sep
                    )
                if span_case is not None:
                    if span_case == _LOWER:
                        l = l.lower()
                    else:
                        l = l.upper()
                if single_case is not None:
                    if single_case == _LOWER:
                        l = l[0:1].lower() + l[1:]
                    else:
                        l = l[0:1].upper() + l[1:]
            text.append(l)

        return sep.join(text)


def _pickle(r):  # type: ignore[no-untyped-def]
    """Pickle."""

    return ReplaceTemplate, (r.groups, r.group_slots, r.literals, r.pattern_hash, r.use_format, r._bytes)


_copyreg.pickle(ReplaceTemplate, _pickle)