from __future__ import unicode_literals

import re
import string

from datetime import date
from datetime import datetime
from datetime import time
from enum import Enum
from typing import Any
from typing import Dict
from typing import Generator
from typing import List
from typing import Optional
from typing import Union


from ._compat import PY2
from ._compat import decode
from ._compat import long
from ._compat import unicode
from ._utils import escape_string

if PY2:
    from functools32 import lru_cache
else:
    from functools import lru_cache


def item(value, _parent=None):
    from .container import Container

    if isinstance(value, Item):
        return value

    if isinstance(value, bool):
        return Bool(value, Trivia())
    elif isinstance(value, int):
        return Integer(value, Trivia(), str(value))
    elif isinstance(value, float):
        return Float(value, Trivia(), str(value))
    elif isinstance(value, dict):
        val = Table(Container(), Trivia(), False)
        for k, v in sorted(value.items(), key=lambda i: (isinstance(i[1], dict), i[0])):
            val[k] = item(v, _parent=val)

        return val
    elif isinstance(value, list):
        if value and isinstance(value[0], dict):
            a = AoT([])
        else:
            a = Array([], Trivia())

        for v in value:
            if isinstance(v, dict):
                table = Table(Container(), Trivia(), True)

                for k, _v in sorted(
                    v.items(), key=lambda i: (isinstance(i[1], dict), i[0])
                ):
                    i = item(_v)
                    if isinstance(table, InlineTable):
                        i.trivia.trail = ""

                    table[k] = item(i)

                v = table

            a.append(v)

        return a
    elif isinstance(value, (str, unicode)):
        escaped = escape_string(value)

        return String(StringType.SLB, value, escaped, Trivia())
    elif isinstance(value, datetime):
        return DateTime(value, Trivia(), value.isoformat().replace("+00:00", "Z"))
    elif isinstance(value, date):
        return Date(value, Trivia(), value.isoformat())
    elif isinstance(value, time):
        return Time(value, Trivia(), value.isoformat())

    raise ValueError("Invalid type {}".format(type(value)))


class StringType(Enum):
    # Single Line Basic
    SLB = '"'
    # Multi Line Basic
    MLB = '"""'
    # Single Line Literal
    SLL = "'"
    # Multi Line Literal
    MLL = "'''"

    @property
    @lru_cache(maxsize=None)
    def unit(self):  # type: () -> str
        return self.value[0]

    @lru_cache(maxsize=None)
    def is_basic(self):  # type: () -> bool
        return self in {StringType.SLB, StringType.MLB}

    @lru_cache(maxsize=None)
    def is_literal(self):  # type: () -> bool
        return self in {StringType.SLL, StringType.MLL}

    @lru_cache(maxsize=None)
    def is_singleline(self):  # type: () -> bool
        return self in {StringType.SLB, StringType.SLL}

    @lru_cache(maxsize=None)
    def is_multiline(self):  # type: () -> bool
        return self in {StringType.MLB, StringType.MLL}

    @lru_cache(maxsize=None)
    def toggle(self):  # type: () -> StringType
        return {
            StringType.SLB: StringType.MLB,
            StringType.MLB: StringType.SLB,
            StringType.SLL: StringType.MLL,
            StringType.MLL: StringType.SLL,
        }[self]


class BoolType(Enum):
    TRUE = "true"
    FALSE = "false"

    @lru_cache(maxsize=None)
    def __bool__(self):
        return {BoolType.TRUE: True, BoolType.FALSE: False}[self]

    if PY2:
        __nonzero__ = __bool__  # for PY2

    def __iter__(self):
        return iter(self.value)

    def __len__(self):
        return len(self.value)


class Trivia:
    """
    Trivia information (aka metadata).
    """

    def __init__(
        self, indent=None, comment_ws=None, comment=None, trail=None
    ):  # type: (str, str, str, str) -> None
        # Whitespace before a value.
        self.indent = indent or ""
        # Whitespace after a value, but before a comment.
        self.comment_ws = comment_ws or ""
        # Comment, starting with # character, or empty string if no comment.
        self.comment = comment or ""
        # Trailing newline.
        if trail is None:
            trail = "\n"

        self.trail = trail


class KeyType(Enum):
    """
    The type of a Key.

    Keys can be bare (unquoted), or quoted using basic ("), or literal (')
    quotes following the same escaping rules as single-line StringType.
    """

    Bare = ""
    Basic = '"'
    Literal = "'"


class Key:
    """
    A key value.
    """

    def __init__(self, k, t=None, sep=None, dotted=False):  # type: (str) -> None
        if t is None:
            if any(
                [c not in string.ascii_letters + string.digits + "-" + "_" for c in k]
            ):
                t = KeyType.Basic
            else:
                t = KeyType.Bare

        self.t = t
        if sep is None:
            sep = " = "

        self.sep = sep
        self.key = k
        self._dotted = dotted

    @property
    def delimiter(self):  # type: () -> str
        return self.t.value

    def is_dotted(self):  # type: () -> bool
        return self._dotted

    def as_string(self):  # type: () -> str
        return "{}{}{}".format(self.delimiter, self.key, self.delimiter)

    def __hash__(self):  # type: () -> int
        return hash(self.key)

    def __eq__(self, other):  # type: (Key) -> bool
        if isinstance(other, Key):
            return self.key == other.key

        return self.key == other

    def __str__(self):  # type: () -> str
        return self.as_string()

    def __repr__(self):  # type: () -> str
        return "<Key {}>".format(self.as_string())


class Item(object):
    """
    An item within a TOML document.
    """

    def __init__(self, trivia):  # type: (Trivia) -> None
        self._trivia = trivia

    @property
    def trivia(self):  # type: () -> Trivia
        return self._trivia

    @property
    def discriminant(self):  # type: () -> int
        raise NotImplementedError()

    def as_string(self):  # type: () -> str
        raise NotImplementedError()

    # Helpers

    def comment(self, comment):  # type: (str) -> Item
        if not comment.strip().startswith("#"):
            comment = "# " + comment

        self._trivia.comment_ws = " "
        self._trivia.comment = comment

        return self

    def indent(self, indent):  # type: (int) -> Item
        if self._trivia.indent.startswith("\n"):
            self._trivia.indent = "\n" + " " * indent
        else:
            self._trivia.indent = " " * indent

        return self

    def _getstate(self, protocol=3):
        return (self._trivia,)

    def __reduce__(self):
        return self.__reduce_ex__(2)

    def __reduce_ex__(self, protocol):
        return self.__class__, self._getstate(protocol)


class Whitespace(Item):
    """
    A whitespace literal.
    """

    def __init__(self, s, fixed=False):  # type: (str, bool) -> None
        self._s = s
        self._fixed = fixed

    @property
    def s(self):  # type: () -> str
        return self._s

    @property
    def value(self):  # type: () -> str
        return self._s

    @property
    def trivia(self):  # type: () -> Trivia
        raise RuntimeError("Called trivia on a Whitespace variant.")

    @property
    def discriminant(self):  # type: () -> int
        return 0

    def is_fixed(self):  # type: () -> bool
        return self._fixed

    def as_string(self):  # type: () -> str
        return self._s

    def __repr__(self):  # type: () -> str
        return "<{} {}>".format(self.__class__.__name__, repr(self._s))

    def _getstate(self, protocol=3):
        return self._s, self._fixed


class Comment(Item):
    """
    A comment literal.
    """

    @property
    def discriminant(self):  # type: () -> int
        return 1

    def as_string(self):  # type: () -> str
        return "{}{}{}".format(
            self._trivia.indent, decode(self._trivia.comment), self._trivia.trail
        )

    def __str__(self):  # type: () -> str
        return "{}{}".format(self._trivia.indent, decode(self._trivia.comment))


class Integer(long, Item):
    """
    An integer literal.
    """

    def __new__(cls, value, trivia, raw):  # type: (int, Trivia, str) -> Integer
        return super(Integer, cls).__new__(cls, value)

    def __init__(self, _, trivia, raw):  # type: (int, Trivia, str) -> None
        super(Integer, self).__init__(trivia)

        self._raw = raw
        self._sign = False

        if re.match(r"^[+\-]\d+$", raw):
            self._sign = True

    @property
    def discriminant(self):  # type: () -> int
        return 2

    @property
    def value(self):  # type: () -> int
        return self

    def as_string(self):  # type: () -> str
        return self._raw

    def __add__(self, other):
        result = super(Integer, self).__add__(other)

        return self._new(result)

    def __radd__(self, other):
        result = super(Integer, self).__radd__(other)

        if isinstance(other, Integer):
            return self._new(result)

        return result

    def __sub__(self, other):
        result = super(Integer, self).__sub__(other)

        return self._new(result)

    def __rsub__(self, other):
        result = super(Integer, self).__rsub__(other)

        if isinstance(other, Integer):
            return self._new(result)

        return result

    def _new(self, result):
        raw = str(result)

        if self._sign:
            sign = "+" if result >= 0 else "-"
            raw = sign + raw

        return Integer(result, self._trivia, raw)

    def _getstate(self, protocol=3):
        return int(self), self._trivia, self._raw


class Float(float, Item):
    """
    A float literal.
    """

    def __new__(cls, value, trivia, raw):  # type: (float, Trivia, str) -> Integer
        return super(Float, cls).__new__(cls, value)

    def __init__(self, _, trivia, raw):  # type: (float, Trivia, str) -> None
        super(Float, self).__init__(trivia)

        self._raw = raw
        self._sign = False

        if re.match(r"^[+\-].+$", raw):
            self._sign = True

    @property
    def discriminant(self):  # type: () -> int
        return 3

    @property
    def value(self):  # type: () -> float
        return self

    def as_string(self):  # type: () -> str
        return self._raw

    def __add__(self, other):
        result = super(Float, self).__add__(other)

        return self._new(result)

    def __radd__(self, other):
        result = super(Float, self).__radd__(other)

        if isinstance(other, Float):
            return self._new(result)

        return result

    def __sub__(self, other):
        result = super(Float, self).__sub__(other)

        return self._new(result)

    def __rsub__(self, other):
        result = super(Float, self).__rsub__(other)

        if isinstance(other, Float):
            return self._new(result)

        return result

    def _new(self, result):
        raw = str(result)

        if self._sign:
            sign = "+" if result >= 0 else "-"
            raw = sign + raw

        return Float(result, self._trivia, raw)

    def _getstate(self, protocol=3):
        return float(self), self._trivia, self._raw


class Bool(Item):
    """
    A boolean literal.
    """

    def __init__(self, t, trivia):  # type: (float, Trivia) -> None
        super(Bool, self).__init__(trivia)

        self._value = bool(t)

    @property
    def discriminant(self):  # type: () -> int
        return 4

    @property
    def value(self):  # type: () -> bool
        return self._value

    def as_string(self):  # type: () -> str
        return str(self._value).lower()

    def _getstate(self, protocol=3):
        return self._value, self._trivia


class DateTime(Item, datetime):
    """
    A datetime literal.
    """

    def __new__(cls, value, *_):  # type: (..., datetime, ...) -> datetime
        return datetime.__new__(
            cls,
            value.year,
            value.month,
            value.day,
            value.hour,
            value.minute,
            value.second,
            value.microsecond,
            tzinfo=value.tzinfo,
        )

    def __init__(self, _, trivia, raw):  # type: (datetime, Trivia, str) -> None
        super(DateTime, self).__init__(trivia)

        self._raw = raw

    @property
    def discriminant(self):  # type: () -> int
        return 5

    @property
    def value(self):  # type: () -> datetime
        return self

    def as_string(self):  # type: () -> str
        return self._raw

    def __add__(self, other):
        result = super(DateTime, self).__add__(other)

        return self._new(result)

    def __sub__(self, other):
        result = super(DateTime, self).__sub__(other)

        if isinstance(result, datetime):
            result = self._new(result)

        return result

    def _new(self, result):
        raw = result.isoformat()

        return DateTime(result, self._trivia, raw)

    def _getstate(self, protocol=3):
        return (
            datetime(
                self.year,
                self.month,
                self.day,
                self.hour,
                self.minute,
                self.second,
                self.microsecond,
                self.tzinfo,
            ),
            self._trivia,
            self._raw,
        )


class Date(Item, date):
    """
    A date literal.
    """

    def __new__(cls, value, *_):  # type: (..., date, ...) -> date
        return date.__new__(cls, value.year, value.month, value.day)

    def __init__(self, _, trivia, raw):  # type: (date, Trivia, str) -> None
        super(Date, self).__init__(trivia)

        self._raw = raw

    @property
    def discriminant(self):  # type: () -> int
        return 6

    @property
    def value(self):  # type: () -> date
        return self

    def as_string(self):  # type: () -> str
        return self._raw

    def __add__(self, other):
        result = super(Date, self).__add__(other)

        return self._new(result)

    def __sub__(self, other):
        result = super(Date, self).__sub__(other)

        return self._new(result)

    def _new(self, result):
        raw = result.isoformat()

        return Date(result, self._trivia, raw)

    def _getstate(self, protocol=3):
        return (datetime(self.year, self.month, self.day), self._trivia, self._raw)


class Time(Item, time):
    """
    A time literal.
    """

    def __new__(cls, value, *_):  # type: (time, ...) -> time
        return time.__new__(
            cls, value.hour, value.minute, value.second, value.microsecond
        )

    def __init__(self, _, trivia, raw):  # type: (time, Trivia, str) -> None
        super(Time, self).__init__(trivia)

        self._raw = raw

    @property
    def discriminant(self):  # type: () -> int
        return 7

    @property
    def value(self):  # type: () -> time
        return self

    def as_string(self):  # type: () -> str
        return self._raw

    def _getstate(self, protocol=3):
        return (
            time(self.hour, self.minute, self.second, self.microsecond, self.tzinfo),
            self._trivia,
            self._raw,
        )


class Array(Item, list):
    """
    An array literal
    """

    def __init__(self, value, trivia):  # type: (list, Trivia) -> None
        super(Array, self).__init__(trivia)

        list.__init__(
            self, [v.value for v in value if not isinstance(v, (Whitespace, Comment))]
        )

        self._value = value

    @property
    def discriminant(self):  # type: () -> int
        return 8

    @property
    def value(self):  # type: () -> list
        return self

    def is_homogeneous(self):  # type: () -> bool
        if not self:
            return True

        discriminants = [
            i.discriminant
            for i in self._value
            if not isinstance(i, (Whitespace, Comment))
        ]

        return len(set(discriminants)) == 1

    def as_string(self):  # type: () -> str
        return "[{}]".format("".join(v.as_string() for v in self._value))

    def append(self, _item):  # type: () -> None
        if self._value:
            self._value.append(Whitespace(", "))

        it = item(_item)
        super(Array, self).append(it.value)

        self._value.append(it)

        if not self.is_homogeneous():
            raise ValueError("Array has mixed types elements")

    if not PY2:

        def clear(self):
            super(Array, self).clear()

            self._value.clear()

    def __iadd__(self, other):  # type: (list) -> Array
        if not isinstance(other, list):
            return NotImplemented

        for v in other:
            self.append(v)

        return self

    def __delitem__(self, key):
        super(Array, self).__delitem__(key)

        j = 0 if key >= 0 else -1
        for i, v in enumerate(self._value if key >= 0 else reversed(self._value)):
            if key < 0:
                i = -i - 1

            if isinstance(v, (Comment, Whitespace)):
                continue

            if j == key:
                del self._value[i]

                if i < 0 and abs(i) > len(self._value):
                    i += 1

                if i < len(self._value) - 1 and isinstance(self._value[i], Whitespace):
                    del self._value[i]

                break

            j += 1 if key >= 0 else -1

    def __str__(self):
        return str(
            [v.value for v in self._value if not isinstance(v, (Whitespace, Comment))]
        )

    def __repr__(self):
        return str(self)

    def _getstate(self, protocol=3):
        return self._value, self._trivia


class Table(Item, dict):
    """
    A table literal.
    """

    def __init__(
        self,
        value,
        trivia,
        is_aot_element,
        is_super_table=False,
        name=None,
        display_name=None,
    ):  # type: (tomlkit.container.Container, Trivia, bool, ...) -> None
        super(Table, self).__init__(trivia)

        self.name = name
        self.display_name = display_name
        self._value = value
        self._is_aot_element = is_aot_element
        self._is_super_table = is_super_table

        for k, v in self._value.body:
            if k is not None:
                super(Table, self).__setitem__(k.key, v)

    @property
    def value(self):  # type: () -> tomlkit.container.Container
        return self._value

    @property
    def discriminant(self):  # type: () -> int
        return 9

    def add(self, key, item=None):  # type: (Union[Key, Item, str], Any) -> Item
        if item is None:
            if not isinstance(key, (Comment, Whitespace)):
                raise ValueError(
                    "Non comment/whitespace items must have an associated key"
                )

            key, item = None, key

        return self.append(key, item)

    def append(self, key, _item):  # type: (Union[Key, str], Any) -> Table
        """
        Appends a (key, item) to the table.
        """
        if not isinstance(_item, Item):
            _item = item(_item)

        self._value.append(key, _item)

        if isinstance(key, Key):
            key = key.key

        if key is not None:
            super(Table, self).__setitem__(key, _item)

        m = re.match("(?s)^[^ ]*([ ]+).*$", self._trivia.indent)
        if not m:
            return self

        indent = m.group(1)

        if not isinstance(_item, Whitespace):
            m = re.match("(?s)^([^ ]*)(.*)$", _item.trivia.indent)
            if not m:
                _item.trivia.indent = indent
            else:
                _item.trivia.indent = m.group(1) + indent + m.group(2)

        return self

    def remove(self, key):  # type: (Union[Key, str]) -> Table
        self._value.remove(key)

        if isinstance(key, Key):
            key = key.key

        if key is not None:
            super(Table, self).__delitem__(key)

        return self

    def is_aot_element(self):  # type: () -> bool
        return self._is_aot_element

    def is_super_table(self):  # type: () -> bool
        return self._is_super_table

    def as_string(self, prefix=None):  # type: () -> str
        return self._value.as_string(prefix=prefix)

    # Helpers

    def indent(self, indent):  # type: (int) -> Table
        super(Table, self).indent(indent)

        m = re.match("(?s)^[^ ]*([ ]+).*$", self._trivia.indent)
        if not m:
            indent = ""
        else:
            indent = m.group(1)

        for k, item in self._value.body:
            if not isinstance(item, Whitespace):
                item.trivia.indent = indent + item.trivia.indent

        return self

    def keys(self):  # type: () -> Generator[str]
        for k in self._value.keys():
            yield k

    def values(self):  # type: () -> Generator[Item]
        for v in self._value.values():
            yield v

    def items(self):  # type: () -> Generator[Item]
        for k, v in self._value.items():
            yield k, v

    def update(self, other):  # type: (Dict) -> None
        for k, v in other.items():
            self[k] = v

    def __contains__(self, key):  # type: (Union[Key, str]) -> bool
        return key in self._value

    def __getitem__(self, key):  # type: (Union[Key, str]) -> Item
        return self._value[key]

    def __setitem__(self, key, value):  # type: (Union[Key, str], Any) -> None
        if not isinstance(value, Item):
            value = item(value)

        self._value[key] = value

        if key is not None:
            super(Table, self).__setitem__(key, value)

        m = re.match("(?s)^[^ ]*([ ]+).*$", self._trivia.indent)
        if not m:
            return

        indent = m.group(1)

        if not isinstance(value, Whitespace):
            m = re.match("(?s)^([^ ]*)(.*)$", value.trivia.indent)
            if not m:
                value.trivia.indent = indent
            else:
                value.trivia.indent = m.group(1) + indent + m.group(2)

    def __delitem__(self, key):  # type: (Union[Key, str]) -> None
        self.remove(key)

    def __repr__(self):
        return super(Table, self).__repr__()

    def _getstate(self, protocol=3):
        return (
            self._value,
            self._trivia,
            self._is_aot_element,
            self._is_super_table,
            self.name,
            self.display_name,
        )


class InlineTable(Item, dict):
    """
    An inline table literal.
    """

    def __init__(
        self, value, trivia
    ):  # type: (tomlkit.container.Container, Trivia) -> None
        super(InlineTable, self).__init__(trivia)

        self._value = value

        for k, v in self._value.body:
            if k is not None:
                super(InlineTable, self).__setitem__(k.key, v)

    @property
    def discriminant(self):  # type: () -> int
        return 10

    @property
    def value(self):  # type: () -> Dict
        return self._value

    def append(self, key, _item):  # type: (Union[Key, str], Any) -> InlineTable
        """
        Appends a (key, item) to the table.
        """
        if not isinstance(_item, Item):
            _item = item(_item)

        if not isinstance(_item, (Whitespace, Comment)):
            if not _item.trivia.indent and len(self._value) > 0:
                _item.trivia.indent = " "
            if _item.trivia.comment:
                _item.trivia.comment = ""

        self._value.append(key, _item)

        if isinstance(key, Key):
            key = key.key

        if key is not None:
            super(InlineTable, self).__setitem__(key, _item)

        return self

    def remove(self, key):  # type: (Union[Key, str]) -> InlineTable
        self._value.remove(key)

        if isinstance(key, Key):
            key = key.key

        if key is not None:
            super(InlineTable, self).__delitem__(key)

        return self

    def as_string(self):  # type: () -> str
        buf = "{"
        for i, (k, v) in enumerate(self._value.body):
            if k is None:
                if i == len(self._value.body) - 1:
                    buf = buf.rstrip(",")

                buf += v.as_string()

                continue

            buf += "{}{}{}{}{}{}".format(
                v.trivia.indent,
                k.as_string(),
                k.sep,
                v.as_string(),
                v.trivia.comment,
                v.trivia.trail.replace("\n", ""),
            )

            if i != len(self._value.body) - 1:
                buf += ","

        buf += "}"

        return buf

    def keys(self):  # type: () -> Generator[str]
        for k in self._value.keys():
            yield k

    def values(self):  # type: () -> Generator[Item]
        for v in self._value.values():
            yield v

    def items(self):  # type: () -> Generator[Item]
        for k, v in self._value.items():
            yield k, v

    def update(self, other):  # type: (Dict) -> None
        for k, v in other.items():
            self[k] = v

    def __contains__(self, key):  # type: (Union[Key, str]) -> bool
        return key in self._value

    def __getitem__(self, key):  # type: (Union[Key, str]) -> Item
        return self._value[key]

    def __setitem__(self, key, value):  # type: (Union[Key, str], Any) -> None
        if not isinstance(value, Item):
            value = item(value)

        self._value[key] = value

        if key is not None:
            super(InlineTable, self).__setitem__(key, value)
        if value.trivia.comment:
            value.trivia.comment = ""

        m = re.match("(?s)^[^ ]*([ ]+).*$", self._trivia.indent)
        if not m:
            return

        indent = m.group(1)

        if not isinstance(value, Whitespace):
            m = re.match("(?s)^([^ ]*)(.*)$", value.trivia.indent)
            if not m:
                value.trivia.indent = indent
            else:
                value.trivia.indent = m.group(1) + indent + m.group(2)

    def __delitem__(self, key):  # type: (Union[Key, str]) -> None
        self.remove(key)

    def __repr__(self):
        return super(InlineTable, self).__repr__()

    def _getstate(self, protocol=3):
        return (self._value, self._trivia)


class String(unicode, Item):
    """
    A string literal.
    """

    def __new__(cls, t, value, original, trivia):
        return super(String, cls).__new__(cls, value)

    def __init__(
        self, t, _, original, trivia
    ):  # type: (StringType, str, original, Trivia) -> None
        super(String, self).__init__(trivia)

        self._t = t
        self._original = original

    @property
    def discriminant(self):  # type: () -> int
        return 11

    @property
    def value(self):  # type: () -> str
        return self

    def as_string(self):  # type: () -> str
        return "{}{}{}".format(self._t.value, decode(self._original), self._t.value)

    def __add__(self, other):
        result = super(String, self).__add__(other)

        return self._new(result)

    def __sub__(self, other):
        result = super(String, self).__sub__(other)

        return self._new(result)

    def _new(self, result):
        return String(self._t, result, result, self._trivia)

    def _getstate(self, protocol=3):
        return self._t, unicode(self), self._original, self._trivia


class AoT(Item, list):
    """
    An array of table literal
    """

    def __init__(
        self, body, name=None, parsed=False
    ):  # type: (List[Table], Optional[str]) -> None
        self.name = name
        self._body = []
        self._parsed = parsed

        super(AoT, self).__init__(Trivia(trail=""))

        for table in body:
            self.append(table)

    @property
    def body(self):  # type: () -> List[Table]
        return self._body

    @property
    def discriminant(self):  # type: () -> int
        return 12

    @property
    def value(self):  # type: () -> List[Dict[Any, Any]]
        return [v.value for v in self._body]

    def append(self, table):  # type: (Table) -> Table
        m = re.match("(?s)^[^ ]*([ ]+).*$", self._trivia.indent)
        if m:
            indent = m.group(1)

            m = re.match("(?s)^([^ ]*)(.*)$", table.trivia.indent)
            if not m:
                table.trivia.indent = indent
            else:
                table.trivia.indent = m.group(1) + indent + m.group(2)

        if not self._parsed and "\n" not in table.trivia.indent and self._body:
            table.trivia.indent = "\n" + table.trivia.indent

        self._body.append(table)

        super(AoT, self).append(table)

        return table

    def as_string(self):  # type: () -> str
        b = ""
        for table in self._body:
            b += table.as_string(prefix=self.name)

        return b

    def __repr__(self):  # type: () -> str
        return "<AoT {}>".format(self.value)

    def _getstate(self, protocol=3):
        return self._body, self.name, self._parsed


class Null(Item):
    """
    A null item.
    """

    def __init__(self):  # type: () -> None
        pass

    @property
    def discriminant(self):  # type: () -> int
        return -1

    @property
    def value(self):  # type: () -> None
        return None

    def as_string(self):  # type: () -> str
        return ""

    def _getstate(self, protocol=3):
        return tuple()
