from __future__ import annotations

import copy

from typing import Any
from typing import Iterator

from tomlkit._compat import decode
from tomlkit._types import _CustomDict
from tomlkit._utils import merge_dicts
from tomlkit.exceptions import KeyAlreadyPresent
from tomlkit.exceptions import NonExistentKey
from tomlkit.exceptions import TOMLKitError
from tomlkit.items import AoT
from tomlkit.items import Comment
from tomlkit.items import Item
from tomlkit.items import Key
from tomlkit.items import Null
from tomlkit.items import SingleKey
from tomlkit.items import Table
from tomlkit.items import Trivia
from tomlkit.items import Whitespace
from tomlkit.items import item as _item


_NOT_SET = object()


class Container(_CustomDict):
    """
    A container for items within a TOMLDocument.

    This class implements the `dict` interface with copy/deepcopy protocol.
    """

    def __init__(self, parsed: bool = False) -> None:
        self._map: dict[SingleKey, int | tuple[int, ...]] = {}
        self._body: list[tuple[Key | None, Item]] = []
        self._parsed = parsed
        self._table_keys = []

    @property
    def body(self) -> list[tuple[Key | None, Item]]:
        return self._body

    def unwrap(self) -> dict[str, Any]:
        unwrapped = {}
        for k, v in self.items():
            if k is None:
                continue

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

            if hasattr(v, "unwrap"):
                v = v.unwrap()

            if k in unwrapped:
                merge_dicts(unwrapped[k], v)
            else:
                unwrapped[k] = v

        return unwrapped

    @property
    def value(self) -> dict[str, Any]:
        d = {}
        for k, v in self._body:
            if k is None:
                continue

            k = k.key
            v = v.value

            if isinstance(v, Container):
                v = v.value

            if k in d:
                merge_dicts(d[k], v)
            else:
                d[k] = v

        return d

    def parsing(self, parsing: bool) -> None:
        self._parsed = parsing

        for _, v in self._body:
            if isinstance(v, Table):
                v.value.parsing(parsing)
            elif isinstance(v, AoT):
                for t in v.body:
                    t.value.parsing(parsing)

    def add(self, key: Key | Item | str, item: Item | None = None) -> Container:
        """
        Adds an item to the current Container.

        :Example:

        >>> # add a key-value pair
        >>> doc.add('key', 'value')
        >>> # add a comment or whitespace or newline
        >>> doc.add(comment('# comment'))
        """
        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 _handle_dotted_key(self, key: Key, value: Item) -> None:
        if isinstance(value, (Table, AoT)):
            raise TOMLKitError("Can't add a table to a dotted key")
        name, *mid, last = key
        name._dotted = True
        table = current = Table(Container(True), Trivia(), False, is_super_table=True)
        for _name in mid:
            _name._dotted = True
            new_table = Table(Container(True), Trivia(), False, is_super_table=True)
            current.append(_name, new_table)
            current = new_table

        last.sep = key.sep
        current.append(last, value)

        self.append(name, table)
        return

    def _get_last_index_before_table(self) -> int:
        last_index = -1
        for i, (k, v) in enumerate(self._body):
            if isinstance(v, Null):
                continue  # Null elements are inserted after deletion

            if isinstance(v, Whitespace) and not v.is_fixed():
                continue

            if isinstance(v, (Table, AoT)) and not k.is_dotted():
                break
            last_index = i
        return last_index + 1

    def append(self, key: Key | str | None, item: Item) -> Container:
        """Similar to :meth:`add` but both key and value must be given."""
        if not isinstance(key, Key) and key is not None:
            key = SingleKey(key)

        if not isinstance(item, Item):
            item = _item(item)

        if key is not None and key.is_multi():
            self._handle_dotted_key(key, item)
            return self

        if isinstance(item, (AoT, Table)) and item.name is None:
            item.name = key.key

        prev = self._previous_item()
        prev_ws = isinstance(prev, Whitespace) or ends_with_whitespace(prev)
        if isinstance(item, Table):
            if not self._parsed:
                item.invalidate_display_name()
            if (
                self._body
                and not (self._parsed or item.trivia.indent or prev_ws)
                and not key.is_dotted()
            ):
                item.trivia.indent = "\n"

        if isinstance(item, AoT) and self._body and not self._parsed:
            item.invalidate_display_name()
            if item and not ("\n" in item[0].trivia.indent or prev_ws):
                item[0].trivia.indent = "\n" + item[0].trivia.indent

        if key is not None and key in self:
            current_idx = self._map[key]
            if isinstance(current_idx, tuple):
                current_body_element = self._body[current_idx[-1]]
            else:
                current_body_element = self._body[current_idx]

            current = current_body_element[1]

            if isinstance(item, Table):
                if not isinstance(current, (Table, AoT)):
                    raise KeyAlreadyPresent(key)

                if item.is_aot_element():
                    # New AoT element found later on
                    # Adding it to the current AoT
                    if not isinstance(current, AoT):
                        current = AoT([current, item], parsed=self._parsed)

                        self._replace(key, key, current)
                    else:
                        current.append(item)

                    return self
                elif current.is_aot():
                    if not item.is_aot_element():
                        # Tried to define a table after an AoT with the same name.
                        raise KeyAlreadyPresent(key)

                    current.append(item)

                    return self
                elif current.is_super_table():
                    if item.is_super_table():
                        # We need to merge both super tables
                        if (
                            self._table_keys[-1] != current_body_element[0]
                            or key.is_dotted()
                            or current_body_element[0].is_dotted()
                        ):
                            if key.is_dotted() and not self._parsed:
                                idx = self._get_last_index_before_table()
                            else:
                                idx = len(self._body)

                            if idx < len(self._body):
                                self._insert_at(idx, key, item)
                            else:
                                self._raw_append(key, item)

                            # Building a temporary proxy to check for errors
                            OutOfOrderTableProxy(self, self._map[key])

                            return self

                        # Create a new element to replace the old one
                        current = copy.deepcopy(current)
                        for k, v in item.value.body:
                            current.append(k, v)
                        self._body[
                            current_idx[-1]
                            if isinstance(current_idx, tuple)
                            else current_idx
                        ] = (current_body_element[0], current)

                        return self
                    elif current_body_element[0].is_dotted():
                        raise TOMLKitError("Redefinition of an existing table")
                elif not item.is_super_table():
                    raise KeyAlreadyPresent(key)
            elif isinstance(item, AoT):
                if not isinstance(current, AoT):
                    # Tried to define an AoT after a table with the same name.
                    raise KeyAlreadyPresent(key)

                for table in item.body:
                    current.append(table)

                return self
            else:
                raise KeyAlreadyPresent(key)

        is_table = isinstance(item, (Table, AoT))
        if (
            key is not None
            and self._body
            and not self._parsed
            and (not is_table or key.is_dotted())
        ):
            # If there is already at least one table in the current container
            # and the given item is not a table, we need to find the last
            # item that is not a table and insert after it
            # If no such item exists, insert at the top of the table
            last_index = self._get_last_index_before_table()

            if last_index < len(self._body):
                return self._insert_at(last_index, key, item)
            else:
                previous_item = self._body[-1][1]
                if not (
                    isinstance(previous_item, Whitespace)
                    or ends_with_whitespace(previous_item)
                    or "\n" in previous_item.trivia.trail
                ):
                    previous_item.trivia.trail += "\n"

        self._raw_append(key, item)
        return self

    def _raw_append(self, key: Key, item: Item) -> None:
        if key in self._map:
            current_idx = self._map[key]
            if not isinstance(current_idx, tuple):
                current_idx = (current_idx,)

            current = self._body[current_idx[-1]][1]
            if key is not None and not isinstance(current, Table):
                raise KeyAlreadyPresent(key)

            self._map[key] = current_idx + (len(self._body),)
        else:
            self._map[key] = len(self._body)

        self._body.append((key, item))
        if item.is_table():
            self._table_keys.append(key)

        if key is not None:
            dict.__setitem__(self, key.key, item.value)

        return self

    def _remove_at(self, idx: int) -> None:
        key = self._body[idx][0]
        index = self._map.get(key)
        if index is None:
            raise NonExistentKey(key)
        self._body[idx] = (None, Null())

        if isinstance(index, tuple):
            index = list(index)
            index.remove(idx)
            if len(index) == 1:
                index = index.pop()
            else:
                index = tuple(index)
            self._map[key] = index
        else:
            dict.__delitem__(self, key.key)
            self._map.pop(key)

    def remove(self, key: Key | str) -> Container:
        """Remove a key from the container."""
        if not isinstance(key, Key):
            key = SingleKey(key)

        idx = self._map.pop(key, None)
        if idx is None:
            raise NonExistentKey(key)

        if isinstance(idx, tuple):
            for i in idx:
                self._body[i] = (None, Null())
        else:
            self._body[idx] = (None, Null())

        dict.__delitem__(self, key.key)

        return self

    def _insert_after(
        self, key: Key | str, other_key: Key | str, item: Any
    ) -> Container:
        if key is None:
            raise ValueError("Key cannot be null in insert_after()")

        if key not in self:
            raise NonExistentKey(key)

        if not isinstance(key, Key):
            key = SingleKey(key)

        if not isinstance(other_key, Key):
            other_key = SingleKey(other_key)

        item = _item(item)

        idx = self._map[key]
        # Insert after the max index if there are many.
        if isinstance(idx, tuple):
            idx = max(idx)
        current_item = self._body[idx][1]
        if "\n" not in current_item.trivia.trail:
            current_item.trivia.trail += "\n"

        # Increment indices after the current index
        for k, v in self._map.items():
            if isinstance(v, tuple):
                new_indices = []
                for v_ in v:
                    if v_ > idx:
                        v_ = v_ + 1

                    new_indices.append(v_)

                self._map[k] = tuple(new_indices)
            elif v > idx:
                self._map[k] = v + 1

        self._map[other_key] = idx + 1
        self._body.insert(idx + 1, (other_key, item))

        if key is not None:
            dict.__setitem__(self, other_key.key, item.value)

        return self

    def _insert_at(self, idx: int, key: Key | str, item: Any) -> Container:
        if idx > len(self._body) - 1:
            raise ValueError(f"Unable to insert at position {idx}")

        if not isinstance(key, Key):
            key = SingleKey(key)

        item = _item(item)

        if idx > 0:
            previous_item = self._body[idx - 1][1]
            if not (
                isinstance(previous_item, Whitespace)
                or ends_with_whitespace(previous_item)
                or isinstance(item, (AoT, Table))
                or "\n" in previous_item.trivia.trail
            ):
                previous_item.trivia.trail += "\n"

        # Increment indices after the current index
        for k, v in self._map.items():
            if isinstance(v, tuple):
                new_indices = []
                for v_ in v:
                    if v_ >= idx:
                        v_ = v_ + 1

                    new_indices.append(v_)

                self._map[k] = tuple(new_indices)
            elif v >= idx:
                self._map[k] = v + 1

        if key in self._map:
            current_idx = self._map[key]
            if not isinstance(current_idx, tuple):
                current_idx = (current_idx,)
            self._map[key] = current_idx + (idx,)
        else:
            self._map[key] = idx
        self._body.insert(idx, (key, item))

        dict.__setitem__(self, key.key, item.value)

        return self

    def item(self, key: Key | str) -> Item:
        """Get an item for the given key."""
        if not isinstance(key, Key):
            key = SingleKey(key)

        idx = self._map.get(key)
        if idx is None:
            raise NonExistentKey(key)

        if isinstance(idx, tuple):
            # The item we are getting is an out of order table
            # so we need a proxy to retrieve the proper objects
            # from the parent container
            return OutOfOrderTableProxy(self, idx)

        return self._body[idx][1]

    def last_item(self) -> Item | None:
        """Get the last item."""
        if self._body:
            return self._body[-1][1]

    def as_string(self) -> str:
        """Render as TOML string."""
        s = ""
        for k, v in self._body:
            if k is not None:
                if isinstance(v, Table):
                    s += self._render_table(k, v)
                elif isinstance(v, AoT):
                    s += self._render_aot(k, v)
                else:
                    s += self._render_simple_item(k, v)
            else:
                s += self._render_simple_item(k, v)

        return s

    def _render_table(self, key: Key, table: Table, prefix: str | None = None) -> str:
        cur = ""

        if table.display_name is not None:
            _key = table.display_name
        else:
            _key = key.as_string()

            if prefix is not None:
                _key = prefix + "." + _key

        if not table.is_super_table() or (
            any(
                not isinstance(v, (Table, AoT, Whitespace, Null))
                for _, v in table.value.body
            )
            and not key.is_dotted()
        ):
            open_, close = "[", "]"
            if table.is_aot_element():
                open_, close = "[[", "]]"

            newline_in_table_trivia = (
                "\n" if "\n" not in table.trivia.trail and len(table.value) > 0 else ""
            )
            cur += (
                f"{table.trivia.indent}"
                f"{open_}"
                f"{decode(_key)}"
                f"{close}"
                f"{table.trivia.comment_ws}"
                f"{decode(table.trivia.comment)}"
                f"{table.trivia.trail}"
                f"{newline_in_table_trivia}"
            )
        elif table.trivia.indent == "\n":
            cur += table.trivia.indent

        for k, v in table.value.body:
            if isinstance(v, Table):
                if v.is_super_table():
                    if k.is_dotted() and not key.is_dotted():
                        # Dotted key inside table
                        cur += self._render_table(k, v)
                    else:
                        cur += self._render_table(k, v, prefix=_key)
                else:
                    cur += self._render_table(k, v, prefix=_key)
            elif isinstance(v, AoT):
                cur += self._render_aot(k, v, prefix=_key)
            else:
                cur += self._render_simple_item(
                    k, v, prefix=_key if key.is_dotted() else None
                )

        return cur

    def _render_aot(self, key, aot, prefix=None):
        _key = key.as_string()
        if prefix is not None:
            _key = prefix + "." + _key

        cur = ""
        _key = decode(_key)
        for table in aot.body:
            cur += self._render_aot_table(table, prefix=_key)

        return cur

    def _render_aot_table(self, table: Table, prefix: str | None = None) -> str:
        cur = ""
        _key = prefix or ""
        open_, close = "[[", "]]"

        cur += (
            f"{table.trivia.indent}"
            f"{open_}"
            f"{decode(_key)}"
            f"{close}"
            f"{table.trivia.comment_ws}"
            f"{decode(table.trivia.comment)}"
            f"{table.trivia.trail}"
        )

        for k, v in table.value.body:
            if isinstance(v, Table):
                if v.is_super_table():
                    if k.is_dotted():
                        # Dotted key inside table
                        cur += self._render_table(k, v)
                    else:
                        cur += self._render_table(k, v, prefix=_key)
                else:
                    cur += self._render_table(k, v, prefix=_key)
            elif isinstance(v, AoT):
                cur += self._render_aot(k, v, prefix=_key)
            else:
                cur += self._render_simple_item(k, v)

        return cur

    def _render_simple_item(self, key, item, prefix=None):
        if key is None:
            return item.as_string()

        _key = key.as_string()
        if prefix is not None:
            _key = prefix + "." + _key

        return (
            f"{item.trivia.indent}"
            f"{decode(_key)}"
            f"{key.sep}"
            f"{decode(item.as_string())}"
            f"{item.trivia.comment_ws}"
            f"{decode(item.trivia.comment)}"
            f"{item.trivia.trail}"
        )

    def __len__(self) -> int:
        return dict.__len__(self)

    def __iter__(self) -> Iterator[str]:
        return iter(dict.keys(self))

    # Dictionary methods
    def __getitem__(self, key: Key | str) -> Item | Container:
        if not isinstance(key, Key):
            key = SingleKey(key)

        idx = self._map.get(key)
        if idx is None:
            raise NonExistentKey(key)

        if isinstance(idx, tuple):
            # The item we are getting is an out of order table
            # so we need a proxy to retrieve the proper objects
            # from the parent container
            return OutOfOrderTableProxy(self, idx)

        item = self._body[idx][1]
        if item.is_boolean():
            return item.value

        return item

    def __setitem__(self, key: Key | str, value: Any) -> None:
        if key is not None and key in self:
            old_key = next(filter(lambda k: k == key, self._map))
            self._replace(old_key, key, value)
        else:
            self.append(key, value)

    def __delitem__(self, key: Key | str) -> None:
        self.remove(key)

    def setdefault(self, key: Key | str, default: Any) -> Any:
        super().setdefault(key, default=default)
        return self[key]

    def _replace(self, key: Key | str, new_key: Key | str, value: Item) -> None:
        if not isinstance(key, Key):
            key = SingleKey(key)

        idx = self._map.get(key)
        if idx is None:
            raise NonExistentKey(key)

        self._replace_at(idx, new_key, value)

    def _replace_at(
        self, idx: int | tuple[int], new_key: Key | str, value: Item
    ) -> None:
        value = _item(value)

        if isinstance(idx, tuple):
            for i in idx[1:]:
                self._body[i] = (None, Null())

            idx = idx[0]

        k, v = self._body[idx]
        if not isinstance(new_key, Key):
            if (
                isinstance(value, (AoT, Table)) != isinstance(v, (AoT, Table))
                or new_key != k.key
            ):
                new_key = SingleKey(new_key)
            else:  # Inherit the sep of the old key
                new_key = k

        del self._map[k]
        self._map[new_key] = idx
        if new_key != k:
            dict.__delitem__(self, k)

        if isinstance(value, (AoT, Table)) != isinstance(v, (AoT, Table)):
            # new tables should appear after all non-table values
            self.remove(k)
            for i in range(idx, len(self._body)):
                if isinstance(self._body[i][1], (AoT, Table)):
                    self._insert_at(i, new_key, value)
                    idx = i
                    break
            else:
                idx = -1
                self.append(new_key, value)
        else:
            # Copying trivia
            if not isinstance(value, (Whitespace, AoT)):
                value.trivia.indent = v.trivia.indent
                value.trivia.comment_ws = value.trivia.comment_ws or v.trivia.comment_ws
                value.trivia.comment = value.trivia.comment or v.trivia.comment
                value.trivia.trail = v.trivia.trail
            self._body[idx] = (new_key, value)

        if hasattr(value, "invalidate_display_name"):
            value.invalidate_display_name()  # type: ignore[attr-defined]

        if isinstance(value, Table):
            # Insert a cosmetic new line for tables if:
            # - it does not have it yet OR is not followed by one
            # - it is not the last item
            last, _ = self._previous_item_with_index()
            idx = last if idx < 0 else idx
            has_ws = ends_with_whitespace(value)
            next_ws = idx < last and isinstance(self._body[idx + 1][1], Whitespace)
            if idx < last and not (next_ws or has_ws):
                value.append(None, Whitespace("\n"))

            dict.__setitem__(self, new_key.key, value.value)

    def __str__(self) -> str:
        return str(self.value)

    def __repr__(self) -> str:
        return repr(self.value)

    def __eq__(self, other: dict) -> bool:
        if not isinstance(other, dict):
            return NotImplemented

        return self.value == other

    def _getstate(self, protocol):
        return (self._parsed,)

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

    def __reduce_ex__(self, protocol):
        return (
            self.__class__,
            self._getstate(protocol),
            (self._map, self._body, self._parsed, self._table_keys),
        )

    def __setstate__(self, state):
        self._map = state[0]
        self._body = state[1]
        self._parsed = state[2]
        self._table_keys = state[3]

        for key, item in self._body:
            if key is not None:
                dict.__setitem__(self, key.key, item.value)

    def copy(self) -> Container:
        return copy.copy(self)

    def __copy__(self) -> Container:
        c = self.__class__(self._parsed)
        for k, v in dict.items(self):
            dict.__setitem__(c, k, v)

        c._body += self.body
        c._map.update(self._map)

        return c

    def _previous_item_with_index(
        self, idx: int | None = None, ignore=(Null,)
    ) -> tuple[int, Item] | None:
        """Find the immediate previous item before index ``idx``"""
        if idx is None or idx > len(self._body):
            idx = len(self._body)
        for i in range(idx - 1, -1, -1):
            v = self._body[i][-1]
            if not isinstance(v, ignore):
                return i, v
        return None

    def _previous_item(self, idx: int | None = None, ignore=(Null,)) -> Item | None:
        """Find the immediate previous item before index ``idx``.
        If ``idx`` is not given, the last item is returned.
        """
        prev = self._previous_item_with_index(idx, ignore)
        return prev[-1] if prev else None


class OutOfOrderTableProxy(_CustomDict):
    def __init__(self, container: Container, indices: tuple[int]) -> None:
        self._container = container
        self._internal_container = Container(True)
        self._tables = []
        self._tables_map = {}

        for i in indices:
            _, item = self._container._body[i]

            if isinstance(item, Table):
                self._tables.append(item)
                table_idx = len(self._tables) - 1
                for k, v in item.value.body:
                    self._internal_container.append(k, v)
                    self._tables_map[k] = table_idx
                    if k is not None:
                        dict.__setitem__(self, k.key, v)

    def unwrap(self) -> str:
        return self._internal_container.unwrap()

    @property
    def value(self):
        return self._internal_container.value

    def __getitem__(self, key: Key | str) -> Any:
        if key not in self._internal_container:
            raise NonExistentKey(key)

        return self._internal_container[key]

    def __setitem__(self, key: Key | str, item: Any) -> None:
        if key in self._tables_map:
            table = self._tables[self._tables_map[key]]
            table[key] = item
        elif self._tables:
            table = self._tables[0]
            table[key] = item
        else:
            self._container[key] = item

        self._internal_container[key] = item
        if key is not None:
            dict.__setitem__(self, key, item)

    def _remove_table(self, table: Table) -> None:
        """Remove table from the parent container"""
        self._tables.remove(table)
        for idx, item in enumerate(self._container._body):
            if item[1] is table:
                self._container._remove_at(idx)
                break

    def __delitem__(self, key: Key | str) -> None:
        if key in self._tables_map:
            table = self._tables[self._tables_map[key]]
            del table[key]
            if not table and len(self._tables) > 1:
                self._remove_table(table)
            del self._tables_map[key]
        else:
            raise NonExistentKey(key)

        del self._internal_container[key]
        if key is not None:
            dict.__delitem__(self, key)

    def __iter__(self) -> Iterator[str]:
        return iter(dict.keys(self))

    def __len__(self) -> int:
        return dict.__len__(self)

    def setdefault(self, key: Key | str, default: Any) -> Any:
        super().setdefault(key, default=default)
        return self[key]


def ends_with_whitespace(it: Any) -> bool:
    """Returns ``True`` if the given item ``it`` is a ``Table`` or ``AoT`` object
    ending with a ``Whitespace``.
    """
    return (
        isinstance(it, Table) and isinstance(it.value._previous_item(), Whitespace)
    ) or (isinstance(it, AoT) and len(it) > 0 and isinstance(it[-1], Whitespace))