# dialects/postgresql/json.py
# Copyright (C) 2005-2026 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: https://www.opensource.org/licenses/mit-license.php

from __future__ import annotations

from typing import Any
from typing import Callable
from typing import List
from typing import Optional
from typing import TYPE_CHECKING
from typing import Union

from .array import ARRAY
from .array import array as _pg_array
from .operators import ASTEXT
from .operators import CONTAINED_BY
from .operators import CONTAINS
from .operators import DELETE_PATH
from .operators import HAS_ALL
from .operators import HAS_ANY
from .operators import HAS_KEY
from .operators import JSONPATH_ASTEXT
from .operators import PATH_EXISTS
from .operators import PATH_MATCH
from ... import types as sqltypes
from ...sql import cast
from ...sql._typing import _T

if TYPE_CHECKING:
    from ...engine.interfaces import Dialect
    from ...sql.elements import ColumnElement
    from ...sql.operators import OperatorType
    from ...sql.type_api import _BindProcessorType
    from ...sql.type_api import _LiteralProcessorType
    from ...sql.type_api import TypeEngine

__all__ = ("JSON", "JSONB")


class JSONPathType(sqltypes.JSON.JSONPathType):
    def _processor(
        self, dialect: Dialect, super_proc: Optional[Callable[[Any], Any]]
    ) -> Callable[[Any], Any]:
        def process(value: Any) -> Any:
            if isinstance(value, str):
                # If it's already a string assume that it's in json path
                # format. This allows using cast with json paths literals
                return value
            elif value:
                # If it's already a string assume that it's in json path
                # format. This allows using cast with json paths literals
                value = "{%s}" % (", ".join(map(str, value)))
            else:
                value = "{}"
            if super_proc:
                value = super_proc(value)
            return value

        return process

    def bind_processor(self, dialect: Dialect) -> _BindProcessorType[Any]:
        return self._processor(dialect, self.string_bind_processor(dialect))  # type: ignore[return-value]  # noqa: E501

    def literal_processor(
        self, dialect: Dialect
    ) -> _LiteralProcessorType[Any]:
        return self._processor(dialect, self.string_literal_processor(dialect))  # type: ignore[return-value]  # noqa: E501


class JSONPATH(JSONPathType):
    """JSON Path Type.

    This is usually required to cast literal values to json path when using
    json search like function, such as ``jsonb_path_query_array`` or
    ``jsonb_path_exists``::

        stmt = sa.select(
            sa.func.jsonb_path_query_array(
                table.c.jsonb_col, cast("$.address.id", JSONPATH)
            )
        )

    """

    __visit_name__ = "JSONPATH"


class JSON(sqltypes.JSON):
    """Represent the PostgreSQL JSON type.

    :class:`_postgresql.JSON` is used automatically whenever the base
    :class:`_types.JSON` datatype is used against a PostgreSQL backend,
    however base :class:`_types.JSON` datatype does not provide Python
    accessors for PostgreSQL-specific comparison methods such as
    :meth:`_postgresql.JSON.Comparator.astext`; additionally, to use
    PostgreSQL ``JSONB``, the :class:`_postgresql.JSONB` datatype should
    be used explicitly.

    .. seealso::

        :class:`_types.JSON` - main documentation for the generic
        cross-platform JSON datatype.

    The operators provided by the PostgreSQL version of :class:`_types.JSON`
    include:

    * Index operations (the ``->`` operator)::

        data_table.c.data["some key"]

        data_table.c.data[5]

    * Index operations returning text
      (the ``->>`` operator)::

        data_table.c.data["some key"].astext == "some value"

      Note that equivalent functionality is available via the
      :attr:`.JSON.Comparator.as_string` accessor.

    * Index operations with CAST
      (equivalent to ``CAST(col ->> ['some key'] AS <type>)``)::

        data_table.c.data["some key"].astext.cast(Integer) == 5

      Note that equivalent functionality is available via the
      :attr:`.JSON.Comparator.as_integer` and similar accessors.

    * Path index operations (the ``#>`` operator)::

        data_table.c.data[("key_1", "key_2", 5, ..., "key_n")]

    * Path index operations returning text (the ``#>>`` operator)::

        data_table.c.data[
            ("key_1", "key_2", 5, ..., "key_n")
        ].astext == "some value"

    Index operations return an expression object whose type defaults to
    :class:`_types.JSON` by default,
    so that further JSON-oriented instructions
    may be called upon the result type.

    Custom serializers and deserializers are specified at the dialect level,
    that is using :func:`_sa.create_engine`.  The reason for this is that when
    using psycopg2, the DBAPI only allows serializers at the per-cursor
    or per-connection level.   E.g.::

        engine = create_engine(
            "postgresql+psycopg2://scott:tiger@localhost/test",
            json_serializer=my_serialize_fn,
            json_deserializer=my_deserialize_fn,
        )

    When using the psycopg2 dialect, the json_deserializer is registered
    against the database using ``psycopg2.extras.register_default_json``.

    .. seealso::

        :class:`_types.JSON` - Core level JSON type

        :class:`_postgresql.JSONB`

    """  # noqa

    render_bind_cast = True
    astext_type: TypeEngine[str] = sqltypes.Text()

    def __init__(
        self,
        none_as_null: bool = False,
        astext_type: Optional[TypeEngine[str]] = None,
    ):
        """Construct a :class:`_types.JSON` type.

        :param none_as_null: if True, persist the value ``None`` as a
         SQL NULL value, not the JSON encoding of ``null``.   Note that
         when this flag is False, the :func:`.null` construct can still
         be used to persist a NULL value::

             from sqlalchemy import null

             conn.execute(table.insert(), {"data": null()})

         .. seealso::

              :attr:`_types.JSON.NULL`

        :param astext_type: the type to use for the
         :attr:`.JSON.Comparator.astext`
         accessor on indexed attributes.  Defaults to :class:`_types.Text`.

        """
        super().__init__(none_as_null=none_as_null)
        if astext_type is not None:
            self.astext_type = astext_type

    class Comparator(sqltypes.JSON.Comparator[_T]):
        """Define comparison operations for :class:`_types.JSON`."""

        type: JSON

        @property
        def astext(self) -> ColumnElement[str]:
            """On an indexed expression, use the "astext" (e.g. "->>")
            conversion when rendered in SQL.

            E.g.::

                select(data_table.c.data["some key"].astext)

            .. seealso::

                :meth:`_expression.ColumnElement.cast`

            """
            if isinstance(self.expr.right.type, sqltypes.JSON.JSONPathType):
                return self.expr.left.operate(  # type: ignore[no-any-return]
                    JSONPATH_ASTEXT,
                    self.expr.right,
                    result_type=self.type.astext_type,
                )
            else:
                return self.expr.left.operate(  # type: ignore[no-any-return]
                    ASTEXT, self.expr.right, result_type=self.type.astext_type
                )

    comparator_factory = Comparator


class JSONB(JSON):
    """Represent the PostgreSQL JSONB type.

    The :class:`_postgresql.JSONB` type stores arbitrary JSONB format data,
    e.g.::

        data_table = Table(
            "data_table",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("data", JSONB),
        )

        with engine.connect() as conn:
            conn.execute(
                data_table.insert(), data={"key1": "value1", "key2": "value2"}
            )

    The :class:`_postgresql.JSONB` type includes all operations provided by
    :class:`_types.JSON`, including the same behaviors for indexing
    operations.
    It also adds additional operators specific to JSONB, including
    :meth:`.JSONB.Comparator.has_key`, :meth:`.JSONB.Comparator.has_all`,
    :meth:`.JSONB.Comparator.has_any`, :meth:`.JSONB.Comparator.contains`,
    :meth:`.JSONB.Comparator.contained_by`,
    :meth:`.JSONB.Comparator.delete_path`,
    :meth:`.JSONB.Comparator.path_exists` and
    :meth:`.JSONB.Comparator.path_match`.

    Like the :class:`_types.JSON` type, the :class:`_postgresql.JSONB`
    type does not detect
    in-place changes when used with the ORM, unless the
    :mod:`sqlalchemy.ext.mutable` extension is used.

    Custom serializers and deserializers
    are shared with the :class:`_types.JSON` class,
    using the ``json_serializer``
    and ``json_deserializer`` keyword arguments.  These must be specified
    at the dialect level using :func:`_sa.create_engine`.  When using
    psycopg2, the serializers are associated with the jsonb type using
    ``psycopg2.extras.register_default_jsonb`` on a per-connection basis,
    in the same way that ``psycopg2.extras.register_default_json`` is used
    to register these handlers with the json type.

    .. seealso::

        :class:`_types.JSON`

    .. warning::

        **For applications that have indexes against JSONB subscript
        expressions**

        SQLAlchemy 2.0.42 made a change in how the subscript operation for
        :class:`.JSONB` is rendered, from ``-> 'element'`` to ``['element']``,
        for PostgreSQL versions greater than 14. This change caused an
        unintended side effect for indexes that were created against
        expressions that use subscript notation, e.g.
        ``Index("ix_entity_json_ab_text", data["a"]["b"].astext)``. If these
        indexes were generated with the older syntax e.g. ``((entity.data ->
        'a') ->> 'b')``, they will not be used by the PostgreSQL query planner
        when a query is made using SQLAlchemy 2.0.42 or higher on PostgreSQL
        versions 14 or higher. This occurs because the new text will resemble
        ``(entity.data['a'] ->> 'b')`` which will fail to produce the exact
        textual syntax match required by the PostgreSQL query planner.
        Therefore, for users upgrading to SQLAlchemy 2.0.42 or higher, existing
        indexes that were created against :class:`.JSONB` expressions that use
        subscripting would need to be dropped and re-created in order for them
        to work with the new query syntax, e.g. an expression like
        ``((entity.data -> 'a') ->> 'b')`` would become ``(entity.data['a'] ->>
        'b')``.

        .. seealso::

            :ticket:`12868` - discussion of this issue

    """

    __visit_name__ = "JSONB"

    def coerce_compared_value(
        self, op: Optional[OperatorType], value: Any
    ) -> TypeEngine[Any]:
        if op in (PATH_MATCH, PATH_EXISTS):
            return JSON.JSONPathType()
        else:
            return super().coerce_compared_value(op, value)

    class Comparator(JSON.Comparator[_T]):
        """Define comparison operations for :class:`_types.JSON`."""

        type: JSONB

        def has_key(self, other: Any) -> ColumnElement[bool]:
            """Boolean expression.  Test for presence of a key (equivalent of
            the ``?`` operator).  Note that the key may be a SQLA expression.
            """
            return self.operate(HAS_KEY, other, result_type=sqltypes.Boolean)

        def has_all(self, other: Any) -> ColumnElement[bool]:
            """Boolean expression.  Test for presence of all keys in jsonb
            (equivalent of the ``?&`` operator)
            """
            return self.operate(HAS_ALL, other, result_type=sqltypes.Boolean)

        def has_any(self, other: Any) -> ColumnElement[bool]:
            """Boolean expression.  Test for presence of any key in jsonb
            (equivalent of the ``?|`` operator)
            """
            return self.operate(HAS_ANY, other, result_type=sqltypes.Boolean)

        def contains(self, other: Any, **kwargs: Any) -> ColumnElement[bool]:
            """Boolean expression.  Test if keys (or array) are a superset
            of/contained the keys of the argument jsonb expression
            (equivalent of the ``@>`` operator).

            kwargs may be ignored by this operator but are required for API
            conformance.
            """
            return self.operate(CONTAINS, other, result_type=sqltypes.Boolean)

        def contained_by(self, other: Any) -> ColumnElement[bool]:
            """Boolean expression.  Test if keys are a proper subset of the
            keys of the argument jsonb expression
            (equivalent of the ``<@`` operator).
            """
            return self.operate(
                CONTAINED_BY, other, result_type=sqltypes.Boolean
            )

        def delete_path(
            self, array: Union[List[str], _pg_array[str]]
        ) -> ColumnElement[JSONB]:
            """JSONB expression. Deletes field or array element specified in
            the argument array (equivalent of the ``#-`` operator).

            The input may be a list of strings that will be coerced to an
            ``ARRAY`` or an instance of :meth:`_postgres.array`.

            .. versionadded:: 2.0
            """
            if not isinstance(array, _pg_array):
                array = _pg_array(array)
            right_side = cast(array, ARRAY(sqltypes.TEXT))
            return self.operate(DELETE_PATH, right_side, result_type=JSONB)

        def path_exists(self, other: Any) -> ColumnElement[bool]:
            """Boolean expression. Test for presence of item given by the
            argument JSONPath expression (equivalent of the ``@?`` operator).

            .. versionadded:: 2.0
            """
            return self.operate(
                PATH_EXISTS, other, result_type=sqltypes.Boolean
            )

        def path_match(self, other: Any) -> ColumnElement[bool]:
            """Boolean expression. Test if JSONPath predicate given by the
            argument JSONPath expression matches
            (equivalent of the ``@@`` operator).

            Only the first item of the result is taken into account.

            .. versionadded:: 2.0
            """
            return self.operate(
                PATH_MATCH, other, result_type=sqltypes.Boolean
            )

    comparator_factory = Comparator
