# mysql/json.py
# Copyright (C) 2005-2018 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php

from __future__ import absolute_import

import json

from ...sql import elements
from ... import types as sqltypes
from ... import util


class JSON(sqltypes.JSON):
    """MySQL JSON type.

    MySQL supports JSON as of version 5.7.  Note that MariaDB does **not**
    support JSON at the time of this writing.

    The :class:`.mysql.JSON` type supports persistence of JSON values
    as well as the core index operations provided by :class:`.types.JSON`
    datatype, by adapting the operations to render the ``JSON_EXTRACT``
    function at the database level.

    .. versionadded:: 1.1

    """

    pass


class _FormatTypeMixin(object):
    def _format_value(self, value):
        raise NotImplementedError()

    def bind_processor(self, dialect):
        super_proc = self.string_bind_processor(dialect)

        def process(value):
            value = self._format_value(value)
            if super_proc:
                value = super_proc(value)
            return value

        return process

    def literal_processor(self, dialect):
        super_proc = self.string_literal_processor(dialect)

        def process(value):
            value = self._format_value(value)
            if super_proc:
                value = super_proc(value)
            return value

        return process


class JSONIndexType(_FormatTypeMixin, sqltypes.JSON.JSONIndexType):

    def _format_value(self, value):
        if isinstance(value, int):
            value = "$[%s]" % value
        else:
            value = '$."%s"' % value
        return value


class JSONPathType(_FormatTypeMixin, sqltypes.JSON.JSONPathType):
    def _format_value(self, value):
        return "$%s" % (
            "".join([
                "[%s]" % elem if isinstance(elem, int)
                else '."%s"' % elem for elem in value
            ])
        )
