from datetime import datetime, timedelta
from typing import Any, Optional, Sequence

from peewee import (
    DoubleField,
    ensure_tuple,
    ForeignKeyField,
    IntegerField,
    ManyToManyField,
    ManyToManyFieldAccessor,
    ManyToManyQuery,
    Model,
    SelectQuery,
    TextField,
)

from sublime.adapters.adapter_base import CachingAdapter


# Custom Fields
# =============================================================================
class CacheConstantsField(TextField):
    def db_value(self, value: CachingAdapter.FunctionNames) -> str:
        return value.value

    def python_value(self, value: str) -> CachingAdapter.FunctionNames:
        return CachingAdapter.FunctionNames(value)


class DurationField(DoubleField):
    def db_value(self, value: timedelta) -> Optional[float]:
        return value.total_seconds() if value else None

    def python_value(self, value: Optional[float]) -> Optional[timedelta]:
        return timedelta(seconds=value) if value else None


class TzDateTimeField(TextField):
    def db_value(self, value: Optional[datetime]) -> Optional[str]:
        return value.isoformat() if value else None

    def python_value(self, value: Optional[str]) -> Optional[datetime]:
        return datetime.fromisoformat(value) if value else None


# Sorted M-N Association Field
# =============================================================================
class SortedManyToManyQuery(ManyToManyQuery):
    def add(self, value: Sequence[Any], clear_existing: bool = False):
        if clear_existing:
            self.clear()

        accessor = self._accessor
        src_id = getattr(self._instance, self._src_attr)
        if isinstance(value, SelectQuery):
            print("TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT")
            raise NotImplementedError()
            # query = value.columns(Value(src_id), accessor.dest_fk.rel_field)
            # accessor.through_model.insert_from(
            #     fields=[accessor.src_fk, accessor.dest_fk],
            #     query=query).execute()
        else:
            value = ensure_tuple(value)
            if not value:
                return

            inserts = [
                {
                    accessor.src_fk.name: src_id,
                    accessor.dest_fk.name: rel_id,
                    "position": i,
                }
                for i, rel_id in enumerate(self._id_list(value))
            ]
            accessor.through_model.insert_many(inserts).execute()

    def remove(self, value: Any) -> Any:
        print("RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR")
        raise NotImplementedError()
        # src_id = getattr(self._instance, self._src_attr)
        # if isinstance(value, SelectQuery):
        #     column = getattr(value.model, self._dest_attr)
        #     subquery = value.columns(column)
        #     return (
        #         self._accessor.through_model.delete().where(
        #             (self._accessor.dest_fk << subquery)
        #             & (self._accessor.src_fk == src_id)).execute())
        # else:
        #     value = ensure_tuple(value)
        #     if not value:
        #         return
        #     return (
        #         self._accessor.through_model.delete().where(
        #             (self._accessor.dest_fk << self._id_list(value))
        #             & (self._accessor.src_fk == src_id)).execute())

    # def clear(self) -> Any:
    #     src_id = getattr(self._instance, self._src_attr)
    #     return (
    #         self._accessor.through_model.delete().where(
    #             self._accessor.src_fk == src_id).execute())


class SortedManyToManyFieldAccessor(ManyToManyFieldAccessor):
    def __get__(
        self, instance: Model, instance_type: Any = None, force_query: bool = False,
    ):
        if instance is not None:
            if not force_query and self.src_fk.backref != "+":
                backref = getattr(instance, self.src_fk.backref)
                if isinstance(backref, list):
                    return [getattr(obj, self.dest_fk.name) for obj in backref]

            src_id = getattr(instance, self.src_fk.rel_field.name)
            return (
                SortedManyToManyQuery(instance, self, self.rel_model)
                .join(self.through_model)
                .join(self.model)
                .where(self.src_fk == src_id)
                .order_by(self.through_model.position)
            )

        return self.field

    def __set__(self, instance: Model, value: Sequence[Any]):
        query = self.__get__(instance, force_query=True)
        query.add(value, clear_existing=True)


class SortedManyToManyField(ManyToManyField):
    accessor_class = SortedManyToManyFieldAccessor

    def _create_through_model(self) -> type:
        lhs, rhs = self.get_models()
        tables = [model._meta.table_name for model in (lhs, rhs)]

        class Meta:
            database = self.model._meta.database
            schema = self.model._meta.schema
            table_name = "{}_{}_through".format(*tables)
            indexes = (((lhs._meta.name, rhs._meta.name, "position"), True),)

        params = {"on_delete": self._on_delete, "on_update": self._on_update}
        attrs = {
            lhs._meta.name: ForeignKeyField(lhs, **params),
            rhs._meta.name: ForeignKeyField(rhs, **params),
            "position": IntegerField(),
            "Meta": Meta,
        }

        klass_name = "{}{}Through".format(lhs.__name__, rhs.__name__)
        return type(klass_name, (Model,), attrs)