from typing import Any

from sqlalchemy import (
    delete,
    func,
    insert,
    select,
)

from sqlalchemy.engine import Engine
from sqlalchemy import event
from sqlalchemy.orm import DeclarativeBase, MappedAsDataclass, Session

from app.db.engine import DbEngine


# Enable foreign key constraints for SQLite
@event.listens_for(Engine, "connect")
def set_sqlite_pragma(dbapi_connection, connection_record):
    cursor = dbapi_connection.cursor()
    cursor.execute("PRAGMA foreign_keys=ON")
    cursor.close()


class DbManager:
    """ """

    def __init__(self, commit: bool = False):
        self.commit = commit
        self.conn = DbEngine.engine.connect()

        with Session(DbEngine.engine) as session:
            session.connection

    def __enter__(self):
        return self.conn.execution_options(preserve_rowcount=True)

    def __exit__(self, exc_type, exc_val, exc_tb):
        if self.commit:
            self.conn.commit()

        self.conn.close()


class Base(MappedAsDataclass, DeclarativeBase):
    """
    Base class for all database models.

    It has methods common to all tables. eg. `insert_one`, `insert_many`, `remove_all`, `remove_one`, `all`, `count`.
    """

    @classmethod
    def execute(cls, stmt: Any, commit: bool = False):
        with DbEngine.manager(commit=commit) as conn:
            return conn.execute(stmt)

    @classmethod
    def insert_many(cls, items: list[dict[str, Any]]):
        """
        Inserts multiple items into the database.
        """
        return cls.execute(insert(cls).values(items), commit=True)

    @classmethod
    def insert_one(cls, item: dict[str, Any]):
        """
        Inserts a single item into the database.
        """
        return cls.insert_many([item])

    @classmethod
    def remove_all(cls):
        return cls.execute(delete(cls), commit=True)

    @classmethod
    def remove_one(cls, id: int):
        return cls.execute(delete(cls).where(cls.id == id), commit=True)

    @classmethod
    def all(cls):
        return cls.execute(select(cls))

    @classmethod
    def count(cls):
        return cls.execute(select(func.count()).select_from(cls)).scalar()


def create_all_tables():
    """
    Creates all the tables that build on the Base class.
    """
    Base().metadata.create_all(DbEngine.engine)