from contextlib import contextmanager

from apscheduler.executors.pool import ProcessPoolExecutor, ThreadPoolExecutor
from apscheduler.jobstores.sqlalchemy import SQLAlchemyJobStore
from apscheduler.schedulers.asyncio import AsyncIOScheduler
from apscheduler.schedulers.background import BackgroundScheduler
from pytz import utc
from sqlalchemy import create_engine
from sqlalchemy.orm import declarative_base, sessionmaker

from services.scheduler.scheduler_service import Reminder
from settings import (
    APschedulerDataBaseSettings,
    AuroraDataBaseSettings,
    PostgresSettings,
    ReadPostgresSettings,
    WalletPostgresSettings,
)

db_settings = PostgresSettings()
aurora_db_settings = AuroraDataBaseSettings()
apscheduler_db_settings = APschedulerDataBaseSettings()
read_db_settings = ReadPostgresSettings()
wallet_db_settings = WalletPostgresSettings()

SQLALCHEMY_DATABASE_URL = (
    "postgresql+psycopg2://"
    f"{db_settings.POSTGRES_USER}:{db_settings.POSTGRES_PASSWORD}@"
    f"{db_settings.POSTGRES_HOST}:{db_settings.POSTGRES_PORT}/"
    f"{db_settings.POSTGRES_DB}"
)

AURORA_SQLALCHEMY_DATABASE_URL = (
    "postgresql+psycopg2://"
    f"{aurora_db_settings.AURORA_POSTGRES_USER}:{aurora_db_settings.AURORA_POSTGRES_PASSWORD}@"
    f"{aurora_db_settings.AURORA_POSTGRES_HOST}:{aurora_db_settings.AURORA_POSTGRES_PORT}/"
    f"{aurora_db_settings.AURORA_POSTGRES_DB}"
)

APSCHEDULER_SQLALCHEMY_DATABASE_URL = (
    "postgresql+psycopg2://"
    f"{apscheduler_db_settings.APSCHEDULER_POSTGRES_USER}:{apscheduler_db_settings.APSCHEDULER_POSTGRES_PASSWORD}@"
    f"{apscheduler_db_settings.APSCHEDULER_POSTGRES_HOST}:{apscheduler_db_settings.APSCHEDULER_POSTGRES_PORT}/"
    f"{apscheduler_db_settings.APSCHEDULER_POSTGRES_DB}"
)

SQLALCHEMY_READ_DATABASE_URL = (
    "postgresql+psycopg2://"
    f"{read_db_settings.READ_POSTGRES_USER}:{read_db_settings.READ_POSTGRES_PASSWORD}@"
    f"{read_db_settings.READ_POSTGRES_HOST}:{read_db_settings.READ_POSTGRES_PORT}/"
    f"{read_db_settings.READ_POSTGRES_DB}"
)

WALLET_SQLALCHEMY_DATABASE_URL = (
    "postgresql+psycopg2://"
    f"{wallet_db_settings.WALLET_POSTGRES_USER}:{wallet_db_settings.WALLET_POSTGRES_PASSWORD}@"
    f"{wallet_db_settings.WALLET_POSTGRES_HOST}:{wallet_db_settings.WALLET_POSTGRES_PORT}/"
    f"{wallet_db_settings.WALLET_POSTGRES_DB}"
)

engine = create_engine(
    SQLALCHEMY_DATABASE_URL,
    pool_size=30,
    max_overflow=30,
)
read_engine = create_engine(
    SQLALCHEMY_READ_DATABASE_URL,
)
aurora_engine = create_engine(
    AURORA_SQLALCHEMY_DATABASE_URL,
    pool_size=30,
    max_overflow=30,
)
wallet_engine = create_engine(
    WALLET_SQLALCHEMY_DATABASE_URL,
)

SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
SessionLocalRead = sessionmaker(autocommit=False, autoflush=False, bind=read_engine)
SessionLocalAurora = sessionmaker(autocommit=False, autoflush=False, bind=aurora_engine)
SessionLocalWallet = sessionmaker(autocommit=False, autoflush=False, bind=wallet_engine)

Base = declarative_base()
BaseAurora = declarative_base()
BaseWallet = declarative_base()

# Schedule Settings
JOBSTORES = {"default": SQLAlchemyJobStore(url=APSCHEDULER_SQLALCHEMY_DATABASE_URL)}
EXECUTORS = {"default": ThreadPoolExecutor(20), "processpool": ProcessPoolExecutor(5)}
JOB_DEFAULTS = {"coalesce": False, "max_instances": 3}

scheduler = AsyncIOScheduler(
    jobstores=JOBSTORES,
    executors=EXECUTORS,
    job_defaults=JOB_DEFAULTS,
    timezone=utc,
)
scheduler.start()
reminder = Reminder(scheduler)


def get_db():
    """
    Get a database session.

    Yields:
        The database session
    """
    with SessionLocal() as db:  # pragma: no cover
        yield db  # pragma: no cover


@contextmanager
def get_read_db():
    """
    Get a read database session.

    Yields:
        The database session
    """
    with SessionLocalRead() as db:  # pragma: no cover
        yield db  # pragma: no cover


def get_db_aurora():
    """
    Get a aurora database session.

    Yields:
        The database session
    """
    with SessionLocalAurora() as db:  # pragma: no cover
        yield db  # pragma: no cover