import json
import logging
import os
from typing import List, Optional
from unittest import mock

from sqlalchemy.engine import Engine, create_engine

from service.conf import settings
from service.conf.secrets import get_secret

logger = logging.getLogger(__name__)

_engine: Optional[Engine] = None


class SchemaPath:
    PUBLIC = "public"
    COMMONS = "commons"
    WORKSPACE = "workspace"
    COMPANY = "company"
    ALLIANCE = "alliance"

    @classmethod
    def choices(cls) -> List[str]:
        return [
            cls.PUBLIC,
            cls.COMMONS,
            cls.WORKSPACE,
            cls.COMPANY,
            cls.ALLIANCE,
        ]


def get_db_url(driver="postgresql+psycopg2") -> str:
    db_url = settings.DATABASE_URL

    if db_url:
        return db_url

    if settings.PROFILE == "auto_test":
        container_name = "database"
        if os.getenv("CODEPIPELINE"):
            # This is an ugly workaround. We didn't figure out in a timely fashion
            # how to rename the "src" to "data-processor" in buildsped_run-tests.yml
            container_name = "src_database"
        # The test db we setup on local container
        return f"{driver}://postgres:password@{container_name}:5432/test_db"

    # TODO! unify naming in fargate templates and secret names so you can use
    #  get_secret(DATABASE_NAME) once
    if settings.DATABASE_NAME == "fansifter":
        secret = get_secret("fansifter-rds")
    elif settings.DATABASE_NAME == "fansifter-dev":
        # For backwards compatibility, temporarily duplicates the above
        # (until we've renamed the actual RDS).
        secret = get_secret("fansifter-rds")
    elif settings.DATABASE_NAME == "fansifter-live":
        secret = get_secret("fansifter-rds-live")
    elif settings.DATABASE_NAME == "fansifter-test":
        secret = get_secret("fansifter-rds-test")
    elif settings.DATABASE_NAME == "fansifter-ztbox":
        secret = get_secret("fansifter-rds-ztbox")
    else:
        raise ValueError(f"Unknown database name: {settings.DATABASE_NAME}")

    config = json.loads(secret)

    params = {
        "driver": driver,
        "host": config["host"],
        "port": config["port"],
        "dbname": config["dbname"],
        "user": config["username"],
        "password": config["password"],
    }

    return "{driver}://{user}:{password}@{host}/{dbname}".format(**params)


def init_rds_engine() -> Engine:
    # Add pool_pre_ping=True if SSL thing continues
    return create_engine(
        url=get_db_url(),
        executemany_mode="values_plus_batch",
        pool_size=20,
        max_overflow=100,
        pool_recycle=3600,
    )


def get_rds_engine() -> Engine:
    """
    Get RDS connection for a given db instance
    """

    # Return mocked SqlAlchemy engine for unit testing only
    if settings.DATABASE_MOCK:
        return mock.MagicMock(spec=Engine)

    global _engine
    if _engine is None:
        _engine = init_rds_engine()
    return _engine


engine = get_rds_engine()