"""Application configuration powered by Pydantic settings."""
from typing import Any
from typing import Optional

from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization
from pydantic import BaseModel
from pydantic import Field
from pydantic_settings import BaseSettings
from secrets_manager.python_ext import PythonSecretsManager


class SnowflakeConfig(BaseModel):
    """Snowflake connection details."""

    account: str
    user: str
    db: str
    schema: str
    warehouse: str
    role: str
    private_key: Any


class AppSettings(BaseSettings):
    """Top-level application configuration."""

    application_name: str = Field('lambda-fan-subscription-preference-sforce-updates', env='APPLICATION_NAME')
    aws_region: str = Field('us-east-1', env='AWS_REGION')
    environment: str = Field('test', env='ENVIRONMENT')
    log_level: str = Field('INFO', env='LOG_LEVEL')
    sentry_dsn: Optional[str] = Field(None, env='SENTRY_DSN')

    snowflake_account: Optional[str] = Field(None, env='SNOWFLAKE_ACCOUNT')
    snowflake_user: Optional[str] = Field(None, env='SNOWFLAKE_USER')
    snowflake_database: Optional[str] = Field(None, env='SNOWFLAKE_DATABASE')
    snowflake_schema: Optional[str] = Field(None, env='SNOWFLAKE_SCHEMA')
    snowflake_warehouse: Optional[str] = Field(None, env='SNOWFLAKE_WAREHOUSE')
    snowflake_role: Optional[str] = Field(None, env='SNOWFLAKE_ROLE')
    snowflake_private_key: Optional[str] = Field('', env='SNOWFLAKE_PRIVATE_KEY')
    snowflake_private_key_passphrase: Optional[str] = Field('', env='SNOWFLAKE_PRIVATE_KEY_PASSPHRASE')

    snowflake_config: Optional[SnowflakeConfig] = None

    kafka_target_topic: str = Field('', env='KAFKA_TARGET_TOPIC')
    kafka_bootstrap_servers: Optional[str] = Field(None, env='KAFKA_BOOTSTRAP_SERVERS')
    kafka_security_protocol: str = Field('SSL', env='KAFKA_SECURITY_PROTOCOL')
    kafka_message_header_key: str = Field('CamelHeader.sObjectIdValue', env='KAFKA_MESSAGE_HEADER_KEY')
    kafka_dlq_topic: Optional[str] = Field(None, env='KAFKA_DLQ_TOPIC')

    class Config:
        """Pydantic configuration settings."""

        env_file = '.env'
        case_sensitive = False

    def model_post_init(self, __context) -> None:
        """Initialize additional attributes after model creation."""
        if self.environment.lower() in ['dev', 'qa', 'prod']:
            secrets_manager_client = PythonSecretsManager(
                environment=self.environment,
                service_name=self.application_name
            )
            snowflake_private_key = secrets_manager_client.get_cred('SNOWFLAKE_PRIVATE_KEY')
            snowflake_private_key_passphrase = secrets_manager_client.get_cred('SNOWFLAKE_PRIVATE_KEY_PASSPHRASE')
            private_key = serialization.load_pem_private_key(
                snowflake_private_key.encode('utf-8'),
                password=snowflake_private_key_passphrase.encode('utf-8'),
                backend=default_backend()
            )
            self.snowflake_config = SnowflakeConfig(
                account=self.snowflake_account,
                user=self.snowflake_user,
                db=self.snowflake_database,
                schema=self.snowflake_schema,
                warehouse=self.snowflake_warehouse,
                role=self.snowflake_role,
                private_key=private_key
            )


settings = AppSettings()