"""Env methods."""

import os
import subprocess

from ..configs import DBConfig, MySQLConfig, SnowflakeConfig
from ..errors import ConfigurationError, GenerationError


def check_sqlacodegen() -> bool:
    """Check if sqlacodegen is installed."""
    try:
        subprocess.run(['sqlacodegen', '--version'], capture_output=True, check=True)
        return True
    except (subprocess.CalledProcessError, FileNotFoundError):
        return False


def get_db_config() -> DBConfig:
    """Get the database config."""
    try_vars(['DB_VENDOR'])
    vendor = str(os.environ.get('DB_VENDOR')).lower()
    if vendor == 'mysql':
        return get_mysql_config()
    if vendor == 'snowflake':
        return get_snowflake_config()
    raise ValueError(f"Unknown DB vendor '{vendor}. Supported: mysql, snowflake")


def get_mysql_config() -> MySQLConfig:
    """Get the MySQL configuration from environment variables."""
    try_vars(['DB_HOST', 'DB_USER', 'DB_PASS', 'DB_NAME'])
    return MySQLConfig(
        host=str(os.environ.get('DB_HOST')),
        user=str(os.environ.get('DB_USER')),
        password=str(os.environ.get('DB_PASS')),
        database=str(os.environ.get('DB_NAME')),
        port=int(os.environ.get('DB_PORT', '3306')),
    )


def get_snowflake_config() -> SnowflakeConfig:
    """Get the MySQL configuration from environment variables."""
    try_vars(['DB_ACCOUNT', 'DB_NAME'])
    return SnowflakeConfig(
        account=str(os.environ.get('DB_ACCOUNT')),
        user=str(os.environ.get('DB_USER')),
        role=str(os.environ.get('DB_ROLE')),
        database=str(os.environ.get('DB_NAME')),
        password=os.environ.get('DB_PASS'),
        private_key_path=os.environ.get('DB_KEY_PATH'),
        private_key_pass=os.environ.get('DB_KEY_PASS'),
        schema=os.environ.get('DB_SCHEMA'),
        warehouse=os.environ.get('DB_WAREHOUSE'),
    )


def try_env() -> None:
    """Run all environment checks."""
    try_sqlacodegen()


def try_sqlacodegen() -> None:
    """Raise an error if sqlacodegen is not installed."""
    if not check_sqlacodegen():
        raise GenerationError('sqlacodegen is not installed')


def try_vars(required: list[str]) -> None:
    """Check for env vars and raise if any are missing."""
    missing = [var for var in required if var not in os.environ]

    if missing:
        raise ConfigurationError(f'Missing required env vars: {", ".join(missing)}')