"""
Database utility functions for the OpenEventDatabase.
"""

import os
import sys
import psycopg2
import psycopg2.extras
from oedb.utils.logging import logger

def load_env_from_file():
    """
    Load environment variables from .env file at the project root directory.
    This ensures that database connection parameters are properly set.
    
    Returns:
        bool: True if the .env file exists and was loaded, False otherwise.
    """
    # Determine the project root directory (parent directory of the oedb package)
    project_root = os.path.abspath(os.path.join(os.path.dirname(__file__), '../..'))
    env_file_path = os.path.join(project_root, '.env')
    
    if os.path.exists(env_file_path):
        logger.info(f"Loading environment variables from {env_file_path}...")
        with open(env_file_path, 'r') as f:
            for line in f:
                line = line.strip()
                if line and not line.startswith('#'):
                    key, value = line.split('=', 1)
                    os.environ[key] = value
        return True
    else:
        logger.warning(f".env file not found at {env_file_path}")
        return False

def db_connect():
    """
    Connect to the PostgreSQL database using environment variables.
    
    Returns:
        psycopg2.connection: A connection to the database.
    """
    # Load environment variables from .env file
    load_env_from_file()
    
    # Get connection parameters from environment variables
    dbname = os.getenv("DB_NAME", "oedb")
    host = os.getenv("DB_HOST", "")
    password = os.getenv("POSTGRES_PASSWORD", None)
    user = os.getenv("DB_USER", "")
    
    # If host is empty, set it to localhost to force TCP/IP connection
    # instead of Unix socket (which uses peer authentication)
    if not host:
        host = "localhost"
    
    logger.debug(f"Connecting to database: {dbname} on {host} as user {user}")
    
    # For localhost connections, add additional parameters to ensure proper connection
    if host in ('localhost', '127.0.0.1'):
        logger.debug("Using TCP/IP connection with additional parameters")
        return psycopg2.connect(
            dbname=dbname,
            host=host,
            password=password,
            user=user,
            options="-c client_encoding=utf8 -c statement_timeout=3000",
            connect_timeout=3,
            application_name="oedb",
            # Disable SSL for local connections
            sslmode='disable')
    else:
        # For remote connections, use standard parameters
        logger.debug("Using standard connection parameters")
        return psycopg2.connect(
            dbname=dbname,
            host=host,
            password=password,
            user=user)

def check_db_connection():
    """
    Check if the database is accessible.
    
    Returns:
        bool: True if the database is accessible, False otherwise.
    """
    try:
        conn = db_connect()
        conn.close()
        logger.success("Successfully connected to PostgreSQL database")
        return True
    except psycopg2.OperationalError as e:
        logger.error(f"Failed to connect to PostgreSQL database: {e}")
        return False