"""Configuration management for the Netdata Zulip bot."""

import os
from pathlib import Path
from typing import Optional

import structlog
from dotenv import load_dotenv

from .models import ZulipConfig, ServerConfig

logger = structlog.get_logger()


def load_config() -> tuple[ZulipConfig, ServerConfig]:
    """Load configuration from environment variables and .env files."""
    
    # Load .env file if present
    env_file = Path(".env")
    if env_file.exists():
        load_dotenv(env_file)
        logger.info("Loaded configuration from .env file")
    
    # Load Zulip configuration
    zulip_config = ZulipConfig(
        site=os.getenv("ZULIP_SITE", ""),
        email=os.getenv("ZULIP_EMAIL", ""),
        api_key=os.getenv("ZULIP_API_KEY", ""),
        stream=os.getenv("ZULIP_STREAM", "netdata-alerts"),
    )
    
    # Validate required Zulip settings
    if not all([zulip_config.site, zulip_config.email, zulip_config.api_key]):
        raise ValueError(
            "Missing required Zulip configuration. Please set ZULIP_SITE, "
            "ZULIP_EMAIL, and ZULIP_API_KEY environment variables."
        )
    
    # Load server configuration
    server_config = ServerConfig(
        host=os.getenv("SERVER_HOST", "0.0.0.0"),
        port=int(os.getenv("SERVER_PORT", "8443")),
        domain=os.getenv("SERVER_DOMAIN", ""),
        cert_path=os.getenv("SERVER_CERT_PATH", "/etc/letsencrypt/live"),
        enable_mtls=os.getenv("SERVER_ENABLE_MTLS", "true").lower() == "true",
    )
    
    # Validate required server settings
    if not server_config.domain:
        raise ValueError(
            "Missing required server configuration. Please set SERVER_DOMAIN "
            "environment variable."
        )
    
    logger.info(
        "Configuration loaded",
        zulip_site=zulip_config.site,
        zulip_email=zulip_config.email,
        zulip_stream=zulip_config.stream,
        server_host=server_config.host,
        server_port=server_config.port,
        server_domain=server_config.domain,
        mtls_enabled=server_config.enable_mtls,
    )
    
    return zulip_config, server_config


def load_zuliprc_config(zuliprc_path: Optional[str] = None) -> ZulipConfig:
    """Load Zulip configuration from a zuliprc file.
    
    Args:
        zuliprc_path: Path to zuliprc file. If None, looks for ~/.zuliprc
        
    Returns:
        ZulipConfig instance
    """
    if zuliprc_path is None:
        zuliprc_path = Path.home() / ".zuliprc"
    else:
        zuliprc_path = Path(zuliprc_path)
    
    if not zuliprc_path.exists():
        raise FileNotFoundError(f"Zuliprc file not found: {zuliprc_path}")
    
    config = {}
    with open(zuliprc_path, 'r') as f:
        for line in f:
            line = line.strip()
            if line and not line.startswith('#') and '=' in line:
                key, value = line.split('=', 1)
                config[key.strip()] = value.strip()
    
    # Map zuliprc keys to our config
    zulip_config = ZulipConfig(
        site=config.get('site', ''),
        email=config.get('email', ''),
        api_key=config.get('key', ''),
        stream=config.get('stream', 'netdata-alerts'),
    )
    
    logger.info(
        "Loaded Zulip configuration from zuliprc",
        path=str(zuliprc_path),
        site=zulip_config.site,
        email=zulip_config.email,
        stream=zulip_config.stream
    )
    
    return zulip_config