"""HTTP client utilities for making requests to the backend API"""
import aiohttp
from typing import Optional
import ssl
import os


def get_windows_host_ip() -> Optional[str]:
    """
    Get the Windows host IP address when running in WSL.
    In WSL2, the Windows host IP is typically the first nameserver in /etc/resolv.conf.
    """
    try:
        if os.path.exists("/etc/resolv.conf"):
            with open("/etc/resolv.conf", "r") as f:
                for line in f:
                    if line.startswith("nameserver"):
                        ip = line.split()[1]
                        if ip not in ["127.0.0.1", "127.0.0.53"] and not ip.startswith("fe80"):
                            return ip
    except Exception:
        pass
    return None


def normalize_backend_url(url: str) -> str:
    """
    Normalize backend URL for better compatibility, especially on WSL and Docker.
    """
    if not ("localhost" in url or "127.0.0.1" in url):
        return url
    if os.path.exists("/.dockerenv"):
        print(f"Warning: Running in Docker but URL contains localhost: {url}")
        print("Please set BACKEND_URL environment variable in docker-compose.yml to use Docker service name (e.g., http://backend:8000/api/v1)")
        return url.replace("localhost", "127.0.0.1")
    try:
        if os.path.exists("/proc/version"):
            with open("/proc/version", "r") as f:
                version_content = f.read().lower()
                if "microsoft" in version_content:
                    windows_ip = get_windows_host_ip()
                    if windows_ip:
                        if "localhost" in url or "127.0.0.1" in url:
                            url = url.replace("localhost", windows_ip).replace("127.0.0.1", windows_ip)
                            print(f"WSL detected: Using Windows host IP {windows_ip} for backend connection")
                            return url
    except Exception as e:
        print(f"Warning: Could not detect WSL environment: {e}")
    
    if url.startswith("http://localhost") or url.startswith("https://localhost"):
        return url.replace("localhost", "127.0.0.1")
    return url


def create_http_session(timeout: Optional[aiohttp.ClientTimeout] = None) -> aiohttp.ClientSession:
    """
    Create a configured aiohttp ClientSession for backend API requests.
    
    Args:
        timeout: Optional timeout configuration. Defaults to 30 seconds total timeout.
    
    Returns:
        Configured aiohttp.ClientSession
    """
    if timeout is None:
        timeout = aiohttp.ClientTimeout(total=30, connect=10)
    
    connector = aiohttp.TCPConnector(
        ssl=False,
        limit=100,
        limit_per_host=30,
        force_close=True,
        enable_cleanup_closed=True
    )
    
    ssl_context = ssl.create_default_context()
    ssl_context.check_hostname = False
    ssl_context.verify_mode = ssl.CERT_NONE
    
    return aiohttp.ClientSession(
        connector=connector,
        timeout=timeout,
        headers={
            "Content-Type": "application/json",
            "Accept": "application/json"
        }
    )