import subprocess
import re
import tempfile
import os
import argparse
import pathlib

SCRIPT_PATH = pathlib.Path(__file__).parent / "worker.py"

def execute_script(provider, location, server_type):
    command = [
        "python", SCRIPT_PATH,
        "--provider", provider,
        "--location", location,
        "--server_type", server_type
    ]
    result = subprocess.run(command, capture_output=True, text=True)
    if result.returncode != 0:
        raise Exception(f"Error executing script: {result.stderr}")
    return result.stdout.strip()

def replace_peer_section(config_content, new_peer_section):
    # Regular expression to match the [Peer] section
    peer_section_pattern = re.compile(r'\[Peer\](?:\n(?!\[)[^\n]*)*')
    
    # Find the existing [Peer] section
    match = peer_section_pattern.search(config_content)
    
    if match:
        # Replace the existing [Peer] section with the new one
        updated_content = config_content[:match.start()] + new_peer_section + config_content[match.end():]
    else:
        # If no [Peer] section exists, append the new one
        updated_content = config_content + "\n" + new_peer_section
    
    return updated_content

def main():
    parser = argparse.ArgumentParser(description="Update local Wireguard configuration with a new peer.")
    parser.add_argument("--provider", type=str, choices=["hetzner", "aws", "digitalocean", "azure"], required=True, help="Cloud provider")
    parser.add_argument("--location", type=str, required=True, help="Server location")
    parser.add_argument("--server_type", type=str, required=True, help="Server type")
    parser.add_argument("--interface", type=str, required=True, help="Wireguard interface (e.g., wg0)")

    args = parser.parse_args()

    provider = args.provider
    location = args.location
    server_type = args.server_type
    interface = args.interface
    config_path = f"/etc/wireguard/{interface}.conf"

    # Step 1: Execute the existing script to set up the remote VPN server
    new_peer_section = execute_script(provider, location, server_type)

    # Step 2: Read the local Wireguard configuration file
    with open(config_path, 'r') as file:
        config_content = file.read()

    # Step 3: Replace the existing [Peer] section with the new one
    updated_content = replace_peer_section(config_content, new_peer_section)

    # Step 4: Save the updated configuration file
    with tempfile.NamedTemporaryFile(delete=False, mode='w') as temp_file:
        temp_file.write(updated_content)
        temp_file_path = temp_file.name

    # Step 5: Apply the updated Wireguard configuration
    subprocess.run(["wg-quick", "down", interface], stderr=subprocess.DEVNULL)
    subprocess.run(["wg-quick", "up", temp_file_path])

    # Overwrite the original config file with the updated content
    os.replace(temp_file_path, config_path)

    print(f"Local Wireguard configuration for {interface} updated and applied successfully.")

if __name__ == "__main__":
    main()