# ssh_manager/edit_host.py

import os
from collections import OrderedDict
from .utils import print_error, print_warning, print_info

def load_config_file(file_path):
    """
    Parse the given config file into a list of host blocks (OrderedDict).
    """
    blocks = []
    host_data = None

    try:
        with open(file_path, 'r') as f:
            lines = f.readlines()
    except Exception as e:
        print_error(f"Error reading SSH config file {file_path}: {e}")
        return blocks

    for line in lines:
        stripped_line = line.strip()
        if not stripped_line or stripped_line.startswith('#'):
            continue

        if stripped_line.lower().startswith('host '):
            host_labels = stripped_line.split()[1:]
            for label in host_labels:
                if '*' not in label:
                    if host_data:
                        blocks.append(host_data)
                    host_data = OrderedDict({'Host': label})
                    break
        elif host_data:
            if ' ' in stripped_line:
                key, value = stripped_line.split(None, 1)
                host_data[key] = value.strip()

    if host_data:
        blocks.append(host_data)
    return blocks

def edit_host(conf_dir):
    """
    Let the user update fields for an existing host in ~/.ssh/conf/<label>/config.
    """
    host_label = input("Enter the Host label to edit: ").strip()
    if not host_label:
        print_error("Host label cannot be empty.")
        return

    host_dir    = os.path.join(conf_dir, host_label)
    config_path = os.path.join(host_dir, "config")
    if not os.path.isfile(config_path):
        print_warning(f"No config file found at {config_path}; cannot edit this host.")
        return

    blocks = load_config_file(config_path)
    if not blocks:
        print_warning(f"No valid Host blocks found in {config_path}")
        return

    target_block = None
    for b in blocks:
        if b.get("Host") == host_label:
            target_block = b
            break

    if not target_block:
        print_warning(f"No matching Host '{host_label}' found in {config_path}")
        return

    old_hostname = target_block.get("HostName", "")
    old_user     = target_block.get("User", "")
    old_port     = target_block.get("Port", "22")
    old_identity = target_block.get("IdentityFile", "")

    print_info("Leave a field blank to keep its current value.")
    new_hostname = input(f"Enter new HostName [{old_hostname}]: ").strip()
    new_user     = input(f"Enter new User [{old_user}]: ").strip()
    new_port     = input(f"Enter new Port [{old_port}]: ").strip()
    new_ident    = input(f"Enter new IdentityFile [{old_identity}]: ").strip()

    final_hostname = new_hostname if new_hostname else old_hostname
    final_user     = new_user if new_user else old_user
    final_port     = new_port if new_port else old_port
    final_ident    = new_ident if new_ident else old_identity

    new_config_lines = [
        f"Host {host_label}",
        f"    HostName {final_hostname}",
        f"    User {final_user}",
        f"    Port {final_port}"
    ]
    if final_ident:
        new_config_lines.append(f"    IdentityFile {final_ident}")

    try:
        with open(config_path, "w") as f:
            for line in new_config_lines:
                f.write(line + "\n")
        print_info(f"Updated config at: {config_path}")
    except Exception as e:
        print_error(f"Failed to update config: {e}")