import os
import asyncio
from collections import OrderedDict
from .utils import print_error, print_warning, print_info, safe_input
from .list_hosts import (
    build_host_list_table,
    load_config_file,
    gather_host_info,
    sort_by_ip
)

async def edit_host(conf_dir):
    """
    Let the user update fields for an existing host in ~/.ssh/conf/<label>/config.
    1) Display the unified table (No. | Host | User | Port | HostName | IP Address | Conf Directory)
    2) Prompt row number or host label
    3) Rewrite config with updated fields
    """

    print_info("Here is the current list of hosts:\n")
    headers, final_data = await build_host_list_table(conf_dir)
    if not final_data:
        print_warning("No hosts to edit.")
        return

    from tabulate import tabulate
    print("\nSSH Conf Subdirectory Host List (Sorted by IP Ascending)")
    print(tabulate(final_data, headers=headers, tablefmt="grid"))

    choice = safe_input("Enter the row number or the Host label to edit: ")
    if choice is None:
        return  # user canceled (Ctrl+C)
    choice = choice.strip()
    if not choice:
        print_error("Host label or row number cannot be empty.")
        return

    # We replicate the approach to find the matching block
    all_blocks = []
    import glob
    for cfile in glob.glob(os.path.join(conf_dir, "*", "config")):
        all_blocks.extend(load_config_file(cfile))

    results = await gather_host_info(all_blocks)
    sorted_rows = sort_by_ip(results)

    target_tuple = None
    if choice.isdigit():
        idx = int(choice)
        if idx < 1 or idx > len(sorted_rows):
            print_warning(f"Row number {idx} is invalid.")
            return
        target_tuple = sorted_rows[idx - 1]
    else:
        for t in sorted_rows:
            if t[0] == choice:  # t[0] => host_label
                target_tuple = t
                break
        if not target_tuple:
            print_warning(f"No matching Host '{choice}' found in the table.")
            return

    host_label = target_tuple[0]
    # find the config block
    found_block = None
    for b in all_blocks:
        if b.get("Host") == host_label:
            found_block = b
            break

    if not found_block:
        print_warning(f"No config block found for '{host_label}'.")
        return

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

    print_info("Leave a field blank to keep its current value.")

    new_hostname = safe_input(f"Enter new HostName [{old_hostname}]: ")
    if new_hostname is None:
        return
    new_hostname = new_hostname.strip()

    new_user = safe_input(f"Enter new User [{old_user}]: ")
    if new_user is None:
        return
    new_user = new_user.strip()

    new_port = safe_input(f"Enter new Port [{old_port}]: ")
    if new_port is None:
        return
    new_port = new_port.strip()

    new_ident = safe_input(f"Enter new IdentityFile [{old_identity}]: ")
    if new_ident is None:
        return
    new_ident = new_ident.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

    # Overwrite the file
    config_path = os.path.join(conf_dir, host_label, "config")
    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}")