"""Click command for exposing a browser over TCP."""
from __future__ import annotations

import asyncio
import sys
from pathlib import Path

import click

from browser_cli import transport
from browser_cli.serve.runtime import (
    _async_framed_send,
    _async_handle_client,
    _async_recv_all,
    _handle_client,
    _serve_async,
    console,
)
from browser_cli.version_manager import get_installed_version

__all__ = [
    "_async_framed_send",
    "_async_handle_client",
    "_async_recv_all",
    "_handle_client",
    "_serve_async",
    "cmd_serve",
]

@click.command("serve")
@click.option("--host", default="127.0.0.1", show_default=True, help="Address to bind.")
@click.option("--port", default=8765, show_default=True, type=int, help="TCP port to listen on.")
@click.option("--no-auth", is_flag=True, default=False, help="Disable authentication (dangerous).")
@click.option(
    "--authorized-keys",
    "auth_keys_file",
    default=None,
    metavar="FILE",
    help="File of trusted Ed25519 public keys (one hex per line). Required unless --no-auth.",
)
@click.option(
    "--no-compress",
    "no_compress",
    is_flag=True,
    default=False,
    help="Disable response compression / msgpack even for clients that support it.",
)
@click.pass_context
def cmd_serve(ctx, host, port, no_auth, auth_keys_file, no_compress):
    """Expose this browser over TCP so remote hosts can control it."""
    profile = ctx.obj.get("browser") if ctx.obj else None
    compress = not no_compress

    if host in ("0.0.0.0", "::"):
        console.print(
            "[yellow]Warning:[/yellow] Binding to all interfaces — "
            "anyone who can reach this port controls your browser."
        )

    auth_keys_path = _resolve_auth_keys_path(auth_keys_file, no_auth)
    if auth_keys_path is False:
        sys.exit(1)

    _print_startup(host, port, profile, auth_keys_path, compress)

    try:
        asyncio.run(_serve_async(host, port, profile, auth_keys_path, compress))
    except OSError as e:
        console.print(f"[red]Cannot bind to {host}:{port}:[/red] {e}")
        sys.exit(1)
    except KeyboardInterrupt:
        console.print("[yellow]Stopped.[/yellow]")

def _resolve_auth_keys_path(auth_keys_file: str | None, no_auth: bool) -> Path | None | bool:
    if auth_keys_file:
        from browser_cli.auth import load_authorized_keys

        auth_keys_path = Path(auth_keys_file)
        if not load_authorized_keys(auth_keys_path):
            console.print(f"[yellow]Warning:[/yellow] No authorized keys found in {auth_keys_path}")
        return auth_keys_path
    if no_auth:
        return None
    console.print(
        "[red]Error:[/red] --authorized-keys FILE is required. "
        "Use --no-auth to explicitly disable auth (dangerous)."
    )
    return False

def _print_startup(host: str, port: int, profile: str | None, auth_keys_path: Path | None, compress: bool) -> None:
    current_ver = get_installed_version()
    browser_hint = f" (browser: {profile})" if profile else ""
    console.print(f"[green]Serving browser{browser_hint} →[/green] [cyan]{host}:{port}[/cyan]  [dim]v{current_ver}[/dim]")

    if auth_keys_path is not None:
        from browser_cli.auth import load_authorized_keys

        n = len(load_authorized_keys(auth_keys_path))
        console.print(f"  Auth:   [bold green]Ed25519 pubkey[/bold green] ({n} trusted key{'s' if n != 1 else ''})")
    else:
        console.print("[yellow]  Auth disabled (--no-auth)[/yellow]")

    console.print(f"  CLI:    [dim]browser-cli --remote {host}:{port} tabs list[/dim]")
    console.print(f"  Python: [dim]BrowserCLI(remote=\"{host}:{port}\").tabs.list()[/dim]")
    _print_encoding_status(compress)
    console.print("Ctrl-C to stop.\n")

def _print_encoding_status(compress: bool) -> None:
    if not compress:
        console.print("  Encode: [yellow]off (--no-compress)[/yellow]")
        return
    codecs = "+".join(transport.supported_compression())
    sers = "+".join(transport.supported_serialization())
    console.print(
        "  Encode: [green]on[/green] "
        f"[dim](compression: {codecs}; serialization: {sers}; per-client negotiated)[/dim]"
    )