unsloth/studio/backend/startup_banner.py

# SPDX-License-Identifier: AGPL-3.0-only
# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0

"""Terminal banner for Studio startup.

Stdlib only — safe to import without the rest of the backend (no structlog/uvicorn).
"""

from __future__ import annotations

import os
import sys


def stdout_supports_color() -> bool:
    """True if we should emit ANSI colors."""
    if os.environ.get("NO_COLOR", "").strip():
        return False
    if os.environ.get("FORCE_COLOR", "").strip():
        return True
    try:
        return sys.stdout.isatty()
    except Exception:
        return False


def print_port_in_use_notice(original_port: int, new_port: int) -> None:
    """Message when the requested port is taken and another is chosen."""
    msg = f"Port {original_port} is in use, using port {new_port} instead."
    if stdout_supports_color():
        print(f"\033[38;5;245m{msg}\033[0m")
    else:
        print(msg)


def print_studio_access_banner(
    *,
    port: int,
    bind_host: str,
    display_host: str,
) -> None:
    """Pretty-print URLs after the server is listening (beginner-friendly)."""
    use_color = stdout_supports_color()
    dim = "\033[38;5;245m"
    title = "\033[38;5;150m"
    local_url_style = "\033[38;5;108;1m"
    secondary = "\033[38;5;109m"
    reset = "\033[0m"

    def style(text: str, code: str) -> str:
        return f"{code}{text}{reset}" if use_color else text

    ipv6_bind = bind_host in ("::", "::1")
    if ipv6_bind:
        local_url = f"http://[::1]:{port}"
        alt_local = f"http://localhost:{port}"
    else:
        local_url = f"http://127.0.0.1:{port}"
        alt_local = f"http://localhost:{port}"
    if ":" in display_host:
        external_url = f"http://[{display_host}]:{port}"
    else:
        external_url = f"http://{display_host}:{port}"
    listen_all = bind_host in ("0.0.0.0", "::")
    loopback_bind = bind_host in ("127.0.0.1", "localhost", "::1")
    api_base = local_url if listen_all or loopback_bind else external_url

    lines: list[str] = [
        "",
        style("🦥 Unsloth Studio is running", title),
        style("─" * 52, dim),
        style("  On this machine — open this in your browser:", dim),
        style(f"    {local_url}", local_url_style),
        style(f"    (same as {alt_local})", dim),
    ]

    if listen_all and display_host not in (
        "127.0.0.1",
        "localhost",
        "::1",
        "0.0.0.0",
        "::",
    ):
        lines.extend(
            [
                "",
                style("  From another device on your network / to share:", dim),
                style(f"    {external_url}", secondary),
            ]
        )
    elif not listen_all and bind_host not in ("127.0.0.1", "localhost", "::1"):
        lines.extend(
            [
                "",
                style("  Bound address:", dim),
                style(f"    {external_url}", secondary),
            ]
        )

    lines.extend(
        [
            "",
            style("  API & health:", dim),
            style(f"    {api_base}/api", secondary),
            style(f"    {api_base}/api/health", secondary),
            style("─" * 52, dim),
            style(
                "  Tip: if you are on the same computer, use the Local link above.",
                dim,
            ),
            "",
        ]
    )

    print("\n".join(lines))