#!/usr/bin/env python3
"""One-shot bootstrap launcher for Hermes Web UI."""

from __future__ import annotations

import argparse
import os
import platform
import shutil
import subprocess
import sys
import time
import urllib.error
import urllib.request
import venv
import webbrowser
from pathlib import Path


INSTALLER_URL = "https://raw.githubusercontent.com/NousResearch/hermes-agent/main/scripts/install.sh"
REPO_ROOT = Path(__file__).resolve().parent


def _load_repo_dotenv() -> None:
    """Load REPO_ROOT/.env into os.environ.

    Mirrors what start.sh does via ``set -a; source .env`` so that running
    ``python3 bootstrap.py`` directly behaves identically to ``./start.sh``.
    Variables are set unconditionally (matching shell source semantics), so a
    value in .env overrides one already present in the shell environment.
    To keep a CLI-supplied value, unset it from .env or launch via start.sh
    and override there.

    Only loads the webui repo .env — not ~/.hermes/.env, which the server
    loads independently at startup for provider credentials.

    Note: does not handle the ``export FOO=bar`` prefix — strip ``export``
    from .env values if copy-pasting from a shell rc file.
    """
    env_path = REPO_ROOT / ".env"
    if not env_path.exists():
        return
    try:
        for raw_line in env_path.read_text(encoding="utf-8").splitlines():
            line = raw_line.strip()
            if not line or line.startswith("#") or "=" not in line:
                continue
            k, v = line.split("=", 1)
            k = k.strip()
            # Strip optional 'export' prefix (common in copy-pasted shell snippets)
            if k.startswith("export "):
                k = k[7:].strip()
            v = v.strip().strip('"').strip("'")
            if k:
                os.environ[k] = v
    except Exception as exc:
        import sys as _sys
        print(f"[bootstrap] Warning: could not load .env — {exc}", file=_sys.stderr)


# Side effect: loads REPO_ROOT/.env into os.environ on import.
# Must run before DEFAULT_HOST / DEFAULT_PORT so os.getenv() picks up
# values from .env even when bootstrap.py is invoked directly (not via start.sh).
_load_repo_dotenv()

DEFAULT_HOST = os.getenv("HERMES_WEBUI_HOST", "127.0.0.1")
DEFAULT_PORT = int(os.getenv("HERMES_WEBUI_PORT", "8787"))
# Set HERMES_WEBUI_SKIP_ONBOARDING=1 to bypass the first-run wizard when
# the environment is already fully configured (e.g. managed hosting).


def info(msg: str) -> None:
    print(f"[bootstrap] {msg}", flush=True)


def is_wsl() -> bool:
    if platform.system() != "Linux":
        return False
    release = platform.release().lower()
    return (
        "microsoft" in release or "wsl" in release or bool(os.getenv("WSL_DISTRO_NAME"))
    )


def ensure_supported_platform() -> None:
    if platform.system() == "Windows" and not is_wsl():
        raise RuntimeError(
            "Native Windows is not supported for this bootstrap yet. "
            "Please run it from Linux, macOS, or inside WSL2."
        )


def _agent_dir_from_hermes_cli() -> Path | None:
    """Resolve the agent install root by inspecting the `hermes` CLI shebang.

    The Hermes Agent installer drops a `hermes` console-script in the user's
    PATH whose shebang points at the agent's bundled venv:

        #!/path/to/hermes-agent/venv/bin/python3

    Walking up the parents until we find a directory that contains
    `run_agent.py` recovers the install root regardless of where the user
    chose to clone the agent (e.g. ~/Projects/GitHub/hermes-agent), which
    the hard-coded candidate list in :func:`discover_agent_dir` cannot.

    Last-resort only: this is invoked after every explicit candidate
    (`HERMES_WEBUI_AGENT_DIR`, `$HERMES_HOME/hermes-agent`, etc.) has missed.
    A stale clone in a known location still wins over the live `hermes` CLI
    — that's intentional, since the candidate list is treated as
    authoritative when present, and matches existing behavior.
    """
    hermes_path = shutil.which("hermes")
    if not hermes_path:
        return None
    try:
        with open(hermes_path, "r", encoding="utf-8", errors="replace") as f:
            first_line = f.readline().strip()
    except OSError:
        return None
    if not first_line.startswith("#!"):
        return None
    interp_field = first_line[2:].strip().split(None, 1)
    if not interp_field:
        return None
    interp = Path(interp_field[0])
    if not interp.is_absolute():
        return None
    for parent in interp.parents:
        if (parent / "run_agent.py").exists():
            return parent.resolve()
    return None


def discover_agent_dir() -> Path | None:
    home = Path(os.getenv("HERMES_HOME", str(Path.home() / ".hermes"))).expanduser()
    candidates = [
        os.getenv("HERMES_WEBUI_AGENT_DIR", ""),
        str(home / "hermes-agent"),
        str(REPO_ROOT.parent / "hermes-agent"),
        str(Path.home() / ".hermes" / "hermes-agent"),
        str(Path.home() / "hermes-agent"),
    ]
    for raw in candidates:
        if not raw:
            continue
        candidate = Path(raw).expanduser().resolve()
        if candidate.exists() and (candidate / "run_agent.py").exists():
            return candidate
    return _agent_dir_from_hermes_cli()


def discover_launcher_python(agent_dir: Path | None) -> str:
    env_python = os.getenv("HERMES_WEBUI_PYTHON")
    if env_python:
        return env_python
    if agent_dir:
        for rel in ("venv/bin/python", "venv/Scripts/python.exe", ".venv/bin/python", ".venv/Scripts/python.exe"):
            candidate = agent_dir / rel
            if candidate.exists():
                return str(candidate)
    for rel in (".venv/bin/python", ".venv/Scripts/python.exe"):
        candidate = REPO_ROOT / rel
        if candidate.exists():
            return str(candidate)
    return shutil.which("python3") or shutil.which("python") or sys.executable


def _python_can_run_webui_and_agent(python_exe: str, agent_dir: Path | None = None) -> bool:
    script = "import yaml\nfrom run_agent import AIAgent\n"
    env = os.environ.copy()
    if agent_dir:
        # PREPEND agent_dir to PYTHONPATH so an `agent_dir/run_agent.py` wins
        # over any stale `run_agent` package in system site-packages (sys.path
        # order: script-dir → PYTHONPATH entries → site-packages). The
        # "if PYTHONPATH unset" branch avoids a leading os.pathsep, which
        # CPython would interpret as "current directory" — a footgun.
        env["PYTHONPATH"] = (
            str(agent_dir)
            if not env.get("PYTHONPATH")
            else f"{agent_dir}{os.pathsep}{env['PYTHONPATH']}"
        )
    check = subprocess.run(
        [python_exe, "-c", script],
        capture_output=True,
        text=True,
        env=env,
    )
    return check.returncode == 0


def ensure_python_has_webui_deps(python_exe: str, agent_dir: Path | None = None) -> str:
    """Return a Python executable that can run both WebUI and Hermes Agent.

    The WebUI can be launched directly with its local .venv. That venv has the
    WebUI dependencies (for example PyYAML), but may not have Hermes Agent on its
    import path. In that case the server starts healthy, then chat fails later
    with "AIAgent not available". Prefer the agent venv when it is usable, and
    validate the final interpreter before starting the server.
    """
    if _python_can_run_webui_and_agent(python_exe, agent_dir):
        return python_exe

    agent_candidates: list[Path] = []
    if agent_dir:
        for rel in (
            "venv/bin/python",
            "venv/Scripts/python.exe",
            ".venv/bin/python",
            ".venv/Scripts/python.exe",
        ):
            agent_candidates.append(agent_dir / rel)
        for candidate in agent_candidates:
            if str(candidate) != python_exe and candidate.exists():
                if _python_can_run_webui_and_agent(str(candidate), agent_dir):
                    return str(candidate)

    venv_dir = REPO_ROOT / ".venv"
    venv_python = venv_dir / (
        "Scripts/python.exe" if platform.system() == "Windows" else "bin/python"
    )
    if not venv_python.exists():
        info(f"Creating local virtualenv at {venv_dir}")
        # symlinks=True: some Python builds (notably mise/asdf shared-library
        # installs on macOS) default venv to copy mode. The copied binary still
        # uses @executable_path/../lib/libpython3.X.dylib for its load command,
        # so the venv binary aborts with SIGABRT on first import because the
        # dylib never gets copied into .venv/lib. Symlinking the interpreter
        # keeps @executable_path resolving back to the original install.
        # CPython's venv falls back to copy mode automatically when symlink
        # creation fails (e.g. older Windows without SeCreateSymbolicLinkPrivilege),
        # so this is safe to set unconditionally.
        venv.EnvBuilder(with_pip=True, symlinks=True).create(venv_dir)

    info("Installing WebUI dependencies into local virtualenv")
    subprocess.run(
        [str(venv_python), "-m", "pip", "install", "--quiet", "--upgrade", "pip"],
        check=True,
    )
    subprocess.run(
        [
            str(venv_python),
            "-m",
            "pip",
            "install",
            "--quiet",
            "-r",
            str(REPO_ROOT / "requirements.txt"),
        ],
        check=True,
    )
    if _python_can_run_webui_and_agent(str(venv_python), agent_dir):
        return str(venv_python)
    raise RuntimeError(
        "Python environment cannot import both WebUI dependencies and Hermes Agent. "
        "Set HERMES_WEBUI_PYTHON to the Hermes Agent venv Python or install the "
        "WebUI requirements into that environment."
    )


def hermes_command_exists() -> bool:
    return shutil.which("hermes") is not None


def install_hermes_agent() -> None:
    info(f"Hermes Agent not found. Attempting install via {INSTALLER_URL}")
    subprocess.run(
        ["/bin/bash", "-lc", f"curl -fsSL {INSTALLER_URL} | bash"], check=True
    )


def wait_for_health(url: str, timeout: float = 25.0) -> bool:
    deadline = time.time() + timeout
    # Validate URL scheme to prevent file:// and other dangerous schemes
    if not url.startswith(("http://", "https://")):
        raise ValueError(f"Invalid health check URL: {url}")
    while time.time() < deadline:
        try:
            with urllib.request.urlopen(url, timeout=2) as response:  # nosec B310
                if b'"status": "ok"' in response.read():
                    return True
        except Exception:
            time.sleep(0.4)
    return False


def open_browser(url: str) -> None:
    try:
        webbrowser.open(url)
    except Exception as exc:
        info(f"Could not open browser automatically: {exc}")


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Bootstrap Hermes Web UI onboarding.")
    parser.add_argument("port", nargs="?", type=int, default=DEFAULT_PORT)
    parser.add_argument("--host", default=DEFAULT_HOST)
    parser.add_argument(
        "--no-browser",
        action="store_true",
        help="Do not open a browser tab automatically.",
    )
    parser.add_argument(
        "--skip-agent-install",
        action="store_true",
        help="Fail instead of attempting the official Hermes installer.",
    )
    parser.add_argument(
        "--foreground",
        action="store_true",
        help=(
            "Run server.py in this process (via os.execv) instead of spawning a "
            "child. Use this under launchd / systemd / supervisord so the "
            "supervisor sees the long-lived server as the original child. "
            "Implies --no-browser. Skips the post-launch health probe — the "
            "supervisor's own KeepAlive / Restart=on-failure handles liveness."
        ),
    )
    return parser.parse_args()


# Env vars whose presence indicates this process was launched by a supervisor
# that wants to manage the server's lifecycle (KeepAlive, Restart=always, etc.).
# When any is set, we auto-promote to --foreground so we don't double-fork.
#
# - INVOCATION_ID            systemd (set on every service activation)
# - JOURNAL_STREAM           systemd (set when stdio is wired to the journal)
# - NOTIFY_SOCKET            systemd Type=notify, s6 sd_notify-style
# - XPC_SERVICE_NAME         launchd (set to the Label of the running plist)
# - SUPERVISOR_ENABLED       supervisord
# - HERMES_WEBUI_FOREGROUND  explicit user opt-in (=1 / true / yes / on)
#
# Note on XPC_SERVICE_NAME: macOS launchd sets this in EVERY Terminal-launched
# shell too — typical values include "0" (truthy in Python!) and
# "application.com.apple.Terminal.<UUID>". A bare existence check would
# false-positive on every Mac dev machine running ./start.sh interactively.
# We narrow to launchd Label-style names (com.<reverse-dns>.<svc>) — those
# are real services. Verified with `launchctl getenv XPC_SERVICE_NAME` and
# Apple's documented launchd behavior.
_SUPERVISOR_ENV_VARS = (
    "INVOCATION_ID",
    "JOURNAL_STREAM",
    "NOTIFY_SOCKET",
    "XPC_SERVICE_NAME",
    "SUPERVISOR_ENABLED",
)


def _is_real_supervisor_value(name: str, value: str) -> bool:
    """Filter out known-noise env-var values that aren't actual supervisors.

    Most env vars in _SUPERVISOR_ENV_VARS are only set by the supervisor we
    care about, so any non-empty value is meaningful. XPC_SERVICE_NAME is the
    exception: macOS launchd sets it in every Terminal-spawned shell with
    values like "0" or "application.com.apple.Terminal.<UUID>". A real
    launchd-managed service has a reverse-DNS Label like "com.example.foo".
    """
    if not value:
        return False
    if name == "XPC_SERVICE_NAME":
        # Reject Apple's noise values; accept Label-style names.
        if value == "0":
            return False
        if value.startswith("application."):
            return False
    return True


def _detect_supervisor() -> str | None:
    """Return the name of the detected supervisor env var, or None.

    Pure inspection of os.environ — no side effects. Returned name is the env
    var that triggered detection, useful for log messages and for tests.
    """
    explicit = os.environ.get("HERMES_WEBUI_FOREGROUND", "").strip().lower()
    if explicit in ("1", "true", "yes", "on"):
        return "HERMES_WEBUI_FOREGROUND"
    for name in _SUPERVISOR_ENV_VARS:
        value = os.environ.get(name, "")
        if _is_real_supervisor_value(name, value):
            return name
    return None


def main() -> int:
    args = parse_args()
    ensure_supported_platform()

    agent_dir = discover_agent_dir()
    if not agent_dir and not hermes_command_exists():
        if args.skip_agent_install:
            raise RuntimeError(
                "Hermes Agent was not found and auto-install was disabled."
            )
        install_hermes_agent()
        agent_dir = discover_agent_dir()

    python_exe = ensure_python_has_webui_deps(discover_launcher_python(agent_dir), agent_dir)
    state_dir = Path(
        os.getenv("HERMES_WEBUI_STATE_DIR", str(Path.home() / ".hermes" / "webui"))
    ).expanduser()
    state_dir.mkdir(parents=True, exist_ok=True)

    # Mutate os.environ so child (or post-execv) inherits the resolved values.
    os.environ["HERMES_WEBUI_HOST"] = args.host
    os.environ["HERMES_WEBUI_PORT"] = str(args.port)
    os.environ.setdefault("HERMES_WEBUI_STATE_DIR", str(state_dir))
    if agent_dir:
        os.environ["HERMES_WEBUI_AGENT_DIR"] = str(agent_dir)

    server_cwd = str(agent_dir or REPO_ROOT)
    server_path = str(REPO_ROOT / "server.py")

    # --foreground (or auto-detected supervisor): replace this process with the
    # server. The supervisor sees the long-lived server as the original child,
    # so KeepAlive / Restart=always / autorestart=true work correctly. No
    # health probe — the supervisor's own restart-on-exit handles liveness.
    foreground_reason = "--foreground" if args.foreground else _detect_supervisor()
    if foreground_reason:
        info(
            f"Starting Hermes Web UI on http://{args.host}:{args.port} "
            f"(foreground mode: {foreground_reason})"
        )
        try:
            os.chdir(server_cwd)
        except OSError as exc:
            raise RuntimeError(
                f"Could not chdir to {server_cwd!r} before exec: {exc}"
            ) from exc
        # Defensive check: if python_exe is missing or non-executable, execv
        # raises OSError, the wrapper catches and SystemExit(1)s, and the
        # supervisor restarts — looping forever, exactly the failure mode this
        # PR is meant to eliminate. Convert to a single visible error.
        if not os.access(python_exe, os.X_OK):
            raise RuntimeError(
                f"Python interpreter at {python_exe!r} is not executable. "
                f"Set HERMES_WEBUI_PYTHON to a working interpreter or fix "
                f"the agent venv at {agent_dir}."
            )
        # os.execv replaces the current process image. Anything after this line
        # only runs if execv itself fails (it raises OSError on failure).
        os.execv(python_exe, [python_exe, server_path])
        # Unreachable — execv either replaces the process or raises.
        raise RuntimeError("os.execv returned unexpectedly")

    # Default (legacy) path: spawn the server as a detached child, probe
    # /health, then return. Suitable for an interactive `bash start.sh` run.
    log_path = state_dir / f"bootstrap-{args.port}.log"

    info(f"Starting Hermes Web UI on http://{args.host}:{args.port}")
    with log_path.open("ab") as log_file:
        proc = subprocess.Popen(
            [python_exe, server_path],
            cwd=server_cwd,
            env=os.environ.copy(),
            stdout=log_file,
            stderr=subprocess.STDOUT,
            start_new_session=True,
        )

    health_url = f"http://{args.host}:{args.port}/health"
    if not wait_for_health(health_url):
        raise RuntimeError(
            f"Web UI did not become healthy at {health_url}. "
            f"Check the log at {log_path}. Server PID: {proc.pid}"
        )

    app_url = (
        f"http://localhost:{args.port}"
        if args.host in ("127.0.0.1", "localhost")
        else f"http://{args.host}:{args.port}"
    )
    info(f"Web UI is ready: {app_url}")
    info(f"Log file: {log_path}")
    if not args.no_browser:
        open_browser(app_url)
    return 0


if __name__ == "__main__":
    try:
        raise SystemExit(main())
    except Exception as exc:
        print(f"[bootstrap] ERROR: {exc}", file=sys.stderr)
        raise SystemExit(1)