"""Per-bottle sidecar bundle bringup for the smolmachines backend
(PRD 0023).

Two docker resources per bottle live here:

  - **A dedicated bridge network**, subnet derived from the slug.
    The bundle container gets a pinned IP at `<subnet>.2` so the
    smolvm guest's TSI allowlist (`<bundle-ip>/32`) has a stable
    target. Without pinning, we'd have to inspect the container's
    assigned IP after start and feed it back into the Smolfile
    — a race we can sidestep with `--ip`.

  - **The bundle container itself**, running the PRD 0024 bundle
    image (`bot-bottle-sidecars:latest` by default). Same
    image, same daemons, same daemon-private env / bind-mounts
    as the docker backend.

This module ships the lifecycle primitives only — create
network, start bundle, stop bundle, remove network — wrapped
around `subprocess.run(["docker", ...])`. Wiring them into the
launch flow + populating the `BundleLaunchSpec` from the inner
Plans (EgressPlan, …) lands in chunk 2d."""

from __future__ import annotations

import os
import socket
import subprocess
from dataclasses import dataclass, field
from pathlib import Path
from typing import Sequence

from ...log import die, warn
from ..docker import util as docker_mod
from ..docker.sidecar_bundle import (
    SIDECAR_BUNDLE_DOCKERFILE,
    SIDECAR_BUNDLE_IMAGE,
)
from . import smolvm as _smolvm


_REPO_DIR = str(Path(__file__).resolve().parent.parent.parent.parent)


def bundle_network_name(slug: str) -> str:
    """`bot-bottle-bundle-<slug>` — distinct from the docker
    backend's `bot-bottle-net-<slug>` so a smolmachines bottle
    and a docker bottle for the same agent don't collide on
    network name."""
    return f"bot-bottle-bundle-{slug}"


def bundle_container_name(slug: str) -> str:
    """`bot-bottle-sidecars-<slug>` — same name shape the docker
    backend uses for the bundle (PRD 0024 chunk 5). The dashboard's
    prefix-based discovery covers both backends with one filter."""
    return f"bot-bottle-sidecars-{slug}"


def bundle_machine_name(slug: str) -> str:
    """Sidecar smolVM machine name."""
    return bundle_container_name(slug)


@dataclass(frozen=True)
class BundleLaunchSpec:
    """Everything `start_bundle` needs to bring up one bundle
    container. Populated by chunk-2d's launch flow from the inner
    Plans the prepare step already produces."""

    slug: str
    network_name: str
    subnet: str
    gateway: str
    bundle_ip: str
    image: str = SIDECAR_BUNDLE_IMAGE
    # Daemon subset CSV for BOT_BOTTLE_SIDECAR_DAEMONS. The
    # supervisor inside the bundle reads it to skip
    # bottle-irrelevant daemons (e.g. supervise=False bottles).
    daemons_csv: str = "egress"
    # Plain "KEY=VALUE" strings + "KEY" bare names (the bare-name
    # form inherits the value from the docker-run subprocess env,
    # matching the docker backend's compose-up secret-forwarding
    # pattern).
    environment: Sequence[str] = field(default_factory=tuple)
    # (host_path, container_path, read_only) bind mounts.
    volumes: Sequence[tuple[str, str, bool]] = field(default_factory=tuple)
    # Container ports to publish on `publish_host_ip`, random
    # host-side port per entry. The smolvm guest's TSI talks via
    # macOS networking, so docker container IPs (192.168.x.x in
    # the daemon's bridge) aren't directly reachable from the
    # guest — host-loopback port-forwards are. Egress's port
    # is bundle-internal and never published.
    ports_to_publish: Sequence[int] = field(default_factory=tuple)
    # Loopback IP to bind published ports against. Per-bottle
    # loopback aliases (`127.0.0.16` etc., added via sudo
    # ifconfig lo0 alias) narrow the TSI allowlist so a bottle
    # can't reach other bottles' (or other host services') ports
    # via 127.0.0.1.
    publish_host_ip: str = "127.0.0.1"


@dataclass(frozen=True)
class BundleVmLaunch:
    raw_ports: dict[int, int]


def ensure_bundle_image(image: str = SIDECAR_BUNDLE_IMAGE) -> None:
    """Build the sidecar bundle image before `docker run`.

    The Docker backend gets this for free from compose's `build:`
    stanza. smolmachines starts the bundle with plain `docker run`,
    so without an explicit build a first launch tries to pull the
    local-only `bot-bottle-sidecars:latest` tag from a registry.
    """
    docker_mod.build_image(
        image,
        _REPO_DIR,
        dockerfile=SIDECAR_BUNDLE_DOCKERFILE,
    )


def allocate_raw_host_ports(container_ports: Sequence[int]) -> dict[int, int]:
    """Reserve candidate host loopback ports for smolVM `-p HOST:GUEST`.

    The sockets are closed before smolVM binds them, so this remains
    best-effort. smolVM failing to bind a selected port is fatal in
    the caller's launch path."""
    out: dict[int, int] = {}
    for container_port in container_ports:
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
            sock.bind(("127.0.0.1", 0))
            out[container_port] = int(sock.getsockname()[1])
    return out


def start_bundle_vm(
    spec: BundleLaunchSpec,
    *,
    from_path: Path,
    host_env: dict[str, str] | None = None,
) -> BundleVmLaunch:
    """Create and start the sidecar bundle as a smolVM.

    smolVM's own published ports are raw host-loopback ports. The
    launch flow wraps them with per-bottle address-bound forwarders
    before exposing anything to the agent VM."""
    raw_ports = allocate_raw_host_ports(spec.ports_to_publish)
    effective_host_env = host_env if host_env is not None else os.environ
    env: dict[str, str] = {"BOT_BOTTLE_SIDECAR_DAEMONS": spec.daemons_csv}
    for entry in spec.environment:
        name, sep, value = entry.partition("=")
        if sep:
            env[name] = value
        elif entry in effective_host_env:
            env[entry] = effective_host_env[entry]
    name = bundle_machine_name(spec.slug)
    _smolvm.machine_create(
        name,
        from_path=from_path,
        net=True,
        env=env,
        volumes=spec.volumes,
        ports=tuple(
            (host_port, guest_port)
            for guest_port, host_port in raw_ports.items()
        ),
    )
    _smolvm.machine_start(name)
    _smolvm.wait_exec_ready(name)
    return BundleVmLaunch(raw_ports=raw_ports)


def stop_bundle_vm(slug: str) -> None:
    """Best-effort sidecar VM teardown."""
    name = bundle_machine_name(slug)
    try:
        _smolvm.machine_stop(name)
    except _smolvm.SmolvmError as exc:
        warn(f"smolvm machine stop {name} failed: {exc}")
    try:
        _smolvm.machine_delete(name)
    except _smolvm.SmolvmError as exc:
        warn(f"smolvm machine delete {name} failed: {exc}")


def create_bundle_network(network_name: str, subnet: str, gateway: str) -> None:
    """`docker network create` with an explicit subnet + gateway
    so the bundle's `--ip` lands on the address the Smolfile's
    TSI allowlist points at. Idempotent on the caller's side —
    `start_bundle` catches the "network exists" error and treats
    it as success (chunk-2d teardown is paired with each create).
    """
    result = subprocess.run(
        ["docker", "network", "create",
         "--subnet", subnet, "--gateway", gateway,
         network_name],
        capture_output=True, text=True, check=False,
    )
    if result.returncode != 0:
        # Already-exists is fine on a resume path; everything else
        # is fatal — the bundle won't have an addressable network.
        if "already exists" in (result.stderr or "").lower():
            return
        die(
            f"docker network create {network_name} failed: "
            f"{(result.stderr or '').strip()}"
        )


def remove_bundle_network(network_name: str) -> None:
    """Idempotent: a missing network returns success."""
    result = subprocess.run(
        ["docker", "network", "rm", network_name],
        capture_output=True, text=True, check=False,
    )
    if result.returncode == 0:
        return
    if "no such network" in (result.stderr or "").lower():
        return
    # Network with attached containers is the common non-fatal
    # case during a partial teardown — warn but don't die.
    warn(
        f"docker network rm {network_name} failed: "
        f"{(result.stderr or '').strip()}"
    )


def start_bundle(spec: BundleLaunchSpec, *,
                 env: dict[str, str] | None = None) -> None:
    """Bring the bundle container up on the per-bottle bridge with
    the pinned IP. Argv is built deterministically from `spec`;
    `env` is the host subprocess env (forwarded values for any
    bare-name entries in `spec.environment`)."""
    container = bundle_container_name(spec.slug)
    argv = [
        "docker", "run",
        "--name", container,
        "--detach",
        "--rm",
        "--network", spec.network_name,
        "--ip", spec.bundle_ip,
        "-e", f"BOT_BOTTLE_SIDECAR_DAEMONS={spec.daemons_csv}",
    ]
    for entry in spec.environment:
        argv += ["-e", entry]
    for host_path, container_path, read_only in spec.volumes:
        suffix = ":ro" if read_only else ""
        argv += ["-v", f"{host_path}:{container_path}{suffix}"]
    # Loopback-only host port-forwards — the smolvm guest's TSI
    # uses macOS networking, and macOS loopback is the only host
    # surface that round-trips into Docker Desktop's daemon VM.
    # Binds to the per-bottle alias so TSI's IP-only allowlist
    # narrows reachability to this bottle's bundle only.
    for port in spec.ports_to_publish:
        argv += ["-p", f"{spec.publish_host_ip}::{port}"]
    argv.append(spec.image)
    result = subprocess.run(
        argv, capture_output=True, text=True,
        env=dict(env) if env is not None else None, check=False,
    )
    if result.returncode != 0:
        die(
            f"docker run for bundle {container} failed: "
            f"{(result.stderr or '').strip()}"
        )


def bundle_host_port(
    slug: str, container_port: int, *, host_ip: str = "127.0.0.1",
) -> int:
    """`docker port <bundle> <container_port>/tcp` → the random
    host-side port docker assigned for the binding on `host_ip`.
    Called after `start_bundle` on each container port listed in
    `BundleLaunchSpec.ports_to_publish` so the launch step can
    build the agent's HTTPS_PROXY / GIT_GATE / SUPERVISE URLs in
    `<host_ip>:<host port>` form."""
    container = bundle_container_name(slug)
    result = subprocess.run(
        ["docker", "port", container, f"{container_port}/tcp"],
        capture_output=True, text=True, check=False,
    )
    if result.returncode != 0:
        die(
            f"docker port {container} {container_port}/tcp failed: "
            f"{(result.stderr or '').strip() or '<no stderr>'}"
        )
    # Each line looks like `127.0.0.16:54321` — one per address
    # family / host IP. Match on the expected host_ip prefix so
    # bottles bound to per-bottle aliases pick the right line.
    for raw in (result.stdout or "").splitlines():
        line = raw.strip()
        if line.startswith(f"{host_ip}:"):
            _, _, port_str = line.rpartition(":")
            try:
                return int(port_str)
            except ValueError:
                die(f"unexpected `docker port` output: {line!r}")
    die(
        f"no port mapping on {host_ip} for {container} "
        f"{container_port}/tcp; got: {(result.stdout or '').strip()!r}"
    )


def stop_bundle(slug: str) -> None:
    """Idempotent: a missing container returns success."""
    container = bundle_container_name(slug)
    result = subprocess.run(
        ["docker", "rm", "-f", container],
        capture_output=True, text=True, check=False,
    )
    if result.returncode == 0:
        return
    if "no such container" in (result.stderr or "").lower():
        return
    warn(
        f"docker rm -f {container} failed: "
        f"{(result.stderr or '').strip()}"
    )