"""Compose-spec rendering for a Docker bottle (PRD 0018, chunk 1).

`bottle_plan_to_compose(plan)` returns a Compose v2 spec dict
describing the per-bottle container topology — one project per
bottle instance, services for the agent + every applicable sidecar,
two networks, no named volumes.

Pure function. No I/O, no subprocess. Expects every launch-time
field (network names, CA host paths, etc.) on the plan's inner
plans to be populated; chunks 2+3 own that ordering.

Conditional services follow the plan content:

  - agent + sidecars bundle: always.
  - git-gate:  iff plan.git_gate_plan.upstreams.
  - egress:    iff plan.egress_plan.routes.
  - supervise: iff plan.supervise_plan is not None.
"""

from __future__ import annotations

import json
import subprocess
import sys
from pathlib import Path
from typing import Any

from ...egress import (
    EGRESS_HOSTNAME,
    EGRESS_ROUTES_IN_CONTAINER,
)
from ...git_gate import GIT_GATE_HOSTNAME
from ...log import die, warn
from ...supervise import (
    CURRENT_CONFIG_DIR_IN_AGENT,
    QUEUE_DIR_IN_CONTAINER,
    SUPERVISE_HOSTNAME,
    SUPERVISE_PORT,
)
from ...util import expand_tilde
from ..util import AGENT_CA_BUNDLE, AGENT_CA_PATH
from .bottle_plan import DockerBottlePlan
from .egress import (
    EGRESS_CA_IN_CONTAINER,
    EGRESS_PORT,
)
from .git_gate import (
    GIT_GATE_ACCESS_HOOK_IN_CONTAINER,
    GIT_GATE_CREDS_DIR_IN_CONTAINER,
    GIT_GATE_ENTRYPOINT_IN_CONTAINER,
    GIT_GATE_HOOK_IN_CONTAINER,
)
from . import network as network_mod
from .sidecar_bundle import (
    SIDECAR_BUNDLE_DOCKERFILE,
    SIDECAR_BUNDLE_IMAGE,
    sidecar_bundle_container_name,
)


# Repo root, used as the build context for the bundle Dockerfile.
_REPO_DIR = str(Path(__file__).resolve().parent.parent.parent.parent)


def bottle_plan_to_compose(plan: DockerBottlePlan) -> dict[str, Any]:
    """Render a Compose v2 spec dict from a fully-resolved
    DockerBottlePlan.

    The plan must have its inner plans (`git_gate_plan`,
    `egress_plan`, `supervise_plan`) populated with launch-time
    fields — network names, CA host paths. The renderer doesn't
    validate; callers feed it a fully-resolved plan or get an
    incomplete compose spec back.
    """
    project = f"bot-bottle-{plan.slug}"
    services: dict[str, Any] = {
        "sidecars": _sidecar_bundle_service(plan),
        "agent": _agent_service(plan),
    }
    return {
        "name": project,
        "services": services,
        "networks": _networks(plan),
    }


def _networks(plan: DockerBottlePlan) -> dict[str, Any]:
    """Compose-managed networks with explicit `name:` matching the
    existing slug-suffixed convention. Compose creates them on `up`
    and destroys them on `down`. The internal one is `--internal`
    (no default gateway); the egress one is a normal user-defined
    bridge."""
    return {
        "internal": {
            "name": network_mod.network_name_for_slug(plan.slug),
            "internal": True,
        },
        "egress": {
            "name": network_mod.network_egress_name_for_slug(plan.slug),
        },
    }


def _bind(host: str | Path, target: str, *, read_only: bool = True) -> dict[str, Any]:
    """One bind-mount entry in the long-form `volumes:` shape.
    Long form is preferred over `host:target:ro` strings because
    it's easier to inspect in tests and survives whitespace in
    host paths."""
    return {
        "type": "bind",
        "source": str(host),
        "target": target,
        "read_only": read_only,
    }


def _sidecar_bundle_service(plan: DockerBottlePlan) -> dict[str, Any]:
    """The `sidecars` service: one container per bottle, bundle
    image, all daemons under a Python init supervisor.

    Daemon subset narrows via `BOT_BOTTLE_SIDECAR_DAEMONS` env.
    egress is always present; git-gate / supervise are conditional.
    """
    daemons: list[str] = ["egress"]
    if plan.git_gate_plan.upstreams:
        daemons.append("git-gate")
    if plan.supervise_plan is not None:
        daemons.append("supervise")

    env: list[str] = [f"BOT_BOTTLE_SIDECAR_DAEMONS={','.join(daemons)}"]
    volumes: list[dict[str, Any]] = []

    # --- egress -------------------------------------------------------
    ep = plan.egress_plan
    volumes.append(_bind(ep.mitmproxy_ca_host_path, EGRESS_CA_IN_CONTAINER))
    if ep.routes:
        volumes.append(_bind(ep.routes_path, EGRESS_ROUTES_IN_CONTAINER))
        for token_env in sorted(ep.token_env_map.keys()):
            env.append(token_env)

    # --- git-gate -----------------------------------------------------
    gp = plan.git_gate_plan
    if gp.upstreams:
        volumes += [
            _bind(gp.entrypoint_script, GIT_GATE_ENTRYPOINT_IN_CONTAINER),
            _bind(gp.hook_script, GIT_GATE_HOOK_IN_CONTAINER),
            _bind(gp.access_hook_script, GIT_GATE_ACCESS_HOOK_IN_CONTAINER),
        ]
        for u in gp.upstreams:
            keypath = expand_tilde(u.identity_file)
            volumes.append(_bind(
                keypath,
                f"{GIT_GATE_CREDS_DIR_IN_CONTAINER}/{u.name}-key",
            ))
            if u.known_hosts_file:
                volumes.append(_bind(
                    u.known_hosts_file,
                    f"{GIT_GATE_CREDS_DIR_IN_CONTAINER}/{u.name}-known_hosts",
                ))

    # --- supervise ----------------------------------------------------
    sp = plan.supervise_plan
    if sp is not None:
        env += [
            f"SUPERVISE_BOTTLE_SLUG={plan.slug}",
            f"SUPERVISE_QUEUE_DIR={QUEUE_DIR_IN_CONTAINER}",
            f"SUPERVISE_PORT={SUPERVISE_PORT}",
        ]
        volumes.append({
            "type": "bind",
            "source": str(sp.queue_dir),
            "target": QUEUE_DIR_IN_CONTAINER,
            "read_only": False,
        })

    internal_aliases = [EGRESS_HOSTNAME]
    if gp.upstreams:
        internal_aliases.append(GIT_GATE_HOSTNAME)
    if sp is not None:
        internal_aliases.append(SUPERVISE_HOSTNAME)

    service: dict[str, Any] = {
        "image": SIDECAR_BUNDLE_IMAGE,
        "build": {
            "context": _REPO_DIR,
            "dockerfile": SIDECAR_BUNDLE_DOCKERFILE,
        },
        "container_name": sidecar_bundle_container_name(plan.slug),
        "networks": {
            "internal": {"aliases": internal_aliases},
            "egress": None,
        },
        "environment": env,
        "volumes": volumes,
    }
    return service


def _agent_service(plan: DockerBottlePlan) -> dict[str, Any]:
    """Agent container. Runs `sleep infinity`; claude is `docker
    exec -it`'d into it later. HTTP_PROXY/HTTPS_PROXY point at the
    egress sidecar."""
    proxy_url = _agent_proxy_url(plan)
    no_proxy = _agent_no_proxy(plan)
    env: list[str] = [
        f"HTTPS_PROXY={proxy_url}",
        f"HTTP_PROXY={proxy_url}",
        f"https_proxy={proxy_url}",
        f"http_proxy={proxy_url}",
        f"NO_PROXY={no_proxy}",
        f"no_proxy={no_proxy}",
        f"NODE_EXTRA_CA_CERTS={AGENT_CA_PATH}",
        f"SSL_CERT_FILE={AGENT_CA_BUNDLE}",
        f"REQUESTS_CA_BUNDLE={AGENT_CA_BUNDLE}",
    ]
    for name, value in sorted(plan.agent_provision.guest_env.items()):
        env.append(f"{name}={value}")
    # Forwarded vars (OAuth token, manifest host-interpolations):
    # bare name → inherits from compose-up process env, value
    # never lands on argv or in the compose file.
    for name in sorted(plan.forwarded_env.keys()):
        env.append(name)

    service: dict[str, Any] = {
        "image": plan.image,
        "container_name": plan.container_name,
        "command": ["sleep", "infinity"],
        "networks": {"internal": None},
        "environment": env,
    }
    if plan.use_runsc:
        service["runtime"] = "runsc"

    volumes: list[dict[str, Any]] = []
    if plan.supervise_plan is not None:
        volumes.append(_bind(
            plan.supervise_plan.current_config_dir,
            CURRENT_CONFIG_DIR_IN_AGENT,
        ))
    if volumes:
        service["volumes"] = volumes

    # The init supervisor inside the bundle owns intra-bundle
    # daemon ordering, so the agent only waits for the bundle
    # container itself.
    service["depends_on"] = ["sidecars"]

    return service


def _agent_proxy_url(plan: DockerBottlePlan) -> str:
    """Agent's HTTP_PROXY — always points at egress."""
    return f"http://{EGRESS_HOSTNAME}:{EGRESS_PORT}"


def _agent_no_proxy(plan: DockerBottlePlan) -> str:
    """NO_PROXY for the agent: loopback always; supervise hostname
    when the supervise sidecar is up (MCP long-poll must bypass
    the egress proxy)."""
    hosts = ["localhost", "127.0.0.1"]
    if plan.supervise_plan is not None:
        hosts.append(SUPERVISE_HOSTNAME)
    return ",".join(hosts)


# --- Lifecycle helpers (PRD 0018 chunk 3) ----------------------------------
#
# The renderer above is pure. The helpers below own the I/O side:
# serialize the spec to disk, drive `docker compose up`, dump the
# merged log file on teardown, and `docker compose down` to clean up
# (networks are pre-created externally so `down` leaves them alone;
# the launch step removes them in its own teardown step).


COMPOSE_FILE_NAME = "docker-compose.yml"
COMPOSE_LOG_NAME = "compose.log"


COMPOSE_PROJECT_PREFIX = "bot-bottle-"


def compose_project_name(slug: str) -> str:
    """Stable mapping from slug → compose project. Matches the
    `name:` field the renderer emits, so `docker compose ls`
    enumeration and direct CLI invocations agree on the project
    identifier."""
    return f"{COMPOSE_PROJECT_PREFIX}{slug}"


def slug_from_compose_project(project: str) -> str:
    """Inverse of `compose_project_name`: strip the prefix to get
    the underlying slug. Returns empty string if the project name
    doesn't start with the expected prefix."""
    if not project.startswith(COMPOSE_PROJECT_PREFIX):
        return ""
    return project[len(COMPOSE_PROJECT_PREFIX):]


def list_compose_projects(
    *, include_stopped: bool = True, warn_on_error: bool = True,
) -> list[str]:
    """All compose project names starting with `bot-bottle-`.
    `include_stopped=True` (default) runs `docker compose ls --all`
    so exited projects appear too; pass False to get only projects
    with at least one running container.

    Returns [] on docker daemon errors or malformed output rather
    than raising — callers should treat the empty list as "no
    projects discoverable", not "no projects exist". `warn_on_error`
    stays true for explicit operator commands like cleanup, but active
    discovery paths set it false so dashboard refreshes don't spam
    stderr while Docker Desktop is stopped."""
    argv = ["docker", "compose", "ls", "--format", "json"]
    if include_stopped:
        argv.insert(3, "--all")
    try:
        result = subprocess.run(
            argv, capture_output=True, text=True, check=False,
        )
    except FileNotFoundError:
        # docker binary not on PATH — same shape as a daemon-down
        # error from the caller's POV: no projects discoverable.
        return []
    if result.returncode != 0:
        if warn_on_error:
            warn(f"docker compose ls failed: {result.stderr.strip()}")
        return []
    try:
        projects = json.loads(result.stdout or "[]")
    except json.JSONDecodeError as e:
        if warn_on_error:
            warn(f"docker compose ls returned malformed JSON: {e}")
        return []
    names: list[str] = []
    for p in projects:
        if not isinstance(p, dict):
            continue
        name = str(p.get("Name", ""))
        if name.startswith(COMPOSE_PROJECT_PREFIX):
            names.append(name)
    return sorted(set(names))


def list_active_slugs(
    *, include_stopped: bool = False, warn_on_error: bool = True,
) -> list[str]:
    """Slugs (project name minus prefix) of currently-running
    bottles. Used by the dashboard's operator-edit verbs to choose
    a bottle to apply a config edit to."""
    return sorted(
        slug for slug in (
            slug_from_compose_project(p)
            for p in list_compose_projects(
                include_stopped=include_stopped,
                warn_on_error=warn_on_error,
            )
        ) if slug
    )


def compose_file_path(state_dir: Path) -> Path:
    return state_dir / COMPOSE_FILE_NAME


def compose_log_path(state_dir: Path) -> Path:
    return state_dir / COMPOSE_LOG_NAME


def write_compose_file(spec: dict[str, Any], path: Path) -> Path:
    """Serialize the compose dict to disk. JSON content with a
    `.yml` filename — JSON is a strict subset of YAML 1.2 for the
    constructs the renderer uses (mappings, lists, strings, bools,
    nulls), and `docker compose -f file.yml` parses it as YAML.
    Avoids a yaml dependency while keeping the file `cat`-readable.
    """
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(json.dumps(spec, indent=2, sort_keys=False) + "\n")
    path.chmod(0o644)
    return path


def _compose_argv(project: str, compose_file: Path, *cmd: str) -> list[str]:
    return [
        "docker", "compose",
        "-p", project,
        "-f", str(compose_file),
        *cmd,
    ]


def compose_up(
    project: str,
    compose_file: Path,
    *,
    env: dict[str, str] | None = None,
) -> None:
    """`docker compose up -d` for the project. Env-inheritance is
    via `env=` on the subprocess — every `environment: [NAME]` (bare
    name) entry in the compose file resolves to whatever value
    `NAME` has in `env` at exec time. Secrets never land on argv or
    in the compose file."""
    argv = _compose_argv(project, compose_file, "up", "-d")
    result = subprocess.run(
        argv, capture_output=True, text=True, env=env, check=False,
    )
    if result.returncode != 0:
        sys.stderr.write(result.stderr)
        die(f"docker compose up failed for project {project}")


def compose_dump_logs(project: str, compose_file: Path, output: Path) -> None:
    """Write the merged stdout/stderr of every service to `output`
    using `docker compose logs --no-color --timestamps`. Best-effort
    — failures here shouldn't block teardown. The interleaved single
    file is what the user reads post-mortem; per-service tail still
    works through `docker compose logs -f <service>` while the
    project is up."""
    output.parent.mkdir(parents=True, exist_ok=True)
    argv = _compose_argv(project, compose_file, "logs", "--no-color", "--timestamps")
    try:
        with open(output, "wb") as f:
            subprocess.run(
                argv,
                stdout=f,
                stderr=subprocess.STDOUT,
                check=False,
            )
        output.chmod(0o644)
    except OSError as e:
        warn(f"failed to write compose log to {output}: {e}")


def compose_down(project: str, compose_file: Path) -> None:
    """`docker compose down` for the project. External networks are
    intentionally NOT removed by compose (`external: true` on the
    networks block); the launch step's own teardown removes them
    via `network_remove` so the per-bottle ephemeral subnet doesn't
    accumulate."""
    argv = _compose_argv(project, compose_file, "down")
    result = subprocess.run(
        argv, capture_output=True, text=True, check=False,
    )
    if result.returncode != 0:
        warn(
            f"docker compose down failed for project {project}: "
            f"{result.stderr.strip()}"
        )


__all__ = [
    "COMPOSE_FILE_NAME",
    "COMPOSE_LOG_NAME",
    "COMPOSE_PROJECT_PREFIX",
    "bottle_plan_to_compose",
    "compose_down",
    "compose_dump_logs",
    "compose_file_path",
    "compose_log_path",
    "compose_project_name",
    "compose_up",
    "list_active_slugs",
    "list_compose_projects",
    "slug_from_compose_project",
    "write_compose_file",
]