"""Per-backend bottle factories.

A bottle is a running, isolated environment with claude inside. Each
backend exposes five methods:

  prepare(spec, stage_dir=...) -> BottlePlan
      Resolves names, validates host-side prerequisites, and writes
      scratch files. No remote/runtime resources are created yet.
      Safe to call before the y/N preflight.

  launch(plan) -> ContextManager[Bottle]
      Brings up the container (or VM, or remote machine), provisions
      it, yields a Bottle handle, and tears everything down on exit.

  prepare_cleanup() -> BottleCleanupPlan
      Enumerates orphaned resources left behind by previous bottles
      (containers, networks, ...). Idempotent; no side effects.

  cleanup(plan) -> None
      Actually removes everything described by the cleanup plan.

  enumerate_active() -> Sequence[ActiveAgent]
      Return every currently-running bottle on this backend, with
      enough metadata for callers (CLI `list active`, dashboard
      agents pane) to render a row.

Selection is driven by `--backend` on `start` or BOT_BOTTLE_BACKEND
(env var). When neither is set, compatible macOS hosts default to
`macos-container`; other hosts default to `smolmachines`. Per PRD 0003
the manifest does not carry a backend field; the host picks.
"""

from __future__ import annotations

import os
import shlex
import sys
from abc import ABC, abstractmethod
from contextlib import AbstractContextManager
from dataclasses import dataclass
from pathlib import Path
from typing import Any, Generic, Sequence, TypeVar

from ..agent_provider import AgentProvisionPlan, get_provider, build_agent_provision_plan
from ..egress import EgressPlan
from ..git_gate import GitGatePlan
from ..log import die, info
from ..manifest import Manifest, ManifestIndex
from ..supervise import SupervisePlan
from ..util import expand_tilde
from ..env import resolve_env, ResolvedEnv
from ..workspace import WorkspacePlan, workspace_plan
from .print_util import print_multi, visible_agent_env_names
from .util import host_skill_dir


@dataclass(frozen=True)
class BottleSpec:
    """CLI-supplied intent. Backend-agnostic — each backend's prepare
    step consumes it and produces its own backend-specific plan.
    Resolved values (image names, container name, scratch paths, runsc
    availability) live on the plan, not the spec."""

    manifest: ManifestIndex
    agent_name: str
    copy_cwd: bool
    user_cwd: str
    # PRD 0016 follow-up: when set, the backend's prepare step uses
    # this identity instead of minting a fresh one — the resume path
    # (`cli.py resume <identity>`) sets this to continue an existing
    # bottle's state. Empty string for a fresh `start`.
    identity: str = ""
    label: str = ""
    color: str = ""
    # Ordered bottle names selected at launch (issue #269). When non-empty
    # they are merged in order and replace the agent's `bottle:` field.
    bottle_names: tuple[str, ...] = ()


@dataclass(frozen=True)
class BottlePlan(ABC):
    """Base output of a backend's prepare step. Concrete subclasses
    (e.g. DockerBottlePlan) add backend-specific resolved fields."""

    spec: BottleSpec
    manifest: Manifest
    stage_dir: Path
    git_gate_plan: GitGatePlan

    @property
    def guest_home(self) -> str:
        return self.agent_provision.guest_home

    @property
    def git_gate_insteadof_host(self) -> str:
        """Host (and optional port) used in git-gate insteadOf URLs.
        Docker uses the compose-network DNS alias; smolmachines
        overrides with a loopback IP:port since TSI has no DNS."""
        return "git-gate"

    @property
    def git_gate_insteadof_scheme(self) -> str:
        """URL scheme for git-gate insteadOf rewrites. 'git' for
        Docker (git daemon); 'http' for smolmachines (HTTP proxy
        over a published host port)."""
        return "git"
    egress_plan: EgressPlan
    supervise_plan: SupervisePlan | None
    agent_provision: AgentProvisionPlan

    @property
    def workspace_plan(self) -> WorkspacePlan:
        return workspace_plan(self.spec, guest_home=self.guest_home)

    def print(self) -> None:
        """Render the y/N preflight summary to stderr."""
        spec = self.spec
        manifest = self.manifest
        agent = manifest.agent
        bottle = manifest.bottle

        env_names = visible_agent_env_names(
            sorted(
                set(bottle.env.keys())
                | set(self.agent_provision.guest_env.keys())
            ),
            hidden_env_names=self.agent_provision.hidden_env_names,
        )

        print(file=sys.stderr)
        info(f"agent           : {spec.agent_name}")
        info(f"provider        : {self.agent_provision.template}")
        print_multi("env             ", env_names)
        print_multi("skills          ", list(agent.skills))
        effective_bottles = (
            list(spec.bottle_names) if spec.bottle_names
            else ([agent.bottle] if agent.bottle else [])
        )
        print_multi("bottle          ", effective_bottles)

        identity = manifest.git_identity_summary()
        if identity:
            info(f"  git identity  : {identity}")

        git_lines = [
            f"{u.name} → {u.upstream_host}:{u.upstream_port}"
            for u in self.git_gate_plan.upstreams
        ]
        if git_lines:
            print_multi("  git gate      ", git_lines)

        if self.egress_plan.routes:
            egress_lines = []
            for r in self.egress_plan.routes:
                auth = f" [auth:{r.auth_scheme}]" if r.auth_scheme else ""
                egress_lines.append(f"{r.host}{auth}")
            print_multi("  egress        ", egress_lines)
        print(file=sys.stderr)


@dataclass(frozen=True)
class BottleCleanupPlan(ABC):
    """Base output of a backend's prepare_cleanup step. Concrete
    subclasses (e.g. DockerBottleCleanupPlan) carry backend-specific
    lists of resources to be removed and implement `print` + `empty`."""

    @abstractmethod
    def print(self) -> None:
        """Render the cleanup y/N summary to stderr."""

    @property
    @abstractmethod
    def empty(self) -> bool:
        """True iff there is nothing to clean up; the CLI uses this to
        short-circuit before showing the y/N."""


@dataclass(frozen=True)
class ExecResult:
    """Captured result of `Bottle.exec`. Backend-neutral: the Docker
    impl populates it from a `subprocess.CompletedProcess`, but a
    future fly/smolmachines backend could populate it from any source
    that produces a returncode + captured streams."""

    returncode: int
    stdout: str
    stderr: str


@dataclass(frozen=True)
class ActiveAgent:
    """One currently-running agent, as the CLI `list active` and
    dashboard agents pane render it. ("Agent" is the project's
    consistent name for the thing running inside a bottle — the
    bottle is the container, the agent is what runs in it.)

    Fields are deliberately backend-neutral. `services` is the set
    of sidecar daemons currently up for this bottle (`egress`,
    `git-gate`, `supervise`); the dashboard uses it to
    gate edit verbs. `backend_name` is the matching key in
    `_BACKENDS` (`docker` / `smolmachines` / `macos-container`) — used by the active-
    list rendering to disambiguate and by the dashboard's
    re-attach path."""

    backend_name: str
    slug: str
    agent_name: str       # from metadata.json; "?" if missing
    started_at: str       # ISO 8601 from metadata.json; "" if missing
    services: tuple[str, ...]  # alphabetical
    label: str = ""
    color: str = ""


class Bottle(ABC):
    """Handle to a running bottle. Yielded by a backend's launch step.

    `exec_agent` runs the selected agent CLI inside the bottle and
    blocks until the session ends. `exec` runs a POSIX shell script inside the bottle
    and returns the captured result. `cp_in` copies a host path into
    the bottle. `close` is an idempotent alias for context-manager
    teardown.
    """

    name: str

    @abstractmethod
    def agent_argv(
        self, argv: list[str], *, tty: bool = True,
    ) -> list[str]:
        """Return the host-side argv that runs the selected agent
        inside the bottle. Used by `exec_agent` for foreground
        handoffs and by the dashboard's tmux `respawn-pane` flow,
        which needs the argv up front (it spawns claude in a tmux
        pane rather than as a child of the current process).

        Implementations transparently inject
        `--append-system-prompt-file` when the bottle was launched
        with a provisioned prompt path."""
        ...

    @abstractmethod
    def exec_agent(self, argv: list[str], *, tty: bool = True) -> int: ...

    @abstractmethod
    def exec(self, script: str, *, user: str = "node") -> ExecResult:
        """Run `script` as a POSIX shell script inside the bottle as
        `user` (default `node`, matching the agent image's USER
        directive) and return the captured stdout/stderr/returncode.
        The bottle's environment (including HTTPS_PROXY pointing at
        the egress sidecar) is inherited by the child. Non-zero
        exit does not raise — callers inspect `returncode`
        themselves.

        Pass `user="root"` for shell-outs that need privileged file
        writes / package install — provisioning calls that need root
        bypass `Bottle.exec` and use the backend-specific raw
        machine-exec helper, but the tests have a legitimate use
        case for arbitrary-user runs."""

    @abstractmethod
    def cp_in(self, host_path: str, container_path: str) -> None: ...

    @abstractmethod
    def close(self) -> None: ...




PlanT = TypeVar("PlanT", bound=BottlePlan)
CleanupT = TypeVar("CleanupT", bound=BottleCleanupPlan)


class BottleBackend(ABC, Generic[PlanT, CleanupT]):
    """Abstract base for selectable bottle backends. Concrete subclasses
    (e.g. DockerBottleBackend) own their own prepare/launch impls.
    Parameterized over the backend's concrete plan + cleanup-plan types
    so subclass methods get the narrow type without isinstance
    boilerplate."""

    name: str

    def prepare(self, spec: BottleSpec, stage_dir: Path) -> PlanT:
        """Template method: run cross-backend host-side validation, then
        delegate to the subclass's `_resolve_plan` for the
        backend-specific resolution (names, scratch files, etc.). The
        validation step is enforced here so a future backend cannot
        accidentally skip it. No remote/runtime resources are created."""
        from .resolve_common import (
            merge_provision_env_vars,
            mint_slug,
            prepare_agent_state_dir,
            prepare_egress,
            prepare_git_gate,
            prepare_supervise,
            resolve_manifest_dockerfile,
            write_launch_metadata,
        )

        manifest = self._validate(spec)

        self._preflight()

        manifest_bottle = manifest.bottle
        manifest_agent_provider = manifest_bottle.agent_provider
        agent_provider = get_provider(manifest_agent_provider.template)
        resolved_env = resolve_env(manifest)
        workspace = workspace_plan(spec, guest_home=agent_provider.guest_home)

        slug = mint_slug(spec)
        write_launch_metadata(slug, spec, compose_project="", backend=self.name)

        # Manifest may override the Dockerfile per-bottle; otherwise fall
        # back to the provider plugin's bundled Dockerfile (next to its
        # agent_provider.py module).
        if manifest_agent_provider.dockerfile:
            agent_dockerfile_path = resolve_manifest_dockerfile(
                manifest_agent_provider.dockerfile, spec,
            )
        else:
            agent_dockerfile_path = str(agent_provider.dockerfile)

        agent_dir, prompt_file = prepare_agent_state_dir(slug, manifest)

        agent_provision_plan = build_agent_provision_plan(
            template=manifest_agent_provider.template,
            dockerfile=agent_dockerfile_path,
            state_dir=agent_dir,
            instance_name=f"bot-bottle-{slug}",
            prompt_file=prompt_file,
            guest_env=self._build_guest_env(resolved_env),
            forward_host_credentials=manifest_agent_provider.forward_host_credentials,
            auth_token=manifest_agent_provider.auth_token,
            host_env=dict(os.environ),
            trusted_project_path=workspace.workdir,
            label=spec.label,
            color=spec.color,
            provider_settings=manifest_agent_provider.settings,
        )
        agent_provision_plan = merge_provision_env_vars(agent_provision_plan)
        egress_plan = prepare_egress(manifest_bottle, slug, agent_provision_plan)
        supervise_plan = prepare_supervise(manifest_bottle, slug)
        git_gate_plan = prepare_git_gate(manifest_bottle, slug)

        return self._resolve_plan(
            spec,
            manifest=manifest,
            slug=slug,
            resolved_env=resolved_env,
            agent_provision_plan=agent_provision_plan,
            egress_plan=egress_plan,
            supervise_plan=supervise_plan,
            git_gate_plan=git_gate_plan,
            stage_dir=stage_dir,
        )

    def _build_guest_env(self, resolved_env: ResolvedEnv) -> dict[str, str]:
        return {}

    def _preflight(self) -> None:
        """
        tasks to do before resolving a plan
        """
        pass

    def _validate(self, spec: BottleSpec) -> Manifest:
        """Cross-backend pre-launch checks. Parses the selected agent and
        its bottle (raising ManifestError on invalid content), confirms
        skills are present on the host, and every git IdentityFile resolves.

        Returns the loaded Manifest for the selected agent. Subclasses with
        additional preconditions should override and call
        `super()._validate(spec)` first."""
        manifest = spec.manifest.load_for_agent(spec.agent_name, spec.bottle_names)
        self._validate_skills(manifest.agent.skills)
        self._validate_agent_provider_dockerfile(spec, manifest)
        return manifest

    def _validate_skills(self, skills: Sequence[str]) -> None:
        """Each named skill must be a directory under the host's
        `~/.claude/skills/`. The check is purely host-side, so the
        default impl covers every backend."""
        for name in skills:
            path = host_skill_dir(name)
            if not os.path.isdir(path):
                die(
                    f"skill '{name}' not found on host at {path}. "
                    f"Create it under ~/.claude/skills/, then re-run."
                )

    def _validate_agent_provider_dockerfile(self, spec: BottleSpec, manifest: Manifest) -> None:
        bottle = manifest.bottle
        dockerfile = bottle.agent_provider.dockerfile
        if not dockerfile:
            return
        path = Path(expand_tilde(dockerfile))
        if not path.is_absolute():
            path = Path(spec.user_cwd) / path
        if not path.is_file():
            effective = (
                ", ".join(spec.bottle_names) if spec.bottle_names else manifest.agent.bottle
            )
            die(
                f"agent_provider.dockerfile for bottle "
                f"'{effective}' not found: {path}"
            )

    @abstractmethod
    def _resolve_plan(self,
                      spec: BottleSpec,
                      *,
                      manifest: Manifest,
                      slug: str,
                      resolved_env: ResolvedEnv,
                      agent_provision_plan: AgentProvisionPlan,
                      egress_plan: EgressPlan,
                      git_gate_plan: GitGatePlan,
                      supervise_plan: SupervisePlan | None,
                      stage_dir: Path) -> PlanT:
        """Backend-specific plan resolution: image/container names,
        env-file, prompt-file, proxy plan, runtime detection. Called by
        `prepare` after `_validate` succeeds. Instance name, image,
        prompt file, Dockerfile path, and guest home all live on
        `agent_provision_plan` — the source of truth."""

    @abstractmethod
    def launch(self, plan: PlanT) -> AbstractContextManager[Bottle]:
        """Build/run the bottle and yield a handle; tear down on exit."""

    def provision(self, plan: PlanT, bottle: "Bottle") -> str | None:
        """Copy host-side files (CA cert, prompt, skills, .git) into
        the running bottle. Called from `launch` after the container
        / machine is up. Returns the in-container prompt path if a
        prompt was provisioned, else None — the Bottle handle uses it
        to decide whether to add provider-specific prompt args to the
        agent's argv.

        Default orchestration: ca → prompt → provider apply → skills
        → workspace → git → supervise-mcp. CA install runs first so
        the agent's trust store is rebuilt before anything inside the
        agent makes a TLS call.

        Per PRD 0050 the per-provider steps (prompt, skills,
        declarative provision-plan apply, supervise MCP registration)
        live on the `AgentProvider` plugin. The backend only owns the
        steps that are about backend infrastructure (CA, workspace,
        git) and surfaces the supervise sidecar URL its launch step
        knows about via `supervise_mcp_url`.

        PRD 0017: cred-proxy's agent-side dotfile rewrites (~/.npmrc,
        ~/.gitconfig insteadOf, tea config) are gone. Egress-proxy is
        on the agent's HTTP_PROXY path so every tool that respects
        HTTPS_PROXY (claude-code, git over HTTPS, npm, curl) is
        intercepted without per-tool reconfiguration."""
        provider = get_provider(plan.agent_provision.template)
        provider.provision_ca(bottle, plan)
        prompt_path = provider.provision_prompt(plan, bottle)
        provider.provision(plan, bottle)
        provider.provision_skills(plan, bottle)
        self.provision_workspace(plan, bottle)
        provider.provision_git(bottle, plan)
        provider.provision_supervise_mcp(
            plan, bottle, self.supervise_mcp_url(plan),
        )
        return prompt_path

    def provision_workspace(self, plan: PlanT, bottle: "Bottle") -> None:
        """Copy the operator workspace into the running bottle.

        This is the only supported workspace-provisioning path: Docker
        does not build a derived image containing the current
        workspace."""
        workspace = plan.workspace_plan
        if not (workspace.enabled and workspace.copy_contents):
            return

        guest_parent = workspace.guest_path.rsplit("/", 1)[0] or "/"
        guest_path = shlex.quote(workspace.guest_path)
        guest_parent = shlex.quote(guest_parent)
        owner = shlex.quote(workspace.owner)
        mode = shlex.quote(workspace.mode)
        info(f"copying {workspace.host_path} -> {bottle.name}:{workspace.guest_path}")
        bottle.exec(
            f"rm -rf {guest_path} && mkdir -p {guest_parent}",
            user="root",
        )
        bottle.cp_in(str(workspace.host_path), workspace.guest_path)
        bottle.exec(
            f"chown -R {owner} {guest_path} && chmod {mode} {guest_path}",
            user="root",
        )

    def supervise_mcp_url(self, plan: PlanT) -> str:
        """Return the agent-side URL of the per-bottle supervise
        sidecar, or "" when this bottle has no sidecar. The provider
        plugin's `provision_supervise_mcp` uses it to register the
        MCP entry inside the guest.

        Default returns "" so backends without supervise support
        don't have to implement it. Docker and smolmachines override."""
        del plan
        return ""

    @abstractmethod
    def prepare_cleanup(self) -> CleanupT:
        """Enumerate orphaned resources from previous bottles. No side
        effects; safe to call before the y/N."""

    @abstractmethod
    def cleanup(self, plan: CleanupT) -> None:
        """Remove everything described by the cleanup plan."""

    @abstractmethod
    def enumerate_active(self) -> Sequence[ActiveAgent]:
        """Return every currently-running agent on this backend.
        Empty when none. Backend-specific: docker queries `docker
        compose ls`; smolmachines queries `smolvm machine ls --json`
        + cross-references its bundle container."""

    @classmethod
    @abstractmethod
    def is_available(cls) -> bool:
        """Whether this backend's runtime prerequisites are satisfied
        on the current host. Docker → `docker` on PATH; smolmachines
        → `smolvm` on PATH. Used by the cross-backend
        `enumerate_active_agents` / `cmd_cleanup` to skip backends
        the operator hasn't installed, so a docker-only host
        doesn't fail when `cli.py list active` walks past
        smolmachines."""


# Import concrete backend classes AFTER the base types are defined, so
# each backend module can pull BottleSpec / BottlePlan / BottleBackend
# via `from . import ...` without hitting a partially-initialized module.
from .docker import DockerBottleBackend  # noqa: E402  # pylint: disable=wrong-import-position
from .macos_container import MacosContainerBottleBackend  # noqa: E402  # pylint: disable=wrong-import-position
from .smolmachines import SmolmachinesBottleBackend  # noqa: E402  # pylint: disable=wrong-import-position

# Freezer is imported after the backend classes for the same reason:
# Freezer.commit_slug constructs ActiveAgent, which must be fully
# defined first.
from .freeze import CommitCancelled, Freezer, get_freezer  # noqa: E402  # pylint: disable=wrong-import-position


# The dict is heterogeneous: each value is a BottleBackend specialized
# over its own plan type. Concrete plan types are erased here because
# the registry is selected at runtime and the CLI only needs the
# unparameterized methods (prepare → plan → launch(plan), cleanup, etc.).
_BACKENDS: dict[str, BottleBackend[Any, Any]] = {
    "docker": DockerBottleBackend(),
    "macos-container": MacosContainerBottleBackend(),
    "smolmachines": SmolmachinesBottleBackend(),
}


def get_bottle_backend(
    name: str | None = None,
) -> BottleBackend[Any, Any]:
    """Resolve the bottle backend.

    `name` precedence:
      1. explicit arg (CLI `--backend=<name>` passes through here)
      2. BOT_BOTTLE_BACKEND env var
      3. `macos-container` on compatible macOS hosts
      4. default `smolmachines`

    Dies with a pointer at the known backends if the chosen name
    isn't implemented."""
    resolved = name or os.environ.get("BOT_BOTTLE_BACKEND") or _default_backend_name()
    if resolved not in _BACKENDS:
        known = ", ".join(sorted(_BACKENDS))
        die(f"unknown backend {resolved!r}; known backends: {known}")
    return _BACKENDS[resolved]


def _default_backend_name() -> str:
    if has_backend("macos-container"):
        return "macos-container"
    return "smolmachines"


def known_backend_names() -> tuple[str, ...]:
    """Sorted tuple of all backend keys in `_BACKENDS`. Used by
    argparse (`--backend` choices) and the dashboard's backend
    picker."""
    return tuple(sorted(_BACKENDS))


def has_backend(name: str) -> bool:
    """Whether the named backend's runtime prerequisites are
    available on the current host. Cross-backend callers (list,
    cleanup) skip unavailable backends so a docker-only host
    doesn't fail when the smolmachines backend isn't installed,
    and vice versa.

    Returns False for unknown names so callers can pass
    arbitrary input without separate validation."""
    if name not in _BACKENDS:
        return False
    return _BACKENDS[name].is_available()


def enumerate_active_agents() -> list[ActiveAgent]:
    """All currently-running agents, across every available
    backend. Used by CLI `list active` and the dashboard's agents
    pane so neither has to know which backends exist. Skips
    backends whose `is_available()` reports False.

    Sorted by `(started_at, slug)` so the list is stable across
    dashboard refresh ticks — agents don't shift position while
    the operator navigates with arrow keys. ISO 8601 timestamps
    sort lexicographically in chronological order; `slug` is the
    deterministic tiebreaker. Agents with missing metadata
    (`started_at == ""`) sort first."""
    out: list[ActiveAgent] = []
    for name in known_backend_names():
        if not has_backend(name):
            continue
        out.extend(_BACKENDS[name].enumerate_active())
    out.sort(key=lambda a: (a.started_at, a.slug))
    return out


__all__ = [
    "ActiveAgent",
    "Bottle",
    "BottleBackend",
    "BottleCleanupPlan",
    "BottlePlan",
    "BottleSpec",
    "CommitCancelled",
    "ExecResult",
    "Freezer",
    "enumerate_active_agents",
    "get_bottle_backend",
    "get_freezer",
    "has_backend",
    "known_backend_names",
]