"""Per-scan sandbox session lifecycle."""

from __future__ import annotations

import logging
from pathlib import Path
from typing import Any

from agents.sandbox.entries import BaseEntry, LocalDir
from agents.sandbox.manifest import Environment, Manifest

from strix.config import load_settings
from strix.runtime.backends import get_backend
from strix.runtime.caido_bootstrap import bootstrap_caido


logger = logging.getLogger(__name__)


# In-container Caido sidecar port (matches the image's caido-cli bind).
_CONTAINER_CAIDO_PORT = 48080


_SESSION_CACHE: dict[str, dict[str, Any]] = {}

# Manifest root inside the container; entry keys hang off this path.
_WORKSPACE_ROOT = "/workspace"


def build_session_entries(
    local_sources: list[dict[str, Any]],
) -> tuple[dict[str | Path, BaseEntry], list[dict[str, Any]]]:
    """Split local sources into copied manifest entries and host bind mounts.

    Sources flagged ``mount`` are bind-mounted read-only at
    ``/workspace/<workspace_subdir>`` (not added to the manifest, so the SDK
    does not stream them in file-by-file). Every other source becomes a
    ``LocalDir`` entry copied into the container as before.
    """
    entries: dict[str | Path, BaseEntry] = {}
    bind_mounts: list[dict[str, Any]] = []
    for src in local_sources:
        ws_subdir = src.get("workspace_subdir") or ""
        host_path = src.get("source_path") or ""
        if not ws_subdir or not host_path:
            continue
        resolved = Path(host_path).expanduser().resolve()
        if src.get("mount"):
            bind_mounts.append(
                {
                    "source": str(resolved),
                    "target": f"{_WORKSPACE_ROOT}/{ws_subdir}",
                    "read_only": True,
                }
            )
        else:
            entries[ws_subdir] = LocalDir(src=resolved)
    return entries, bind_mounts


async def create_or_reuse(
    scan_id: str,
    *,
    image: str,
    local_sources: list[dict[str, Any]],
) -> dict[str, Any]:
    """Return the existing session bundle for ``scan_id`` or create a new one.

    Each ``local_sources`` entry exposes its host ``source_path`` at
    ``/workspace/<workspace_subdir>`` inside the container — copied in, or
    bind-mounted read-only when the entry is flagged ``mount``.
    """
    cached = _SESSION_CACHE.get(scan_id)
    if cached is not None:
        logger.info("Reusing existing sandbox session for scan %s", scan_id)
        return cached

    entries, bind_mounts = build_session_entries(local_sources)

    # Caido runs as an in-container sidecar; HTTP(S) traffic from any
    # process started via ``session.exec`` (the SDK's Shell tool, etc.)
    # picks up these env vars automatically. ``NO_PROXY`` keeps the
    # agent-browser CDP daemon's localhost traffic from looping back
    # through Caido.
    container_caido_url = f"http://127.0.0.1:{_CONTAINER_CAIDO_PORT}"
    manifest = Manifest(
        entries=entries,
        environment=Environment(
            value={
                "PYTHONUNBUFFERED": "1",
                "HOST_GATEWAY": "host.docker.internal",
                "http_proxy": container_caido_url,
                "https_proxy": container_caido_url,
                "ALL_PROXY": container_caido_url,
                "NO_PROXY": "localhost,127.0.0.1",
            },
        ),
    )

    backend_name = load_settings().runtime.backend
    backend = get_backend(backend_name)

    logger.info(
        "Creating sandbox session for scan %s (backend=%s, image=%s)",
        scan_id,
        backend_name,
        image,
    )
    client, session = await backend(
        image=image,
        manifest=manifest,
        exposed_ports=(_CONTAINER_CAIDO_PORT,),
        bind_mounts=bind_mounts,
    )

    caido_endpoint = await session.resolve_exposed_port(_CONTAINER_CAIDO_PORT)
    host_caido_url = f"http://{caido_endpoint.host}:{caido_endpoint.port}"
    logger.debug("Caido host endpoint resolved: %s", host_caido_url)

    caido_client = await bootstrap_caido(
        session,
        host_url=host_caido_url,
        container_url=container_caido_url,
    )

    bundle = {
        "client": client,
        "session": session,
        "caido_client": caido_client,
    }
    _SESSION_CACHE[scan_id] = bundle
    logger.info("Sandbox session for scan %s ready and cached", scan_id)
    return bundle


async def cleanup(scan_id: str) -> None:
    """Tear down ``scan_id``'s container and drop its cache entry.

    Best-effort: any error during ``client.delete`` is logged and
    swallowed. We never want a cleanup failure to prevent the next
    scan from starting; the worst case is a stranded container that
    Docker's normal reaping will catch on next ``docker prune``.
    """
    bundle = _SESSION_CACHE.pop(scan_id, None)
    if bundle is None:
        logger.debug("cleanup(%s): no cached session", scan_id)
        return

    caido_client = bundle.get("caido_client")
    if caido_client is not None:
        try:
            await caido_client.aclose()
        except Exception:  # noqa: BLE001
            logger.debug("cleanup(%s): caido_client.aclose() raised", scan_id, exc_info=True)

    try:
        await bundle["client"].delete(bundle["session"])
        logger.info("Cleaned up sandbox session for scan %s", scan_id)
    except Exception:
        logger.exception(
            "cleanup(%s): client.delete raised; container may need manual reaping",
            scan_id,
        )