DocsGPT/application/api/devices/session.py

"""Device session endpoints: poll, SSE, ack, output."""

from __future__ import annotations

import gzip
import io
import json
import logging
import time
from queue import Empty
from typing import Iterator

from flask import Response, jsonify, make_response, request, stream_with_context

from application.api.devices.auth import verify_device_session
from application.core.settings import settings
from application.devices.broker import get_broker
from application.storage.db.repositories.device_audit_log import (
    DeviceAuditLogRepository,
)
from application.storage.db.session import db_session


logger = logging.getLogger(__name__)


# Window (seconds) the CLI has to upgrade a poll-issued ticket to an SSE
# stream. Advertised to the CLI as ``expires_in`` and used as the broker
# ticket TTL so the two never drift.
_SESSION_TICKET_TTL_SECONDS = 30


def poll() -> Response:
    """``GET /api/devices/poll`` — long-poll for queued invocations.

    Returns ``202`` with empty body when nothing is queued and ``200`` with
    a session ticket payload when work is waiting.
    """
    device, err = verify_device_session()
    if err is not None:
        return err
    broker = get_broker()
    ticket = broker.claim_ticket(device["id"], _SESSION_TICKET_TTL_SECONDS)
    if ticket is None:
        return make_response("", 202)
    return make_response(
        jsonify(
            {
                "session_ticket": ticket,
                "session_url": f"/api/devices/sessions/{ticket}/events",
                "expires_in": _SESSION_TICKET_TTL_SECONDS,
            }
        ),
        200,
    )


def me() -> Response:
    """``GET /api/devices/me`` — return the calling device's own record.

    Auth: device session token (same as ``/poll``). Used by ``docsgpt-cli
    host status`` to show live server state.
    """
    device, err = verify_device_session()
    if err is not None:
        return err
    out = {
        "id": device.get("id"),
        "name": device.get("name"),
        "hostname": device.get("hostname"),
        "os": device.get("os"),
        "status": device.get("status"),
        "approval_mode": device.get("approval_mode"),
        "description": device.get("description"),
        "paired_at": device.get("paired_at"),
        "last_seen_at": device.get("last_seen_at"),
    }
    for key in ("paired_at", "last_seen_at"):
        value = out.get(key)
        if value is not None and not isinstance(value, str):
            out[key] = value.isoformat()
    return make_response(jsonify(out), 200)


def session_events(session_id: str) -> Response:
    """``GET /api/devices/sessions/{id}/events`` — SSE invocation stream.

    The ``session_id`` must be the ``session_ticket`` the device's own
    ``/poll`` just issued (the path it was handed as ``session_url``). A
    stale, mismatched, or fabricated ticket is rejected with ``410 Gone``
    before any stream is opened.
    """
    device, err = verify_device_session()
    if err is not None:
        return err
    broker = get_broker()
    if not broker.validate_ticket(device["id"], session_id):
        return make_response(
            jsonify({"success": False, "error": "session_ticket_invalid"}), 410
        )
    sess = broker.register_session(device["id"], device["user_id"])

    keepalive_interval = float(settings.SSE_KEEPALIVE_SECONDS)
    idle_seconds = float(settings.REMOTE_DEVICE_SESSION_IDLE_SECONDS)

    @stream_with_context
    def generate() -> Iterator[str]:
        try:
            last_keepalive = time.time()
            while not sess.closed.is_set():
                now = time.time()
                if now - sess.last_activity_at > idle_seconds:
                    yield _sse_event(
                        "session_end",
                        {"reason": "inactivity_timeout"},
                        sess.last_event_id + 1,
                    )
                    sess.last_event_id += 1
                    broker.close_session(sess.session_id, reason="idle")
                    return
                try:
                    inv = sess.invocation_queue.get(timeout=1.0)
                except Empty:
                    if time.time() - last_keepalive >= keepalive_interval:
                        last_keepalive = time.time()
                        yield ": heartbeat\n\n"
                    continue
                sess.last_event_id += 1
                sess.last_activity_at = time.time()
                yield _sse_event("invocation", inv.envelope, sess.last_event_id)
                last_keepalive = time.time()
        except GeneratorExit:
            logger.debug("device SSE generator exiting for session %s", sess.session_id)
            raise
        finally:
            broker.close_session(sess.session_id, reason="generator_exit")

    return Response(
        generate(),
        mimetype="text/event-stream",
        headers={
            "Cache-Control": "no-cache",
            "X-Accel-Buffering": "no",
        },
    )


def ack_invocation(session_id: str, invocation_id: str) -> Response:
    """CLI acks (accepted / denied / auto_approved) the invocation."""
    device, err = verify_device_session()
    if err is not None:
        return err
    body = request.get_json(silent=True) or {}
    decision = body.get("decision")
    reason = body.get("reason")
    if decision not in {"accepted", "denied", "auto_approved"}:
        return make_response(
            jsonify({"success": False, "error": "invalid_decision"}), 400
        )
    broker = get_broker()
    inv = broker.get_invocation(invocation_id)
    if inv is None or inv.device_id != device["id"]:
        return make_response(
            jsonify({"success": False, "error": "invocation_not_found"}), 404
        )
    broker.submit_ack(invocation_id, decision, reason)
    return make_response(jsonify({"success": True}), 200)


def submit_output(session_id: str, invocation_id: str) -> Response:
    """CLI streams stdout/stderr/control chunks (NDJSON, gzip-aware)."""
    device, err = verify_device_session()
    if err is not None:
        return err
    broker = get_broker()
    inv = broker.get_invocation(invocation_id)
    if inv is None or inv.device_id != device["id"]:
        return make_response(
            jsonify({"success": False, "error": "invocation_not_found"}), 404
        )

    body = request.get_data() or b""
    if request.headers.get("Content-Encoding", "").lower() == "gzip":
        try:
            body = gzip.decompress(body)
        except OSError:
            return make_response(
                jsonify({"success": False, "error": "invalid_gzip"}), 400
            )

    received = 0
    for line in io.BytesIO(body):
        line = line.strip()
        if not line:
            continue
        try:
            chunk = json.loads(line.decode("utf-8"))
        except (UnicodeDecodeError, json.JSONDecodeError):
            continue
        if not isinstance(chunk, dict):
            continue
        broker.submit_output_chunk(invocation_id, chunk)
        received += 1

    # Persist outcome on the audit row when a control chunk closed the stream.
    if inv.completed.is_set():
        try:
            from datetime import datetime, timezone
            with db_session() as conn:
                DeviceAuditLogRepository(conn).record_result(
                    invocation_id,
                    started_at=(
                        datetime.fromtimestamp(inv.started_at, tz=timezone.utc)
                        if inv.started_at else None
                    ),
                    finished_at=(
                        datetime.fromtimestamp(inv.finished_at, tz=timezone.utc)
                        if inv.finished_at else None
                    ),
                    exit_code=inv.exit_code,
                    duration_ms=inv.duration_ms,
                    stdout_bytes=sum(
                        len(c) for c in inv.stdout_parts
                    ),
                    stderr_bytes=sum(
                        len(c) for c in inv.stderr_parts
                    ),
                    error=inv.error,
                )
        except Exception:
            logger.exception("audit record_result failed for %s", invocation_id)

    return make_response(
        jsonify({"success": True, "received": received}), 200
    )


def _sse_event(name: str, payload: dict, event_id: int) -> str:
    return (
        f"event: {name}\n"
        f"id: {event_id}\n"
        f"data: {json.dumps(payload)}\n\n"
    )