api/app/core/output_formatter.py

"""Output Formatter — transforms deep-agent event streams into WS frame sequences.

Consumes ``(event_type, data)`` tuples yielded by ``deep_agent.run_*_stream()``:
  * ``("token", str)``       — supervisor text token
  * ``("tool_end", dict)``   — sub-agent finished: ``{name, result}``
  * ``("mutations", list)``  — collected CRUD mutations for ``stream_end``

HomeFormatter:
  * Sniffs ``tool_end`` events → emits ``WsStreamBlock`` (entity_ref with raw data)
  * Streams text tokens        → emits ``WsStreamText``
  * Attaches mutations         → injects into ``WsStreamEnd``

FloatingFormatter:
  * Sniffs first ``tool_end`` name → emits ``WsFloatingDomain``
  * Streams text tokens             → emits ``WsStreamText``
  * Attaches mutations              → injects into ``WsStreamEnd``
"""

from __future__ import annotations

import logging
from collections.abc import AsyncGenerator
from typing import Any

from app.schemas import (
    WsFloatingDomain,
    WsStreamBlock,
    WsStreamEnd,
    WsStreamStart,
    WsStreamText,
)

logger = logging.getLogger(__name__)

# Map sub-agent tool name → floating domain / entity type
_AGENT_DOMAIN: dict[str, str] = {
    "task_agent": "tasks",
    "timeline_agent": "timelines",
    "note_agent": "notes",
    "project_agent": "projects",
}

WsFrame = WsStreamStart | WsStreamText | WsStreamBlock | WsStreamEnd | WsFloatingDomain


class HomeFormatter:
    """Consumes a deep-agent event stream and yields WS frames for the Home view.

    ``tool_end`` events from sub-agents are emitted as ``WsStreamBlock``
    (entity_ref) so the client can render structured data.  Text tokens are
    forwarded as ``WsStreamText``.  Mutations are attached to ``WsStreamEnd``.
    """

    def __init__(self, request_id: str) -> None:
        self.request_id = request_id
        self._mutations: list[dict] = []

    async def format(
        self,
        event_stream: AsyncGenerator[tuple[str, Any], None],
    ) -> AsyncGenerator[WsFrame, None]:
        yield WsStreamStart(request_id=self.request_id)

        async for event_type, data in event_stream:
            if event_type == "token":
                if data:
                    yield WsStreamText(request_id=self.request_id, chunk=data)

            elif event_type == "tool_end":
                # Sub-agent finished — emit its result as an entity_ref block
                name = data.get("name", "")
                entity = _AGENT_DOMAIN.get(name)
                if entity:
                    yield WsStreamBlock(
                        request_id=self.request_id,
                        block_type="entity_ref",
                        data={"entity": entity, "result": data.get("result", "")},
                    )

            elif event_type == "mutations":
                self._mutations = data or []

        yield WsStreamEnd(
            request_id=self.request_id,
            mutations=[
                {"action": m["action"], "table": m["table"], "data": m["data"]}
                for m in self._mutations
            ],
        )


class FloatingFormatter:
    """Consumes a deep-agent event stream and yields WS frames for the Floating view.

    Sniffs the first ``tool_end`` event name to derive the domain (e.g.
    ``task_agent`` → ``"tasks"``), then streams text tokens as plain
    ``WsStreamText``.  No block parsing for floating context.
    """

    def __init__(self, request_id: str) -> None:
        self.request_id = request_id
        self._mutations: list[dict] = []

    async def format(
        self,
        event_stream: AsyncGenerator[tuple[str, Any], None],
    ) -> AsyncGenerator[WsFrame, None]:
        domain_sent = False

        async for event_type, data in event_stream:
            if event_type == "tool_end" and not domain_sent:
                # Sniff domain from the first sub-agent that completes
                name = data.get("name", "")
                domain = _AGENT_DOMAIN.get(name, "tasks")
                yield WsFloatingDomain(
                    request_id=self.request_id,
                    domain=domain,  # type: ignore[arg-type]
                )
                yield WsStreamStart(request_id=self.request_id)
                domain_sent = True

            elif event_type == "token":
                if not domain_sent:
                    # First token arrived before any tool_end — default domain
                    yield WsFloatingDomain(
                        request_id=self.request_id,
                        domain="tasks",  # type: ignore[arg-type]
                    )
                    yield WsStreamStart(request_id=self.request_id)
                    domain_sent = True
                if data:
                    yield WsStreamText(request_id=self.request_id, chunk=data)

            elif event_type == "mutations":
                self._mutations = data or []

        # If no events triggered domain_sent (edge case), still emit structure
        if not domain_sent:
            yield WsFloatingDomain(
                request_id=self.request_id,
                domain="tasks",  # type: ignore[arg-type]
            )
            yield WsStreamStart(request_id=self.request_id)

        yield WsStreamEnd(
            request_id=self.request_id,
            mutations=[
                {"action": m["action"], "table": m["table"], "data": m["data"]}
                for m in self._mutations
            ],
        )