"""Dispatch-node factory: carry an approved diff into org CI (§3.3, §7.1 P3).

:mod:`agent_team.nodes.builders` proposes the diff;
:mod:`agent_team.nodes.verifier` clears the pure-code gate; this node is the
final in-graph step that calls
:func:`agent_team.dispatcher.dispatch_apply_verify` to push the head branch and
fire ``workflow_dispatch``.

Model/role: this node executes only when the verifier emits the
``APPROVED_ROUTE`` signal. It reads the already-validated candidate diff and
task context from graph state, assembles the dispatch inputs (``owner``/``repo``
injected at coordinator startup), and calls the dispatcher's seams. The actual
diff was hashed and scope-checked by the verifier; this node transports — it
makes no new trust decision.

INERT unless configured: the node is built only when the coordinator threads a
``dispatch_node_wiring`` factory through
:func:`~agent_team.coordinator.Coordinator`. With no factory,
:func:`agent_team.graph.build_graph` leaves ``APPROVED_ROUTE → END`` unchanged
and no dispatch ever fires. This keeps the default path inert and the P3
subgraph opt-in, exactly as the verifier node.

Fail-safe: any dispatch error (invalid state, empty diff, owner/repo
misconfigured, network/subprocess failure) parks the task rather than crashing
the graph. The verifier already validated the diff hash; a dispatch error is an
infrastructure problem, not a security bypass.
"""

from __future__ import annotations

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

__all__ = ["DispatchNodeFactory", "make_dispatch_node"]

_LOG = logging.getLogger("agent_team.nodes.dispatch_invoker")

# A dispatch-node factory type: takes no args, returns the LangGraph node
# callable.  Mirrors the other node-factory types in coordinator.py.
DispatchNodeFactory = Callable[[], "Callable[[Any], Any]"]


def make_dispatch_node(
    *,
    owner: str,
    repo: str,
    base: str = "main",
    pusher: Any = None,
    dispatcher: Any = None,
    locator: Any = None,
) -> Callable[[Any], Any]:
    """Build a LangGraph dispatch node for ``owner``/``repo``.

    Returns a single-arg ``(state) -> dict`` node. At runtime it reads
    ``thread_id``, ``candidate_diff``, and ``plan.scope`` from ``state``, then
    calls :func:`agent_team.dispatcher.dispatch_apply_verify` with the injected
    ``pusher``/``dispatcher`` seams (default: real git/gh subprocess paths).

    Fail-safe: any :class:`~agent_team.dispatcher.DispatcherError` or unexpected
    exception parks the task (returns ``status=PARKED``); the caller retains the
    full graph state, so the coordinator can ALARM and a human can inspect.
    """
    # Deferred import: no orchestrator / subprocess module at module load.
    from agent_team.dispatcher import DispatcherError, dispatch_apply_verify
    from agent_team.task_model import Phase, TaskStatus

    def dispatch_node(state: Any) -> Any:
        thread_id: str = state.get("thread_id") or ""
        diff_text: str = state.get("candidate_diff") or ""
        plan: Any = state.get("plan") or {}
        scope_list: list[Any] = (
            plan.get("scope") or [] if isinstance(plan, dict) else []
        )
        declared_scope: str = "\n".join(str(s) for s in scope_list if s)

        _parked: dict[str, Any] = {
            "status": TaskStatus.PARKED.value,
            "current_phase": Phase.PARKED.value,
        }

        if not thread_id or not diff_text.strip():
            _LOG.warning("dispatch_node: missing thread_id or candidate_diff; parking")
            return _parked
        if not declared_scope.strip():
            _LOG.warning("dispatch_node: empty declared_scope from plan; parking")
            return _parked

        try:
            result = dispatch_apply_verify(
                owner=owner,
                repo=repo,
                task_id=thread_id,
                diff_text=diff_text,
                declared_scope=declared_scope,
                base=base,
                pusher=pusher,
                dispatcher=dispatcher,
                locator=locator,
            )
        except DispatcherError as exc:
            _LOG.error(
                "dispatch_node: DispatcherError for task %s: %s; parking",
                thread_id,
                exc,
            )
            return _parked
        except Exception as exc:  # noqa: BLE001
            _LOG.error(
                "dispatch_node: unexpected error for task %s (%s); parking",
                thread_id,
                type(exc).__name__,
            )
            return _parked

        if not result.run_id:
            # Fired, but the run could not be correlated. Persist the watermark
            # anyway and let the verifier gate fail closed (no authenticated run
            # to read -> BLOCK/park) rather than fabricating progress.
            _LOG.warning(
                "dispatch_node: task %s dispatched but run_id unresolved; "
                "downstream verify will fail closed",
                thread_id,
            )

        _LOG.info(
            "dispatch_node: dispatched task %s to %s/%s (base=%s, run_id=%s)",
            thread_id,
            owner,
            repo,
            base,
            result.run_id,
        )
        # Persist the located run identity so the verifier's read-only fetcher
        # polls THIS task's run and the pure-code gate binds its verdict to it.
        return {
            "run_id": result.run_id,
            "dispatched_at": result.dispatched_at,
            "ci_correlation_tag": result.correlation_tag,
        }

    return dispatch_node