"""Tests for async (background) delegation — tools/async_delegation.py.

Covers the dispatch handle, non-blocking behavior, completion-event delivery
onto the shared process_registry.completion_queue, the rich re-injection block
formatting, capacity rejection, and crash handling.
"""

import queue
import threading
import time

import pytest

from tools import async_delegation as ad
from tools.process_registry import process_registry, format_process_notification


@pytest.fixture(autouse=True)
def _clean_state():
    ad._reset_for_tests()
    while not process_registry.completion_queue.empty():
        process_registry.completion_queue.get_nowait()
    yield
    ad._reset_for_tests()
    while not process_registry.completion_queue.empty():
        process_registry.completion_queue.get_nowait()


def _drain_one(timeout=5.0):
    deadline = time.monotonic() + timeout
    while time.monotonic() < deadline:
        if not process_registry.completion_queue.empty():
            return process_registry.completion_queue.get_nowait()
        time.sleep(0.02)
    return None


def test_dispatch_returns_immediately_without_blocking():
    gate = threading.Event()

    def runner():
        gate.wait(timeout=5)
        return {"status": "completed", "summary": "done", "api_calls": 1,
                "duration_seconds": 0.1, "model": "m"}

    t0 = time.monotonic()
    res = ad.dispatch_async_delegation(
        goal="g", context=None, toolsets=None, role="leaf", model="m",
        session_key="", runner=runner, max_async_children=3,
    )
    elapsed = time.monotonic() - t0

    assert res["status"] == "dispatched"
    assert res["delegation_id"].startswith("deleg_")
    # Non-blocking invariant: dispatch returned while the runner is still
    # gated (active), so it cannot have waited on the gate. The active_count
    # check is the environment-independent proof; the generous wall-clock
    # bound is a loose sanity backstop, not the primary assertion (a loaded
    # CI runner can be slow but never anywhere near the runner's 5s gate).
    assert ad.active_count() == 1
    assert elapsed < 4.0, f"dispatch blocked {elapsed:.2f}s (gate is 5s)"
    gate.set()


def test_async_executor_workers_are_daemon_threads():
    gate = threading.Event()

    def runner():
        gate.wait(timeout=5)
        return {"status": "completed", "summary": "done"}

    res = ad.dispatch_async_delegation(
        goal="daemon check", context=None, toolsets=None, role="leaf", model="m",
        session_key="", runner=runner, max_async_children=1,
    )
    assert res["status"] == "dispatched"

    deadline = time.monotonic() + 2
    worker = None
    while time.monotonic() < deadline:
        worker = next(
            (t for t in threading.enumerate() if t.name.startswith("async-delegate")),
            None,
        )
        if worker is not None:
            break
        time.sleep(0.02)
    assert worker is not None
    assert worker.daemon is True
    gate.set()
    assert _drain_one() is not None


def test_completion_event_lands_on_shared_queue_with_session_key():
    def runner():
        return {"status": "completed", "summary": "the result",
                "api_calls": 3, "duration_seconds": 2.0, "model": "test-model"}

    res = ad.dispatch_async_delegation(
        goal="compute X", context="some context", toolsets=["web", "file"],
        role="leaf", model="test-model", session_key="agent:main:cli:dm:local",
        runner=runner, max_async_children=3,
    )
    assert res["status"] == "dispatched"

    evt = _drain_one()
    assert evt is not None
    assert evt["type"] == "async_delegation"
    assert evt["summary"] == "the result"
    assert evt["session_key"] == "agent:main:cli:dm:local"
    assert evt["delegation_id"] == res["delegation_id"]


def test_rich_reinjection_block_is_self_contained():
    def runner():
        return {"status": "completed", "summary": "The answer is 42.",
                "api_calls": 7, "duration_seconds": 3.5, "model": "test-model"}

    ad.dispatch_async_delegation(
        goal="Compute the meaning of life",
        context="User is a philosopher. Respond tersely.",
        toolsets=["web"], role="leaf", model="test-model",
        session_key="", runner=runner, max_async_children=3,
    )
    evt = _drain_one()
    assert evt is not None
    text = format_process_notification(evt)
    assert text is not None
    for needle in [
        "ASYNC DELEGATION COMPLETE",
        "Compute the meaning of life",
        "User is a philosopher",
        "Toolsets: web",
        "The answer is 42.",
        "Status: completed",
        "API calls: 7",
    ]:
        assert needle in text, f"missing {needle!r}"


def test_dispatch_rejected_at_capacity():
    ev = threading.Event()

    def blocker():
        ev.wait(timeout=5)
        return {"status": "completed", "summary": "x"}

    for i in range(2):
        r = ad.dispatch_async_delegation(
            goal=f"task{i}", context=None, toolsets=None, role="leaf",
            model="m", session_key="", runner=blocker, max_async_children=2,
        )
        assert r["status"] == "dispatched"

    r3 = ad.dispatch_async_delegation(
        goal="task3", context=None, toolsets=None, role="leaf", model="m",
        session_key="", runner=blocker, max_async_children=2,
    )
    assert r3["status"] == "rejected"
    assert "capacity reached" in r3["error"]
    ev.set()


def test_crashed_runner_produces_error_completion():
    def boom():
        raise RuntimeError("subagent exploded")

    r = ad.dispatch_async_delegation(
        goal="risky", context=None, toolsets=None, role="leaf", model="m",
        session_key="", runner=boom, max_async_children=3,
    )
    assert r["status"] == "dispatched"
    evt = _drain_one()
    assert evt is not None
    assert evt["status"] == "error"
    text = format_process_notification(evt)
    assert text is not None
    assert "did not complete successfully" in text
    assert "subagent exploded" in text


def test_interrupt_all_signals_running_children():
    ev = threading.Event()
    interrupted = {"count": 0}

    def blocker():
        ev.wait(timeout=5)
        return {"status": "interrupted", "summary": None,
                "error": "cancelled"}

    def interrupt_fn():
        interrupted["count"] += 1
        ev.set()

    ad.dispatch_async_delegation(
        goal="long task", context=None, toolsets=None, role="leaf",
        model="m", session_key="", runner=blocker,
        interrupt_fn=interrupt_fn, max_async_children=3,
    )
    n = ad.interrupt_all(reason="test")
    assert n == 1
    assert interrupted["count"] == 1
    # child still emits a completion event after interrupt
    evt = _drain_one()
    assert evt is not None
    assert evt["status"] == "interrupted"


def test_completed_records_pruned_to_cap():
    # Run more than the retention cap quickly; ensure list doesn't grow forever.
    for i in range(ad._MAX_RETAINED_COMPLETED + 10):
        ad.dispatch_async_delegation(
            goal=f"t{i}", context=None, toolsets=None, role="leaf", model="m",
            session_key="", runner=lambda: {"status": "completed", "summary": "ok"},
            max_async_children=ad._MAX_RETAINED_COMPLETED + 20,
        )
    # let workers finish
    deadline = time.monotonic() + 10
    while time.monotonic() < deadline and ad.active_count() > 0:
        time.sleep(0.05)
    assert len(ad.list_async_delegations()) <= ad._MAX_RETAINED_COMPLETED


# ---------------------------------------------------------------------------
# Integration: delegate_task(background=True) routing
# ---------------------------------------------------------------------------

def test_delegate_task_background_routes_async_and_does_not_block(monkeypatch):
    """delegate_task(background=True) returns a handle without running the
    child synchronously, and the child completes on the background thread."""
    from unittest.mock import MagicMock, patch
    import tools.delegate_tool as dt

    parent = MagicMock()
    parent._delegate_depth = 0
    parent.session_id = "sess"
    parent._interrupt_requested = False
    fake_child = MagicMock()
    fake_child._delegate_role = "leaf"
    fake_child._subagent_id = "s1"

    gate = threading.Event()

    def slow_child(task_index, goal, child=None, parent_agent=None, **kw):
        gate.wait(timeout=5)  # a sync impl would hang delegate_task here
        return {
            "task_index": 0, "status": "completed", "summary": f"done: {goal}",
            "api_calls": 1, "duration_seconds": 0.1, "model": "m",
            "exit_reason": "completed",
        }

    creds = {
        "model": "m", "provider": None, "base_url": None, "api_key": None,
        "api_mode": None, "command": None, "args": None,
    }
    with patch.object(dt, "_build_child_agent", return_value=fake_child), \
         patch.object(dt, "_run_single_child", side_effect=slow_child), \
         patch.object(dt, "_resolve_delegation_credentials", return_value=creds):
        out = dt.delegate_task(
            goal="the real task", context="ctx", toolsets=["web"],
            background=True, parent_agent=parent,
        )

    import json
    parsed = json.loads(out)
    assert parsed["status"] == "dispatched"
    assert parsed["mode"] == "background"
    assert parsed["delegation_id"].startswith("deleg_")
    # The real non-blocking invariant (environment-independent — no wall-clock
    # threshold that flakes on a loaded CI runner): delegate_task returned
    # while the child is STILL blocked on the closed gate, so no completion
    # event exists yet. A synchronous impl could not have returned here — it
    # would still be inside slow_child waiting on the gate.
    assert process_registry.completion_queue.empty()
    assert ad.active_count() == 1  # child running in background, not finished

    gate.set()
    evt = _drain_one()
    assert evt is not None
    assert evt["type"] == "async_delegation"
    assert evt["summary"] == "done: the real task"
    text = format_process_notification(evt)
    assert text is not None
    assert "the real task" in text and "ctx" in text


def test_delegate_task_background_rejects_batch(monkeypatch):
    """background=True with a multi-item tasks batch is rejected (v1: single-task only)."""
    import json
    from unittest.mock import MagicMock
    import tools.delegate_tool as dt

    parent = MagicMock()
    parent._delegate_depth = 0
    parent.session_id = "sess"

    out = dt.delegate_task(
        tasks=[{"goal": "a"}, {"goal": "b"}],
        background=True,
        parent_agent=parent,
    )
    parsed = json.loads(out)
    assert "error" in parsed
    assert "single-task only" in parsed["error"]


def test_delegate_task_background_detaches_child_from_parent(monkeypatch):
    """A background child must NOT remain in parent._active_children —
    otherwise parent-turn interrupts / cache evicts / session close would
    kill the detached subagent mid-run."""
    from unittest.mock import MagicMock, patch
    import tools.delegate_tool as dt

    parent = MagicMock()
    parent._delegate_depth = 0
    parent.session_id = "sess"
    parent._active_children = []
    parent._active_children_lock = threading.Lock()
    fake_child = MagicMock()
    fake_child._delegate_role = "leaf"
    fake_child._subagent_id = "s1"

    gate = threading.Event()

    def slow_child(task_index, goal, child=None, parent_agent=None, **kw):
        gate.wait(timeout=5)
        return {"task_index": 0, "status": "completed", "summary": "ok"}

    def build_and_register(**kw):
        # Mirror what the real _build_child_agent does: register the child
        # for interrupt propagation.
        parent._active_children.append(fake_child)
        return fake_child

    creds = {
        "model": "m", "provider": None, "base_url": None, "api_key": None,
        "api_mode": None, "command": None, "args": None,
    }
    with patch.object(dt, "_build_child_agent", side_effect=build_and_register), \
         patch.object(dt, "_run_single_child", side_effect=slow_child), \
         patch.object(dt, "_resolve_delegation_credentials", return_value=creds):
        out = dt.delegate_task(goal="bg task", background=True, parent_agent=parent)

    import json
    assert json.loads(out)["status"] == "dispatched"
    # Child detached immediately at dispatch, while it is still running.
    assert fake_child not in parent._active_children
    gate.set()
    assert _drain_one() is not None


def test_concurrent_dispatch_respects_capacity():
    """Two threads racing dispatch with cap=1 must yield exactly one accept
    (capacity check and record insert are atomic under the records lock)."""
    gate = threading.Event()

    def blocker():
        gate.wait(timeout=5)
        return {"status": "completed", "summary": "x"}

    results = []
    barrier = threading.Barrier(2)

    def racer():
        barrier.wait(timeout=5)
        results.append(
            ad.dispatch_async_delegation(
                goal="race", context=None, toolsets=None, role="leaf",
                model="m", session_key="", runner=blocker,
                max_async_children=1,
            )
        )

    threads = [threading.Thread(target=racer) for _ in range(2)]
    for t in threads:
        t.start()
    for t in threads:
        t.join(timeout=10)
    statuses = sorted(r["status"] for r in results)
    assert statuses == ["dispatched", "rejected"]
    gate.set()


# ---------------------------------------------------------------------------
# Gateway routing: session_key -> platform/chat_id, rich formatting, injection
# ---------------------------------------------------------------------------

def _make_async_evt(**over):
    evt = {
        "type": "async_delegation",
        "delegation_id": "deleg_x1",
        "session_key": "agent:main:telegram:dm:12345:678",
        "goal": "Investigate flaky test",
        "context": "repo /tmp/p",
        "toolsets": ["terminal"],
        "role": "leaf",
        "model": "m",
        "status": "completed",
        "summary": "Found the bug in test_foo",
        "api_calls": 4,
        "duration_seconds": 12.0,
        "dispatched_at": 1000.0,
        "completed_at": 1012.0,
    }
    evt.update(over)
    return evt


def test_gateway_enriches_routing_from_session_key():
    from gateway.run import GatewayRunner

    runner = object.__new__(GatewayRunner)
    evt = _make_async_evt()
    runner._enrich_async_delegation_routing(evt)
    assert evt["platform"] == "telegram"
    assert evt["chat_id"] == "12345"
    assert evt["thread_id"] == "678"


def test_gateway_formatter_renders_async_block():
    from gateway.run import _format_gateway_process_notification

    txt = _format_gateway_process_notification(_make_async_evt())
    assert txt is not None
    assert "ASYNC DELEGATION COMPLETE" in txt
    assert "Found the bug in test_foo" in txt
    assert "Investigate flaky test" in txt


def test_gateway_watch_drain_requeues_async_without_looping():
    from gateway.run import _drain_gateway_watch_events

    q = queue.Queue()
    async_evt = _make_async_evt()
    watch_evt = {
        "type": "watch_match",
        "session_id": "proc_1",
        "command": "pytest",
        "pattern": "READY",
        "output": "READY",
    }
    q.put(async_evt)
    q.put(watch_evt)

    watch_events = _drain_gateway_watch_events(q)

    assert watch_events == [watch_evt]
    assert q.qsize() == 1
    assert q.get_nowait() == async_evt


def test_gateway_builds_routable_source_from_enriched_event():
    from gateway.run import GatewayRunner

    runner = object.__new__(GatewayRunner)
    evt = _make_async_evt()
    runner._enrich_async_delegation_routing(evt)
    src = runner._build_process_event_source(evt)
    assert src is not None
    assert src.platform.value == "telegram"
    assert src.chat_id == "12345"


def test_gateway_cli_origin_event_left_unrouted():
    """An empty session_key (CLI origin) is left without routing fields."""
    from gateway.run import GatewayRunner

    runner = object.__new__(GatewayRunner)
    evt = _make_async_evt(session_key="")
    runner._enrich_async_delegation_routing(evt)
    assert "platform" not in evt