import json
from pathlib import Path

from phase_memory.contracts import graph_from_markitect
from phase_memory.models import MemoryEvent, MemoryPath, MemoryPathState
from phase_memory.retrieval import (
    WordCountTokenEstimator,
    activation_quality_report,
    plan_neighborhood_activation,
    retrieve_graph_neighborhood,
    select_event_path,
)


FIXTURES = Path(__file__).parent / "fixtures"


def _graph():
    return graph_from_markitect(json.loads((FIXTURES / "memory-graph.json").read_text(encoding="utf-8"))).value


def test_retrieve_graph_neighborhood_is_stable_and_filterable() -> None:
    candidates = retrieve_graph_neighborhood(
        _graph(),
        seed_node_ids=("decision.boundary",),
        max_hops=1,
        edge_kinds=("governs",),
        direction="out",
    )

    assert [candidate.node_id for candidate in candidates] == ["decision.boundary", "artifact.profile"]
    assert candidates[0].reasons[:2] == ("graph_distance:0", "explicit_priority")


def test_event_path_selection_respects_path_state_and_budget() -> None:
    events = (
        MemoryEvent("event.a", "user_turn"),
        MemoryEvent("event.b", "agent_turn"),
        MemoryEvent("event.c", "tool_call"),
    )
    active = MemoryPath("path.active", event_ids=("event.a", "event.b", "event.c"))
    abandoned = MemoryPath("path.abandoned", event_ids=("event.a",), state=MemoryPathState.ABANDONED)

    assert select_event_path(events, active, max_events=2) == ("event.a", "event.b")
    assert select_event_path(events, abandoned, max_events=2) == ()
    assert select_event_path(events, abandoned, max_events=2, include_inactive=True) == ("event.a",)


def test_neighborhood_activation_uses_retrieval_order_and_estimator_label() -> None:
    plan, candidates = plan_neighborhood_activation(
        _graph(),
        seed_node_ids=("decision.boundary",),
        max_hops=1,
        max_items=2,
        max_tokens=40,
        profile_id="phase-memory-fixture-profile",
    )

    assert [candidate.node_id for candidate in candidates][:2] == ["decision.boundary", "artifact.profile"]
    assert plan.selected_node_ids[:2] == ("decision.boundary", "artifact.profile")
    assert plan.selection["metadata"]["estimator"] == "WordCountTokenEstimator"


def test_token_estimator_accounts_for_nodes_and_events() -> None:
    graph = _graph()
    estimator = WordCountTokenEstimator()

    assert estimator.estimate_node(graph.nodes[0]) == 9
    assert estimator.estimate_event(graph.events[0]) >= 2


def test_activation_quality_report_is_deterministic() -> None:
    plan, _ = plan_neighborhood_activation(
        _graph(),
        seed_node_ids=("decision.boundary",),
        max_hops=1,
        max_items=1,
        max_tokens=20,
        profile_id="phase-memory-fixture-profile",
    )

    report = activation_quality_report(
        plan,
        expected_node_ids=("decision.boundary", "artifact.profile"),
        policy_denied_node_ids=("artifact.profile",),
    )

    expected = json.loads((FIXTURES / "activation-quality-report.json").read_text(encoding="utf-8"))
    assert report["selected_expected_nodes"] == ["decision.boundary"]
    assert report["omitted_required_nodes"] == ["artifact.profile"]
    assert report["policy_denied_required_nodes"] == ["artifact.profile"]
    assert report["token_budget_utilization"] == 0.45
    assert report["source_span_coverage"] == 1.0
    assert report["explanation_coverage"] == 1.0
    assert report == expected