"""Unit tests for agent_team.nodes.clarifier (design §3.3, §7.1 P1).

Covers the clarifier's two responsibilities: the **98% confidence loop** driven
by LangGraph ``interrupt()``/resume (the §7.1 P1 "riskiest mechanic"), and the
**human gate** — only a run clearing the bar advances to planning, a run that
hits the turn cap parks instead of spinning.

The loop tests drive a real compiled ``StateGraph`` with an in-memory
checkpointer so the suspend/resume + replay semantics are exercised exactly as
they will be on the box (the box swaps in the SQLite checkpointer; the node
itself is checkpointer-agnostic). Confidence and question generation are
injected as deterministic callables, so the tests assert control flow without a
live Claude call.
"""

from __future__ import annotations

from collections.abc import Sequence

import pytest
from langgraph.checkpoint.memory import MemorySaver
from langgraph.graph import END, START, StateGraph
from langgraph.types import Command

from agent_team.nodes.clarifier import (
    DEFAULT_CONFIDENCE_THRESHOLD,
    DEFAULT_MAX_TURNS,
    ClarifierConfig,
    build_question_set,
    make_clarifier_node,
)
from agent_team.task_model import (
    Phase,
    PipelineState,
    TaskStatus,
    new_thread_id,
)
from agent_team.transport import QuestionSet

# --------------------------------------------------------------------------- #
# Test helpers: deterministic injected assessor / generator.
# --------------------------------------------------------------------------- #


def _confidence_after_n_answers(target_turns: int) -> object:
    """Assessor that clears the 98% bar once ``target_turns`` answers exist.

    Confidence is 0.0 with no answers and steps to 1.0 once enough answers have
    been collected. Lets a test pin exactly how many interrupt turns the loop
    should take.
    """

    def assess(qa_history: Sequence[object], state: PipelineState) -> float:
        return 1.0 if len(qa_history) >= target_turns else 0.0

    return assess


def _always_questions(*prompts: str):
    """Generator returning a fixed question-set every turn."""

    def generate(qa_history: Sequence[object], state: PipelineState) -> list[str]:
        return list(prompts) or ["What is the goal?"]

    return generate


def _build_graph(node):
    """Compile a one-node graph around ``node`` with an in-memory checkpointer."""
    graph = StateGraph(PipelineState)
    graph.add_node("clarify", node)
    graph.add_edge(START, "clarify")
    graph.add_edge("clarify", END)
    return graph.compile(checkpointer=MemorySaver())


def _initial_state(thread_id: str, transport: str = "slack") -> PipelineState:
    return {
        "thread_id": thread_id,
        "status": TaskStatus.ACTIVE.value,
        "current_phase": Phase.CLARIFY.value,
        "qa_history": [],
        "transport": transport,
    }


# --------------------------------------------------------------------------- #
# build_question_set — the §3.3.1 interrupt payload.
# --------------------------------------------------------------------------- #


def test_build_question_set_returns_foundation_questionset() -> None:
    qs = build_question_set(thread_id="t1", turn=2, questions=["a", "b"])
    assert isinstance(qs, QuestionSet)
    assert qs.thread_id == "t1"
    assert qs.turn == 2
    assert qs.questions == ["a", "b"]
    assert qs.context == {}


def test_build_question_set_mints_unique_question_ids() -> None:
    a = build_question_set(thread_id="t", turn=0, questions=["x"])
    b = build_question_set(thread_id="t", turn=0, questions=["x"])
    assert a.question_id != b.question_id
    assert len(a.question_id) == 32  # uuid4 hex


def test_build_question_set_honours_explicit_question_id() -> None:
    qs = build_question_set(
        thread_id="t", turn=0, questions=["x"], question_id="fixed-id"
    )
    assert qs.question_id == "fixed-id"


def test_build_question_set_copies_inputs_defensively() -> None:
    questions = ["x"]
    context = {"repo": "r"}
    qs = build_question_set(thread_id="t", turn=0, questions=questions, context=context)
    questions.append("y")
    context["repo"] = "mutated"
    assert qs.questions == ["x"]
    assert qs.context == {"repo": "r"}


# --------------------------------------------------------------------------- #
# ClarifierConfig validation.
# --------------------------------------------------------------------------- #


def test_config_defaults_match_design_constants() -> None:
    cfg = ClarifierConfig()
    assert cfg.confidence_threshold == DEFAULT_CONFIDENCE_THRESHOLD == 0.98
    assert cfg.max_turns == DEFAULT_MAX_TURNS


@pytest.mark.parametrize("bad", [0.0, -0.1, 1.5])
def test_config_rejects_threshold_out_of_range(bad: float) -> None:
    with pytest.raises(ValueError, match="confidence_threshold"):
        ClarifierConfig(confidence_threshold=bad)


def test_config_accepts_threshold_of_one() -> None:
    assert ClarifierConfig(confidence_threshold=1.0).confidence_threshold == 1.0


@pytest.mark.parametrize("bad", [0, -3])
def test_config_rejects_nonpositive_max_turns(bad: int) -> None:
    with pytest.raises(ValueError, match="max_turns"):
        ClarifierConfig(max_turns=bad)


# --------------------------------------------------------------------------- #
# Confidence loop: already-confident, no interrupt (human gate opens at once).
# --------------------------------------------------------------------------- #


def test_no_interrupt_when_already_confident() -> None:
    node = make_clarifier_node(
        assess_confidence=_confidence_after_n_answers(0),  # confident immediately
        generate_questions=_always_questions("q"),
    )
    app = _build_graph(node)
    cfg = {"configurable": {"thread_id": "t1"}}
    result = app.invoke(_initial_state("t1"), cfg)

    assert "__interrupt__" not in result
    assert result["current_phase"] == Phase.PLAN.value
    assert result["status"] == TaskStatus.ACTIVE.value
    assert result["qa_history"] == []


# --------------------------------------------------------------------------- #
# Confidence loop: interrupts until the 98% bar is cleared, then human gate.
# --------------------------------------------------------------------------- #


def test_single_turn_loop_clears_bar_and_opens_gate() -> None:
    node = make_clarifier_node(
        assess_confidence=_confidence_after_n_answers(1),
        generate_questions=_always_questions("What is the goal?"),
    )
    app = _build_graph(node)
    cfg = {"configurable": {"thread_id": "t1"}}

    first = app.invoke(_initial_state("t1"), cfg)
    assert "__interrupt__" in first  # suspended on the question-set

    final = app.invoke(Command(resume="ship feature X"), cfg)
    assert "__interrupt__" not in final
    assert final["qa_history"] == ["ship feature X"]
    assert final["current_phase"] == Phase.PLAN.value
    assert final["status"] == TaskStatus.ACTIVE.value


def test_multi_turn_loop_accumulates_answers_until_confident() -> None:
    node = make_clarifier_node(
        assess_confidence=_confidence_after_n_answers(3),
        generate_questions=_always_questions("q?"),
    )
    app = _build_graph(node)
    cfg = {"configurable": {"thread_id": "t1"}}

    assert "__interrupt__" in app.invoke(_initial_state("t1"), cfg)
    assert "__interrupt__" in app.invoke(Command(resume="a1"), cfg)
    assert "__interrupt__" in app.invoke(Command(resume="a2"), cfg)
    final = app.invoke(Command(resume="a3"), cfg)

    assert "__interrupt__" not in final
    assert final["qa_history"] == ["a1", "a2", "a3"]
    assert final["current_phase"] == Phase.PLAN.value
    assert final["status"] == TaskStatus.ACTIVE.value


# --------------------------------------------------------------------------- #
# Interrupt payload shape (§3.3.1): {thread_id, question_id, turn, ...}.
# --------------------------------------------------------------------------- #


def test_interrupt_payload_carries_design_fields() -> None:
    node = make_clarifier_node(
        assess_confidence=_confidence_after_n_answers(1),
        generate_questions=_always_questions("Q1", "Q2"),
        config=ClarifierConfig(transport="slack"),
    )
    app = _build_graph(node)
    cfg = {"configurable": {"thread_id": "tid-123"}}
    app.invoke(_initial_state("tid-123", transport="ignored"), cfg)

    state = app.get_state(cfg)
    assert len(state.interrupts) == 1
    payload = state.interrupts[0].value

    assert payload["thread_id"] == "tid-123"
    assert payload["turn"] == 0
    assert payload["transport"] == "slack"  # config wins over state
    assert payload["deadline"] is None  # owned by the ledger/timer seam
    assert isinstance(payload["question_id"], str) and payload["question_id"]

    qs = payload["question_set"]
    assert isinstance(qs, QuestionSet)
    assert qs.questions == ["Q1", "Q2"]
    assert qs.question_id == payload["question_id"]
    assert qs.thread_id == "tid-123"


def test_interrupt_payload_transport_falls_back_to_state() -> None:
    node = make_clarifier_node(
        assess_confidence=_confidence_after_n_answers(1),
        generate_questions=_always_questions("q"),
        config=ClarifierConfig(),  # empty transport
    )
    app = _build_graph(node)
    cfg = {"configurable": {"thread_id": "t1"}}
    app.invoke(_initial_state("t1", transport="github"), cfg)

    payload = app.get_state(cfg).interrupts[0].value
    assert payload["transport"] == "github"


def test_turn_index_increments_across_interrupts() -> None:
    node = make_clarifier_node(
        assess_confidence=_confidence_after_n_answers(2),
        generate_questions=_always_questions("q"),
    )
    app = _build_graph(node)
    cfg = {"configurable": {"thread_id": "t1"}}

    app.invoke(_initial_state("t1"), cfg)
    assert app.get_state(cfg).interrupts[0].value["turn"] == 0

    app.invoke(Command(resume="a1"), cfg)
    assert app.get_state(cfg).interrupts[0].value["turn"] == 1


# --------------------------------------------------------------------------- #
# Turn cap (§7.1): park rather than spin; never advance to planning.
# --------------------------------------------------------------------------- #


def test_turn_cap_parks_instead_of_advancing() -> None:
    # Never confident; cap at 2 turns.
    node = make_clarifier_node(
        assess_confidence=_confidence_after_n_answers(999),
        generate_questions=_always_questions("q"),
        config=ClarifierConfig(max_turns=2),
    )
    app = _build_graph(node)
    cfg = {"configurable": {"thread_id": "t1"}}

    assert "__interrupt__" in app.invoke(_initial_state("t1"), cfg)
    assert "__interrupt__" in app.invoke(Command(resume="a1"), cfg)
    final = app.invoke(Command(resume="a2"), cfg)  # cap reached

    assert "__interrupt__" not in final
    assert final["current_phase"] == Phase.PARKED.value
    assert final["status"] == TaskStatus.PARKED.value
    assert final["qa_history"] == ["a1", "a2"]
    # Human gate stayed shut: never advanced to PLAN.
    assert final["current_phase"] != Phase.PLAN.value


def test_clearing_bar_on_the_cap_turn_still_opens_gate() -> None:
    # Confident exactly on the last allowed turn — gate must open, not park.
    node = make_clarifier_node(
        assess_confidence=_confidence_after_n_answers(2),
        generate_questions=_always_questions("q"),
        config=ClarifierConfig(max_turns=2),
    )
    app = _build_graph(node)
    cfg = {"configurable": {"thread_id": "t1"}}

    app.invoke(_initial_state("t1"), cfg)
    app.invoke(Command(resume="a1"), cfg)
    final = app.invoke(Command(resume="a2"), cfg)

    assert final["current_phase"] == Phase.PLAN.value
    assert final["status"] == TaskStatus.ACTIVE.value


# --------------------------------------------------------------------------- #
# Durable resume across a "restart" (§7.1 P1 exit (a)): a fresh app object
# bound to the same checkpointer resumes mid-wait to the right thread.
# --------------------------------------------------------------------------- #


def test_resume_after_restart_uses_same_checkpoint() -> None:
    saver = MemorySaver()

    def compile_app():
        node = make_clarifier_node(
            assess_confidence=_confidence_after_n_answers(1),
            generate_questions=_always_questions("q"),
        )
        graph = StateGraph(PipelineState)
        graph.add_node("clarify", node)
        graph.add_edge(START, "clarify")
        graph.add_edge("clarify", END)
        return graph.compile(checkpointer=saver)

    cfg = {"configurable": {"thread_id": "t1"}}
    app1 = compile_app()
    assert "__interrupt__" in app1.invoke(_initial_state("t1"), cfg)

    # Simulate a process restart: a brand-new app object, same checkpointer.
    app2 = compile_app()
    state = app2.get_state(cfg)
    assert state.next == ("clarify",)  # still suspended at the node

    final = app2.invoke(Command(resume="late answer"), cfg)
    assert final["qa_history"] == ["late answer"]
    assert final["current_phase"] == Phase.PLAN.value


# --------------------------------------------------------------------------- #
# Parallel-task isolation (§7.1 P1 exit (d)): two threads resume independently.
# --------------------------------------------------------------------------- #


def test_two_threads_resume_independently() -> None:
    node = make_clarifier_node(
        assess_confidence=_confidence_after_n_answers(1),
        generate_questions=_always_questions("q"),
    )
    app = _build_graph(node)
    cfg_a = {"configurable": {"thread_id": "task-a"}}
    cfg_b = {"configurable": {"thread_id": "task-b"}}

    # Suspend both.
    app.invoke(_initial_state("task-a"), cfg_a)
    app.invoke(_initial_state("task-b"), cfg_b)

    # Resume out of order; each carries its own answer + thread_id.
    final_b = app.invoke(Command(resume="answer-b"), cfg_b)
    final_a = app.invoke(Command(resume="answer-a"), cfg_a)

    assert final_a["qa_history"] == ["answer-a"]
    assert final_b["qa_history"] == ["answer-b"]
    assert final_a["current_phase"] == Phase.PLAN.value
    assert final_b["current_phase"] == Phase.PLAN.value


# --------------------------------------------------------------------------- #
# Resumed task keeps prior Q&A history (a re-opened parked task adds context).
# --------------------------------------------------------------------------- #


def test_existing_qa_history_is_preserved_and_extended() -> None:
    node = make_clarifier_node(
        # Need 2 total answers; one already exists, so one more interrupt.
        assess_confidence=_confidence_after_n_answers(2),
        generate_questions=_always_questions("q"),
    )
    app = _build_graph(node)
    cfg = {"configurable": {"thread_id": "t1"}}
    seeded = _initial_state("t1")
    seeded["qa_history"] = ["prior answer"]

    assert "__interrupt__" in app.invoke(seeded, cfg)
    final = app.invoke(Command(resume="new answer"), cfg)

    assert final["qa_history"] == ["prior answer", "new answer"]
    assert final["current_phase"] == Phase.PLAN.value


# --------------------------------------------------------------------------- #
# The node is callable factory output and integrates with new_thread_id intake.
# --------------------------------------------------------------------------- #


def test_node_runs_against_freshly_minted_thread_id() -> None:
    tid = new_thread_id()
    node = make_clarifier_node(
        assess_confidence=_confidence_after_n_answers(0),
        generate_questions=_always_questions("q"),
    )
    app = _build_graph(node)
    cfg = {"configurable": {"thread_id": tid}}
    result = app.invoke(_initial_state(tid), cfg)
    assert result["current_phase"] == Phase.PLAN.value