"""Unit tests for the worldtree-sdk adapter (`ratatoskr.wt`) — slice-1 foundation.

Covers the two foundation surfaces (issue #20 cutover contract, slice 1):
  * `build_client` — construction wiring + injected-transport ownership (INV-CUT-1:
    the SDK must never close ratatoskr's transport).
  * `translate_error` — the § Error map DEFAULT (`ApiError` → `SessionApiFailed`)
    plus discriminated-`WorldtreeError` passthrough (INV-CUT-2).

No ratatoskr surface (CLI / web / TUI) is exercised here — that wiring lands in
slice 2. These tests hit no network (WorldtreeClient does no I/O at construction).
"""

from __future__ import annotations

from typing import Any, cast

import httpx
import pytest
import worldtree_sdk as wtsdk
from worldtree_sdk import ApiError, CancelResult, WorldtreeClient

from ratatoskr.sessions import (
    AgentNotFound,
    BifrostBinding,
    BifrostConsumerKeyMissing,
    BifrostHandshakeFailed,
    InvalidCursor,
)
from ratatoskr.sse_client import (
    AgentNotAvailable,
    CancelAlreadyCompleted,
    CancelFailed,
    CancelTurnNotFound,
    MalformedSseData,
    MalformedSseId,
    SseConnectFailed,
    SseConnectionDropped,
    TurnIdFlip,
    TurnLaunchUnavailable,
)
from ratatoskr.wt import (
    SessionApiFailed,
    build_client,
    cancel_turn,
    create_session,
    get_session_messages,
    get_session_tools,
    list_sessions,
    stream_turn,
    translate_error,
)


class _FakeSessions:
    """A stand-in for `WorldtreeClient.sessions` — records the last call and
    returns a canned result or raises a canned error. Lets the adapter's
    body-building + error-mapping be unit-tested without any SDK HTTP."""

    def __init__(
        self,
        *,
        result: Any = None,
        error: BaseException | None = None,
        events: list[Any] | None = None,
        stream_error: BaseException | None = None,
    ) -> None:
        self._result = result
        self._error = error
        self._events = events or []
        self._stream_error = stream_error
        self.calls: list[tuple[str, tuple[Any, ...], dict[str, Any]]] = []

    async def _dispatch(self, name: str, *args: Any, **kwargs: Any) -> Any:
        self.calls.append((name, args, kwargs))
        if self._error is not None:
            raise self._error
        return self._result

    async def create(self, *args: Any, **kwargs: Any) -> Any:
        return await self._dispatch("create", *args, **kwargs)

    async def list(self, *args: Any, **kwargs: Any) -> Any:
        return await self._dispatch("list", *args, **kwargs)

    async def messages(self, *args: Any, **kwargs: Any) -> Any:
        return await self._dispatch("messages", *args, **kwargs)

    async def tools(self, *args: Any, **kwargs: Any) -> Any:
        return await self._dispatch("tools", *args, **kwargs)

    def stream_turn(self, *args: Any, **kwargs: Any) -> Any:
        self.calls.append(("stream_turn", args, kwargs))
        return self._astream()

    async def _astream(self) -> Any:
        for event in self._events:
            yield event
        if self._stream_error is not None:
            raise self._stream_error

    async def cancel_turn(self, *args: Any, **kwargs: Any) -> Any:
        return await self._dispatch("cancel_turn", *args, **kwargs)


class _FakeClient:
    def __init__(self, sessions: _FakeSessions) -> None:
        self.sessions = sessions


def _wt(sessions: _FakeSessions) -> WorldtreeClient:
    """Cast the structural fake to the nominal client type the adapter is typed
    against — the route functions only touch `client.sessions.*`, which the fake
    provides. (No network; construction does no I/O.)"""
    return cast(WorldtreeClient, _FakeClient(sessions))


class TestBuildClient:
    async def test_constructs_worldtree_client(self) -> None:
        transport = httpx.AsyncClient()
        try:
            client = build_client(
                "https://wt.example:8081", api_key="ck-test", transport=transport
            )
            assert isinstance(client, WorldtreeClient)
            assert client.base_url == "https://wt.example:8081"
        finally:
            await transport.aclose()

    async def test_injected_transport_is_ratatoskr_owned(self) -> None:
        # INV-CUT-1 [hard]: aclose() on the SDK client must NOT close ratatoskr's
        # transport — ratatoskr owns the lifecycle exactly as it does today.
        transport = httpx.AsyncClient()
        client = build_client("https://wt.example", api_key="ck", transport=transport)
        await client.aclose()
        assert client.closed is True
        assert transport.is_closed is False
        await transport.aclose()

    async def test_admin_key_optional(self) -> None:
        transport = httpx.AsyncClient()
        try:
            # Absent admin_key → admin_auth=None; still constructs.
            without_admin = build_client(
                "https://wt.example", api_key="ck", transport=transport
            )
            assert isinstance(without_admin, WorldtreeClient)
            # Present admin_key → constructs (admin surface available in later slices).
            with_admin = build_client(
                "https://wt.example", api_key="ck", admin_key="ak", transport=transport
            )
            assert isinstance(with_admin, WorldtreeClient)
        finally:
            await transport.aclose()


class TestTranslateError:
    def test_apierror_maps_to_session_api_failed_default(self) -> None:
        exc = ApiError("some_code", "boom", status=500, body="raw-body")
        mapped = translate_error(exc)
        assert isinstance(mapped, SessionApiFailed)
        assert mapped.status == 500
        assert mapped.error_code == "some_code"
        assert mapped.body == "raw-body"

    def test_apierror_with_no_body_maps_cleanly(self) -> None:
        exc = ApiError("nope", "no body", status=404)
        mapped = translate_error(exc)
        assert isinstance(mapped, SessionApiFailed)
        assert mapped.status == 404
        assert mapped.error_code == "nope"
        assert mapped.body is None

    def test_discriminated_subclass_passes_through_unchanged(self) -> None:
        # Discriminated WorldtreeError subclasses are already the right semantic
        # type at the REST layer — translate_error passes them through by identity
        # (the stream routes re-wrap them; that is stream_turn's job, not this one).
        exc = wtsdk.AgentNotAvailable("agent_not_available", "gone", status=409)
        assert translate_error(exc) is exc

    def test_non_worldtree_error_passes_through_unchanged(self) -> None:
        exc = ValueError("unrelated")
        assert translate_error(exc) is exc


class TestCreateSession:
    async def test_happy_returns_sdk_dict_and_builds_body(self) -> None:
        info = {"session_id": "s-1", "agent_id": "mimir", "created_at": "t", "last_active": "t"}
        fake = _FakeSessions(result=info)
        client = _wt(fake)
        out = await create_session(client, "mimir", end_user_id="u-9")
        assert out is info  # open-world passthrough — no re-shaping
        name, args, kwargs = fake.calls[-1]
        assert name == "create"
        assert args[0] == {"agent_id": "mimir", "end_user_id": "u-9"}
        assert kwargs["consumer_key"] is None

    async def test_config_passthrough(self) -> None:
        fake = _FakeSessions(result={"session_id": "s"})
        await create_session(
            _wt(fake), "echo", config={"system_prompt": "be terse"}
        )
        assert fake.calls[-1][1][0] == {
            "agent_id": "echo",
            "config": {"system_prompt": "be terse"},
        }

    async def test_bifrost_bound_body_and_consumer_key(self) -> None:
        fake = _FakeSessions(result={"session_id": "s"})
        binding = BifrostBinding(endpoint_url="http://h:8391", scope=None)
        await create_session(
            _wt(fake), "sindra", bifrost=binding, consumer_key="ck-real"
        )
        _name, args, kwargs = fake.calls[-1]
        assert args[0] == {
            "agent_id": "sindra",
            "bifrost": {"endpoint_url": "http://h:8391", "scope": None},
        }
        # INV-CUT: the consumer key rides the SDK's per-request auth, NOT a header.
        assert kwargs["consumer_key"] == "ck-real"

    async def test_unbound_create_drops_consumer_key(self) -> None:
        # A consumer_key must NOT reach the SDK on an UNBOUND create — the SDK's
        # credential precedence would otherwise auth as the Bifrost consumer instead
        # of the default bearer (heid-bug-hunt Gróa#4 / Regin#4).
        fake = _FakeSessions(result={"session_id": "s"})
        await create_session(_wt(fake), "mimir", consumer_key="ck-should-be-dropped")
        assert fake.calls[-1][2]["consumer_key"] is None

    async def test_bifrost_without_consumer_key_rejected_pre_http(self) -> None:
        fake = _FakeSessions(result={"session_id": "s"})
        binding = BifrostBinding(endpoint_url="http://h:8391", scope=None)
        with pytest.raises(BifrostConsumerKeyMissing):
            await create_session(_wt(fake), "sindra", bifrost=binding)
        assert fake.calls == []  # never reached the SDK

    async def test_404_maps_to_agent_not_found(self) -> None:
        fake = _FakeSessions(error=ApiError("agent_not_found", "no", status=404))
        with pytest.raises(AgentNotFound) as ei:
            await create_session(_wt(fake), "ghost")
        assert ei.value.agent_id == "ghost"

    async def test_bound_502_maps_to_bifrost_handshake_failed(self) -> None:
        body = '{"detail": {"bifrost_error": "bifrost.auth_rejected"}}'
        fake = _FakeSessions(
            error=ApiError("bifrost_handshake_failed", "boom", status=502, body=body)
        )
        binding = BifrostBinding(endpoint_url="http://h:8391", scope=None)
        with pytest.raises(BifrostHandshakeFailed) as ei:
            await create_session(
                _wt(fake), "sindra", bifrost=binding, consumer_key="ck"
            )
        assert ei.value.bifrost_error == "bifrost.auth_rejected"

    async def test_unbound_502_stays_session_api_failed(self) -> None:
        fake = _FakeSessions(error=ApiError("upstream", "boom", status=502, body="x"))
        with pytest.raises(SessionApiFailed) as ei:
            await create_session(_wt(fake), "mimir")
        assert ei.value.status == 502

    async def test_default_error_maps_to_session_api_failed(self) -> None:
        fake = _FakeSessions(error=ApiError("weird", "boom", status=418, body="teapot"))
        with pytest.raises(SessionApiFailed) as ei:
            await create_session(_wt(fake), "mimir")
        assert ei.value.status == 418
        assert ei.value.error_code == "weird"


class TestListSessions:
    async def test_passes_params_and_returns_dict(self) -> None:
        page: dict[str, Any] = {"items": [], "next_cursor": None}
        fake = _FakeSessions(result=page)
        out = await list_sessions(_wt(fake), limit=10, cursor="c1", include_archived=True)
        assert out is page
        kwargs = fake.calls[-1][2]
        assert kwargs["limit"] == 10
        assert kwargs["cursor"] == "c1"
        assert kwargs["include_archived"] is True

    async def test_422_cursor_invalid_maps_to_invalid_cursor(self) -> None:
        fake = _FakeSessions(error=ApiError("cursor_invalid", "bad", status=422))
        with pytest.raises(InvalidCursor) as ei:
            await list_sessions(_wt(fake), cursor="bogus")
        assert ei.value.raw == "bogus"

    async def test_other_422_stays_session_api_failed(self) -> None:
        fake = _FakeSessions(error=ApiError("validation_failed", "x", status=422))
        with pytest.raises(SessionApiFailed):
            await list_sessions(_wt(fake))


class TestReadPassthroughs:
    async def test_messages_returns_dict(self) -> None:
        data = {"session_id": "s", "items": []}
        fake = _FakeSessions(result=data)
        assert await get_session_messages(_wt(fake), "s") is data
        assert fake.calls[-1][0] == "messages"

    async def test_tools_returns_dict(self) -> None:
        data = {"agent_id": "mimir", "builtin_tools": []}
        fake = _FakeSessions(result=data)
        assert await get_session_tools(_wt(fake), "s") is data
        assert fake.calls[-1][0] == "tools"

    async def test_messages_error_maps_to_session_api_failed(self) -> None:
        fake = _FakeSessions(error=ApiError("auth_revoked", "no", status=401))
        with pytest.raises(SessionApiFailed) as ei:
            await get_session_messages(_wt(fake), "s")
        assert ei.value.status == 401

    async def test_tools_error_maps_to_session_api_failed(self) -> None:
        fake = _FakeSessions(error=ApiError("auth_revoked", "no", status=401))
        with pytest.raises(SessionApiFailed) as ei:
            await get_session_tools(_wt(fake), "s")
        assert ei.value.status == 401


async def _drain(aiter: Any) -> list[Any]:
    out: list[Any] = []
    async for ev in aiter:
        out.append(ev)
    return out


class TestStreamTurn:
    async def test_yields_events_verbatim(self) -> None:
        e1, e2 = object(), object()
        fake = _FakeSessions(events=[e1, e2])
        got = await _drain(stream_turn(_wt(fake), "s-1", "hello"))
        assert got == [e1, e2]
        assert fake.calls[-1] == ("stream_turn", ("s-1", "hello"), {})

    async def test_session_retired_maps_to_session_api_failed(self) -> None:
        fake = _FakeSessions(
            stream_error=wtsdk.SessionRetired("session_retired", "gone", status=410)
        )
        with pytest.raises(SessionApiFailed) as ei:
            await _drain(stream_turn(_wt(fake), "s", "hi"))
        assert ei.value.status == 410
        assert ei.value.error_code == "session_retired"

    async def test_agent_not_available_rewraps_to_ratatoskr(self) -> None:
        fake = _FakeSessions(
            stream_error=wtsdk.AgentNotAvailable("agent_not_available", "no agent", status=409)
        )
        with pytest.raises(AgentNotAvailable) as ei:
            await _drain(stream_turn(_wt(fake), "s", "hi"))
        assert ei.value.error_code == "agent_not_available"
        assert ei.value.status == 409

    async def test_turn_launch_unavailable_rewraps_to_ratatoskr(self) -> None:
        fake = _FakeSessions(
            stream_error=wtsdk.TurnLaunchUnavailable("not_ready", "busy", status=503)
        )
        with pytest.raises(TurnLaunchUnavailable) as ei:
            await _drain(stream_turn(_wt(fake), "s", "hi"))
        assert ei.value.retryable is True

    async def test_generic_connect_failed_maps_to_sse_connect_failed(self) -> None:
        fake = _FakeSessions(stream_error=wtsdk.ConnectFailed("connect_failed", "boom", status=500))
        with pytest.raises(SseConnectFailed) as ei:
            await _drain(stream_turn(_wt(fake), "s", "hi"))
        assert ei.value.status == 500

    async def test_connection_dropped_maps_and_carries_cursor(self) -> None:
        fake = _FakeSessions(stream_error=wtsdk.ConnectionDropped("12:3"))
        with pytest.raises(SseConnectionDropped) as ei:
            await _drain(stream_turn(_wt(fake), "s", "hi"))
        assert ei.value.last_seen_sse_id == "12:3"

    async def test_resume_error_maps_to_sse_connect_failed(self) -> None:
        fake = _FakeSessions(stream_error=wtsdk.ResumeError("resume_failed", "boom", status=412))
        with pytest.raises(SseConnectFailed) as ei:
            await _drain(stream_turn(_wt(fake), "s", "hi"))
        assert ei.value.status == 412

    async def test_malformed_sse_id_passes_through_as_ratatoskr(self) -> None:
        fake = _FakeSessions(stream_error=wtsdk.MalformedSseId("bad-id"))
        with pytest.raises(MalformedSseId) as ei:
            await _drain(stream_turn(_wt(fake), "s", "hi"))
        assert ei.value.raw == "bad-id"

    async def test_malformed_sse_data_passes_through_as_ratatoskr(self) -> None:
        fake = _FakeSessions(stream_error=wtsdk.MalformedSseData("not json"))
        with pytest.raises(MalformedSseData):
            await _drain(stream_turn(_wt(fake), "s", "hi"))

    async def test_turn_id_flip_carries_established_and_got(self) -> None:
        fake = _FakeSessions(stream_error=wtsdk.TurnIdFlip(5, 7))
        with pytest.raises(TurnIdFlip) as ei:
            await _drain(stream_turn(_wt(fake), "s", "hi"))
        assert (ei.value.established, ei.value.got) == (5, 7)

    async def test_undiscriminated_api_error_maps_to_session_api_failed(self) -> None:
        # INV-CUT-2 default: an undiscriminated ApiError surfacing from the stream
        # (not a discriminated stream error) → SessionApiFailed.
        fake = _FakeSessions(stream_error=ApiError("weird", "boom", status=500))
        with pytest.raises(SessionApiFailed) as ei:
            await _drain(stream_turn(_wt(fake), "s", "hi"))
        assert ei.value.status == 500


class TestCancelTurn:
    async def test_happy_returns_cancel_result(self) -> None:
        res = CancelResult(turn_id=42, cancelled=True, reason=None, partial_message_id=None)
        fake = _FakeSessions(result=res)
        out = await cancel_turn(_wt(fake), "s-1", 42, persist_partial=True)
        assert out is res
        assert fake.calls[-1] == ("cancel_turn", ("s-1", 42), {"persist_partial": True})

    async def test_late_cancel_race_is_a_result_not_an_error(self) -> None:
        # B-CAN-3: a 200 with cancelled=False is the benign late-cancel no-op.
        res = CancelResult(turn_id=42, cancelled=False, reason=None, partial_message_id=None)
        out = await cancel_turn(_wt(_FakeSessions(result=res)), "s", 42)
        assert out.cancelled is False

    async def test_turn_not_found_maps_to_ratatoskr(self) -> None:
        fake = _FakeSessions(
            error=wtsdk.CancelTurnNotFound(42, error_code="turn_not_found", message="gone")
        )
        with pytest.raises(CancelTurnNotFound) as ei:
            await cancel_turn(_wt(fake), "s", 42)
        assert ei.value.turn_id == 42

    async def test_turn_finished_maps_to_ratatoskr(self) -> None:
        fake = _FakeSessions(
            error=wtsdk.CancelAlreadyCompleted(42, error_code="turn_finished", message="done")
        )
        with pytest.raises(CancelAlreadyCompleted):
            await cancel_turn(_wt(fake), "s", 42)

    async def test_other_cancel_failure_maps_to_cancel_failed(self) -> None:
        fake = _FakeSessions(error=wtsdk.CancelFailed(42, error_code="boom", message="failed"))
        with pytest.raises(CancelFailed):
            await cancel_turn(_wt(fake), "s", 42)

    async def test_undiscriminated_api_error_maps_to_session_api_failed(self) -> None:
        # INV-CUT-2 default: an undiscriminated ApiError on the cancel route (not a
        # typed Cancel* race) → SessionApiFailed, never leaked as a bare ApiError.
        fake = _FakeSessions(error=ApiError("weird", "boom", status=500))
        with pytest.raises(SessionApiFailed) as ei:
            await cancel_turn(_wt(fake), "s", 42)
        assert ei.value.status == 500