"""HUX-06 adoption: the stored friendly mode shapes the next route boundary."""

from __future__ import annotations

import hashlib
import hmac
import importlib.util
import json
import sys
from pathlib import Path
from types import SimpleNamespace

ROOT = Path(__file__).parents[2]
PLUGIN = ROOT / "services/hermes/plugins/auto-router"
sys.path.insert(0, str(PLUGIN.parent))

SPEC = importlib.util.spec_from_file_location("hermes_hux_mode", PLUGIN / "hux_mode.py")
assert SPEC and SPEC.loader
hux_mode = importlib.util.module_from_spec(SPEC)
sys.modules[SPEC.name] = hux_mode
SPEC.loader.exec_module(hux_mode)

ROUTER_SPEC = importlib.util.spec_from_file_location(
    "hermes_auto_router_hux", PLUGIN / "__init__.py"
)
assert ROUTER_SPEC and ROUTER_SPEC.loader
router = importlib.util.module_from_spec(ROUTER_SPEC)
sys.modules[ROUTER_SPEC.name] = router
ROUTER_SPEC.loader.exec_module(router)

KEY = bytes(range(32))
SUBJECT = "usr_" + "ab" * 32
SLOT = "slot-3"


def _files(tmp_path: Path) -> dict[str, str]:
    for name in ("context-key", "subject", "worker-key"):
        existing = tmp_path / name
        if existing.exists():
            existing.chmod(0o600)
            existing.unlink()
    context = tmp_path / "context-key"
    context.write_bytes(KEY)
    context.chmod(0o600)
    subject = tmp_path / "subject"
    subject.write_text(SUBJECT + "\n")
    subject.chmod(0o400)
    worker = tmp_path / "worker-key"
    worker.write_text("worker-key-value\n")
    worker.chmod(0o400)
    return {
        "HUX_BASE_URL": "http://127.0.0.1:8790",
        "HUX_TENANT_SLOT": SLOT,
        "HUX_CONTEXT_KEY_FILE": str(context),
        "HUX_SUBJECT_FILE": str(subject),
        "HUX_WORKER_KEY_FILE": str(worker),
        "HUX_PROJECT_SOURCE": "profile:default",
    }


def _record(mode: str, override: str | None = None) -> dict:
    switchyard: dict = {"route_id": "atlas/auto/fast"}
    if override:
        switchyard["override_route_id"] = override
    return {"mode": {"mode": mode, "switchyard": switchyard}}


def _fetch_for(record: dict, status: int = 200, seen: dict | None = None):
    def fetch(url: str, headers: dict) -> tuple[int, dict]:
        if seen is not None:
            seen["url"] = url
            seen["headers"] = headers
            seen["calls"] = seen.get("calls", 0) + 1
        return status, record
    return fetch


def _selection(tmp_path, record, session="sess-1", status=200, seen=None):
    hux_mode._cache.clear()
    return hux_mode.selection(
        session, _files(tmp_path), _fetch_for(record, status, seen)
    )


def test_every_friendly_mode_maps_to_a_provider_neutral_pool(tmp_path):
    assert _selection(tmp_path, _record("fast")) == ("atlas/auto/fast", "")
    assert _selection(tmp_path, _record("thoughtful")) == ("atlas/auto/deep", "")
    assert _selection(tmp_path, _record("research")) == ("atlas/auto/deep", "")
    assert _selection(tmp_path, _record("create")) == ("atlas/auto/balanced", "")
    for route in ("atlas/auto/fast", "atlas/auto/deep", "atlas/auto/balanced"):
        assert route in router.AUTO_ROUTES  # both providers stay eligible


def test_private_mode_is_local_only(tmp_path):
    assert _selection(tmp_path, _record("private")) == (
        "atlas/manual/local/qwen-14b", "",
    )
    # A hosted override can never escape private mode.
    assert _selection(
        tmp_path, _record("private", "atlas/manual/claude/opus")
    ) is None
    assert _selection(
        tmp_path, _record("private", "atlas/manual/local/qwen-14b")
    ) == ("atlas/manual/local/qwen-14b", "")


def test_advanced_override_is_honoured_for_hosted_modes(tmp_path):
    assert _selection(
        tmp_path, _record("create", "atlas/manual/claude/sonnet")
    ) == ("atlas/manual/claude/sonnet", "")
    # A tampered override never breaks routing: the neutral pool wins.
    assert _selection(tmp_path, _record("create", "not-a-route")) == (
        "atlas/auto/balanced", "",
    )


def test_identity_and_derivation_reach_the_service_exactly(tmp_path):
    seen: dict = {}
    _selection(tmp_path, _record("fast"), seen=seen)
    conv = "conv_" + hmac.new(
        KEY,
        "\0".join(
            ("hux.context.id.v1", "conversation", SLOT, SUBJECT, "sess-1")
        ).encode(),
        hashlib.sha256,
    ).hexdigest()[:32]
    prj = "prj_" + hmac.new(
        KEY,
        "\0".join(
            ("hux.context.id.v1", "project", SLOT, SUBJECT, "profile:default")
        ).encode(),
        hashlib.sha256,
    ).hexdigest()[:32]
    assert seen["url"] == (
        f"http://127.0.0.1:8790/hux/v1/projects/{prj}/conversations/{conv}/mode"
    )
    assert seen["headers"]["X-Hux-Trust"] == "worker"
    assert seen["headers"]["X-Hux-Surface"] == "worker"
    assert seen["headers"]["X-Hux-Subject"] == SUBJECT
    assert seen["headers"]["X-Hux-Relay-Key"] == "worker-key-value"


def test_every_failure_is_fail_open(tmp_path):
    assert hux_mode.selection("", _files(tmp_path), _fetch_for(_record("fast"))) is None
    assert _selection(tmp_path, _record("fast"), status=404) is None
    assert _selection(tmp_path, _record("unknown")) is None
    assert _selection(tmp_path, {"mode": "not-a-dict"}) is None
    env = _files(tmp_path)
    env["HUX_TENANT_SLOT"] = "slot-nope"
    hux_mode._cache.clear()
    assert hux_mode.selection("s", env, _fetch_for(_record("fast"))) is None
    env = _files(tmp_path)
    env["HUX_BASE_URL"] = "http://10.0.0.1:8790"
    hux_mode._cache.clear()
    assert hux_mode.selection("s", env, _fetch_for(_record("fast"))) is None
    env = _files(tmp_path)
    Path(env["HUX_CONTEXT_KEY_FILE"]).write_bytes(b"short")
    hux_mode._cache.clear()
    assert hux_mode.selection("s", env, _fetch_for(_record("fast"))) is None

    def broken(url, headers):
        raise OSError("down")

    hux_mode._cache.clear()
    assert hux_mode.selection("s", _files(tmp_path), broken) is None


def test_secret_file_guards_reject_links_and_bad_shapes(tmp_path):
    env = _files(tmp_path)
    target = tmp_path / "elsewhere"
    target.write_bytes(KEY)
    link = tmp_path / "context-link"
    link.symlink_to(target)
    env["HUX_CONTEXT_KEY_FILE"] = str(link)
    hux_mode._cache.clear()
    assert hux_mode.selection("s", env, _fetch_for(_record("fast"))) is None
    env = _files(tmp_path)
    env["HUX_SUBJECT_FILE"] = str(tmp_path / "does-not-exist")
    hux_mode._cache.clear()
    assert hux_mode.selection("s", env, _fetch_for(_record("fast"))) is None
    env = _files(tmp_path)
    Path(env["HUX_SUBJECT_FILE"]).chmod(0o600)
    Path(env["HUX_SUBJECT_FILE"]).write_text("not-a-subject\n")
    hux_mode._cache.clear()
    assert hux_mode.selection("s", env, _fetch_for(_record("fast"))) is None
    env = _files(tmp_path)
    Path(env["HUX_WORKER_KEY_FILE"]).chmod(0o600)
    Path(env["HUX_WORKER_KEY_FILE"]).write_text("\n")
    hux_mode._cache.clear()
    assert hux_mode.selection("s", env, _fetch_for(_record("fast"))) is None
    # A malformed raw session id never reaches HMAC derivation.
    hux_mode._cache.clear()
    assert hux_mode.selection("bad session", _files(tmp_path), _fetch_for(_record("fast"))) is None


def test_real_fetch_round_trip_and_refusals(tmp_path):
    import http.server
    import threading

    record = _record("fast")

    class Handler(http.server.BaseHTTPRequestHandler):
        def do_GET(self):  # noqa: N802 - stdlib naming
            body = json.dumps(record).encode()
            self.send_response(200)
            self.send_header("Content-Type", "application/json")
            self.send_header("Content-Length", str(len(body)))
            self.end_headers()
            self.wfile.write(body)

        def log_message(self, *args):  # noqa: D102
            return

    server = http.server.HTTPServer(("127.0.0.1", 0), Handler)
    thread = threading.Thread(target=server.serve_forever, daemon=True)
    thread.start()
    try:
        env = _files(tmp_path)
        env["HUX_BASE_URL"] = f"http://127.0.0.1:{server.server_port}"
        hux_mode._cache.clear()
        assert hux_mode.selection("sess-live", env) == ("atlas/auto/fast", "")
    finally:
        server.shutdown()
        thread.join(timeout=5)
    # A dead loopback port fails open through the real fetch path too.
    env = _files(tmp_path)
    env["HUX_BASE_URL"] = f"http://127.0.0.1:{server.server_port}"
    hux_mode._cache.clear()
    assert hux_mode.selection("sess-dead", env) is None


def test_cache_is_bounded(tmp_path):
    env = _files(tmp_path)
    hux_mode._cache.clear()
    for index in range(514):
        hux_mode.selection(f"sess-{index}", env, _fetch_for(_record("fast")))
    assert len(hux_mode._cache) <= 513


def test_selection_is_cached_per_session(tmp_path):
    seen: dict = {}
    env = _files(tmp_path)
    hux_mode._cache.clear()
    first = hux_mode.selection("sess-c", env, _fetch_for(_record("fast"), seen=seen))
    second = hux_mode.selection("sess-c", env, _fetch_for(_record("fast"), seen=seen))
    assert first == second == ("atlas/auto/fast", "")
    assert seen["calls"] == 1


def test_boundary_prefers_ui_pick_and_adopts_hux_mode(tmp_path, monkeypatch):
    monkeypatch.setattr(router, "POLICY_PATH", tmp_path / "route-policy.json")
    monkeypatch.setattr(
        router, "_hux_mode_selection", lambda session: ("atlas/auto/deep", "")
    )
    agent = SimpleNamespace(
        _hermes_explicit_model_pick=False,
        _hermes_explicit_reasoning_effort="",
        _hermes_routing_priority="",
    )
    assert router._boundary_selection(agent, "sess-1") == (
        "atlas/auto/deep", "", "hux-mode",
    )
    # No session means no adoption and the existing default is untouched.
    assert router._boundary_selection(agent, "")[2] == "auto"
    # An explicit UI pick always outranks the stored mode.
    picked = SimpleNamespace(
        _hermes_explicit_model_pick=True,
        model="atlas/manual/claude/opus",
        _hermes_explicit_reasoning_effort="high",
        _hermes_routing_priority="",
    )
    assert router._boundary_selection(picked, "sess-1") == (
        "atlas/manual/claude/opus", "high", "ui-manual",
    )
    monkeypatch.setattr(router, "_hux_mode_selection", lambda session: None)
    assert router._boundary_selection(agent, "sess-1")[2] == "auto"