from __future__ import annotations

import importlib.util
import json
from pathlib import Path

import pytest


SCRIPT_PATH = (
    Path(__file__).resolve().parents[1] / "scripts" / "write_diagnosis_routing.py"
)
SPEC = importlib.util.spec_from_file_location("write_diagnosis_routing", SCRIPT_PATH)
MODULE = importlib.util.module_from_spec(SPEC)
assert SPEC and SPEC.loader
SPEC.loader.exec_module(MODULE)


def _routing_payload() -> dict:
    return {
        "schema_version": "2.0",
        "status": "awaiting_user",
        "scope": {
            "cluster_id": "cluster-1",
            "time_range": {
                "start": "2026-08-25T04:00:00Z",
                "end": "2026-08-25T05:00:00Z",
            },
        },
        "candidates": [
            {
                "route": "memory_or_oom_pressure",
                "label": "Memory / OOM",
                "routing_confidence": 0.8,
                "evidence_for": ["memory increased"],
                "evidence_against": [],
            }
        ],
        "recommended_route": "memory_or_oom_pressure",
        "selection": None,
    }


def test_validate_routing_accepts_v2_standard_taxonomy() -> None:
    assert MODULE.validate_routing(_routing_payload())["schema_version"] == "2.0"


def test_writer_taxonomy_matches_workspace_schema() -> None:
    schema_path = (
        Path(__file__).resolve().parents[4]
        / "config"
        / "investibook"
        / "schemas"
        / "diagnosis-routing.schema.json"
    )
    schema = json.loads(schema_path.read_text(encoding="utf-8"))

    assert set(schema["$defs"]["standardRoute"]["enum"]) == MODULE.STANDARD_ROUTES


@pytest.mark.parametrize(
    ("field", "value"),
    [
        ("schema_version", "1.0"),
        ("candidate_route", "tidb_memory_oom_or_panic"),
        ("recommended_route", "custom_memory_route"),
    ],
)
def test_validate_routing_rejects_non_v2_or_invented_routes(
    field: str, value: str
) -> None:
    payload = _routing_payload()
    if field == "candidate_route":
        payload["candidates"][0]["route"] = value
    else:
        payload[field] = value

    with pytest.raises(ValueError):
        MODULE.validate_routing(payload)


def test_validate_routing_requires_recommendation_to_be_a_candidate() -> None:
    payload = _routing_payload()
    payload["recommended_route"] = "sql_plan_or_query"

    with pytest.raises(ValueError, match="one of the candidate routes"):
        MODULE.validate_routing(payload)


def test_validate_selected_routes_against_standard_taxonomy() -> None:
    payload = _routing_payload()
    payload["status"] = "selected"
    payload["selection"] = {
        "routes": ["memory_or_oom_pressure", "sql_plan_or_query"],
        "source": "feedback",
    }

    assert MODULE.validate_routing(payload)["selection"]["routes"] == [
        "memory_or_oom_pressure",
        "sql_plan_or_query",
    ]