import asyncio
from types import SimpleNamespace
from unittest.mock import AsyncMock
from uuid import uuid4

import pytest
from fastapi import HTTPException
from pydantic import ValidationError

from app.mcp import query_service
from app.mcp.analysis_models import ContaminantSourceTraceInput
from app.mcp.calculation_jobs import should_queue
from app.mcp.catalog import TOOLS
from app.services import contaminant_source_trace as trace


def arguments(**extra):
    return ContaminantSourceTraceInput(context_handle="a" * 43,
        **({"candidate_node_ids": ["J2", "J1", "missing"],
            "start": "2026-07-16T08:00:00+08:00", "end": "2026-07-16T08:15:00+08:00"} | extra))


@pytest.mark.parametrize("nodes", [[{"id": "J2"}, {"id": "J1"}], [{"id": "J1"}, {"id": "J2"}]])
def test_trace_is_immediate_project_scoped_stable_and_explicit_about_algorithm(monkeypatch, nodes):
    read = AsyncMock(return_value=nodes)
    monkeypatch.setattr(trace, "read_rows", read)
    connection = object()
    args = arguments()
    result = asyncio.run(trace.trace_contaminant_source(connection, args))
    assert result["located_node"] == "J1"
    assert result["missing_node_ids"] == ["missing"]
    assert result["top_candidates"] == [{"node_id": "J1"}]
    assert result["algorithm_status"] == "provisional"
    assert result["selection_basis"] == "lexicographically_first_existing_candidate_node"
    assert "相似度" not in result and "confidence" not in result
    assert read.await_args.args[0] is connection
    assert "network.nodes" in read.await_args.args[1] and "ANY(%s)" in read.await_args.args[1]
    assert read.await_args.args[2] == (args.candidate_node_ids,)
    assert not should_queue(TOOLS["run_contaminant_source_trace"], args)


@pytest.mark.parametrize("change", [{"candidate_node_ids": []}, {"candidate_node_ids": ["J1", "J1"]},
    {"candidate_node_ids": [str(index) for index in range(21)]},
    {"start": "2026-07-16T08:00:00"}, {"end": "2026-07-16T08:00:00+08:00"},
    {"end": "2026-07-18T08:00:00+08:00"}])
def test_trace_rejects_unbounded_or_ambiguous_inputs(change):
    with pytest.raises(ValidationError):
        arguments(**change)


@pytest.mark.parametrize("nodes", [[], [{"id": "J1"}]])
def test_dispatch_preserves_provenance_and_reports_only_actual_node_gaps(monkeypatch, nodes):
    monkeypatch.setattr(trace, "read_rows", AsyncMock(return_value=nodes))
    monkeypatch.setattr(query_service, "permissions_for_context", lambda _: {"simulation.run"})
    scope = SimpleNamespace(connection=object(), project=SimpleNamespace(project_role="member"))
    binding = SimpleNamespace(tool_cap=["run_contaminant_source_trace"], purpose="task_execution",
        permission_cap=["simulation.run"], task_id=uuid4(), task_scope_cap=[], replay_context=None)
    result = asyncio.run(query_service.execute_query(scope, binding, TOOLS["run_contaminant_source_trace"], arguments()))
    assert result.origin == "synthetic" and result.semantics == "analysis"
    assert (result.data["result"]["located_node"] is None) == (not nodes)
    assert bool(result.data_gaps) == (not nodes)
    assert "context_handle" not in result.data["parameters"]


def test_replay_trace_cannot_escape_frozen_window(monkeypatch):
    monkeypatch.setattr(query_service, "permissions_for_context", lambda _: {"simulation.run"})
    scope = SimpleNamespace(project=SimpleNamespace(project_role="member"))
    binding = SimpleNamespace(tool_cap=["run_contaminant_source_trace"], purpose="task_execution",
        permission_cap=["simulation.run"], task_id=uuid4(), task_scope_cap=[],
        replay_context={"knowledge_cutoff": "2026-07-16T08:00:00+08:00"})
    with pytest.raises(HTTPException) as caught:
        asyncio.run(query_service.authorize_query(scope, binding, TOOLS["run_contaminant_source_trace"], arguments()))
    assert caught.value.status_code == 422