"""Tests for /api/meet-kevin/backtest/* routes (mocked DB)."""

from __future__ import annotations

import uuid
from datetime import datetime, timezone
from unittest.mock import AsyncMock, MagicMock

import pytest
from fastapi.testclient import TestClient

from services.api_gateway.auth.jwt import create_access_token
from services.api_gateway.auth.middleware import get_config, get_current_user
from services.api_gateway.config import ApiGatewayConfig
from services.api_gateway.main import create_app


@pytest.fixture
def config() -> ApiGatewayConfig:
    return ApiGatewayConfig(
        jwt_secret_key="test-secret-for-routes-kevin-backtest",
        database_url="sqlite+aiosqlite:///:memory:",
        redis_url="redis://localhost:6379/0",
    )


@pytest.fixture
def auth_headers(config: ApiGatewayConfig) -> dict[str, str]:
    token = create_access_token("user-test", "tester", config)
    return {"Authorization": f"Bearer {token}"}


def _make_session() -> tuple[MagicMock, AsyncMock]:
    session = AsyncMock()
    session.__aenter__ = AsyncMock(return_value=session)
    session.__aexit__ = AsyncMock(return_value=False)
    factory = MagicMock()
    factory.return_value = session
    return factory, session


def _make_execute_result(scalars: list, scalar_one_or_none=None):
    result = MagicMock()
    result.scalars.return_value.all.return_value = scalars
    result.scalar_one_or_none.return_value = scalar_one_or_none
    return result


@pytest.fixture
def app(config: ApiGatewayConfig):
    factory, session = _make_session()
    app = create_app(config)
    app.dependency_overrides[get_current_user] = lambda: {
        "sub": "user-test",
        "username": "tester",
        "type": "access",
    }
    app.dependency_overrides[get_config] = lambda: config
    app.state.db_session_factory = factory
    app.state.config = config
    app.state.redis = AsyncMock()
    app.state.db_engine = MagicMock()
    app._test_session = session  # type: ignore[attr-defined]
    return app


def test_list_runs_returns_empty_initially(app, auth_headers):
    session: AsyncMock = app._test_session  # type: ignore[attr-defined]
    session.execute = AsyncMock(return_value=_make_execute_result([]))

    client = TestClient(app, raise_server_exceptions=False)
    resp = client.get("/api/meet-kevin/backtest/runs", headers=auth_headers)
    assert resp.status_code == 200
    assert resp.json() == []


def test_get_run_by_uuid_returns_404_if_unknown(app, auth_headers):
    session: AsyncMock = app._test_session  # type: ignore[attr-defined]
    session.execute = AsyncMock(
        return_value=_make_execute_result([], scalar_one_or_none=None)
    )

    client = TestClient(app, raise_server_exceptions=False)
    unknown = uuid.uuid4()
    resp = client.get(
        f"/api/meet-kevin/backtest/runs/{unknown}", headers=auth_headers
    )
    assert resp.status_code == 404


def test_list_runs_returns_persisted_row(app, auth_headers):
    """When the DB has a row, the route serialises it correctly."""
    fake_row = MagicMock()
    fake_row.run_uuid = uuid.uuid4()
    fake_row.status = MagicMock(value="completed")
    fake_row.started_at = datetime.now(timezone.utc)
    fake_row.finished_at = datetime.now(timezone.utc)
    fake_row.metrics_json = {"total_return_pct": 3.5, "trade_count": 2}

    session: AsyncMock = app._test_session  # type: ignore[attr-defined]
    session.execute = AsyncMock(return_value=_make_execute_result([fake_row]))

    client = TestClient(app, raise_server_exceptions=False)
    resp = client.get("/api/meet-kevin/backtest/runs", headers=auth_headers)
    assert resp.status_code == 200
    rows = resp.json()
    assert len(rows) == 1
    assert rows[0]["status"] == "completed"
    assert rows[0]["total_return_pct"] == 3.5


def test_latest_returns_404_if_no_completed(app, auth_headers):
    session: AsyncMock = app._test_session  # type: ignore[attr-defined]
    session.execute = AsyncMock(
        return_value=_make_execute_result([], scalar_one_or_none=None)
    )

    client = TestClient(app, raise_server_exceptions=False)
    resp = client.get("/api/meet-kevin/backtest/latest", headers=auth_headers)
    assert resp.status_code == 404


def test_run_backtest_returns_run_uuid(app, auth_headers):
    session: AsyncMock = app._test_session  # type: ignore[attr-defined]
    session.commit = AsyncMock()
    session.add = MagicMock()

    client = TestClient(app, raise_server_exceptions=False)
    resp = client.post(
        "/api/meet-kevin/backtest/run",
        headers=auth_headers,
        json={"initial_capital": 100000.0, "slippage_pct": 0.0005},
    )
    assert resp.status_code == 202
    data = resp.json()
    assert "run_uuid" in data
    assert data["status"] == "running"