from fastapi.testclient import TestClient
import pytest

from main import app
from services.reporting import generate_report


def test_generate_report_empty():
    report = generate_report([])
    assert report == {
        "count": 0,
        "mean": 0.0,
        "median": 0.0,
        "min": 0.0,
        "max": 0.0,
        "std_dev": 0.0,
        "percentile_10": 0.0,
        "percentile_90": 0.0,
    }


def test_generate_report_with_values():
    values = [{"iteration": 1, "result": 10.0}, {
        "iteration": 2, "result": 20.0}, {"iteration": 3, "result": 30.0}]
    report = generate_report(values)
    assert report["count"] == 3
    assert report["mean"] == pytest.approx(20.0)
    assert report["median"] == pytest.approx(20.0)
    assert report["min"] == pytest.approx(10.0)
    assert report["max"] == pytest.approx(30.0)
    assert report["std_dev"] == pytest.approx(8.1649658, rel=1e-6)
    assert report["percentile_10"] == pytest.approx(12.0)
    assert report["percentile_90"] == pytest.approx(28.0)


def test_reporting_endpoint_invalid_input():
    client = TestClient(app)
    resp = client.post("/api/reporting/summary", json={})
    assert resp.status_code == 400
    assert resp.json()["detail"] == "Invalid input format"


def test_reporting_endpoint_success():
    client = TestClient(app)
    input_data = [
        {"iteration": 1, "result": 10.0},
        {"iteration": 2, "result": 20.0},
        {"iteration": 3, "result": 30.0},
    ]
    resp = client.post("/api/reporting/summary", json=input_data)
    assert resp.status_code == 200
    data = resp.json()
    assert data["count"] == 3
    assert data["mean"] == pytest.approx(20.0)


@pytest.mark.parametrize(
    "payload,expected_detail",
    [
        (["not-a-dict"], "Entry at index 0 must be an object"),
        ([{"iteration": 1}], "Entry at index 0 must include numeric 'result'"),
        ([{"iteration": 1, "result": "bad"}],
         "Entry at index 0 must include numeric 'result'"),
    ],
)
def test_reporting_endpoint_validation_errors(payload, expected_detail):
    client = TestClient(app)
    resp = client.post("/api/reporting/summary", json=payload)
    assert resp.status_code == 400
    assert resp.json()["detail"] == expected_detail