"""Regression tests for defects found while walking the live health journey.

Each test below fails on the code as it was before the matching fix:

1. an unknown value on an enum-backed query filter (`sport_type`, `meal`,
   `status`) reached SQLAlchemy and raised `LookupError` -> HTTP 500 with no
   French error envelope;
2. `/health/weights/stats` drew `plan_line` from the goal start to the LAST DAY
   OF THE REQUESTED WINDOW, so the plan reference line of the weight chart
   moved with the chart period and was ~7x too steep for a `weekly_rate` goal
   (datamodel-health-vape.md §5.6b: `days = delta / (weekly_rate_kg / 7)`);
3. `/health/goals/active` reported `deficit_target_kcal` as
   `tdee_smoothed - budget`, i.e. the deficit left AFTER the calorie floor
   clamped the budget, instead of the deficit AIMED AT by the goal
   (§5.3 `BudgetResult.deficit_target = rate x 7700 / 7`).
"""

import datetime as dt
from zoneinfo import ZoneInfo

from fastapi.testclient import TestClient

BASE = "/api/health"
PARIS = ZoneInfo("Europe/Paris")

PROFILE = {
    "height_cm": 178.0,
    "sex": "male",
    "birthdate": "1990-05-12",
    "activity_level": "moderate",
    "timezone": "Europe/Paris",
}


def _today() -> dt.date:
    return dt.datetime.now(dt.UTC).astimezone(PARIS).date()


def _at(day: dt.date, hour: int) -> str:
    return (
        dt.datetime(day.year, day.month, day.day, hour, tzinfo=PARIS)
        .astimezone(dt.UTC)
        .isoformat()
        .replace("+00:00", "Z")
    )


def _seed(client: TestClient, headers: dict[str, str]) -> None:
    assert (
        client.put(f"{BASE}/profile", json=PROFILE, headers=headers).status_code == 200
    )
    today = _today()
    for offset, weight in ((6, 95.0), (4, 94.6), (2, 94.3), (0, 94.0)):
        response = client.post(
            f"{BASE}/weights",
            json={
                "measured_at": _at(today - dt.timedelta(days=offset), 7),
                "weight_kg": weight,
            },
            headers=headers,
        )
        assert response.status_code == 201, response.text


# --- 1. Unknown enum filter values must be rejected, never crash --------------


def test_unknown_sport_type_filter_is_rejected(
    client: TestClient, auth_headers: dict[str, str]
) -> None:
    response = client.get(
        f"{BASE}/workouts", params={"sport_type": "quidditch"}, headers=auth_headers
    )
    assert response.status_code == 422, response.text
    assert response.json()["error"]["code"] == "validation_error"


def test_unknown_meal_filter_is_rejected(
    client: TestClient, auth_headers: dict[str, str]
) -> None:
    response = client.get(
        f"{BASE}/nutrition/entries", params={"meal": "brunch"}, headers=auth_headers
    )
    assert response.status_code == 422, response.text
    assert response.json()["error"]["code"] == "validation_error"


def test_unknown_goal_status_filter_is_rejected(
    client: TestClient, auth_headers: dict[str, str]
) -> None:
    response = client.get(
        f"{BASE}/goals", params={"status": "zzz"}, headers=auth_headers
    )
    assert response.status_code == 422, response.text
    assert response.json()["error"]["code"] == "validation_error"


def test_known_enum_filters_still_work(
    client: TestClient, auth_headers: dict[str, str]
) -> None:
    assert (
        client.get(
            f"{BASE}/workouts", params={"sport_type": "cycling"}, headers=auth_headers
        ).status_code
        == 200
    )
    assert (
        client.get(
            f"{BASE}/nutrition/entries", params={"meal": "lunch"}, headers=auth_headers
        ).status_code
        == 200
    )
    assert (
        client.get(
            f"{BASE}/goals", params={"status": "active"}, headers=auth_headers
        ).status_code
        == 200
    )


# --- 2. plan_line must follow the goal rate, not the chart window -------------


def test_plan_line_follows_the_weekly_rate_not_the_window(
    client: TestClient, auth_headers: dict[str, str]
) -> None:
    _seed(client, auth_headers)
    today = _today()
    start = today - dt.timedelta(days=6)
    created = client.post(
        f"{BASE}/goals",
        json={
            "mode": "weekly_rate",
            "start_date": start.isoformat(),
            "start_weight_kg": 95.0,
            "target_weight_kg": 85.0,
            "weekly_rate_kg": 0.5,
        },
        headers=auth_headers,
    )
    assert created.status_code == 201, created.text

    # 10 kg at 0.5 kg/week = 20 weeks = 140 days after the goal start date.
    expected_end = (start + dt.timedelta(days=140)).isoformat()

    def plan_line(params: dict) -> list:
        response = client.get(
            f"{BASE}/weights/stats", params=params, headers=auth_headers
        )
        assert response.status_code == 200, response.text
        body = response.json()
        found = [s for s in body["series"] if s["name"] == "plan_line"]
        assert found, "plan_line series missing"
        assert body["meta"]["plan_end_date"] == expected_end
        return found[0]["points"]

    wide = plan_line({"from": start.isoformat(), "to": today.isoformat()})
    narrow = plan_line(
        {"from": (today - dt.timedelta(days=2)).isoformat(), "to": today.isoformat()}
    )
    assert wide == narrow, "plan_line must not depend on the requested window"
    assert wide[0] == [start.isoformat(), 95.0]
    assert wide[1] == [expected_end, 85.0]


def test_plan_line_uses_target_date_when_the_goal_has_one(
    client: TestClient, auth_headers: dict[str, str]
) -> None:
    _seed(client, auth_headers)
    today = _today()
    start = today - dt.timedelta(days=6)
    target_date = today + dt.timedelta(days=200)
    assert (
        client.post(
            f"{BASE}/goals",
            json={
                "mode": "target_date",
                "start_date": start.isoformat(),
                "start_weight_kg": 95.0,
                "target_weight_kg": 85.0,
                "target_date": target_date.isoformat(),
            },
            headers=auth_headers,
        ).status_code
        == 201
    )
    body = client.get(
        f"{BASE}/weights/stats",
        params={"from": start.isoformat(), "to": today.isoformat()},
        headers=auth_headers,
    ).json()
    points = next(s for s in body["series"] if s["name"] == "plan_line")["points"]
    assert points[1] == [target_date.isoformat(), 85.0]


def test_maintain_goal_has_no_plan_line(
    client: TestClient, auth_headers: dict[str, str]
) -> None:
    _seed(client, auth_headers)
    today = _today()
    assert (
        client.post(
            f"{BASE}/goals",
            json={
                "mode": "maintain",
                "start_date": (today - dt.timedelta(days=6)).isoformat(),
                "start_weight_kg": 95.0,
                "target_weight_kg": 95.0,
            },
            headers=auth_headers,
        ).status_code
        == 201
    )
    body = client.get(f"{BASE}/weights/stats", headers=auth_headers).json()
    assert [s for s in body["series"] if s["name"] == "plan_line"] == []
    assert body["meta"]["plan_end_date"] is None


# --- 3. deficit_target_kcal is the AIMED deficit, floor or not ----------------


def test_deficit_target_is_the_goal_target_even_when_the_floor_applies(
    client: TestClient, auth_headers: dict[str, str]
) -> None:
    _seed(client, auth_headers)
    today = _today()
    assert (
        client.post(
            f"{BASE}/goals",
            json={
                "mode": "weekly_rate",
                "start_date": (today - dt.timedelta(days=6)).isoformat(),
                "start_weight_kg": 95.0,
                "target_weight_kg": 85.0,
                "weekly_rate_kg": 1.5,
            },
            headers=auth_headers,
        ).status_code
        == 201
    )
    budget = client.get(f"{BASE}/goals/active", headers=auth_headers).json()["budget"]
    # 1.5 kg/week -> 1.5 * 7700 / 7 = 1650 kcal/day, whatever the floor does.
    assert budget["deficit_target_kcal"] == 1650.0
    assert budget["floor_applied"] is True
    assert budget["kcal"] == 1500.0


def test_energy_balance_meta_exposes_the_target_deficit(
    client: TestClient, auth_headers: dict[str, str]
) -> None:
    _seed(client, auth_headers)
    today = _today()
    assert (
        client.post(
            f"{BASE}/goals",
            json={
                "mode": "weekly_rate",
                "start_date": (today - dt.timedelta(days=6)).isoformat(),
                "start_weight_kg": 95.0,
                "target_weight_kg": 85.0,
                "weekly_rate_kg": 0.5,
            },
            headers=auth_headers,
        ).status_code
        == 201
    )
    meta = client.get(
        f"{BASE}/energy-balance",
        params={
            "from": (today - dt.timedelta(days=6)).isoformat(),
            "to": today.isoformat(),
        },
        headers=auth_headers,
    ).json()["meta"]
    assert meta["deficit_target_kcal"] == 550.0  # 0.5 * 7700 / 7