lifetrack/apps/api/app/modules/health/stats.py

"""Chart-ready aggregations for the health module.

Every `stats/*` response follows the contract of datamodel-health-vape.md §8.1:
{from, to, unit, series:[{name, type, points:[[date, value|null]]}], meta}.
Points are ready for `dataset.source` in ECharts; series names are stable
identifiers (the UI maps them to French labels).
"""

import datetime as dt
from dataclasses import dataclass
from zoneinfo import ZoneInfo

from sqlalchemy.orm import Session

from app.modules.health import calculations as calc
from app.modules.health import service
from app.modules.health.models import Goal, HealthProfile, MealType, ScheduleKind
from app.modules.health.schemas import (
    AdherenceDay,
    AdherenceKind,
    AdherenceResponse,
    BudgetRead,
    DashboardResponse,
    GoalRead,
    MealTotals,
    NutritionDayDetail,
    NutritionDayRead,
    ProjectionRead,
    Series,
    StatsResponse,
    StreakRead,
    TodayItem,
    TodayResponse,
)

STREAK_WINDOW_DAYS = 365
MACRO_KCAL = {"protein_g": 4.0, "carbs_g": 4.0, "fat_g": 9.0}

# Calendar-heatmap encoding of an adherence day. `None` (rest) keeps the cell
# empty in ECharts; the UI colours 0/1/2 via visualMap pieces.
ADHERENCE_STATUS_CODES: dict[str, int | None] = {
    "rest": None,
    "missed": 0,
    "done_unplanned": 1,
    "done": 2,
}


def _iso(day: dt.date) -> str:
    return day.isoformat()


def _round(value: float | None, digits: int = 1) -> float | None:
    return None if value is None else round(value, digits)


# --- Daily energy model -------------------------------------------------------


@dataclass
class DailyModel:
    day: dt.date
    trend_weight_kg: float | None = None
    bmr_kcal: float | None = None
    tdee_kcal: float | None = None
    tdee_method: str | None = None
    tdee_smoothed_kcal: float | None = None
    intake_kcal: float | None = None
    budget_kcal: float | None = None
    deficit_target_kcal: float | None = None
    balance_kcal: float | None = None
    steps: int | None = None
    active_kcal: float | None = None
    total_kcal: float | None = None
    distance_m: int | None = None
    floor_applied: bool = False
    rate_clamped: bool = False


def build_daily_models(
    db: Session,
    user_id: int,
    start: dt.date,
    end: dt.date,
    tz: ZoneInfo,
    profile: HealthProfile | None = None,
    goal: Goal | None = None,
) -> list[DailyModel]:
    """One model per local day of [start, end], TDEE smoothed over 7 days."""
    if profile is None:
        profile = service.get_profile(db, user_id)
    if goal is None:
        goal = service.active_goal(db, user_id)
    warmup = start - dt.timedelta(days=calc.TDEE_SMOOTHING_DAYS - 1)
    days = calc.date_range(warmup, end)
    trend = calc.weight_trend(service.daily_weights(db, user_id, tz, until=end))
    activity = service.merged_activity(db, user_id, warmup, end)
    intake = service.intake_by_day(db, user_id, warmup, end, tz)

    models: list[DailyModel] = []
    for day in days:
        model = DailyModel(day=day)
        merged = activity.get(day)
        if merged is not None:
            model.steps = merged.steps
            model.active_kcal = merged.active_kcal
            model.total_kcal = merged.total_kcal
            model.distance_m = merged.distance_m
        model.trend_weight_kg = calc.trend_at_day(trend, day)
        if profile is not None and model.trend_weight_kg is not None:
            model.bmr_kcal = calc.bmr_mifflin(
                model.trend_weight_kg,
                float(profile.height_cm),
                calc.age_on(day, profile.birthdate),
                profile.sex.value,
            )
            tdee = calc.tdee_effective(
                model.bmr_kcal,
                profile.activity_level.value,
                total_kcal=model.total_kcal,
                active_kcal=model.active_kcal,
            )
            model.tdee_kcal = tdee.kcal
            model.tdee_method = tdee.method
        bucket = intake.get(day)
        model.intake_kcal = bucket["kcal"] if bucket else None
        models.append(model)

    smoothed = calc.moving_average(
        [m.tdee_kcal for m in models], calc.TDEE_SMOOTHING_DAYS
    )
    for model, value in zip(models, smoothed, strict=True):
        model.tdee_smoothed_kcal = value
        model.balance_kcal = calc.energy_balance(model.intake_kcal, model.tdee_kcal)
        if profile is None or value is None:
            continue
        rate = calc.resolve_goal_rate(
            mode=goal.mode.value if goal else "maintain",
            day=model.day,
            trend_now=model.trend_weight_kg or 0.0,
            target_weight_kg=float(goal.target_weight_kg) if goal else 0.0,
            weekly_rate_kg=float(goal.weekly_rate_kg)
            if goal and goal.weekly_rate_kg is not None
            else None,
            target_date=goal.target_date if goal else None,
        )
        budget = calc.daily_budget(
            value, rate, profile.sex.value, profile.calorie_floor_kcal
        )
        model.budget_kcal = budget.kcal
        model.deficit_target_kcal = budget.deficit_target
        model.floor_applied = budget.floor_applied
        model.rate_clamped = budget.rate_clamped
    return [m for m in models if m.day >= start]


def plan_end_date(goal: Goal) -> dt.date | None:
    """Day the PLAN reaches the target weight (§5.6b) — never the chart bound.

    `target_date` goals carry it; `weekly_rate` goals derive it from the rate
    (`days = delta / (weekly_rate_kg / 7)`). Returns None when the plan cannot
    converge (maintain, zero rate, or a rate pushing away from the target).
    """
    if goal.target_date is not None:
        return goal.target_date
    rate = float(goal.weekly_rate_kg) if goal.weekly_rate_kg is not None else 0.0
    delta = float(goal.start_weight_kg) - float(goal.target_weight_kg)
    if rate == 0.0 or delta == 0.0 or delta / rate <= 0:
        return None
    return goal.start_date + dt.timedelta(days=round(delta / rate * 7))


# --- Weight -------------------------------------------------------------------


def weight_stats(
    db: Session, user_id: int, start: dt.date, end: dt.date, tz: ZoneInfo
) -> StatsResponse:
    raw_all = service.daily_weights(db, user_id, tz, until=end)
    trend_all = calc.weight_trend(raw_all)
    raw = [(d, w) for d, w in raw_all if start <= d <= end]
    trend = [(d, w) for d, w in trend_all if start <= d <= end]
    goal = service.active_goal(db, user_id)

    series = [
        Series(
            name="weight_raw",
            type="scatter",
            points=[[_iso(d), w] for d, w in raw],
        ),
        Series(
            name="weight_trend",
            type="line",
            points=[[_iso(d), w] for d, w in trend],
        ),
    ]

    slope_14 = calc.regression_slope(
        [p for p in trend_all if p[0] > end - dt.timedelta(days=14)]
    )
    slope_30 = calc.regression_slope(
        [p for p in trend_all if p[0] > end - dt.timedelta(days=30)]
    )
    trend_now = trend_all[-1][1] if trend_all else None

    projection = calc.Projection(status="not_converging")
    if trend_now is not None and goal is not None:
        projection = calc.project_target_date(
            trend_now, float(goal.target_weight_kg), slope_30 or slope_14, end
        )
        plan_end = plan_end_date(goal)
        if plan_end is not None:
            series.append(
                Series(
                    name="plan_line",
                    type="line",
                    points=[
                        [_iso(goal.start_date), float(goal.start_weight_kg)],
                        [_iso(plan_end), float(goal.target_weight_kg)],
                    ],
                )
            )
        if projection.status == "ok" and projection.date is not None:
            series.append(
                Series(
                    name="projection",
                    type="line",
                    points=[
                        [_iso(trend_all[-1][0]), trend_now],
                        [_iso(projection.date), float(goal.target_weight_kg)],
                    ],
                )
            )

    profile = service.get_profile(db, user_id)
    bmi = (
        calc.bmi(trend_now, float(profile.height_cm))
        if trend_now is not None and profile is not None
        else None
    )
    meta = {
        "trend_now_kg": _round(trend_now, 2),
        "last_weight_kg": _round(raw_all[-1][1], 2) if raw_all else None,
        "slope_14d_kg_day": _round(slope_14, 4),
        "slope_14d_kg_week": _round(slope_14 * 7, 3) if slope_14 is not None else None,
        "slope_30d_kg_day": _round(slope_30, 4),
        "slope_30d_kg_week": _round(slope_30 * 7, 3) if slope_30 is not None else None,
        "total_change_kg": _round(trend[-1][1] - trend[0][1], 2)
        if len(trend) > 1
        else None,
        "bmi": _round(bmi, 1),
        "target_weight_kg": float(goal.target_weight_kg) if goal else None,
        "plan_end_date": _iso(plan_end_date(goal))
        if goal and plan_end_date(goal)
        else None,
        "projection": {
            "status": projection.status,
            "date": _iso(projection.date) if projection.date else None,
        },
        "count": len(raw),
    }
    return StatsResponse(from_=start, to=end, unit="kg", series=series, meta=meta)


def measurement_stats(
    db: Session, user_id: int, start: dt.date, end: dt.date, tz: ZoneInfo
) -> StatsResponse:
    from app.modules.health.schemas import MEASUREMENT_SITES

    rows = service.measurements_between(db, user_id, start, end, tz)
    series: list[Series] = []
    for site in MEASUREMENT_SITES:
        points = [
            [_iso(service.local_day_of(row.measured_at, tz)), float(getattr(row, site))]
            for row in rows
            if getattr(row, site) is not None
        ]
        if points:
            series.append(Series(name=site, type="line", points=points))

    profile = service.get_profile(db, user_id)
    navy_points: list[list] = []
    if profile is not None:
        for row in rows:
            value = calc.navy_body_fat_pct(
                profile.sex.value,
                float(profile.height_cm),
                float(row.waist_cm) if row.waist_cm is not None else None,
                float(row.neck_cm) if row.neck_cm is not None else None,
                float(row.hips_cm) if row.hips_cm is not None else None,
            )
            if value is not None:
                navy_points.append(
                    [_iso(service.local_day_of(row.measured_at, tz)), round(value, 1)]
                )
    if navy_points:
        series.append(Series(name="body_fat_navy_pct", type="line", points=navy_points))
    return StatsResponse(
        from_=start,
        to=end,
        unit="cm",
        series=series,
        meta={"count": len(rows), "sites": [s.name for s in series]},
    )


# --- Activity -----------------------------------------------------------------


def activity_stats(
    db: Session, user_id: int, start: dt.date, end: dt.date, tz: ZoneInfo
) -> StatsResponse:
    merged = service.merged_activity(db, user_id, start, end)
    days = calc.date_range(start, end)
    fields = ("steps", "active_kcal", "total_kcal", "distance_m")
    series: list[Series] = []
    meta: dict = {}
    for field in fields:
        values: list[float | None] = []
        for day in days:
            row = merged.get(day)
            value = getattr(row, field) if row else None
            values.append(float(value) if value is not None else None)
        series.append(
            Series(
                name=field,
                type="bar" if field in {"steps", "active_kcal"} else "line",
                points=[[_iso(d), v] for d, v in zip(days, values, strict=True)],
            )
        )
        ma = calc.moving_average(values, 7)
        series.append(
            Series(
                name=f"{field}_ma7",
                type="line",
                points=[[_iso(d), _round(v)] for d, v in zip(days, ma, strict=True)],
            )
        )
        tracked = [v for v in values if v is not None]
        meta[f"avg_{field}"] = _round(sum(tracked) / len(tracked)) if tracked else None
        meta[f"total_{field}"] = _round(sum(tracked)) if tracked else None
    meta["tracked_days"] = len(merged)
    meta["days"] = len(days)
    return StatsResponse(from_=start, to=end, unit="mixed", series=series, meta=meta)


def workout_stats(
    db: Session, user_id: int, start: dt.date, end: dt.date, tz: ZoneInfo
) -> StatsResponse:
    workouts = service.workouts_between(db, user_id, start, end, tz)
    weekly: dict[dt.date, dict[str, float]] = {}
    by_sport: dict[str, dict[str, float]] = {}
    for workout in workouts:
        day = service.local_day_of(workout.started_at, tz)
        week_start = day - dt.timedelta(days=day.weekday())
        bucket = weekly.setdefault(
            week_start,
            {
                "sessions_count": 0.0,
                "total_kcal": 0.0,
                "total_distance_m": 0.0,
                "total_duration_min": 0.0,
            },
        )
        bucket["sessions_count"] += 1
        bucket["total_kcal"] += float(workout.kcal or 0)
        bucket["total_distance_m"] += float(workout.distance_m or 0)
        bucket["total_duration_min"] += service.workout_duration_s(workout) / 60
        sport = workout.sport_type.value
        sbucket = by_sport.setdefault(
            sport, {"sessions": 0.0, "duration_min": 0.0, "kcal": 0.0}
        )
        sbucket["sessions"] += 1
        sbucket["duration_min"] += service.workout_duration_s(workout) / 60
        sbucket["kcal"] += float(workout.kcal or 0)

    weeks = sorted(weekly)
    series = [
        Series(
            name=name,
            type="bar",
            points=[[_iso(week), _round(weekly[week][name])] for week in weeks],
        )
        for name in (
            "sessions_count",
            "total_kcal",
            "total_distance_m",
            "total_duration_min",
        )
    ]
    series.append(
        Series(
            name="by_sport_duration_min",
            type="pie",
            points=[
                [sport, _round(values["duration_min"])]
                for sport, values in sorted(
                    by_sport.items(),
                    key=lambda item: item[1]["duration_min"],
                    reverse=True,
                )
            ],
        )
    )
    total_duration = sum(service.workout_duration_s(w) for w in workouts) / 60
    meta = {
        "sessions": len(workouts),
        "total_duration_min": _round(total_duration),
        "total_kcal": _round(sum(float(w.kcal or 0) for w in workouts)),
        "total_distance_m": _round(sum(float(w.distance_m or 0) for w in workouts)),
        "by_sport": by_sport,
    }
    return StatsResponse(from_=start, to=end, unit="mixed", series=series, meta=meta)


# --- Energy balance -----------------------------------------------------------


def energy_balance_stats(
    db: Session, user_id: int, start: dt.date, end: dt.date, tz: ZoneInfo
) -> StatsResponse:
    profile = service.get_profile(db, user_id)
    models = build_daily_models(db, user_id, start, end, tz, profile=profile)
    days = [m.day for m in models]

    cumulative: list[float | None] = []
    running = 0.0
    for model in models:
        if model.balance_kcal is not None:
            running += model.balance_kcal
        cumulative.append(round(running, 1))

    series = [
        Series(
            name="intake_kcal",
            type="bar",
            points=[[_iso(m.day), _round(m.intake_kcal)] for m in models],
        ),
        Series(
            name="tdee_kcal",
            type="line",
            points=[[_iso(m.day), _round(m.tdee_kcal)] for m in models],
        ),
        Series(
            name="balance_kcal",
            type="bar",
            points=[[_iso(m.day), _round(m.balance_kcal)] for m in models],
        ),
        Series(
            name="budget_kcal",
            type="line",
            points=[[_iso(m.day), _round(m.budget_kcal)] for m in models],
        ),
        Series(
            name="cumulative_balance_kcal",
            type="line",
            points=[[_iso(d), v] for d, v in zip(days, cumulative, strict=True)],
        ),
    ]

    tracked = [
        (m.intake_kcal, m.tdee_kcal)
        for m in models
        if m.intake_kcal is not None and m.tdee_kcal is not None
    ]
    trend_all = calc.weight_trend(service.daily_weights(db, user_id, tz, until=end))
    calibration = calc.tdee_calibration(
        tracked,
        calc.trend_at_day(trend_all, start),
        calc.trend_at_day(trend_all, end),
    )
    meta = {
        "tdee_methods": {
            _iso(m.day): m.tdee_method for m in models if m.tdee_method is not None
        },
        "cumulative_balance_kcal": _round(running),
        "cumulative_kg_equivalent": _round(running / calc.KCAL_PER_KG_FAT, 2),
        # Daily deficit aimed at by the active goal on the last day of the range
        # (the UI draws it as the target line of the balance chart).
        "deficit_target_kcal": _round(models[-1].deficit_target_kcal)
        if models
        else None,
        "tracked_days": calibration.tracked_days,
        "days": len(models),
        "profile_missing": profile is None,
        "calibration_status": calibration.status,
        "expected_change_kg": _round(calibration.expected_change_kg, 2),
        "actual_change_kg": _round(calibration.actual_change_kg, 2),
        "gap_kg": _round(calibration.gap_kg, 2),
        "tdee_adaptive_kcal": _round(calibration.tdee_adaptive_kcal),
        "tdee_correction_kcal": _round(calibration.tdee_correction_kcal),
    }
    return StatsResponse(from_=start, to=end, unit="kcal", series=series, meta=meta)


# --- Nutrition ----------------------------------------------------------------


def nutrition_stats(
    db: Session, user_id: int, start: dt.date, end: dt.date, tz: ZoneInfo
) -> StatsResponse:
    models = build_daily_models(db, user_id, start, end, tz)
    budgets = {m.day: m.budget_kcal for m in models}
    totals = service.intake_by_day(db, user_id, start, end, tz)
    meals = service.meal_kcal_by_day(db, user_id, start, end, tz)
    days = calc.date_range(start, end)

    series = [
        Series(
            name="kcal",
            type="bar",
            points=[
                [_iso(d), _round(totals[d]["kcal"]) if d in totals else None]
                for d in days
            ],
        ),
        Series(
            name="budget_kcal",
            type="line",
            points=[[_iso(d), _round(budgets.get(d))] for d in days],
        ),
    ]
    for macro, factor in MACRO_KCAL.items():
        series.append(
            Series(
                name=f"{macro}_kcal",
                type="bar",
                points=[
                    [
                        _iso(d),
                        _round(totals[d][macro] * factor) if d in totals else None,
                    ]
                    for d in days
                ],
            )
        )
        series.append(
            Series(
                name=macro,
                type="bar",
                points=[
                    [_iso(d), _round(totals[d][macro]) if d in totals else None]
                    for d in days
                ],
            )
        )
    for meal in MealType:
        series.append(
            Series(
                name=f"meal_{meal.value}_kcal",
                type="bar",
                points=[
                    [
                        _iso(d),
                        _round(meals[d][meal.value]) if d in meals else None,
                    ]
                    for d in days
                ],
            )
        )
    ranked = service.top_foods(db, user_id, start, end, tz)
    series.append(
        Series(
            name="top_foods_kcal",
            type="bar",
            points=[[item["name"], _round(item["kcal"])] for item in ranked],
        )
    )

    tracked = [totals[d] for d in days if d in totals]
    tracked_kcal = [t["kcal"] for t in tracked]
    macro_totals = {macro: sum(t[macro] for t in tracked) for macro in MACRO_KCAL}
    macro_kcal_total = sum(macro_totals[m] * MACRO_KCAL[m] for m in MACRO_KCAL)
    gaps = [
        totals[d]["kcal"] - budgets[d]
        for d in days
        if d in totals and budgets.get(d) is not None
    ]
    meta = {
        "tracked_days": len(tracked),
        "days": len(days),
        "avg_kcal": _round(sum(tracked_kcal) / len(tracked_kcal))
        if tracked_kcal
        else None,
        "avg_protein_g": _round(macro_totals["protein_g"] / len(tracked))
        if tracked
        else None,
        "avg_carbs_g": _round(macro_totals["carbs_g"] / len(tracked))
        if tracked
        else None,
        "avg_fat_g": _round(macro_totals["fat_g"] / len(tracked)) if tracked else None,
        "macro_split_pct": {
            macro: _round(
                100 * macro_totals[macro] * MACRO_KCAL[macro] / macro_kcal_total
            )
            for macro in MACRO_KCAL
        }
        if macro_kcal_total > 0
        else {},
        "days_in_budget": sum(1 for gap in gaps if gap <= 0),
        "days_with_budget": len(gaps),
        "avg_gap_kcal": _round(sum(gaps) / len(gaps)) if gaps else None,
        # Rounded like every other kcal figure: raw float sums otherwise leak
        # binary artefacts (3667.9000000000005) straight into the UI.
        "top_foods": [{**item, "kcal": _round(item["kcal"])} for item in ranked],
    }
    return StatsResponse(from_=start, to=end, unit="kcal", series=series, meta=meta)


def nutrition_days(
    db: Session, user_id: int, start: dt.date, end: dt.date, tz: ZoneInfo
) -> list[NutritionDayRead]:
    models = build_daily_models(db, user_id, start, end, tz)
    totals = service.intake_by_day(db, user_id, start, end, tz)
    out: list[NutritionDayRead] = []
    for model in models:
        bucket = totals.get(model.day)
        vs_budget = (
            bucket["kcal"] - model.budget_kcal
            if bucket is not None and model.budget_kcal is not None
            else None
        )
        out.append(
            NutritionDayRead(
                date=model.day,
                kcal=_round(bucket["kcal"]) if bucket else None,
                protein_g=_round(bucket["protein_g"]) if bucket else None,
                carbs_g=_round(bucket["carbs_g"]) if bucket else None,
                fat_g=_round(bucket["fat_g"]) if bucket else None,
                fiber_g=_round(bucket["fiber_g"]) if bucket else None,
                budget_kcal=_round(model.budget_kcal),
                vs_budget_kcal=_round(vs_budget),
            )
        )
    return out


def nutrition_day_detail(
    db: Session, user_id: int, day: dt.date, tz: ZoneInfo
) -> NutritionDayDetail:
    from app.modules.health.schemas import FoodEntryRead

    entries = service.food_entries_between(db, user_id, day, day, tz)
    meals: dict[str, MealTotals] = {
        meal.value: MealTotals(meal=meal) for meal in MealType
    }
    for entry in entries:
        bucket = meals[entry.meal.value]
        bucket.kcal += float(entry.kcal)
        bucket.protein_g += float(entry.protein_g or 0)
        bucket.carbs_g += float(entry.carbs_g or 0)
        bucket.fat_g += float(entry.fat_g or 0)
        bucket.entries.append(FoodEntryRead.model_validate(entry))
    for bucket in meals.values():
        bucket.kcal = round(bucket.kcal, 1)
        bucket.protein_g = round(bucket.protein_g, 1)
        bucket.carbs_g = round(bucket.carbs_g, 1)
        bucket.fat_g = round(bucket.fat_g, 1)
    totals = nutrition_days(db, user_id, day, day, tz)[0]
    profile = service.get_profile(db, user_id)
    water = sum(
        row.volume_ml for row in service.water_between(db, user_id, day, day, tz)
    )
    return NutritionDayDetail(
        date=day,
        totals=totals,
        water_ml=water,
        water_goal_ml=profile.water_goal_ml if profile else None,
        meals=list(meals.values()),
    )


def water_stats(
    db: Session, user_id: int, start: dt.date, end: dt.date, tz: ZoneInfo
) -> StatsResponse:
    rows = service.water_between(db, user_id, start, end, tz)
    per_day: dict[dt.date, int] = {}
    for row in rows:
        day = service.local_day_of(row.drunk_at, tz)
        per_day[day] = per_day.get(day, 0) + row.volume_ml
    days = calc.date_range(start, end)
    profile = service.get_profile(db, user_id)
    goal_ml = profile.water_goal_ml if profile else None
    series = [
        Series(
            name="volume_ml",
            type="bar",
            points=[[_iso(d), per_day.get(d, 0)] for d in days],
        ),
        Series(
            name="goal_ml",
            type="line",
            points=[[_iso(d), goal_ml] for d in days],
        ),
    ]
    tracked = [v for v in per_day.values()]
    meta = {
        "goal_ml": goal_ml,
        "avg_ml": _round(sum(tracked) / len(tracked)) if tracked else None,
        "tracked_days": len(tracked),
        "days_goal_reached": sum(1 for v in tracked if goal_ml and v >= goal_ml),
    }
    return StatsResponse(from_=start, to=end, unit="ml", series=series, meta=meta)


# --- Planning: today & adherence ----------------------------------------------


def today_view(db: Session, user_id: int, tz: ZoneInfo) -> TodayResponse:
    today = service.today_local(tz)
    start = today - dt.timedelta(days=STREAK_WINDOW_DAYS)
    schedules = service.schedule_map(db, user_id)
    done = service.done_days_by_kind(db, user_id, start, today, tz)

    items: list[TodayItem] = []
    streaks: dict[str, StreakRead] = {}
    for kind in calc.SCHEDULE_KINDS:
        schedule = schedules[kind]
        days = calc.build_adherence(
            start, today, schedule.weekdays, schedule.enabled, set(done[kind])
        )
        streak = calc.compute_streaks(days, today)
        streaks[kind] = StreakRead(current=streak.current, best=streak.best)
        items.append(
            TodayItem(
                kind=ScheduleKind(kind),
                planned=calc.is_planned(schedule.weekdays, today, schedule.enabled),
                done=today in done[kind],
                value=_round(done[kind].get(today), 2),
            )
        )
    return TodayResponse(date=today, items=items, streaks=streaks)


def adherence_stats(
    db: Session,
    user_id: int,
    start: dt.date,
    end: dt.date,
    tz: ZoneInfo,
    kind: str | None = None,
) -> AdherenceResponse:
    today = service.today_local(tz)
    schedules = service.schedule_map(db, user_id)
    # Streaks look further back than the requested window on purpose.
    streak_start = min(start, end - dt.timedelta(days=STREAK_WINDOW_DAYS))
    done = service.done_days_by_kind(db, user_id, streak_start, end, tz)

    kinds: list[AdherenceKind] = []
    for name in calc.SCHEDULE_KINDS:
        if kind and name != kind:
            continue
        schedule = schedules[name]
        done_days = set(done[name])
        window = calc.build_adherence(
            start, end, schedule.weekdays, schedule.enabled, done_days
        )
        full = calc.build_adherence(
            streak_start, end, schedule.weekdays, schedule.enabled, done_days
        )
        streak = calc.compute_streaks(full, today)
        planned = [d for d in window if d.planned]
        kinds.append(
            AdherenceKind(
                kind=ScheduleKind(name),
                weekdays=list(schedule.weekdays or []),
                enabled=schedule.enabled,
                planned_days=len(planned),
                done_days=sum(1 for d in planned if d.done),
                missed_days=sum(1 for d in planned if d.missed),
                adherence_pct=_round(calc.adherence_pct(window)),
                streak=StreakRead(current=streak.current, best=streak.best),
                days=[
                    AdherenceDay(
                        date=d.day, planned=d.planned, done=d.done, status=d.status
                    )
                    for d in window
                ],
            )
        )

    # §8.1 envelope: one calendar-heatmap series per habit, points [day, code].
    series = [
        Series(
            name=item.kind.value,
            type="heatmap",
            points=[
                [_iso(d.date), ADHERENCE_STATUS_CODES[d.status]] for d in item.days
            ],
        )
        for item in kinds
    ]
    meta = {
        "status_codes": ADHERENCE_STATUS_CODES,
        "kinds": {
            item.kind.value: {
                "enabled": item.enabled,
                "weekdays": item.weekdays,
                "planned_days": item.planned_days,
                "done_days": item.done_days,
                "missed_days": item.missed_days,
                "adherence_pct": item.adherence_pct,
                "streak_current": item.streak.current,
                "streak_best": item.streak.best,
            }
            for item in kinds
        },
    }
    return AdherenceResponse(
        from_=start, to=end, unit="day", series=series, meta=meta, kinds=kinds
    )


# --- Dashboard ----------------------------------------------------------------


def dashboard(db: Session, user_id: int, tz: ZoneInfo) -> DashboardResponse:
    today = service.today_local(tz)
    start = today - dt.timedelta(days=29)
    profile = service.get_profile(db, user_id)
    goal = service.active_goal(db, user_id)
    models = build_daily_models(
        db, user_id, start, today, tz, profile=profile, goal=goal
    )
    current = models[-1] if models else DailyModel(day=today)

    raw_all = service.daily_weights(db, user_id, tz, until=today)
    trend_all = calc.weight_trend(raw_all)
    trend_now = trend_all[-1][1] if trend_all else None
    trend_7d_ago = calc.trend_at_day(trend_all, today - dt.timedelta(days=7))
    last_entry = db.scalar(
        service.weights_query(user_id, None, None, tz, "-measured_at").limit(1)
    )

    cumulative = sum(m.balance_kcal for m in models if m.balance_kcal is not None)
    week_start = today - dt.timedelta(days=today.weekday())
    workouts_week = service.workouts_between(db, user_id, week_start, today, tz)
    water_today = sum(
        row.volume_ml for row in service.water_between(db, user_id, today, today, tz)
    )

    projection = None
    if goal is not None and trend_now is not None:
        slope = calc.regression_slope(
            [p for p in trend_all if p[0] > today - dt.timedelta(days=30)]
        ) or calc.regression_slope(
            [p for p in trend_all if p[0] > today - dt.timedelta(days=14)]
        )
        result = calc.project_target_date(
            trend_now, float(goal.target_weight_kg), slope, today
        )
        projection = ProjectionRead(status=result.status, date=result.date)

    remaining = (
        current.budget_kcal - current.intake_kcal
        if current.budget_kcal is not None and current.intake_kcal is not None
        else current.budget_kcal
    )
    return DashboardResponse(
        date=today,
        weight_kg=_round(float(last_entry.weight_kg), 2) if last_entry else None,
        weight_measured_at=last_entry.measured_at if last_entry else None,
        trend_weight_kg=_round(trend_now, 2),
        trend_delta_7d_kg=_round(trend_now - trend_7d_ago, 2)
        if trend_now is not None and trend_7d_ago is not None
        else None,
        bmi=_round(calc.bmi(trend_now, float(profile.height_cm)), 1)
        if trend_now is not None and profile is not None
        else None,
        intake_kcal=_round(current.intake_kcal),
        budget_kcal=_round(current.budget_kcal),
        remaining_kcal=_round(remaining),
        tdee_kcal=_round(current.tdee_kcal),
        tdee_method=current.tdee_method,
        balance_kcal=_round(current.balance_kcal),
        cumulative_balance_30d_kcal=_round(cumulative),
        steps=current.steps,
        active_kcal=_round(current.active_kcal),
        distance_m=current.distance_m,
        water_ml=water_today,
        water_goal_ml=profile.water_goal_ml if profile else None,
        workouts_this_week=len(workouts_week),
        goal=GoalRead.model_validate(goal) if goal else None,
        projection=projection,
        weight_series=[[_iso(d), w] for d, w in trend_all if d >= start],
        today=today_view(db, user_id, tz),
    )


def active_goal_view(db: Session, user_id: int, tz: ZoneInfo):
    """Active goal + budget of the day + projection + progress (§8.2)."""
    from app.modules.health.schemas import ActiveGoalRead

    goal = service.active_goal(db, user_id)
    if goal is None:
        return ActiveGoalRead()
    today = service.today_local(tz)
    profile = service.get_profile(db, user_id)
    models = build_daily_models(
        db, user_id, today, today, tz, profile=profile, goal=goal
    )
    model = models[-1] if models else DailyModel(day=today)
    trend_all = calc.weight_trend(service.daily_weights(db, user_id, tz, until=today))
    trend_now = trend_all[-1][1] if trend_all else None

    budget = None
    if model.budget_kcal is not None and model.tdee_kcal is not None:
        budget = BudgetRead(
            kcal=_round(model.budget_kcal),
            # The deficit AIMED AT by the goal (rate x 7700 / 7), not the one the
            # floored budget happens to leave — §5.3 BudgetResult.deficit_target.
            deficit_target_kcal=_round(model.deficit_target_kcal or 0.0),
            floor_applied=model.floor_applied,
            rate_clamped=model.rate_clamped,
            tdee_kcal=_round(model.tdee_kcal),
            tdee_method=model.tdee_method or "estimated",
        )
    projection = None
    if trend_now is not None:
        slope = calc.regression_slope(
            [p for p in trend_all if p[0] > today - dt.timedelta(days=30)]
        )
        result = calc.project_target_date(
            trend_now, float(goal.target_weight_kg), slope, today
        )
        projection = ProjectionRead(status=result.status, date=result.date)

    start_w = float(goal.start_weight_kg)
    target_w = float(goal.target_weight_kg)
    done_kg = remaining_kg = progress = None
    if trend_now is not None:
        done_kg = start_w - trend_now
        remaining_kg = trend_now - target_w
        span = start_w - target_w
        progress = 100 * done_kg / span if span else None
        progress = None if progress is None else max(0.0, min(100.0, progress))
    return ActiveGoalRead(
        goal=GoalRead.model_validate(goal),
        budget=budget,
        projection=projection,
        trend_weight_kg=_round(trend_now, 2),
        done_kg=_round(done_kg, 2),
        remaining_kg=_round(remaining_kg, 2),
        progress_pct=_round(progress),
    )