"""
Layer 2b: Ernährungs-Verlauf — ein Bundle für die UI (Issue #53).

Single Source: nutrition_metrics + dieselben Tabellen wie Ernährungs-Platzhalter.
"""

from __future__ import annotations

from datetime import date, datetime, timedelta
from typing import Any, Dict, List, Optional

from db import get_db, get_cursor, r2d
from data_layer.nutrition_body_merge import build_merged_daily_nutrition_body_rows
from data_layer.nutrition_interpretation import (
    build_energy_availability_kpi_tile,
    build_macro_donut_from_averages,
    build_nutrition_correlation_heuristic_items,
    build_nutrition_history_kpi_tiles,
)
from data_layer.nutrition_chart_payloads import (
    build_energy_balance_chart_payload,
    build_nutrition_adherence_score_payload,
    build_protein_adequacy_chart_payload,
)
from data_layer.nutrition_metrics import (
    estimate_tdee_kcal_from_latest_weight,
    get_energy_availability_warning_payload,
    get_energy_balance_data,
    get_nutrition_average_data,
    get_protein_targets_data,
    get_weekly_macro_distribution_chart_data,
)
from data_layer.utils import safe_float


def _cutoff_sql(days: int) -> Optional[str]:
    if days >= 9999:
        return None
    return (datetime.now() - timedelta(days=days)).strftime("%Y-%m-%d")


def _iso(d: Any) -> Optional[str]:
    if d is None:
        return None
    if hasattr(d, "isoformat"):
        return d.isoformat()[:10]
    return str(d)[:10]


def _rolling_avg(rows: List[Dict[str, Any]], key: str, window: int) -> List[Dict[str, Any]]:
    out: List[Dict[str, Any]] = []
    for i, d in enumerate(rows):
        sl = rows[max(0, i - window + 1) : i + 1]
        vals: List[float] = []
        for x in sl:
            v = safe_float(x.get(key))
            if v is not None:
                vals.append(v)
        if not vals:
            out.append({**d, f"{key}_avg": None})
            continue
        avg = round(sum(vals) / len(vals), 1)
        out.append({**d, f"{key}_avg": avg})
    return out


def _has_nutrition_entries(profile_id: str) -> bool:
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute(
            "SELECT 1 FROM nutrition_log WHERE profile_id=%s LIMIT 1",
            (profile_id,),
        )
        return cur.fetchone() is not None


def _last_nutrition_date(profile_id: str) -> Optional[str]:
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute(
            "SELECT MAX(date) AS d FROM nutrition_log WHERE profile_id=%s",
            (profile_id,),
        )
        row = cur.fetchone()
        if not row or row["d"] is None:
            return None
        return _iso(row["d"])


def _fetch_daily_macro_totals(profile_id: str, cutoff: Optional[str]) -> List[Dict[str, Any]]:
    with get_db() as conn:
        cur = get_cursor(conn)
        if cutoff:
            cur.execute(
                """SELECT date,
                    COALESCE(SUM(kcal), 0)::float AS kcal,
                    COALESCE(SUM(protein_g), 0)::float AS protein_g,
                    COALESCE(SUM(carbs_g), 0)::float AS carbs_g,
                    COALESCE(SUM(fat_g), 0)::float AS fat_g
                   FROM nutrition_log
                   WHERE profile_id=%s AND date >= %s
                   GROUP BY date
                   ORDER BY date ASC""",
                (profile_id, cutoff),
            )
        else:
            cur.execute(
                """SELECT date,
                    COALESCE(SUM(kcal), 0)::float AS kcal,
                    COALESCE(SUM(protein_g), 0)::float AS protein_g,
                    COALESCE(SUM(carbs_g), 0)::float AS carbs_g,
                    COALESCE(SUM(fat_g), 0)::float AS fat_g
                   FROM nutrition_log
                   WHERE profile_id=%s
                   GROUP BY date
                   ORDER BY date ASC""",
                (profile_id,),
            )
        return [r2d(r) for r in cur.fetchall()]


def _filter_merged_rows_by_cutoff(
    merged: List[Dict[str, Any]], cutoff: Optional[str]
) -> List[Dict[str, Any]]:
    if not cutoff:
        return list(merged)
    return [r for r in merged if str(r.get("date"))[:10] >= cutoff]


def _calorie_balance_daily_series(
    merged_filtered: List[Dict[str, Any]], tdee: float
) -> List[Dict[str, Any]]:
    """Tagesbilanz (Aufnahme − TDEE) + 7-Tage-Mittel der Bilanz — gleiche TDEE-Quelle wie kcal_vs_weight."""
    rows: List[Dict[str, Any]] = []
    for r in merged_filtered:
        if r.get("kcal") is None:
            continue
        ds = _iso(r.get("date"))
        if not ds:
            continue
        bal = round(float(r["kcal"]) - float(tdee))
        rows.append({"date": ds, "balance_kcal": bal})
    rolled = _rolling_avg([dict(x) for x in rows], "balance_kcal", 7)
    out: List[Dict[str, Any]] = []
    for x in rolled:
        out.append(
            {
                "date": x["date"],
                "balance_kcal": x.get("balance_kcal"),
                "balance_kcal_avg": x.get("balance_kcal_avg"),
            }
        )
    return out


def _protein_lean_mass_points(merged_filtered: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
    out: List[Dict[str, Any]] = []
    for r in merged_filtered:
        if r.get("protein_g") is None or r.get("lean_mass") is None:
            continue
        ds = _iso(r.get("date"))
        if not ds:
            continue
        out.append(
            {
                "date": ds,
                "protein_g": round(safe_float(r.get("protein_g")) or 0, 1),
                "lean_mass_kg": round(safe_float(r.get("lean_mass")) or 0, 2),
            }
        )
    return out


def _kcal_weight_points_for_window(
    profile_id: str, cutoff: Optional[str]
) -> List[Dict[str, Any]]:
    """Gemeinsame Tage: Tages-kcal vs. Gewicht; gleiche Idee wie /nutrition/correlations, gefiltert."""
    with get_db() as conn:
        cur = get_cursor(conn)
        if cutoff:
            cur.execute(
                """SELECT date, SUM(kcal)::float AS kcal
                   FROM nutrition_log
                   WHERE profile_id=%s AND date >= %s AND kcal IS NOT NULL
                   GROUP BY date""",
                (profile_id, cutoff),
            )
        else:
            cur.execute(
                """SELECT date, SUM(kcal)::float AS kcal
                   FROM nutrition_log
                   WHERE profile_id=%s AND kcal IS NOT NULL
                   GROUP BY date""",
                (profile_id,),
            )
        nk = { _iso(r["date"]): safe_float(r["kcal"]) for r in cur.fetchall() }

        if cutoff:
            cur.execute(
                "SELECT date, weight FROM weight_log WHERE profile_id=%s AND date >= %s ORDER BY date",
                (profile_id, cutoff),
            )
        else:
            cur.execute(
                "SELECT date, weight FROM weight_log WHERE profile_id=%s ORDER BY date",
                (profile_id,),
            )
        wk = { _iso(r["date"]): safe_float(r["weight"]) for r in cur.fetchall() if r.get("weight") is not None }

    common = sorted(set(nk) & set(wk))
    raw: List[Dict[str, Any]] = []
    for ds in common:
        raw.append({"date": ds, "kcal": nk[ds], "weight": wk[ds]})
    rolled = _rolling_avg(raw, "kcal", 7)
    out: List[Dict[str, Any]] = []
    for r in rolled:
        out.append(
            {
                "date": r["date"],
                "kcal": r.get("kcal"),
                "weight": r.get("weight"),
                "kcal_avg": r.get("kcal_avg"),
            }
        )
    return out


def get_nutrition_history_viz_bundle(profile_id: str, days: int) -> Dict[str, Any]:
    """
    Layer 2b Bundle für Verlauf «Ernährung».

    days: Analysefenster (>=9999 = gesamte Historie für Mittelwerte / Reihen).
    """
    if not _has_nutrition_entries(profile_id):
        return {
            "confidence": "insufficient",
            "has_nutrition_entries": False,
            "message": "Noch keine Ernährungsdaten",
            "kpi_tiles": [],
            "summary": {},
            "daily_macros": [],
            "donut_avg_pct": None,
            "kcal_vs_weight": {"points": [], "tdee_reference_kcal": None, "common_days_count": 0},
            "weekly_macro_chart": {},
            "tdee_reference_kcal": None,
            "energy_balance_meta": {},
            "interpretation_tiles": [],
            "energy_availability_warning": None,
            "calorie_balance_daily": [],
            "protein_vs_lean_mass": {"points": [], "protein_target_low_g": None},
            "nutrition_correlation_heuristics": [],
            "chart_payloads": {},
            "chart_payloads_days": None,
            "meta": {"layer_1": "nutrition_metrics", "layer_2b": "nutrition_viz"},
        }

    all_history = days >= 9999
    eff_days = 3650 if all_history else max(7, min(int(days), 3650))
    cutoff = _cutoff_sql(days)
    chart_days_for_pipeline = 90 if all_history else max(7, min(eff_days, 365))

    navg = get_nutrition_average_data(profile_id, eff_days, all_history=all_history)
    targets = get_protein_targets_data(profile_id)
    energy_days = eff_days if not all_history else min(9999, 3650)
    energy_meta = get_energy_balance_data(profile_id, energy_days)
    tdee = estimate_tdee_kcal_from_latest_weight(profile_id)
    if tdee is None:
        tdee = safe_float(energy_meta.get("estimated_tdee")) or None
    else:
        tdee = float(tdee)

    daily_rows = _fetch_daily_macro_totals(profile_id, cutoff)
    daily_macros: List[Dict[str, Any]] = []
    for r in daily_rows:
        daily_macros.append(
            {
                "date": _iso(r["date"]),
                "kcal": round(safe_float(r.get("kcal")) or 0),
                "Protein": round(safe_float(r.get("protein_g")) or 0),
                "KH": round(safe_float(r.get("carbs_g")) or 0),
                "Fett": round(safe_float(r.get("fat_g")) or 0),
            }
        )

    date_span_label = ""
    if daily_macros:
        date_span_label = f"{daily_macros[0]['date']} – {daily_macros[-1]['date']}"

    n_days = int(navg.get("data_points") or 0)
    kpi_tiles = build_nutrition_history_kpi_tiles(
        navg, targets, date_span_label or "—", max(1, n_days)
    )

    ea_days = min(28, max(7, chart_days_for_pipeline))
    ea_payload = get_energy_availability_warning_payload(profile_id, ea_days)
    ea_tile = build_energy_availability_kpi_tile(ea_payload)
    kpi_tiles_out: List[Dict[str, Any]] = list(kpi_tiles)
    if ea_tile:
        kpi_tiles_out.append(ea_tile)

    donut = build_macro_donut_from_averages(navg)

    kw_points = _kcal_weight_points_for_window(profile_id, cutoff)
    pt_low = round(float(targets.get("protein_target_low") or 0))

    merged_all = build_merged_daily_nutrition_body_rows(profile_id)
    merged_win = _filter_merged_rows_by_cutoff(merged_all, cutoff)
    tdee_eff = float(tdee) if tdee is not None else float(safe_float(energy_meta.get("estimated_tdee")) or 0)
    calorie_balance_daily: List[Dict[str, Any]] = (
        _calorie_balance_daily_series(merged_win, tdee_eff) if tdee_eff > 0 else []
    )
    pl_points = _protein_lean_mass_points(merged_win)
    nutrition_correlation_heuristics = (
        build_nutrition_correlation_heuristic_items(merged_win, tdee_eff, float(pt_low))
        if tdee_eff > 0
        else []
    )

    weeks_for_weekly = max(4, min(52, (chart_days_for_pipeline + 6) // 7))
    weekly_chart = get_weekly_macro_distribution_chart_data(profile_id, weeks_for_weekly)

    # E1/E2/E4 Chart.js-Payloads — gleiche Funktionen wie /api/charts/* (kein zweiter HTTP-Roundtrip im Verlauf)
    days_for_embedded_charts = max(7, min(int(chart_days_for_pipeline), 90))
    chart_payloads = {
        "energy_balance": build_energy_balance_chart_payload(
            profile_id, days_for_embedded_charts
        ),
        "protein_adequacy": build_protein_adequacy_chart_payload(
            profile_id, days_for_embedded_charts
        ),
        "nutrition_adherence": build_nutrition_adherence_score_payload(
            profile_id, days_for_embedded_charts
        ),
    }

    conf = navg.get("confidence") or "medium"
    if targets.get("confidence") == "insufficient":
        conf = "insufficient"

    return {
        "confidence": conf,
        "has_nutrition_entries": True,
        "days_requested": days,
        "effective_window_days": eff_days,
        "nutrition_charts_days": chart_days_for_pipeline,
        "weekly_macro_weeks_used": weeks_for_weekly,
        "last_updated": _last_nutrition_date(profile_id),
        "summary": {
            "kcal_avg": navg.get("kcal_avg"),
            "protein_avg": navg.get("protein_avg"),
            "carbs_avg": navg.get("carbs_avg"),
            "fat_avg": navg.get("fat_avg"),
            "data_points": navg.get("data_points"),
            "days_analyzed": navg.get("days_analyzed"),
            "protein_target_low": targets.get("protein_target_low"),
            "protein_target_high": targets.get("protein_target_high"),
            "reference_weight_kg": targets.get("current_weight"),
        },
        "kpi_tiles": kpi_tiles_out,
        "interpretation_tiles": [],
        "energy_availability_warning": ea_payload,
        "daily_macros": daily_macros,
        "donut_avg_pct": donut,
        "protein_reference_line_g": pt_low,
        "kcal_vs_weight": {
            "points": kw_points,
            "tdee_reference_kcal": tdee,
            "common_days_count": len(kw_points),
        },
        "weekly_macro_chart": weekly_chart,
        "tdee_reference_kcal": tdee,
        "energy_balance_meta": {
            "energy_balance": energy_meta.get("energy_balance"),
            "avg_intake": energy_meta.get("avg_intake"),
            "estimated_tdee": energy_meta.get("estimated_tdee"),
            "status": energy_meta.get("status"),
            "confidence": energy_meta.get("confidence"),
            "data_points": energy_meta.get("data_points"),
        },
        "calorie_balance_daily": calorie_balance_daily,
        "protein_vs_lean_mass": {
            "points": pl_points,
            "protein_target_low_g": pt_low if pt_low > 0 else None,
        },
        "nutrition_correlation_heuristics": nutrition_correlation_heuristics,
        "chart_payloads": chart_payloads,
        "chart_payloads_days": days_for_embedded_charts,
        "meta": {
            "layer_1": "nutrition_metrics",
            "layer_2b": "nutrition_viz",
            "issue": "53-phase-0c",
        },
    }