"""
Reference values — Layer 1 (read paths + structured rows)

Structured retrieval for profile reference values and the active type catalog.
Mutations (INSERT/UPDATE/DELETE) stay in routers/reference_values.py with validation.

Dates are normalized to ISO strings; Decimals to float — suitable for JSON/API layers.
"""

from __future__ import annotations

from datetime import date
from decimal import Decimal
from typing import Any, Optional

from db import get_cursor, get_db, r2d

# Spalten des Messwerts (ohne Typ-Metadaten) für Snapshot-Payloads / Platzhalter-JSON
_REFERENCE_ENTRY_KEYS = frozenset(
    {
        "id",
        "profile_id",
        "reference_value_type_id",
        "effective_date",
        "value_numeric",
        "value_text",
        "unit",
        "source",
        "confidence",
        "method",
        "notes",
        "extra",
        "created_at",
        "updated_at",
        "type_key",
        "type_label",
    }
)


def normalize_reference_row(d: Optional[dict[str, Any]]) -> dict[str, Any]:
    """Normalize DB row dict for JSON (dates → ISO, Decimal → float)."""
    if not d:
        return d
    out = dict(d)
    for k in ("effective_date", "created_at", "updated_at"):
        v = out.get(k)
        if v is not None and hasattr(v, "isoformat"):
            out[k] = v.isoformat()
    vn = out.get("value_numeric")
    if vn is not None and isinstance(vn, Decimal):
        out["value_numeric"] = float(vn)
    return out


def fetch_reference_type_by_key(cur, key: str, require_active: bool = True) -> Optional[dict[str, Any]]:
    """Single type row by key; for use inside router transactions (shared cursor)."""
    q = (
        "SELECT id, key, label, description, default_unit, active, category, "
        "value_data_type, validation_rules, metadata "
        "FROM reference_value_types WHERE key = %s "
    )
    if require_active:
        q += "AND active = TRUE "
    cur.execute(q, (key,))
    row = cur.fetchone()
    return r2d(row) if row else None


def list_active_reference_value_types_data() -> list[dict[str, Any]]:
    """All active reference_value_types rows, catalog sort order."""
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute(
            """
            SELECT
                id, key, label, description, default_unit, sort_order, active,
                category, value_data_type, validation_rules, metadata, created_at
            FROM reference_value_types
            WHERE active = TRUE
            ORDER BY sort_order ASC, id ASC
            """
        )
        return [normalize_reference_row(r2d(r)) for r in cur.fetchall()]


def list_profile_reference_values_for_type(
    profile_id: str, type_key: str
) -> Optional[list[dict[str, Any]]]:
    """
    Historical entries for one type, newest first.
    Returns None if type_key does not resolve to an active type.
    """
    with get_db() as conn:
        cur = get_cursor(conn)
        t = fetch_reference_type_by_key(cur, type_key, require_active=True)
        if not t:
            return None
        cur.execute(
            """
            SELECT
                v.id,
                v.profile_id,
                v.reference_value_type_id,
                v.effective_date,
                v.value_numeric,
                v.value_text,
                v.unit,
                v.source,
                v.confidence,
                v.method,
                v.notes,
                v.extra,
                v.created_at,
                v.updated_at,
                rt.key AS type_key,
                rt.label AS type_label
            FROM profile_reference_values v
            JOIN reference_value_types rt ON rt.id = v.reference_value_type_id
            WHERE v.profile_id = %s AND rt.key = %s
            ORDER BY v.effective_date DESC, v.created_at DESC
            """,
            (profile_id, t["key"]),
        )
        return [normalize_reference_row(r2d(r)) for r in cur.fetchall()]


def build_summary_tiles_from_ranked_rows(raw_rows: list[dict[str, Any]]) -> list[dict[str, Any]]:
    """
    Build /summary.tile payloads from SQL rows (rn 1..2 per type).
    Each row still contains rn, type_sort_order, value_data_type before stripping.
    """
    by_key: dict[str, dict[str, Any]] = {}
    skip_cols = frozenset({"rn", "type_sort_order", "value_data_type"})
    for row in raw_rows:
        rn = int(row.get("rn") or 0)
        key = row["type_key"]
        if key not in by_key:
            by_key[key] = {
                "type_key": key,
                "type_label": row.get("type_label") or key,
                "value_data_type": (row.get("value_data_type") or "decimal").strip().lower(),
                "sort_key": (row.get("type_sort_order") or 0, key),
                "latest": None,
                "previous": None,
            }
        entry = {k: v for k, v in row.items() if k not in skip_cols}
        api_entry = normalize_reference_row(entry)
        if rn == 1:
            by_key[key]["latest"] = api_entry
        elif rn == 2:
            by_key[key]["previous"] = api_entry

    tiles = sorted(by_key.values(), key=lambda t: t["sort_key"])
    for t in tiles:
        t.pop("sort_key", None)
    return tiles


def get_profile_reference_values_summary(profile_id: str) -> dict[str, Any]:
    """latest + previous entry per type (active types only), tiles sorted like catalog."""
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute(
            """
            WITH ranked AS (
                SELECT
                    v.id,
                    v.profile_id,
                    v.reference_value_type_id,
                    v.effective_date,
                    v.value_numeric,
                    v.value_text,
                    v.unit,
                    v.source,
                    v.confidence,
                    v.method,
                    v.notes,
                    v.extra,
                    v.created_at,
                    v.updated_at,
                    rt.key AS type_key,
                    rt.label AS type_label,
                    rt.sort_order AS type_sort_order,
                    rt.value_data_type,
                    ROW_NUMBER() OVER (
                        PARTITION BY v.reference_value_type_id
                        ORDER BY v.effective_date DESC, v.created_at DESC
                    ) AS rn
                FROM profile_reference_values v
                JOIN reference_value_types rt ON rt.id = v.reference_value_type_id
                WHERE v.profile_id = %s AND rt.active = TRUE
            )
            SELECT * FROM ranked WHERE rn <= 2
            ORDER BY type_sort_order ASC, type_key ASC, rn ASC
            """,
            (profile_id,),
        )
        raw_rows = [r2d(r) for r in cur.fetchall()]

    tiles = build_summary_tiles_from_ranked_rows(raw_rows)
    return {"tiles": tiles}


def _entry_dict_from_ranked_row(d: dict[str, Any]) -> dict[str, Any]:
    """Eintragsfelder inkl. type_key/type_label für KI-Kontext."""
    out = {k: d[k] for k in _REFERENCE_ENTRY_KEYS if k in d}
    return normalize_reference_row(out)


def get_profile_reference_values_current_snapshot(profile_id: str) -> dict[str, Any]:
    """
    Layer 1: Alle **aktuellen** Referenzwerte (jüngster Eintrag pro aktivem Typ), Katalog-Sortierung.

    Struktur: ``items`` = Liste mit ``type_key``, ``type_label``, ``value_data_type``,
    ``type_sort_order``, ``latest`` (vollständiger Eintrag).
    """
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute(
            """
            WITH ranked AS (
                SELECT
                    v.id,
                    v.profile_id,
                    v.reference_value_type_id,
                    v.effective_date,
                    v.value_numeric,
                    v.value_text,
                    v.unit,
                    v.source,
                    v.confidence,
                    v.method,
                    v.notes,
                    v.extra,
                    v.created_at,
                    v.updated_at,
                    rt.key AS type_key,
                    rt.label AS type_label,
                    rt.sort_order AS type_sort_order,
                    rt.value_data_type,
                    ROW_NUMBER() OVER (
                        PARTITION BY v.reference_value_type_id
                        ORDER BY v.effective_date DESC, v.created_at DESC
                    ) AS rn
                FROM profile_reference_values v
                JOIN reference_value_types rt ON rt.id = v.reference_value_type_id
                WHERE v.profile_id = %s AND rt.active = TRUE
            )
            SELECT * FROM ranked WHERE rn = 1
            ORDER BY type_sort_order ASC, type_key ASC
            """,
            (profile_id,),
        )
        raw_rows = [r2d(r) for r in cur.fetchall()]

    items: list[dict[str, Any]] = []
    for row in raw_rows:
        row.pop("rn", None)
        vdt = (row.get("value_data_type") or "decimal").strip().lower()
        latest = _entry_dict_from_ranked_row(row)
        items.append(
            {
                "type_key": row.get("type_key"),
                "type_label": row.get("type_label"),
                "value_data_type": vdt,
                "type_sort_order": int(row.get("type_sort_order") or 0),
                "latest": latest,
            }
        )

    return {
        "schema": "profile_reference_values_current_v1",
        "count": len(items),
        "items": items,
    }


def get_profile_reference_values_recent_snapshot(
    profile_id: str,
    *,
    limit_per_type: int = 5,
    date_from: Optional[date | str] = None,
    date_to: Optional[date | str] = None,
) -> dict[str, Any]:
    """
    Layer 1: Pro Referenztyp die **letzten N** Einträge (neueste zuerst), optional nach
    ``effective_date`` gefiltert.

    ``date_from`` / ``date_to``: inclusive; als ``date`` oder ISO-``YYYY-MM-DD``-String.
    """
    lim = max(1, min(int(limit_per_type), 50))

    df = date_from
    dt = date_to
    if isinstance(df, str) and df.strip():
        df = date.fromisoformat(df.strip())
    elif df is not None and not isinstance(df, date):
        df = None
    if isinstance(dt, str) and dt.strip():
        dt = date.fromisoformat(dt.strip())
    elif dt is not None and not isinstance(dt, date):
        dt = None

    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute(
            """
            WITH filtered AS (
                SELECT
                    v.id,
                    v.profile_id,
                    v.reference_value_type_id,
                    v.effective_date,
                    v.value_numeric,
                    v.value_text,
                    v.unit,
                    v.source,
                    v.confidence,
                    v.method,
                    v.notes,
                    v.extra,
                    v.created_at,
                    v.updated_at,
                    rt.key AS type_key,
                    rt.label AS type_label,
                    rt.sort_order AS type_sort_order,
                    rt.value_data_type
                FROM profile_reference_values v
                JOIN reference_value_types rt ON rt.id = v.reference_value_type_id
                WHERE v.profile_id = %s
                  AND rt.active = TRUE
                  AND (%s::date IS NULL OR v.effective_date >= %s::date)
                  AND (%s::date IS NULL OR v.effective_date <= %s::date)
            ),
            ranked AS (
                SELECT
                    f.*,
                    ROW_NUMBER() OVER (
                        PARTITION BY f.reference_value_type_id
                        ORDER BY f.effective_date DESC, f.created_at DESC
                    ) AS rn
                FROM filtered f
            )
            SELECT * FROM ranked WHERE rn <= %s
            ORDER BY type_sort_order ASC, type_key ASC, rn ASC
            """,
            (profile_id, df, df, dt, dt, lim),
        )
        raw_rows = [r2d(r) for r in cur.fetchall()]

    by_type: dict[str, list[dict[str, Any]]] = {}
    type_order: list[str] = []
    seen: set[str] = set()

    for row in raw_rows:
        row.pop("rn", None)
        tk = row.get("type_key") or ""
        if tk not in seen:
            seen.add(tk)
            type_order.append(tk)
        entry = _entry_dict_from_ranked_row(row)
        by_type.setdefault(tk, []).append(entry)

    return {
        "schema": "profile_reference_values_recent_v1",
        "limit_per_type": lim,
        "date_from": df.isoformat() if isinstance(df, date) else None,
        "date_to": dt.isoformat() if isinstance(dt, date) else None,
        "ordered_type_keys": type_order,
        "by_type_key": by_type,
    }