"""FDDB → food_catalog mapping: normalize, lookup (user then global), learn, apply."""
from __future__ import annotations

import re
import unicodedata
from typing import Any

LEADING_QTY_RE = re.compile(
    r"^\s*\d+(?:[.,]\d+)?\s*(?:g|kg|ml|l|stück|stk|st\.?|portion(?:en)?)\b[\s,.:\-–]*",
    re.IGNORECASE,
)
MULTISPACE_RE = re.compile(r"\s+")
DECIMAL_IN_NAME_RE = re.compile(r"(\d),(\d)")


def normalize_food_name(raw: str | None) -> str:
    if not raw:
        return ""
    s = unicodedata.normalize("NFKC", str(raw)).strip().strip('"').strip("'")
    s = LEADING_QTY_RE.sub("", s)
    s = DECIMAL_IN_NAME_RE.sub(r"\1.\2", s)
    s = MULTISPACE_RE.sub(" ", s).strip().lower()
    return s


def parse_quantity_g(raw: str | None) -> float | None:
    if raw is None or str(raw).strip() == "":
        return None
    text = str(raw).strip().replace(",", ".")
    m = re.match(r"^\s*(\d+(?:\.\d+)?)\s*(g|gramm)?\s*$", text, re.IGNORECASE)
    if m:
        return round(float(m.group(1)), 3)
    return None


def get_food_mapping_with_cursor(
    cur,
    source_name: str,
    profile_id: str | None = None,
    source_system: str = "fddb",
) -> dict[str, Any] | None:
    norm = normalize_food_name(source_name)
    if not norm:
        return None
    if profile_id:
        cur.execute(
            """
            SELECT m.id AS mapping_id, m.food_id, m.profile_id, m.source,
                   f.bls_code, f.name_de, f.catalog_kind
            FROM food_name_mappings m
            JOIN food_catalog f ON f.id = m.food_id
            WHERE m.source_system = %s AND m.source_name_normalized = %s
              AND m.profile_id = %s
            LIMIT 1
            """,
            (source_system, norm, profile_id),
        )
        row = cur.fetchone()
        if row:
            return dict(row)
    cur.execute(
        """
        SELECT m.id AS mapping_id, m.food_id, m.profile_id, m.source,
               f.bls_code, f.name_de, f.catalog_kind
        FROM food_name_mappings m
        JOIN food_catalog f ON f.id = m.food_id
        WHERE m.source_system = %s AND m.source_name_normalized = %s
          AND m.profile_id IS NULL
        LIMIT 1
        """,
        (source_system, norm),
    )
    row = cur.fetchone()
    return dict(row) if row else None


def upsert_food_mapping(
    cur,
    *,
    source_name_raw: str,
    food_id: str,
    profile_id: str | None,
    source: str = "bulk",
    source_system: str = "fddb",
) -> int:
    norm = normalize_food_name(source_name_raw)
    if not norm:
        raise ValueError("Leerer Lebensmittelname")
    if profile_id:
        cur.execute(
            """
            SELECT id FROM food_name_mappings
            WHERE source_system = %s AND source_name_normalized = %s AND profile_id = %s
            """,
            (source_system, norm, profile_id),
        )
    else:
        cur.execute(
            """
            SELECT id FROM food_name_mappings
            WHERE source_system = %s AND source_name_normalized = %s AND profile_id IS NULL
            """,
            (source_system, norm),
        )
    existing = cur.fetchone()
    raw = source_name_raw.strip()
    if existing:
        cur.execute(
            """
            UPDATE food_name_mappings
            SET food_id = %s, source_name_raw = %s, source = %s, updated_at = NOW()
            WHERE id = %s
            """,
            (food_id, raw, source, existing["id"]),
        )
        return int(existing["id"])
    cur.execute(
        """
        INSERT INTO food_name_mappings
            (source_system, source_name_raw, source_name_normalized, food_id, profile_id, source, updated_at)
        VALUES (%s, %s, %s, %s, %s, %s, NOW())
        RETURNING id
        """,
        (source_system, raw, norm, food_id, profile_id, source),
    )
    return int(cur.fetchone()["id"])


def apply_mapping_to_items(cur, profile_id: str, source_name_normalized: str, food_id: str, mapping_id: int) -> int:
    origin = _value_origin_for_food(cur, food_id)
    cur.execute(
        """
        UPDATE nutrition_items
        SET food_id = %s, mapping_id = %s, value_origin = %s, updated_at = NOW()
        WHERE profile_id = %s AND source_name_normalized = %s
        """,
        (food_id, mapping_id, origin, profile_id, source_name_normalized),
    )
    return cur.rowcount or 0


def clear_mapping_from_items(cur, profile_id: str, source_name_normalized: str) -> int:
    cur.execute(
        """
        UPDATE nutrition_items
        SET food_id = NULL, mapping_id = NULL, value_origin = 'fddb', updated_at = NOW()
        WHERE profile_id = %s AND source_name_normalized = %s
        """,
        (profile_id, source_name_normalized),
    )
    return cur.rowcount or 0


def _value_origin_for_food(cur, food_id: str) -> str:
    cur.execute("SELECT catalog_kind FROM food_catalog WHERE id = %s", (food_id,))
    row = cur.fetchone()
    if not row:
        return "fddb"
    kind = row["catalog_kind"]
    if kind == "official_bls":
        return "bls"
    return "manual_catalog"


def suggest_catalog_foods(cur, query: str, profile_id: str | None, limit: int = 8) -> list[dict]:
    q = (query or "").strip()
    if not q:
        return []
    like = f"%{q}%"
    norm = normalize_food_name(q)
    cur.execute(
        """
        SELECT id, bls_code, name_de, name_en, catalog_kind, food_group
        FROM food_catalog
        WHERE is_active = true
          AND (
              owner_profile_id IS NULL
              OR owner_profile_id = %s
          )
          AND (
              name_de ILIKE %s OR COALESCE(name_en, '') ILIKE %s
              OR COALESCE(bls_code, '') ILIKE %s
              OR lower(name_de) = %s
          )
        ORDER BY
            CASE WHEN lower(name_de) = %s THEN 0
                 WHEN COALESCE(bls_code, '') ILIKE %s THEN 1
                 ELSE 2 END,
            name_de
        LIMIT %s
        """,
        (profile_id, like, like, like, norm, norm, q, limit),
    )
    return [dict(r) for r in cur.fetchall()]