"""Admin CRUD for food_name_mappings."""
from __future__ import annotations

from typing import Optional

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel

from auth import require_admin
from data_layer.food_mapping import apply_mapping_to_items, upsert_food_mapping
from data_layer.nutrition_items import dates_for_normalized_name, rebuild_daily_nutrients
from db import get_cursor, get_db, r2d

router = APIRouter(prefix="/api/admin/food-mappings", tags=["admin", "food-mappings"])


class FoodMappingCreate(BaseModel):
    source_name: str
    food_id: str
    profile_id: Optional[str] = None
    source_system: str = "fddb"


class FoodMappingUpdate(BaseModel):
    food_id: str
    grams_per_unit: Optional[float] = None
    source_unit: Optional[str] = None


@router.get("")
def list_food_mappings(
    profile_id: Optional[str] = None,
    global_only: bool = False,
    session: dict = Depends(require_admin),
):
    with get_db() as conn:
        cur = get_cursor(conn)
        q = """
            SELECT m.id, m.source_name_raw, m.source_name_normalized, m.food_id,
                   m.profile_id, m.source, m.created_at, m.updated_at,
                   f.name_de AS food_name_de, f.bls_code, f.catalog_kind
            FROM food_name_mappings m
            JOIN food_catalog f ON f.id = m.food_id
        """
        conds, params = [], []
        if global_only:
            conds.append("m.profile_id IS NULL")
        elif profile_id:
            conds.append("m.profile_id = %s")
            params.append(profile_id)
        if conds:
            q += " WHERE " + " AND ".join(conds)
        q += " ORDER BY m.source_name_normalized"
        cur.execute(q, params)
        return [r2d(r) for r in cur.fetchall()]


@router.get("/stats/coverage")
def mapping_coverage(session: dict = Depends(require_admin)):
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute(
            """
            SELECT
                COUNT(*) AS total_items,
                COUNT(food_id) AS mapped_items,
                COUNT(*) - COUNT(food_id) AS unmapped_items,
                COUNT(DISTINCT source_name_normalized) AS unique_names,
                COUNT(DISTINCT CASE WHEN food_id IS NULL THEN source_name_normalized END) AS unmapped_names
            FROM nutrition_items
            """
        )
        return r2d(cur.fetchone())


@router.post("")
def create_food_mapping(body: FoodMappingCreate, session: dict = Depends(require_admin)):
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("SELECT id FROM food_catalog WHERE id = %s", (body.food_id,))
        if not cur.fetchone():
            raise HTTPException(404, "Lebensmittel nicht gefunden")
        mid = upsert_food_mapping(
            cur,
            source_name_raw=body.source_name,
            food_id=body.food_id,
            profile_id=body.profile_id or None,
            source="admin",
            source_system=body.source_system,
        )
        cur.execute(
            """
            SELECT m.*, f.name_de AS food_name_de, f.bls_code
            FROM food_name_mappings m
            JOIN food_catalog f ON f.id = m.food_id
            WHERE m.id = %s
            """,
            (mid,),
        )
        return r2d(cur.fetchone())


@router.put("/{mapping_id}")
def update_food_mapping(mapping_id: int, body: FoodMappingUpdate, session: dict = Depends(require_admin)):
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute(
            """
            SELECT id, source_name_raw, source_name_normalized, profile_id
            FROM food_name_mappings WHERE id = %s
            """,
            (mapping_id,),
        )
        row = cur.fetchone()
        if not row:
            raise HTTPException(404, "Mapping nicht gefunden")
        cur.execute("SELECT id FROM food_catalog WHERE id = %s AND is_active = true", (body.food_id,))
        if not cur.fetchone():
            raise HTTPException(404, "Lebensmittel nicht gefunden")
        cur.execute(
            """
            UPDATE food_name_mappings
            SET food_id = %s, grams_per_unit = COALESCE(%s, grams_per_unit),
                source_unit = COALESCE(%s, source_unit), source = 'admin', updated_at = NOW()
            WHERE id = %s
            """,
            (body.food_id, body.grams_per_unit, body.source_unit, mapping_id),
        )
        if row.get("profile_id"):
            apply_mapping_to_items(cur, str(row["profile_id"]), row["source_name_normalized"], body.food_id, mapping_id)
            dates = dates_for_normalized_name(cur, str(row["profile_id"]), row["source_name_normalized"])
            for d in dates:
                rebuild_daily_nutrients(cur, str(row["profile_id"]), d)
        cur.execute(
            """
            SELECT m.*, f.name_de AS food_name_de, f.bls_code
            FROM food_name_mappings m
            JOIN food_catalog f ON f.id = m.food_id
            WHERE m.id = %s
            """,
            (mapping_id,),
        )
        return r2d(cur.fetchone())


@router.delete("/{mapping_id}")
def delete_food_mapping(mapping_id: int, session: dict = Depends(require_admin)):
    with get_db() as conn:
        cur = get_cursor(conn)
        cur.execute("DELETE FROM food_name_mappings WHERE id = %s RETURNING id", (mapping_id,))
        if not cur.fetchone():
            raise HTTPException(404, "Mapping nicht gefunden")
    return {"ok": True}