from __future__ import annotations

from typing import List, Optional
from uuid import UUID

from fastapi import APIRouter, Depends, HTTPException, Query, Response, status
from sqlalchemy.orm import Session

from app.database import get_db
from app.models import Ingredient, Recipe
from app.schemas.recipe import RecipeCreate, RecipeRead, RecipeUpdate
from app.security import require_admin


public_router = APIRouter(prefix="/api/recipes", tags=["recipes"])
admin_router = APIRouter(
    prefix="/api/admin/recipes",
    tags=["recipes-admin"],
    dependencies=[Depends(require_admin)],
)


def _validate_ingredient_ids(db: Session, ingredient_refs) -> None:
    ids = [ref.ingredient_id for ref in ingredient_refs]
    found = (
        db.query(Ingredient.id).filter(Ingredient.id.in_(ids)).all()
    )
    found_ids = {row[0] for row in found}
    missing = [str(i) for i in ids if i not in found_ids]
    if missing:
        raise HTTPException(
            status_code=422,
            detail={"error": "unknown ingredient_ids", "missing": missing},
        )


def _serialize(row: Recipe) -> dict:
    return {
        "id": row.id,
        "name": row.name,
        "description": row.description,
        "image_url": row.image_url,
        "prep_time_minutes": row.prep_time_minutes or 0,
        "cook_time_minutes": row.cook_time_minutes or 0,
        "servings": row.servings,
        "cuisine_tags": list(row.cuisine_tags or []),
        "dietary_tags": list(row.dietary_tags or []),
        "protein_type": row.protein_type,
        "spice_level": row.spice_level,
        "calories_per_serving": row.calories_per_serving,
        "ingredients": row.ingredients or [],
        "instructions": list(row.instructions or []),
        "source_url": row.source_url,
    }


@public_router.get("", response_model=List[RecipeRead])
def list_recipes(
    q: Optional[str] = Query(default=None),
    limit: int = Query(default=100, le=500),
    db: Session = Depends(get_db),
):
    query = db.query(Recipe)
    if q:
        like = f"%{q.lower()}%"
        query = query.filter(Recipe.name.ilike(like))
    rows = query.order_by(Recipe.name).limit(limit).all()
    return [_serialize(r) for r in rows]


@public_router.get("/{recipe_id}", response_model=RecipeRead)
def get_recipe(recipe_id: UUID, db: Session = Depends(get_db)):
    row = db.query(Recipe).filter(Recipe.id == recipe_id).first()
    if row is None:
        raise HTTPException(status_code=404, detail="recipe not found")
    return _serialize(row)


@admin_router.post("", response_model=RecipeRead, status_code=status.HTTP_201_CREATED)
def create_recipe(payload: RecipeCreate, db: Session = Depends(get_db)):
    _validate_ingredient_ids(db, payload.ingredients)
    row = Recipe(
        name=payload.name,
        description=payload.description,
        image_url=payload.image_url,
        prep_time_minutes=payload.prep_time_minutes,
        cook_time_minutes=payload.cook_time_minutes,
        servings=payload.servings,
        cuisine_tags=payload.cuisine_tags,
        dietary_tags=payload.dietary_tags,
        protein_type=payload.protein_type,
        spice_level=payload.spice_level,
        calories_per_serving=payload.calories_per_serving,
        ingredients=[ref.model_dump(mode="json") for ref in payload.ingredients],
        instructions=payload.instructions,
        source_url=payload.source_url,
        is_manually_added=True,
    )
    db.add(row)
    db.commit()
    db.refresh(row)
    return _serialize(row)


@admin_router.patch("/{recipe_id}", response_model=RecipeRead)
def update_recipe(recipe_id: UUID, payload: RecipeUpdate, db: Session = Depends(get_db)):
    row = db.query(Recipe).filter(Recipe.id == recipe_id).first()
    if row is None:
        raise HTTPException(status_code=404, detail="recipe not found")
    data = payload.model_dump(exclude_unset=True)
    if "ingredients" in data and data["ingredients"] is not None:
        _validate_ingredient_ids(db, payload.ingredients)
        row.ingredients = [ref.model_dump(mode="json") for ref in payload.ingredients]
        data.pop("ingredients")
    for field, value in data.items():
        setattr(row, field, value)
    db.commit()
    db.refresh(row)
    return _serialize(row)


@admin_router.delete("/{recipe_id}", status_code=status.HTTP_204_NO_CONTENT, response_class=Response)
def delete_recipe(recipe_id: UUID, db: Session = Depends(get_db)):
    row = db.query(Recipe).filter(Recipe.id == recipe_id).first()
    if row is None:
        raise HTTPException(status_code=404, detail="recipe not found")
    db.delete(row)
    db.commit()
    return Response(status_code=status.HTTP_204_NO_CONTENT)