"""End-to-end planner orchestration: load → filter → score → select → persist."""
from __future__ import annotations

from datetime import date
from decimal import Decimal
from typing import Dict, List, Optional, Set
from uuid import UUID

from sqlalchemy import func
from sqlalchemy.orm import Session

from app.models import (
    FamilyProfile,
    GroceryItem,
    HomePantry,
    Ingredient,
    IngredientGroceryMatch,
    MealPlan,
    MealPlanItem,
    MealPlanItemStatus,
    MealPlanStatus,
    MealType,
    NeverSuggest,
    Recipe,
)
from app.services.planner.config import DEFAULT, PlannerConfig
from app.services.planner.cost import compute_recipe_cost
from app.services.planner.filter import filter_recipes
from app.services.planner.score import score_recipes
from app.services.planner.select import select_set
from app.services.planner.types import GenerationResult


def _load_match_index(db: Session) -> Dict[UUID, List[dict]]:
    """ingredient_id → list of match dicts ordered by confidence DESC."""
    rows = (
        db.query(IngredientGroceryMatch, GroceryItem, Ingredient)
        .join(GroceryItem, GroceryItem.id == IngredientGroceryMatch.grocery_item_id)
        .join(Ingredient, Ingredient.id == IngredientGroceryMatch.ingredient_id)
        .order_by(IngredientGroceryMatch.confidence.desc())
        .all()
    )
    index: Dict[UUID, List[dict]] = {}
    for match, grocery, ingredient in rows:
        index.setdefault(match.ingredient_id, []).append(
            {
                "grocery_item_id": grocery.id,
                "grocery_item_name": grocery.name,
                "current_price": grocery.current_price,
                "regular_price": grocery.regular_price,
                "is_on_sale": bool(grocery.is_on_sale),
                "confidence": match.confidence,
                "ingredient_name": ingredient.name.lower(),
                "grocery_unit": grocery.unit,
            }
        )
    return index


def _load_blocklists(
    db: Session, family_id: UUID
) -> tuple[Set[UUID], Set[UUID], Set[UUID]]:
    """Sprint 8: returns 3 sets of UUIDs.

    - blocked_ingredients: ingredient-level NeverSuggest entries
    - blocked_recipes: recipe-level NeverSuggest entries (permanent, no decay)
    - soft_denied_recipes: meal_plan_item rows with approval_status='denied'
      and denial_expires_at > now() (decaying in DENIAL_DECAY_DAYS; auto-
      promoted to blocked_recipes on the 2nd denial in the window by the
      /deny API path).

    Both recipe sets are hard filters (user decision: "Hard filter. If it
    is denied this week twice, it should be considered denied for good.").
    """
    blocked_ingredients: Set[UUID] = set()
    blocked_recipes: Set[UUID] = set()
    for row in db.query(NeverSuggest).filter(NeverSuggest.family_profile_id == family_id).all():
        if row.ingredient_id is not None:
            blocked_ingredients.add(row.ingredient_id)
        if row.recipe_id is not None:
            blocked_recipes.add(row.recipe_id)

    soft_denied_recipes: Set[UUID] = set()
    rows = (
        db.query(MealPlanItem.recipe_id)
        .join(MealPlan, MealPlanItem.meal_plan_id == MealPlan.id)
        .filter(
            MealPlan.family_profile_id == family_id,
            MealPlanItem.approval_status == MealPlanItemStatus.denied,
            MealPlanItem.denial_expires_at.isnot(None),
            MealPlanItem.denial_expires_at > func.now(),
            MealPlanItem.recipe_id.isnot(None),
        )
        .distinct()
        .all()
    )
    for (rid,) in rows:
        soft_denied_recipes.add(rid)

    return blocked_ingredients, blocked_recipes, soft_denied_recipes


def _load_pantry(db: Session, family_id: UUID) -> Set[UUID]:
    return {
        row.ingredient_id
        for row in db.query(HomePantry).filter(HomePantry.family_profile_id == family_id).all()
        if row.ingredient_id is not None
    }


def _load_last_cooked(db: Session, family_id: UUID) -> Dict[UUID, date]:
    rows = (
        db.query(MealPlanItem, MealPlan)
        .join(MealPlan, MealPlan.id == MealPlanItem.meal_plan_id)
        .filter(MealPlan.family_profile_id == family_id)
        .all()
    )
    last: Dict[UUID, date] = {}
    for item, plan in rows:
        if item.recipe_id is None:
            continue
        if item.recipe_id not in last or plan.week_start_date > last[item.recipe_id]:
            last[item.recipe_id] = plan.week_start_date
    return last


def generate_meal_plan(
    db: Session,
    *,
    family_id: UUID,
    week_start_date: date,
    config: PlannerConfig = DEFAULT,
    today: Optional[date] = None,
    exclude_recipe_ids: Optional[Set[UUID]] = None,
) -> GenerationResult:
    today = today or date.today()
    family = db.query(FamilyProfile).filter(FamilyProfile.id == family_id).first()
    if family is None:
        raise ValueError(f"family_profile {family_id} not found")

    # Merge family-level planner overrides if present
    effective_config = config
    if family.planner_config:
        from app.services.planner.config import PlannerConfig
        try:
            effective_config = config.merge(family.planner_config)
        except (ValueError, TypeError) as exc:
            logger.warning("Invalid planner_config for family %s: %s", family_id, exc)

    recipes = db.query(Recipe).all()
    exclude_set = exclude_recipe_ids or set()
    recipe_dicts = [
        {
            "id": r.id,
            "name": r.name,
            "prep_time_minutes": r.prep_time_minutes,
            "cook_time_minutes": r.cook_time_minutes,
            "calories_per_serving": r.calories_per_serving,
            "protein_type": r.protein_type,
            "cuisine_tags": list(r.cuisine_tags or []),
            "ingredients": list(r.ingredients or []),
            "servings": r.servings or 4,
        }
        for r in recipes
        if r.id not in exclude_set
    ]

    recipe_ingredient_ids: Dict[UUID, Set[UUID]] = {}
    for r in recipe_dicts:
        ids: Set[UUID] = set()
        for line in r["ingredients"]:
            ing_id = line.get("ingredient_id")
            if isinstance(ing_id, str):
                ing_id = UUID(ing_id)
            if ing_id is not None:
                ids.add(ing_id)
        recipe_ingredient_ids[r["id"]] = ids

    match_index = _load_match_index(db)
    pantry_ids = _load_pantry(db, family_id)
    blocked_ings, blocked_recipes, soft_denied_recipes = _load_blocklists(db, family_id)
    last_cooked = _load_last_cooked(db, family_id)

    # Sprint 8: union the soft-denied set with the permanent blocklist
    # so the filter treats them identically. The `rejected[rid]` reason
    # is "blocked_recipe" for both — operators reading the planner's
    # `rejected_summary` see a single bucket. The soft set is also
    # passed in separately so the diagnostic label could be split
    # later if needed.
    all_blocked_recipes = blocked_recipes | soft_denied_recipes

    recipe_costs = {
        r["id"]: compute_recipe_cost(
            recipe_id=r["id"],
            ingredients=r["ingredients"],
            match_index=match_index,
            pantry_ingredient_ids=pantry_ids,
            servings=r["servings"],
        )
        for r in recipe_dicts
    }

    filtered = filter_recipes(
        recipes=recipe_dicts,
        recipe_ingredient_ids=recipe_ingredient_ids,
        recipe_costs=recipe_costs,
        blocked_ingredient_ids=blocked_ings,
        blocked_recipe_ids=all_blocked_recipes,
        last_cooked_at=last_cooked,
        family_calorie_target=family.calorie_target,
        config=effective_config,
        today=today,
    )

    feasible_recipes = [r for r in recipe_dicts if r["id"] in filtered.feasible_recipe_ids]
    scored = score_recipes(
        recipes=feasible_recipes,
        recipe_costs=recipe_costs,
        last_cooked_at=last_cooked,
        config=effective_config,
        today=today,
    )
    chosen, set_score = select_set(scored, effective_config)

    plan = MealPlan(
        family_profile_id=family_id,
        week_start_date=week_start_date,
        status=MealPlanStatus.DRAFT,
        total_estimated_cost=sum(
            (s.cost.total_cost for s in chosen), Decimal("0.00")
        ),
    )
    db.add(plan)
    db.flush()

    _dinner_days = [1, 3, 5]  # Mon, Wed, Fri — spread across the week
    for index, scored_recipe in enumerate(chosen):
        day = _dinner_days[index] if index < len(_dinner_days) else index + 1
        meal_type = MealType.DINNER
        item = MealPlanItem(
            meal_plan_id=plan.id,
            recipe_id=scored_recipe.recipe_id,
            day_of_week=day,
            meal_type=meal_type,
            approval_status=MealPlanItemStatus.pending,
            estimated_cost=scored_recipe.cost.total_cost,
            score=scored_recipe.score,
            components=scored_recipe.components,
        )
        db.add(item)

    db.commit()
    db.refresh(plan)

    rejected_summary: Dict[str, int] = {}
    for reason in filtered.rejected.values():
        rejected_summary[reason] = rejected_summary.get(reason, 0) + 1
    # Sprint 8: surface how many recipes are blocked specifically because
    # of soft denials (vs. permanent NeverSuggest entries). Both are
    # bucketed under "blocked_recipe" in the filter; this adds a
    # "soft_denied_recipe" sub-bucket for diagnostics.
    if soft_denied_recipes:
        # Only count those that were actually candidates (in recipe_dicts).
        soft_in_pool = sum(1 for r in recipe_dicts if r["id"] in soft_denied_recipes)
        if soft_in_pool > 0:
            rejected_summary["soft_denied_recipe"] = soft_in_pool

    return GenerationResult(
        meal_plan_id=plan.id,
        selected=chosen,
        feasible_count=len(filtered.feasible_recipe_ids),
        rejected_summary=rejected_summary,
        set_score=set_score,
    )