// ---------------------------------------------------------------------------
// Shared types for the whole app (client + server).
// Keep this file dependency-free so it can be imported anywhere.
// ---------------------------------------------------------------------------

export type Appliance = "stovetop" | "oven" | "air_fryer" | "slow_cooker" | "microwave" | "blender" | "rice_cooker";

export type Cuisine =
  | "american"
  | "southern"
  | "mexican"
  | "caribbean"
  | "italian"
  | "mediterranean"
  | "middle_eastern"
  | "indian"
  | "chinese"
  | "japanese"
  | "korean"
  | "thai";

/** "caydens_corner" marks the family recipes collection. */
export type CookingStyle = "comfort" | "quick" | "healthy" | "meal_prep" | "vegetarian" | "seafood" | "caydens_corner";

/**
 * Breakfast slots only get breakfast recipes; lunch/dinner slots get mains.
 * Sides and desserts live in the library and can be added to a slot by hand,
 * but auto-fill never picks them.
 */
export type MealKind = "breakfast" | "main" | "side" | "dessert";

// --- Units -----------------------------------------------------------------

/** Units recipes are written in (what a human would type). */
export type RecipeUnit = "g" | "oz" | "lb" | "ml" | "tsp" | "tbsp" | "cup" | "each";

/** Units the store catalog is priced in. Every recipe unit converts to one of these. */
export type BaseUnit = "g" | "ml" | "each";

// --- Store catalog ---------------------------------------------------------

export type ItemId = string;

export type Aisle = "Meat & Eggs" | "Seafood" | "Dairy" | "Produce" | "Frozen" | "Pantry" | "International" | "Spices & Sauces" | "Bakery";

/** One purchasable product, e.g. "Long Grain White Rice, 2 lb bag". */
export interface StoreItem {
  id: ItemId;
  name: string;
  aisle: Aisle;
  /** How much is in one package, in `baseUnit`. */
  packageSize: number;
  baseUnit: BaseUnit;
  /** Human label for one package, e.g. "2 lb bag". */
  packageLabel: string;
  /** Price of one package, USD. */
  price: number;
  /**
   * Lets weight-priced items be measured by volume in recipes
   * (e.g. rice: 1 cup ≈ 185 g → 0.78 g/ml). Only needed for `g` items.
   */
  gramsPerMl?: number;
  /** Salt, oil, etc. Marked "have it" by default for new users. */
  pantryStaple?: boolean;
}

// --- Recipes ---------------------------------------------------------------

export interface RecipeIngredient {
  /** Points at a StoreItem. Cost is derived from the catalog, never hard-coded per recipe. */
  itemId: ItemId;
  amount: number;
  unit: RecipeUnit;
  /** Optional display note, e.g. "diced". */
  note?: string;
}

export interface Recipe {
  id: string;
  title: string;
  description: string;
  cuisine: Cuisine;
  styles: CookingStyle[];
  kind: MealKind;
  /** Minutes, hands-on + cook. */
  prepTime: number;
  /** ALL of these are needed. An empty array means no-cook. */
  requiredAppliances: Appliance[];
  /** How many people one batch feeds. Ingredients scale to household size. */
  servings: number;
  ingredients: RecipeIngredient[];
  /** Cooking instructions, in order. Kept in recipes/steps/ and joined in by recipes/index.ts. */
  steps: string[];
  /** Optional cook's tip shown under the steps. */
  tip?: string;
}

/** A recipe as written in the data files, before its steps are attached. */
export type RecipeData = Omit<Recipe, "steps">;

// --- Plan state --------------------------------------------------------------

export interface MealSlot {
  dayIndex: number; // 0-6
  mealNumber: number; // 1-3
  recipeId: string | null;
}

export interface MealPlanState {
  targetBudget: number;
  daysCount: number; // 1-7
  mealsPerDay: number; // 1-3
  householdSize: number; // 1-6
  selectedAppliances: Appliance[];
  /** Empty = any cuisine. */
  preferredCuisines: Cuisine[];
  /** Empty = any style. */
  preferredStyles: CookingStyle[];
  /** Never plan recipes that use these store items. */
  avoidedItems: ItemId[];
  /** Already in the kitchen: listed on the grocery list but cost $0. */
  onHandItems: ItemId[];
  /**
   * Keyed "<day>-<meal>" (day 0 = Mon; meal 1/2/3 = Breakfast/Lunch/Dinner) → recipe id.
   * Only filled slots are stored. Slots outside daysCount/mealsPerDay are kept but hidden.
   */
  slots: Record<string, string>;
}

// --- Grocery output ----------------------------------------------------------

export interface GroceryLine {
  item: StoreItem;
  /** Total amount all recipes need, in the item's base unit. */
  neededAmount: number;
  /** Whole packages to buy. */
  packages: number;
  /** What you pay at checkout for this line. */
  checkoutCost: number;
  /** Value of what actually gets eaten this week. */
  usedCost: number;
  /** Left over after the week, in base unit (goes to your pantry). */
  leftoverAmount: number;
  /** User marked this item as already in their kitchen. */
  onHand: boolean;
  /** Recipe titles that use this item. Length > 1 means ingredient overlap. */
  usedBy: string[];
}

export interface GrocerySummary {
  lines: GroceryLine[];
  /** Sum of checkout costs (excludes on-hand lines). */
  checkoutTotal: number;
  /** Value of food actually eaten this plan. */
  usedTotal: number;
  /** checkoutTotal - usedTotal: what you carry into next week. */
  carryoverValue: number;
  /** How many store items are shared by 2+ recipes. */
  sharedItemCount: number;
}

/** Per-ingredient setting in the Ingredients panel. */
export type ItemPreference = "avoid" | "use" | "have";

// --- Server action contract -------------------------------------------------

export type FillMode = "empty" | "all";

export interface GeneratePlanInput {
  state: MealPlanState;
  fillMode: FillMode;
  /** Changing the seed gives a different (but still cost-optimized) plan. */
  seed: number;
}

export interface GeneratePlanResult {
  slots: Record<string, string>;
  summary: GrocerySummary;
  /** Human-readable notes, e.g. when filters had to be relaxed. */
  notes: string[];
}