import { describe, expect, test } from "bun:test";
import type { MealPlanState } from "@/app/types";
import { activeRecipeIds, mealKindFor, mealLabel, visibleMeals } from "./plan";
import { DEFAULT_STATE } from "./sanitize";
import { RECIPES } from "./recipes";
import { planReducer } from "./usePlanState";

// ---------------------------------------------------------------------------
// Meal slots. Regression tests for the "change meals per day and your
// breakfast turns into lunch" bug. Meal numbers are fixed:
//   1 = Breakfast, 2 = Lunch, 3 = Dinner
// and "meals per day" only decides which ones you can see.
// ---------------------------------------------------------------------------

// Any real recipes will do; names are just for readability.
const PANCAKES = RECIPES.find((r) => r.kind === "breakfast")!.id;
const [SANDWICH, STEW] = RECIPES.filter((r) => r.kind === "main").map((r) => r.id);

/** Monday with all three meals planned. */
const fullMonday: MealPlanState = {
  ...DEFAULT_STATE,
  daysCount: 1,
  mealsPerDay: 3,
  slots: { "0-1": PANCAKES, "0-2": SANDWICH, "0-3": STEW },
};

/** What the grid shows, as "Label: recipe". */
function visibleGrid(state: MealPlanState): string[] {
  return visibleMeals(state.mealsPerDay).map((meal) => `${mealLabel(meal)}: ${state.slots[`0-${meal}`] ?? "—"}`);
}

describe("visible meals", () => {
  test("fewer meals hides from the front of the day", () => {
    expect(visibleMeals(3).map(mealLabel)).toEqual(["Breakfast", "Lunch", "Dinner"]);
    expect(visibleMeals(2).map(mealLabel)).toEqual(["Lunch", "Dinner"]);
    expect(visibleMeals(1).map(mealLabel)).toEqual(["Dinner"]);
  });

  test("only meal 1 is breakfast", () => {
    expect([1, 2, 3].map(mealKindFor)).toEqual(["breakfast", "main", "main"]);
  });
});

describe("changing meals per day", () => {
  test("3 → 2 keeps lunch as lunch and dinner as dinner", () => {
    const state = planReducer(fullMonday, { type: "setMealsPerDay", value: 2 });
    expect(visibleGrid(state)).toEqual([`Lunch: ${SANDWICH}`, `Dinner: ${STEW}`]);
  });

  test("3 → 1 → 3 brings breakfast and lunch back (nothing deleted)", () => {
    const down = planReducer(fullMonday, { type: "setMealsPerDay", value: 1 });
    expect(visibleGrid(down)).toEqual([`Dinner: ${STEW}`]);

    const backUp = planReducer(down, { type: "setMealsPerDay", value: 3 });
    expect(visibleGrid(backUp)).toEqual([`Breakfast: ${PANCAKES}`, `Lunch: ${SANDWICH}`, `Dinner: ${STEW}`]);
  });

  test("hidden meals don't count toward the cart", () => {
    expect(activeRecipeIds({ ...fullMonday, mealsPerDay: 1 })).toEqual([STEW]);
    expect(activeRecipeIds({ ...fullMonday, mealsPerDay: 2 })).toEqual([SANDWICH, STEW]);
  });
});

describe("Clear", () => {
  test("empties the visible grid but keeps hidden meals", () => {
    const lunchAndDinner = { ...fullMonday, mealsPerDay: 2 };
    const cleared = planReducer(lunchAndDinner, { type: "clearSlots" });

    expect(visibleGrid(cleared)).toEqual(["Lunch: —", "Dinner: —"]);
    expect(cleared.slots).toEqual({ "0-1": PANCAKES }); // breakfast was hidden, so untouched
  });
});