package handlers

import (
	"sort"

	"task-dashboard/internal/models"
)

// groupMeals groups meals by date+mealType, combining recipe names into CombinedMeal entries.
// Results are sorted by date then meal type (breakfast → lunch → dinner).
func groupMeals(meals []models.Meal) []CombinedMeal {
	type mealKey struct {
		date     string
		mealType string
	}
	mealGroups := make(map[mealKey][]models.Meal)
	for _, meal := range meals {
		key := mealKey{
			date:     meal.Date.Format("2006-01-02"),
			mealType: meal.MealType,
		}
		mealGroups[key] = append(mealGroups[key], meal)
	}

	var combined []CombinedMeal
	for _, group := range mealGroups {
		if len(group) == 0 {
			continue
		}
		cm := CombinedMeal{
			ID:        group[0].ID,
			Date:      group[0].Date,
			MealType:  group[0].MealType,
			RecipeURL: group[0].RecipeURL,
			Meals:     group,
		}
		for _, m := range group {
			cm.RecipeNames = append(cm.RecipeNames, m.RecipeName)
		}
		combined = append(combined, cm)
	}

	sort.Slice(combined, func(i, j int) bool {
		if !combined[i].Date.Equal(combined[j].Date) {
			return combined[i].Date.Before(combined[j].Date)
		}
		return mealTypeOrder(combined[i].MealType) < mealTypeOrder(combined[j].MealType)
	})

	return combined
}