RecipeSearch.java

package mi.hdm.recipes;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.util.ArrayList;
import java.util.List;

public class RecipeSearch {
    //private final List<Recipe> recipesToSearch; //not needed when methods are static
    private static final Logger log = LogManager.getLogger(RecipeSearch.class);

    //public RecipeSearch (List<Recipe> recipesToSearch) { this.recipesToSearch = recipesToSearch; }  //not needed when methods are static

    /**
     * A method to search a list of recipes for keywords.
     * The method searches the recipe names and the ingredients for the keywords.
     *
     * @param query a String with keywords to search for
     * @return a list of Recipes which contain one or several of the keywords in its name or its ingredients
     */
    public static List<Recipe> searchByQuery(List<Recipe> recipesToSearch, String query) {
        if (query == null) return recipesToSearch;
        query = query.replaceAll("[.,!+?;-]", " ").trim();
        if (query.isBlank()) return recipesToSearch;
        log.debug("Searching for {}", query);

        List<Recipe> result = new ArrayList<>();
        String[] split = query.split(" ");  //split String into separate words and put them into a String Array
        for (final Recipe r : recipesToSearch) {  //search all recipes from recipesToSearch
            for (final String s : split) {
                String l = s.toLowerCase(); //convert current string of the query to lowercase!
                if (r.getName().toLowerCase().contains(l)) {  //check if recipe name contains words from query (convert name of recipe to lowercase too)
                    result.add(r);
                }
                for (final RecipeComponent c : r.getIngredients().keySet()) {
                    if (c.getName().toLowerCase().contains(l)) {  //check if ingredients contain words from query
                        result.add(r);
                    }
                }
            }
        }
        return result;
    }

    /** A method to search a list of recipes for categories.
     * The method filters recipes which belong to all requested categories.
     *
     * @param categoriesToSearch a list of categories to which the recipes shall belong
     * @return a list of recipes which belong to all categories of categoriesToSearch
     */
    public static List<Recipe> searchByCategory(List<Recipe> recipesToSearch, List<Category> categoriesToSearch) {
        if (categoriesToSearch == null || categoriesToSearch.isEmpty()) return recipesToSearch;

        List<Recipe> result = new ArrayList<>(recipesToSearch); //create List containing all the recipes to search

        for (final Recipe r : recipesToSearch) {
            for (final Category c : categoriesToSearch) {
                if (!r.getCategories().contains(c)) { //if a recipe does not contain one of the categories it will be removed from the result set
                    result.remove(r);
                }
            }
        }
        return result;
    }
}