refactor: revised class layout for JPA entities

commons/src/main/java/commons/FormalIngredient.java

@@ -0,0 +1,53 @@
+package commons;
+
+import jakarta.persistence.Entity;
+
+import java.util.Optional;
+
+/**
+ * A formal ingredient inheriting from base {@link RecipeIngredient RecipeIngredient},
+ * holds an amount and a unit suffix in {@link String String} form.
+ * @see RecipeIngredient
+ */
+@Entity
+public class FormalIngredient extends RecipeIngredient {
+    private double amount;
+    private String unitSuffix;
+
+    public double getAmount() {
+        return amount;
+    }
+
+    public void setAmount(double amount) {
+        this.amount = amount;
+    }
+
+    public String getUnitSuffix() {
+        return unitSuffix;
+    }
+
+    public void setUnitSuffix(String unitSuffix) {
+        this.unitSuffix = unitSuffix;
+    }
+
+    public FormalIngredient(Ingredient ingredient, double amount, String unitSuffix) {
+        super(ingredient);
+        this.amount = amount;
+        this.unitSuffix = unitSuffix;
+    }
+
+    public FormalIngredient() {
+        // ORM
+    }
+
+    public double amountInBaseUnit() {
+        Optional<Unit> unit = Unit.fromString(unitSuffix);
+        if (unit.isEmpty() || !unit.get().isFormal() || unit.get().conversionFactor <= 0) {
+            return 0.0;
+        }
+        return amount * unit.get().conversionFactor;
+    }
+    public String toString() {
+        return amount + unitSuffix + " of " + ingredient.name;
+    }
+}

commons/src/main/java/commons/Ingredient.java

@@ -20,7 +20,8 @@ public class Ingredient {
     @GeneratedValue(strategy = GenerationType.AUTO)
     public long id;
 
-    @Column(name = "name", nullable = false, unique = true)
+    // FIXME Dec 22 2025::temporarily made this not a unique constraint because of weird JPA behaviour
+    @Column(name = "name", nullable = false, unique = false)
     public String name;
 
 
@@ -35,10 +36,24 @@ public class Ingredient {
 
     public Ingredient() {}
 
-    public Ingredient(String name,
+    public Ingredient(
+            Long id,
+            String name,
             double proteinPer100g,
             double fatPer100g,
             double carbsPer100g) {
+        this.id = id;
+        this.name = name;
+        this.proteinPer100g = proteinPer100g;
+        this.fatPer100g = fatPer100g;
+        this.carbsPer100g = carbsPer100g;
+    }
+    public Ingredient(
+            String name,
+            double proteinPer100g,
+            double fatPer100g,
+            double carbsPer100g) {
+
         this.name = name;
         this.proteinPer100g = proteinPer100g;
         this.fatPer100g = fatPer100g;

commons/src/main/java/commons/Recipe.java

@@ -15,16 +15,17 @@
  */
 package commons;
 
-import jakarta.persistence.GenerationType;
-import jakarta.persistence.Id;
-import jakarta.persistence.Table;
-import jakarta.persistence.Entity;
 import jakarta.persistence.CollectionTable;
 import jakarta.persistence.Column;
-import jakarta.persistence.JoinColumn;
-import jakarta.persistence.OrderColumn;
-import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.ElementCollection;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.OrderColumn;
+import jakarta.persistence.Table;
 
 
 import java.util.ArrayList;
@@ -59,11 +60,11 @@ public class Recipe {
     // | 1 (Steak)           | 40g pepper |
     // | 1 (Steak)           | Meat       |
     // |----------------------------------|
-    @ElementCollection
+    @OneToMany
     @CollectionTable(name = "recipe_ingredients", joinColumns = @JoinColumn(name = "recipe_id"))
     @Column(name = "ingredient")
     // TODO: Replace String with Embeddable Ingredient Class
-    private List<String> ingredients = new ArrayList<>();
+    private List<RecipeIngredient> ingredients = new ArrayList<>();
 
     // Creates another table named recipe_preparation which stores:
     // recipe_preparation(recipe_id -> recipes(id), preparation_step, step_order).
@@ -94,7 +95,7 @@ public class Recipe {
     }
 
     // TODO: Replace String with Embeddable Ingredient Class for ingredients
-    public Recipe(Long id, String name, List<String> ingredients, List<String> preparationSteps) {
+    public Recipe(Long id, String name, List<RecipeIngredient> ingredients, List<String> preparationSteps) {
         // Not used by JPA/Spring
         this.id = id;
         this.name = name;
@@ -119,14 +120,14 @@ public class Recipe {
     }
 
     // TODO: Replace String with Embeddable Ingredient Class
-    public List<String> getIngredients() {
+    public List<RecipeIngredient> getIngredients() {
         // Disallow modifying the returned list.
         // You can still copy it with List.copyOf(...)
         return Collections.unmodifiableList(ingredients);
     }
 
     // TODO: Replace String with Embeddable Ingredient Class
-    public void setIngredients(List<String> ingredients) {
+    public void setIngredients(List<RecipeIngredient> ingredients) {
         this.ingredients = ingredients;
     }
 

commons/src/main/java/commons/RecipeIngredient.java

@@ -1,77 +1,60 @@
 package commons;
 
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import jakarta.persistence.Entity;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
+import jakarta.persistence.Inheritance;
+import jakarta.persistence.InheritanceType;
 import jakarta.persistence.JoinColumn;
 import jakarta.persistence.ManyToOne;
 
+/**
+ * The base RecipeIngredient class, holding a reference to the
+ * {@link Ingredient Ingredient} it has an (in)formal amount
+ * linked to.
+ * It uses {@link JsonSubTypes JsonSubTypes} such that the
+ * Jackson framework can conveniently decode JSON data sent
+ * by client, which could be either a formal or vague
+ * ingredient.
+ * @see Ingredient
+ */
 @Entity
-public class RecipeIngredient {
-
+@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
+@JsonTypeInfo(
+        use = JsonTypeInfo.Id.NAME,      // identifies subtype by logical name
+        include = JsonTypeInfo.As.PROPERTY,
+        property = "type"                // JSON property carrying the subtype id
+)
+@JsonSubTypes({
+        @JsonSubTypes.Type(value = FormalIngredient.class, name = "formal"),
+        @JsonSubTypes.Type(value = VagueIngredient.class,  name = "vague")
+})
+public abstract class RecipeIngredient {
     @Id
-    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @GeneratedValue(strategy = GenerationType.AUTO)
     public Long id;
 
-    // which recipe is used
-    @ManyToOne(optional = false)
-    @JoinColumn(name = "recipe_id")
-    public Recipe recipe;
-
-    //which ingredient is used
+    /**
+     * Many-to-one: Many {@link RecipeIngredient RecipeIngredient}
+     * can use the same {@link Ingredient Ingredient} with varying
+     * amounts. This allows better ingredient collecting for
+     * nutrition view.
+     */
     @ManyToOne(optional = false)
     @JoinColumn(name = "ingredient_id")
     public Ingredient ingredient;
 
-    public double amount;
-
-    // store the unit name in the database
-    public String unitName;
-
     @SuppressWarnings("unused")
     protected RecipeIngredient() {
-        // for sebastian
+        // for ORM
     }
 
-    public RecipeIngredient(Recipe recipe,   //which recipe
-                            Ingredient ingredient,   // which ingredient
-                            double amount,      // the amount
-                            String unit) {      //gram liter etc
-        //store it im tha field
-        this.recipe = recipe;
+    public RecipeIngredient(
+                            Ingredient ingredient) {
+        //store it in the field
         this.ingredient = ingredient;
-        this.amount = amount;
-        this.unitName = unit;
-    }
-
-    // Convert unitName to Unit object so java can read it
-    public Unit getUnit() {
-        return switch (unitName) {
-            case "GRAM"       -> Unit.GRAM;
-            case "KILOGRAM"   -> Unit.KILOGRAM;
-            case "MILLILITER" -> Unit.MILLILITER;
-            case "LITER"      -> Unit.LITER;
-            case "TABLESPOON" -> Unit.TABLESPOON;
-            case "TEASPOON"   -> Unit.TEASPOON;
-            case "CUP"        -> Unit.CUP;
-            case "PIECE"      -> Unit.PIECE;
-
-            case "PINCH"      -> Unit.PINCH;
-            case "HANDFUL"    -> Unit.HANDFUL;
-            case "TO_TASTE"   -> Unit.TO_TASTE;
-
-            default -> null;
-        };
-    }
-
-
-
-    public double amountInBaseUnit() {
-        Unit unit = getUnit();
-        if (unit == null || !unit.isFormal() || unit.conversionFactor <= 0) {
-            return 0.0;
-        }
-        return amount * unit.conversionFactor;
     }
 }

commons/src/main/java/commons/Unit.java

@@ -1,33 +1,30 @@
 package commons;
 
-//what is a record class and why is it recommended
+import java.util.Optional;
+
+/**
+ * A unit enum that holds some values.
+ * A {@link Unit Unit} enum holds primarily formal mass-units
+ * Except for an informal unit that always has a factor of zero
+ * is made for user input purposes.
+ * @see VagueIngredient
+ * @see FormalIngredient
+ */
 public enum Unit {
-    //formal units
-    //weight units
-    GRAM("GRAM", true, 1.0),
-    KILOGRAM("KILOGRAM", true, 1000.0 ),
+    // Mass units with their absolute scale
+    GRAMME("g", true, 1.0),
+    KILOGRAMME("kg", true, 1_000.0 ),
+    TONNE("t", true, 1_000_000.0),
 
-    //volume units
-    MILLILITER("MILLILITER",true, 1.0),
-    LITER("LITER", true, 1000.0),
-    TABLESPOON("TABLESPOON",true, 15.0),
-    TEASPOON("TEASPOON", true, 5),
-    CUP ("CUP", true, 240.0),
+    // A special informal unit
+    INFORMAL("<NONE>", false, 0.0);
 
-    //piece should be a formal unit to converse for portions like 3eggs can become 1,5 eggs this way
-    PIECE("PIECE", true, 1.0),
-
-    //informal units
-    PINCH("PINCH", false, 0.0),
-    HANDFUL("HANDFUL", false, 0.0),
-    TO_TASTE("TO_TASTE", false, 0.0);
-
-    public final String name;
+    public final String suffix;
     public final boolean formal;
     public final double conversionFactor;
 
-    Unit(String name, boolean formal, double conversionFactor) {
-        this.name = name;
+    Unit(String suffix, boolean formal, double conversionFactor) {
+        this.suffix = suffix;
         this.formal = formal;
         this.conversionFactor = conversionFactor;
     }
@@ -36,12 +33,16 @@ public enum Unit {
         return formal;
     }
 
-    public boolean isInformal() {
-        return !formal;
-    }  //for oskar
-
     @Override
     public String toString() {
-        return name;
+        return suffix;
+    }
+    public static Optional<Unit> fromString(String suffix) {
+        for (Unit unit : Unit.values()) {
+            if (unit.suffix != null && unit.suffix.equals(suffix)) {
+                return Optional.of(unit);
+            }
+        }
+        return Optional.empty();
     }
 }

commons/src/main/java/commons/VagueIngredient.java

@@ -0,0 +1,34 @@
+package commons;
+
+import jakarta.persistence.Entity;
+
+/**
+ * A vague ingredient inheriting from {@link RecipeIngredient RecipeIngredient}.
+ * It has a {@link String String} description that describes an informal quantity.
+ * The vague ingredient renders as its descriptor and its ingredient name
+ * conjugated by a space via {@link VagueIngredient#toString() toString()} method.
+ * @see RecipeIngredient
+ */
+@Entity
+public class VagueIngredient extends RecipeIngredient {
+    private String description;
+    public VagueIngredient() {}
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public VagueIngredient(Ingredient ingredient, String description) {
+        super(ingredient);
+        this.description = description;
+    }
+
+    @Override
+    public String toString() {
+        return description + " " + ingredient.name;
+    }
+}