Implemented allergen functionality by showing the user a bottom sheet

app/src/main/java/com/denizk0461/studip/sheet/AllergenSheet.kt

@@ -5,6 +5,7 @@ import android.view.View
 import com.denizk0461.studip.R
 import com.denizk0461.studip.data.viewBinding
 import com.denizk0461.studip.databinding.SheetAllergenBinding
+import com.denizk0461.studip.model.Allergens
 import com.denizk0461.studip.model.CanteenOfferGroupElement
 
 class AllergenSheet(private val offer: CanteenOfferGroupElement) : AppSheet(R.layout.sheet_allergen) {
@@ -16,7 +17,43 @@ class AllergenSheet(private val offer: CanteenOfferGroupElement) : AppSheet(R.la
 
         binding.apply {
             title.text = offer.title
-            textContent.text = "hello there"
+            textContent.text = offer.allergens.compileAllergenString()
         }
     }
+
+    /**
+     * Retrieves localised strings for all allergens present in a given offer and compiles them into
+     * a human-readable string, if any allergens are present.
+     *
+     * @return  a string of all allergens
+     */
+    private fun String.compileAllergenString(): String {
+
+        // Let the user know if no allergens are present
+        if (this.isBlank()) return getString(R.string.allergens_none)
+
+        // Stores all localised allergens
+        var allergenString = ""
+
+        // Used to insert a delimiter if more than one allergen is found
+        var isFirst = true
+
+        // Split all allergens to iterate through them
+        val allergens = this.replace(" ", "").split(",")
+
+        // Iterate through all allergens
+        allergens.forEach { allergen ->
+            // Insert a delimiter if more than one allergen is found
+            if (!isFirst) allergenString += ", "
+
+            // Add a localised string for the allergen
+            allergenString += getString(Allergens.getStringRes(allergen))
+
+            // Set when the first allergen has been processed
+            isFirst = false
+        }
+
+        // Insert the allergens into a template string
+        return getString(R.string.allergens_contains, allergenString)
+    }
 }