From 575eecfc691a085d5c43237aba4327eb47483a10 Mon Sep 17 00:00:00 2001
From: Anika Raemer <araemer@laptop-anika.raemer.net>
Date: Sat, 11 Oct 2025 12:08:56 +0200
Subject: [PATCH] add dragging to step list

---
 frontend/package-lock.json                    |  62 +++++++++
 frontend/package.json                         |   3 +
 frontend/src/App.css                          |  11 +-
 frontend/src/components/basics/Button.tsx     |   4 +
 frontend/src/components/basics/SvgIcon.tsx    |   4 +-
 .../InstructionStepDesktopListItem.tsx        |  65 ++++++++++
 .../InstructionStepListDesktopEditor.tsx      |  86 +++++++++++++
 .../recipes/InstructionStepListEditor.tsx     | 120 +++++++++++-------
 .../InstructionStepListMobileEditor.tsx       |  86 +++++++++++++
 .../components/recipes/RecipeDetailPage.tsx   |  10 +-
 .../src/components/recipes/RecipeEditPage.tsx |   2 +-
 .../{recipeMapper.ts => RecipeMapper.ts}      |   8 +-
 frontend/src/models/InstructionStepModel.ts   |   5 +
 13 files changed, 406 insertions(+), 60 deletions(-)
 create mode 100644 frontend/src/components/recipes/InstructionStepDesktopListItem.tsx
 create mode 100644 frontend/src/components/recipes/InstructionStepListDesktopEditor.tsx
 create mode 100644 frontend/src/components/recipes/InstructionStepListMobileEditor.tsx
 rename frontend/src/mappers/{recipeMapper.ts => RecipeMapper.ts} (88%)

diff --git a/frontend/package-lock.json b/frontend/package-lock.json
index 66ad2f9..7c7cea3 100644
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
@@ -8,6 +8,9 @@
       "name": "frontend",
       "version": "0.0.0",
       "dependencies": {
+        "@dnd-kit/core": "^6.3.1",
+        "@dnd-kit/sortable": "^10.0.0",
+        "@dnd-kit/utilities": "^3.2.2",
         "react": "^19.1.1",
         "react-dom": "^19.1.1",
         "react-router-dom": "^7.8.2"
@@ -327,6 +330,59 @@
         "node": ">=6.9.0"
       }
     },
+    "node_modules/@dnd-kit/accessibility": {
+      "version": "3.1.1",
+      "resolved": "https://registry.npmjs.org/@dnd-kit/accessibility/-/accessibility-3.1.1.tgz",
+      "integrity": "sha512-2P+YgaXF+gRsIihwwY1gCsQSYnu9Zyj2py8kY5fFvUM1qm2WA2u639R6YNVfU4GWr+ZM5mqEsfHZZLoRONbemw==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=16.8.0"
+      }
+    },
+    "node_modules/@dnd-kit/core": {
+      "version": "6.3.1",
+      "resolved": "https://registry.npmjs.org/@dnd-kit/core/-/core-6.3.1.tgz",
+      "integrity": "sha512-xkGBRQQab4RLwgXxoqETICr6S5JlogafbhNsidmrkVv2YRs5MLwpjoF2qpiGjQt8S9AoxtIV603s0GIUpY5eYQ==",
+      "license": "MIT",
+      "dependencies": {
+        "@dnd-kit/accessibility": "^3.1.1",
+        "@dnd-kit/utilities": "^3.2.2",
+        "tslib": "^2.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=16.8.0",
+        "react-dom": ">=16.8.0"
+      }
+    },
+    "node_modules/@dnd-kit/sortable": {
+      "version": "10.0.0",
+      "resolved": "https://registry.npmjs.org/@dnd-kit/sortable/-/sortable-10.0.0.tgz",
+      "integrity": "sha512-+xqhmIIzvAYMGfBYYnbKuNicfSsk4RksY2XdmJhT+HAC01nix6fHCztU68jooFiMUB01Ky3F0FyOvhG/BZrWkg==",
+      "license": "MIT",
+      "dependencies": {
+        "@dnd-kit/utilities": "^3.2.2",
+        "tslib": "^2.0.0"
+      },
+      "peerDependencies": {
+        "@dnd-kit/core": "^6.3.0",
+        "react": ">=16.8.0"
+      }
+    },
+    "node_modules/@dnd-kit/utilities": {
+      "version": "3.2.2",
+      "resolved": "https://registry.npmjs.org/@dnd-kit/utilities/-/utilities-3.2.2.tgz",
+      "integrity": "sha512-+MKAJEOfaBe5SmV6t34p80MMKhjvUz0vRrvVJbPT0WElzaOJ/1xs+D+KDv+tD/NE5ujfrChEcshd4fLn0wpiqg==",
+      "license": "MIT",
+      "dependencies": {
+        "tslib": "^2.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=16.8.0"
+      }
+    },
     "node_modules/@esbuild/aix-ppc64": {
       "version": "0.25.9",
       "resolved": "https://registry.npmjs.org/@esbuild/aix-ppc64/-/aix-ppc64-0.25.9.tgz",
@@ -3990,6 +4046,12 @@
         "typescript": ">=4.8.4"
       }
     },
+    "node_modules/tslib": {
+      "version": "2.8.1",
+      "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.8.1.tgz",
+      "integrity": "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w==",
+      "license": "0BSD"
+    },
     "node_modules/type-check": {
       "version": "0.4.0",
       "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.4.0.tgz",
diff --git a/frontend/package.json b/frontend/package.json
index e092d2e..05a2c30 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -10,6 +10,9 @@
     "preview": "vite preview"
   },
   "dependencies": {
+    "@dnd-kit/core": "^6.3.1",
+    "@dnd-kit/sortable": "^10.0.0",
+    "@dnd-kit/utilities": "^3.2.2",
     "react": "^19.1.1",
     "react-dom": "^19.1.1",
     "react-router-dom": "^7.8.2"
diff --git a/frontend/src/App.css b/frontend/src/App.css
index b015a65..cc584c0 100644
--- a/frontend/src/App.css
+++ b/frontend/src/App.css
@@ -43,7 +43,7 @@
     @apply  text-gray-600 
   }
   .primary-button-bg {
-    @apply bg-blue-300 hover:bg-blue-400 text-gray-600
+    @apply bg-blue-300 hover:bg-blue-400
   }
   .primary-button-text {
     @apply text-gray-600
@@ -55,6 +55,13 @@
     @apply text-white
   }
 
+  .transparent-button-bg {
+    @apply bg-transparent hover:bg-transparent
+  }
+  .transparent-button-text {
+    @apply text-gray-600
+  }
+
   /* input fields like input and textarea */
   .input-field {
     @apply p-2 w-full border rounded-md placeholder-gray-400 border-gray-600 hover:border-blue-600 transition-colors text-gray-600 focus:outline-none focus:border-blue-800;
@@ -79,7 +86,7 @@
   }
 
   .enumeration-indicator{
-    @apply flex-shrink-0 w-7 h-7 rounded-full bg-blue-300 text-white flex items-center justify-center 
+    @apply flex-shrink-0 w-7 h-7 rounded-full bg-blue-300 text-white flex items-center justify-center shadow-sm
   }
   
 }
\ No newline at end of file
diff --git a/frontend/src/components/basics/Button.tsx b/frontend/src/components/basics/Button.tsx
index c186039..2423833 100644
--- a/frontend/src/components/basics/Button.tsx
+++ b/frontend/src/components/basics/Button.tsx
@@ -20,6 +20,10 @@ export const ButtonType = {
     DefaultButton: {
         textColor: "default-button-text",
         backgroundColor: "default-button-bg"
+    },
+    TransparentButton: {
+        textColor: "transparent-button-text",
+        backgroundColor: "transparent-button-bg"
     }
 } as const;
 
diff --git a/frontend/src/components/basics/SvgIcon.tsx b/frontend/src/components/basics/SvgIcon.tsx
index 8a86c8a..75a5d4c 100644
--- a/frontend/src/components/basics/SvgIcon.tsx
+++ b/frontend/src/components/basics/SvgIcon.tsx
@@ -9,7 +9,9 @@
 export const Icon = {
   LookingGlass: "M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z",
   X: "M6 18L18 6M6 6l12 12",
-  Plus:  "M3 12L21 12M12 3L12 21"
+  Plus:  "M3 12L21 12M12 3L12 21",
+  ArrowUp: "M3 18L12 6L21 18",
+  ArrowDown: "M3 6L12 18L21 6",
 } as const;
 
 export type Icon = typeof Icon[keyof typeof Icon];
diff --git a/frontend/src/components/recipes/InstructionStepDesktopListItem.tsx b/frontend/src/components/recipes/InstructionStepDesktopListItem.tsx
new file mode 100644
index 0000000..4e32531
--- /dev/null
+++ b/frontend/src/components/recipes/InstructionStepDesktopListItem.tsx
@@ -0,0 +1,65 @@
+/**
+ * Single step component for Desktop editor with drag-and-drop support.
+ */
+
+import { useSortable } from "@dnd-kit/sortable";
+import { CSS } from "@dnd-kit/utilities";
+import type { InstructionStepModel } from "../../models/InstructionStepModel";
+import Button, { ButtonType } from "../basics/Button";
+import { Icon } from "../basics/SvgIcon";
+
+type InstructionStepDesktopListItemProps = {
+  id: string | number;
+  index: number;
+  step: InstructionStepModel;
+  onUpdate: (index: number, value: string) => void;
+  onRemove: (index: number) => void;
+};
+
+export function InstructionStepDesktopListItem({
+  id,
+  index,
+  step,
+  onUpdate,
+  onRemove,
+}: InstructionStepDesktopListItemProps) {
+  const { attributes, listeners, setNodeRef, transform, transition } = useSortable({ id });
+
+  const style = { transform: CSS.Transform.toString(transform), transition };
+
+  return (
+    <div
+      ref={setNodeRef}
+      style={style}
+      className="flex items-start gap-3"
+    >
+      <div
+        {...attributes}
+        {...listeners}
+        className="enumeration-indicator cursor-grab"
+        title="Ziehen, um neu zu ordnen"
+      >
+        {index + 1}
+      </div>
+
+      <textarea
+        className="input-field w-full min-h-[60px] resize-none overflow-hidden"
+        placeholder={`Schritt ${index + 1}`}
+        value={step.text}
+        onChange={(e) => onUpdate(index, e.target.value)}
+        onInput={(e) => {
+          const el = e.target as HTMLTextAreaElement;
+          el.style.height = "auto";
+          el.style.height = `${el.scrollHeight}px`;
+        }}
+      />
+
+      <Button
+        onClick={() => onRemove(index)}
+        icon={Icon.X}
+        buttonType={ButtonType.DarkButton}
+        title="Schritt löschen"
+      />
+    </div>
+  );
+}
diff --git a/frontend/src/components/recipes/InstructionStepListDesktopEditor.tsx b/frontend/src/components/recipes/InstructionStepListDesktopEditor.tsx
new file mode 100644
index 0000000..49d68d4
--- /dev/null
+++ b/frontend/src/components/recipes/InstructionStepListDesktopEditor.tsx
@@ -0,0 +1,86 @@
+/**
+ * Desktop editor using drag-and-drop via @dnd-kit
+ */
+
+import {
+  DndContext,
+  closestCenter,
+  PointerSensor,
+  useSensor,
+  useSensors,
+} from "@dnd-kit/core";
+import {
+  arrayMove,
+  SortableContext,
+  verticalListSortingStrategy,
+} from "@dnd-kit/sortable";
+import type { InstructionStepModel } from "../../models/InstructionStepModel";
+import { InstructionStepDesktopListItem } from "./InstructionStepDesktopListItem";
+import { useInstructionStepListEditor } from "./InstructionStepListEditor";
+import Button, { ButtonType } from "../basics/Button";
+import { Icon } from "../basics/SvgIcon";
+
+type InstructionStepListDesktopEditorProps = {
+  instructionStepList: InstructionStepModel[];
+  onChange: (steps: InstructionStepModel[]) => void;
+};
+
+export function InstructionStepListDesktopEditor({
+  instructionStepList,
+  onChange,
+}: InstructionStepListDesktopEditorProps) {
+  const { handleUpdate, handleAdd, handleRemove } = useInstructionStepListEditor(
+    instructionStepList,
+    onChange
+  );
+
+  const sensors = useSensors(useSensor(PointerSensor, { activationConstraint: { distance: 8 } }));
+
+  const handleDragEnd = (event: any) => {
+    const { active, over } = event;
+    if (active.id !== over.id) {
+      /* find element by internal id
+       * Caution! Due to new elements not having a real ID yet, each list item has an internal ID
+       * in order to give it a unique identifier before saving it to the backend. We have to compare 
+       * the id of the drag item to the internalId of the list item here!
+       */
+      const oldIndex = instructionStepList.findIndex((i) => i.internalId === active.id);
+      const newIndex = instructionStepList.findIndex((i) => i.internalId === over.id);
+      // move element to new position
+      const newOrder = arrayMove(instructionStepList, oldIndex, newIndex);
+      onChange(newOrder);
+    }
+  };
+
+  return (
+    <div>
+      <h3 className="subsection-heading mb-3">Zubereitung</h3>
+      <DndContext sensors={sensors} collisionDetection={closestCenter} onDragEnd={handleDragEnd}>
+        <SortableContext
+          items={instructionStepList.map((i) => i.internalId)}
+          strategy={verticalListSortingStrategy}
+        >
+          <div className="flex flex-col gap-3">
+            {instructionStepList.map((step, index) => (
+              <InstructionStepDesktopListItem
+                key={step.internalId}
+                id={step.internalId}
+                index={index}
+                step={step}
+                onUpdate={handleUpdate}
+                onRemove={handleRemove}
+              />
+            ))}
+          </div>
+        </SortableContext>
+      </DndContext>
+      <Button
+        onClick={handleAdd}
+        icon={Icon.Plus}
+        text="Schritt hinzufügen"
+        buttonType={ButtonType.PrimaryButton}
+        className="mt-4"
+    />
+    </div>
+  );
+}
diff --git a/frontend/src/components/recipes/InstructionStepListEditor.tsx b/frontend/src/components/recipes/InstructionStepListEditor.tsx
index c1fb4ee..7fc21b0 100644
--- a/frontend/src/components/recipes/InstructionStepListEditor.tsx
+++ b/frontend/src/components/recipes/InstructionStepListEditor.tsx
@@ -1,56 +1,86 @@
-import type { InstructionStepModel } from "../../models/InstructionStepModel"
-import Button, { ButtonType } from "../basics/Button"
-import { Icon } from "../basics/SvgIcon"
+/**
+ * InstructionStepListEditor.tsx
+ *
+ * Hybrid editor for recipe instruction steps:
+ * - Detects device type and renders Desktop or Mobile editor accordingly.
+ * - Common functionality for adding, removing, and updating steps is centralized.
+ */
 
-/** 
- * Editor for handling the instruction step list
- * Ingredients can be edited, added and removed
+import { useState, useEffect } from "react";
+import type { InstructionStepModel } from "../../models/InstructionStepModel";
+import { InstructionStepListDesktopEditor } from "./InstructionStepListDesktopEditor";
+import { InstructionStepListMobileEditor } from "./InstructionStepListMobileEditor";
+
+/**
+ * Props for the hybrid InstructionStepListEditor
  */
 type InstructionStepListEditorProps = {
-  instructionStepList: InstructionStepModel[]
-  onChange: (ingredients: InstructionStepModel[]) => void
+  instructionStepList: InstructionStepModel[];
+  onChange: (steps: InstructionStepModel[]) => void;
+};
+
+/**
+ * Hybrid wrapper that decides between desktop (drag-and-drop) or mobile (buttons)
+ */
+export function InstructionStepListEditor({
+  instructionStepList,
+  onChange,
+}: InstructionStepListEditorProps) {
+  const [isTouch, setIsTouch] = useState(false);
+
+  useEffect(() => {
+    setIsTouch("ontouchstart" in window || navigator.maxTouchPoints > 0);
+  }, []);
+
+  return isTouch ? (
+    <InstructionStepListMobileEditor
+      instructionStepList={instructionStepList}
+      onChange={onChange}
+    />
+  ) : (
+    <InstructionStepListDesktopEditor
+      instructionStepList={instructionStepList}
+      onChange={onChange}
+    />
+  );
 }
 
-export function InstructionStepListEditor({ instructionStepList, onChange }: InstructionStepListEditorProps) {
-  const handleUpdate = (index: number, field: keyof InstructionStepModel, value: string) => {
-    const updated = instructionStepList.map((ing, i) =>
-      i === index ? { ...ing, [field]: value } : ing
-    )
-    onChange(updated)
-  }
+/**
+ * ======= Shared hook for common logic =======
+ *
+ * Provides add/remove/update functionality used by both mobile and desktop editors.
+ */
+export function useInstructionStepListEditor(
+  instructionStepList: InstructionStepModel[],
+  onChange: (steps: InstructionStepModel[]) => void
+) {
+  /**
+   * Update the text of a specific step
+   */
+  const handleUpdate = (index: number, value: string) => {
+    const updated = instructionStepList.map((step, i) =>
+      i === index ? { ...step, text: value } : step
+    );
+    onChange(updated);
+  };
 
+  /**
+   * Add a new step at the end
+   */
   const handleAdd = () => {
-    onChange([...instructionStepList, { text: "" }])
-  }
+    onChange([...instructionStepList, 
+        { 
+            text: "", 
+            internalId: crypto.randomUUID() // add internalId required for drag & drop
+        }]);
+  };
 
+  /**
+   * Remove a step by index
+   */
   const handleRemove = (index: number) => {
-    onChange(instructionStepList.filter((_, i) => i !== index))
-  }
+    onChange(instructionStepList.filter((_, i) => i !== index));
+  };
 
-  return (
-    <div>
-      <h3 className="subsection-heading">Zubereitung</h3>
-      {instructionStepList.map((step, index) => (
-        <div key={index} className="horizontal-input-group">
-          <input
-            className="input-field"
-            placeholder="Description"
-            value={step.text}
-            onChange={e => handleUpdate(index, "text", e.target.value)}
-          />
-          <Button 
-            onClick={() => handleRemove(index)}
-            icon={Icon.X}
-            buttonType={ButtonType.DarkButton}
-          />
-        </div>
-      ))}
-      <Button 
-        onClick={handleAdd}
-        icon={Icon.Plus}
-        text={"Schritt hinzufügen"}
-        buttonType={ButtonType.PrimaryButton}
-      />
-    </div>
-  )
+  return { handleUpdate, handleAdd, handleRemove };
 }
diff --git a/frontend/src/components/recipes/InstructionStepListMobileEditor.tsx b/frontend/src/components/recipes/InstructionStepListMobileEditor.tsx
new file mode 100644
index 0000000..7cee76a
--- /dev/null
+++ b/frontend/src/components/recipes/InstructionStepListMobileEditor.tsx
@@ -0,0 +1,86 @@
+/**
+ * Mobile editor using Up/Down buttons for reordering
+ */
+
+import type { InstructionStepModel } from "../../models/InstructionStepModel";
+import Button, { ButtonType } from "../basics/Button";
+import { Icon } from "../basics/SvgIcon";
+import { useInstructionStepListEditor } from "./InstructionStepListEditor";
+
+type InstructionStepListEditorMobileProps = {
+  instructionStepList: InstructionStepModel[];
+  onChange: (steps: InstructionStepModel[]) => void;
+};
+
+export function InstructionStepListMobileEditor({
+  instructionStepList,
+  onChange,
+}: InstructionStepListEditorMobileProps) {
+  const { handleUpdate, handleAdd, handleRemove } = useInstructionStepListEditor(
+    instructionStepList,
+    onChange
+  );
+
+  const moveStep = (index: number, direction: "up" | "down") => {
+    const newIndex = direction === "up" ? index - 1 : index + 1;
+    if (newIndex < 0 || newIndex >= instructionStepList.length) return;
+    const newList = [...instructionStepList];
+    const [moved] = newList.splice(index, 1);
+    newList.splice(newIndex, 0, moved);
+    onChange(newList);
+  };
+
+  return (
+    <div className="flex flex-col gap-3">
+      {instructionStepList.map((step, index) => (
+        <div
+          key={step.id}
+          className="flex items-start gap-3 bg-gray-50 rounded-xl p-3 shadow-sm"
+        >
+          <div className="flex flex-col items-center pt-1">
+            <div className="w-8 h-8 rounded-full bg-gray-300 flex items-center justify-center text-sm font-semibold text-gray-800">
+              {index + 1}
+            </div>
+            <div className="flex flex-col mt-2">
+              <Button
+                icon={Icon.ArrowUp}
+                onClick={() => moveStep(index, "up")}
+                buttonType={ButtonType.TransparentButton}
+              />
+              <Button
+                icon={Icon.ArrowDown}
+                onClick={() => moveStep(index, "down")}
+                buttonType={ButtonType.TransparentButton}
+              />
+            </div>
+          </div>
+
+          <textarea
+            className="input-field w-full min-h-[60px] resize-none overflow-hidden"
+            placeholder={`Schritt ${index + 1}`}
+            value={step.text}
+            onChange={(e) => handleUpdate(index, e.target.value)}
+            onInput={(e) => {
+              const el = e.target as HTMLTextAreaElement;
+              el.style.height = "auto";
+              el.style.height = `${el.scrollHeight}px`;
+            }}
+          />
+
+          <Button
+            onClick={() => handleRemove(index)}
+            icon={Icon.X}
+            buttonType={ButtonType.DarkButton}
+          />
+        </div>
+      ))}
+      <Button
+        onClick={handleAdd}
+        icon={Icon.Plus}
+        text="Schritt hinzufügen"
+        buttonType={ButtonType.PrimaryButton}
+        className="mt-4"
+      />
+    </div>
+  );
+}
diff --git a/frontend/src/components/recipes/RecipeDetailPage.tsx b/frontend/src/components/recipes/RecipeDetailPage.tsx
index 6c1b68e..6b798b8 100644
--- a/frontend/src/components/recipes/RecipeDetailPage.tsx
+++ b/frontend/src/components/recipes/RecipeDetailPage.tsx
@@ -4,7 +4,7 @@ import { useEffect, useState } from "react"
 import { fetchRecipe } from "../../api/points/RecipePoint"
 import { getRecipeEditUrl, getRecipeListUrl } from "../../routes"
 import ButtonLink from "../basics/ButtonLink"
-import { mapRecipeDtoToModel } from "../../mappers/recipeMapper"
+import { mapRecipeDtoToModel } from "../../mappers/RecipeMapper"
 
 
 /**
@@ -123,14 +123,6 @@ export default function RecipeDetailPage() {
       </ul>
 
       {/* Instructions - @todo add reasonable list delegate component*/}
-      {/*<h2 className="section-heading">Zubereitung</h2>
-      <ol className="default-list mb-6">
-        {recipe.instructionStepList.map((step,j) =>(
-          <li key={j}>
-            {step.text}
-          </li>
-        ))}
-      </ol>*/}
       <ol className="space-y-4">
         {recipe.instructionStepList.map((step, j) => (
           <li key={j} className="flex items-start gap-4">
diff --git a/frontend/src/components/recipes/RecipeEditPage.tsx b/frontend/src/components/recipes/RecipeEditPage.tsx
index 2b9d8b2..594b42e 100644
--- a/frontend/src/components/recipes/RecipeEditPage.tsx
+++ b/frontend/src/components/recipes/RecipeEditPage.tsx
@@ -4,7 +4,7 @@ import type { RecipeModel } from "../../models/RecipeModel"
 import  RecipeEditor  from "./RecipeEditor"
 import { fetchRecipe, createOrUpdateRecipe } from "../../api/points/RecipePoint"
 import { getRecipeDetailUrl, getRecipeListUrl } from "../../routes"
-import { mapRecipeDtoToModel, mapRecipeModelToDto } from "../../mappers/recipeMapper"
+import { mapRecipeDtoToModel, mapRecipeModelToDto } from "../../mappers/RecipeMapper"
 import type { RecipeDto } from "../../api/dtos/RecipeDto"
 
 export default function RecipeEditPage() {
diff --git a/frontend/src/mappers/recipeMapper.ts b/frontend/src/mappers/RecipeMapper.ts
similarity index 88%
rename from frontend/src/mappers/recipeMapper.ts
rename to frontend/src/mappers/RecipeMapper.ts
index d398687..fe72204 100644
--- a/frontend/src/mappers/recipeMapper.ts
+++ b/frontend/src/mappers/RecipeMapper.ts
@@ -16,13 +16,17 @@ export function mapRecipeDtoToModel(dto: RecipeDto): RecipeModel {
       amount: dto.amount ?? 1,
       unit: dto.amountDescription ?? "",
     },
-    // @todo implement steps in frontend
     // join all instruction step texts into a single string for display
     instructionStepList: dto.instructions
       .sort((a, b) => a.sortOrder - b.sortOrder) // ensure correct order
       .map(step => ({
           text: step.text,
-          id: step.id
+          id: step.id,
+          /* When mapping a stepDTO, it should already contain a UUID. If
+           * If, however, for some reason, it does not, add a UUID as sorting
+           * steps in teh GUI requires a unique identifier for each item.
+           */
+          internalId: step.id !== undefined? step.id : crypto.randomUUID()
         })
       ),
 
diff --git a/frontend/src/models/InstructionStepModel.ts b/frontend/src/models/InstructionStepModel.ts
index bdcfdf1..fec1123 100644
--- a/frontend/src/models/InstructionStepModel.ts
+++ b/frontend/src/models/InstructionStepModel.ts
@@ -3,5 +3,10 @@
  */
 export interface InstructionStepModel{
     id?: string;
+    /**
+     * Unique id required for sorting via drag & drop
+     * Local to the frontend!
+     */
+    internalId: string;
     text: string;
 }
\ No newline at end of file