feat: article version history with abstract/title diff

articles/api.py

@@ -16,6 +16,7 @@
 from articles.models import (
     Article,
     ArticlePDF,
+    ArticleVersion,
     Discussion,
     Reaction,
     Review,
@@ -29,6 +30,7 @@
     ArticleOut,
     ArticlesListOut,
     ArticleUpdateSchema,
+    ArticleVersionDiffOut,
     CommunityArticleStatsResponse,
     DateCount,
     Message,
@@ -473,6 +475,15 @@ def update_article(
                 }
 
             try:
+                # Save current state as a version before overwriting
+                latest_version = ArticleVersion.objects.filter(article=article).count()
+                ArticleVersion.objects.create(
+                    article=article,
+                    version=latest_version + 1,
+                    title=article.title,
+                    abstract=article.abstract,
+                )
+
                 # Update the article fields only if they are provided
                 article.title = details.payload.title
                 article.abstract = details.payload.abstract
@@ -551,6 +562,60 @@ def update_article(
         return 500, {"message": "An unexpected error occurred. Please try again later."}
 
 
+@router.get(
+    "/{article_id}/versions",
+    response={200: List[ArticleVersionDiffOut], codes_4xx: Message, codes_5xx: Message},
+    auth=OptionalJWTAuth,
+    summary="Get article version history with diffs",
+)
+def get_article_versions(request, article_id: int):
+    import difflib
+
+    try:
+        article = Article.objects.get(id=article_id)
+    except Article.DoesNotExist:
+        return 404, {"message": "Article not found."}
+
+    versions = list(ArticleVersion.objects.filter(article=article).order_by("version"))
+    if not versions:
+        return 200, []
+
+    # Build diff pairs: each version vs the next (or current article for the latest)
+    result = []
+    for i, version in enumerate(versions):
+        if i + 1 < len(versions):
+            next_title = versions[i + 1].title
+            next_abstract = versions[i + 1].abstract
+        else:
+            next_title = article.title
+            next_abstract = article.abstract
+
+        title_diff = list(
+            difflib.unified_diff(
+                version.title.splitlines(),
+                next_title.splitlines(),
+                lineterm="",
+            )
+        )
+        abstract_diff = list(
+            difflib.unified_diff(
+                version.abstract.splitlines(),
+                next_abstract.splitlines(),
+                lineterm="",
+            )
+        )
+        result.append(
+            ArticleVersionDiffOut(
+                version=version.version,
+                created_at=version.created_at,
+                title_diff=title_diff,
+                abstract_diff=abstract_diff,
+            )
+        )
+
+    return 200, result
+
+
 @router.get(
     "/",
     response={

articles/migrations/0034_articleversion.py

@@ -0,0 +1,41 @@
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("articles", "0033_alter_userflag_entity_type_alter_userflag_flag_type"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="ArticleVersion",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("version", models.PositiveIntegerField()),
+                ("title", models.CharField(max_length=500)),
+                ("abstract", models.TextField()),
+                ("created_at", models.DateTimeField(auto_now_add=True)),
+                (
+                    "article",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="versions",
+                        to="articles.article",
+                    ),
+                ),
+            ],
+            options={
+                "ordering": ["-version"],
+            },
+        ),
+    ]

articles/models.py

@@ -67,6 +67,22 @@ def __str__(self):
         return self.title
 
 
+class ArticleVersion(models.Model):
+    article = models.ForeignKey(
+        Article, on_delete=models.CASCADE, related_name="versions"
+    )
+    version = models.PositiveIntegerField()
+    title = models.CharField(max_length=500)
+    abstract = models.TextField()
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        ordering = ["-version"]
+
+    def __str__(self):
+        return f"Version {self.version} of {self.article.title}"
+
+
 class ArticlePDF(models.Model):
     def get_pdf_upload_path(instance, filename):
         # Get file extension

articles/schemas.py

@@ -10,6 +10,7 @@
     AnonymousIdentity,
     Article,
     ArticlePDF,
+    ArticleVersion,
     Discussion,
     DiscussionComment,
     DiscussionSubscription,
@@ -370,6 +371,19 @@ class ArticleFilters(Schema):
     community_id: Optional[int] = None
 
 
+class ArticleVersionOut(ModelSchema):
+    class Config:
+        model = ArticleVersion
+        model_fields = ["id", "version", "title", "abstract", "created_at"]
+
+
+class ArticleVersionDiffOut(Schema):
+    version: int
+    created_at: datetime
+    title_diff: List[str]
+    abstract_diff: List[str]
+
+
 """
 Article Reviews Schemas for serialization and validation
 """