Finish MVP and dockerize

apps/backend/fastapi/app/services/versions.py

@@ -0,0 +1,78 @@
+from __future__ import annotations
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import selectinload
+
+from dlib.cv import (
+    StructuredBlock,
+    StructuredDocument,
+    PatchPayload,
+    apply_patchset,
+    validate_patchset,
+)
+
+from app.models import CvDocument, CvPatch, CvVersion
+
+
+async def create_branch(
+    session: AsyncSession,
+    *,
+    owner_id: str,
+    parent_version_id: str,
+    branch_name: str,
+    version_label: str | None,
+    patches: list[dict],
+) -> CvVersion | None:
+    stmt = (
+        select(CvVersion)
+        .join(CvDocument)
+        .where(CvVersion.id == parent_version_id, CvDocument.owner_id == owner_id)
+        .options(selectinload(CvVersion.patches))
+    )
+    result = await session.execute(stmt)
+    parent = result.scalars().one_or_none()
+    if not parent:
+        return None
+
+    base_doc = StructuredDocument(
+        version_label=parent.version_label,
+        blocks=[
+            StructuredBlock.model_validate(block)
+            for block in parent.structured_blocks or []
+        ],
+    )
+    patch_models = [PatchPayload.model_validate(item) for item in patches]
+    if patch_models:
+        validate_patchset(base_doc, patch_models)
+        updated_doc = apply_patchset(base_doc, patch_models)
+    else:
+        updated_doc = base_doc
+
+    new_version = CvVersion(
+        document_id=parent.document_id,
+        parent_version_id=parent.id,
+        branch_name=branch_name,
+        version_label=version_label or branch_name,
+        artifact_docx_key=parent.artifact_docx_key,
+        structured_blocks=[block.model_dump() for block in updated_doc.blocks],
+        metadata_json={"patch_count": len(patch_models)},
+    )
+
+    session.add(new_version)
+    await session.flush()
+    for patch in patch_models:
+        session.add(
+            CvPatch(
+                version_id=new_version.id,
+                target_path=patch.target_path,
+                operation=patch.operation.value,
+                old_value=patch.old_value,
+                new_value=patch.new_value,
+                metadata_json=patch.metadata,
+            )
+        )
+
+    await session.commit()
+    await session.refresh(new_version)
+    return new_version