Add approval template revision administration

src/govoplan_approvals/backend/router.py

@@ -173,6 +173,80 @@ def api_publish_template(
         raise _error(exc) from exc
 
 
+@router.get("/templates/{template_id}", response_model=dict[str, Any])
+def api_get_template(
+    template_id: str,
+    revision: int | None = Query(default=None, ge=1),
+    session: Session = Depends(get_session),
+    principal: ApiPrincipal = Depends(get_api_principal),
+) -> dict[str, Any]:
+    from govoplan_approvals.backend.manifest import READ_SCOPE
+
+    _require(principal, READ_SCOPE)
+    item = SqlApprovalRequests().get_template(
+        session,
+        principal,
+        template_id=template_id,
+        revision=revision,
+    )
+    if item is None:
+        raise HTTPException(status_code=404, detail="Approval template not found")
+    return dict(item)
+
+
+@router.get(
+    "/templates/{template_id}/history",
+    response_model=list[dict[str, Any]],
+)
+def api_get_template_history(
+    template_id: str,
+    session: Session = Depends(get_session),
+    principal: ApiPrincipal = Depends(get_api_principal),
+) -> list[dict[str, Any]]:
+    from govoplan_approvals.backend.manifest import READ_SCOPE
+
+    _require(principal, READ_SCOPE)
+    try:
+        return [
+            dict(item)
+            for item in SqlApprovalRequests().template_history(
+                session,
+                principal,
+                template_id=template_id,
+            )
+        ]
+    except (ApprovalStoreError, LookupError) as exc:
+        raise _error(exc) from exc
+
+
+@router.get(
+    "/templates/{template_id}/compare",
+    response_model=dict[str, Any],
+)
+def api_compare_template_revisions(
+    template_id: str,
+    from_revision: int = Query(ge=1),
+    to_revision: int = Query(ge=1),
+    session: Session = Depends(get_session),
+    principal: ApiPrincipal = Depends(get_api_principal),
+) -> dict[str, Any]:
+    from govoplan_approvals.backend.manifest import READ_SCOPE
+
+    _require(principal, READ_SCOPE)
+    try:
+        return dict(
+            SqlApprovalRequests().compare_template_revisions(
+                session,
+                principal,
+                template_id=template_id,
+                from_revision=from_revision,
+                to_revision=to_revision,
+            )
+        )
+    except (ApprovalStoreError, LookupError) as exc:
+        raise _error(exc) from exc
+
+
 @router.get("/{request_id}", response_model=dict[str, Any])
 def api_get_request(
     request_id: str,