From ab944564d8f1622c4ca28060a10cdb13303a1c47 Mon Sep 17 00:00:00 2001
From: Emmie Maeda <emmie.maeda@gmail.com>
Date: Mon, 7 Oct 2024 21:21:44 -0400
Subject: [PATCH] Add check for last revision ID.

---
 deepwell/src/services/file/service.rs | 28 +++++++++++++++++++++++++++
 deepwell/src/services/file/structs.rs |  3 +++
 2 files changed, 31 insertions(+)

diff --git a/deepwell/src/services/file/service.rs b/deepwell/src/services/file/service.rs
index efdbf52818..50decc8b48 100644
--- a/deepwell/src/services/file/service.rs
+++ b/deepwell/src/services/file/service.rs
@@ -110,6 +110,7 @@ impl FileService {
             page_id,
             file_id,
             user_id,
+            last_revision_id,
             revision_comments,
             bypass_filter,
             body,
@@ -121,6 +122,8 @@ impl FileService {
         let last_revision =
             FileRevisionService::get_latest(ctx, site_id, page_id, file_id).await?;
 
+        check_last_revision(&last_revision, last_revision_id)?;
+
         let EditFileBody {
             name,
             licensing,
@@ -203,6 +206,7 @@ impl FileService {
             destination_page_id,
             file_id,
             user_id,
+            last_revision_id,
             revision_comments,
         }: MoveFile,
     ) -> Result<Option<MoveFileOutput>> {
@@ -211,6 +215,8 @@ impl FileService {
             FileRevisionService::get_latest(ctx, site_id, current_page_id, file_id)
                 .await?;
 
+        check_last_revision(&last_revision, last_revision_id)?;
+
         // Get destination filename
         let name = name.unwrap_or_else(|| last_revision.name.clone());
 
@@ -261,6 +267,7 @@ impl FileService {
     pub async fn delete(
         ctx: &ServiceContext<'_>,
         DeleteFile {
+            last_revision_id,
             revision_comments,
             site_id,
             page_id,
@@ -284,6 +291,8 @@ impl FileService {
         let last_revision =
             FileRevisionService::get_latest(ctx, site_id, page_id, file_id).await?;
 
+        check_last_revision(&last_revision, last_revision_id)?;
+
         // Create tombstone revision
         // This outdates the page, etc
         let output = FileRevisionService::create_tombstone(
@@ -567,3 +576,22 @@ impl FileService {
         Ok(())
     }
 }
+
+/// Verifies that the `last_revision_id` argument is the most recent.
+///
+/// See the helper function with the same name in `services/page/service.rs`.
+fn check_last_revision(
+    last_revision_model: &FileRevisionModel,
+    arg_last_revision_id: i64,
+) -> Result<()> {
+    if last_revision_model.revision_id != arg_last_revision_id {
+        error!(
+            "Latest revision ID in file table is {}, but user argument has ID {}",
+            last_revision_model.revision_id, arg_last_revision_id,
+        );
+
+        return Err(Error::NotLatestRevisionId);
+    }
+
+    Ok(())
+}
diff --git a/deepwell/src/services/file/structs.rs b/deepwell/src/services/file/structs.rs
index 8969487426..1913b0f34e 100644
--- a/deepwell/src/services/file/structs.rs
+++ b/deepwell/src/services/file/structs.rs
@@ -85,6 +85,7 @@ pub struct EditFile {
     pub page_id: i64,
     pub file_id: i64,
     pub user_id: i64,
+    pub last_revision_id: i64,
     pub revision_comments: String,
 
     #[serde(flatten)]
@@ -110,6 +111,7 @@ pub struct MoveFile {
     pub site_id: i64,
     pub file_id: i64,
     pub user_id: i64,
+    pub last_revision_id: i64,
     pub name: Option<String>,
     pub current_page_id: i64,
     pub destination_page_id: i64,
@@ -119,6 +121,7 @@ pub type MoveFileOutput = CreateFileRevisionOutput;
 
 #[derive(Deserialize, Debug, Clone)]
 pub struct DeleteFile<'a> {
+    pub last_revision_id: i64,
     pub revision_comments: String,
     pub site_id: i64,
     pub page_id: i64,