[history-ot] initial implementation of using doc-level history-ot (#25054)

* [history-v1-ot] initial implementation of using doc-level history-v1-ot

* [web] fix advancing of the otMigrationStage

Use 'nextStage' for the user provided, desired stage when advancing.

Co-authored-by: Brian Gough <brian.gough@overleaf.com>

* [document-updater] document size check in editor-core

* [history-ot] rename history-v1-ot to history-ot and add types

* [history-ot] apply review feedback

- remove extra !!
- merge variable assignment when processing diff-match-match output
- add helper function for getting docstore lines view of StringFileData

Co-authored-by: Alf Eaton <alf.eaton@overleaf.com>

* Revert "[document-updater] add safe rollback point for history-ot (#25283)"

This reverts commit d7230dd14a379a27d2c6ab03a006463a18979d06

Signed-off-by: Jakob Ackermann <jakob.ackermann@overleaf.com>

---------

Signed-off-by: Jakob Ackermann <jakob.ackermann@overleaf.com>
Co-authored-by: Brian Gough <brian.gough@overleaf.com>
Co-authored-by: Alf Eaton <alf.eaton@overleaf.com>
GitOrigin-RevId: 89c497782adb0427635d50d02263d6f535b12481

services/document-updater/app/js/DiffCodec.js

@@ -1,4 +1,5 @@
 const DMP = require('diff-match-patch')
+const { TextOperation } = require('overleaf-editor-core')
 const dmp = new DMP()
 
 // Do not attempt to produce a diff for more than 100ms
@@ -16,8 +17,7 @@ module.exports = {
     const ops = []
     let position = 0
     for (const diff of diffs) {
-      const type = diff[0]
-      const content = diff[1]
+      const [type, content] = diff
       if (type === this.ADDED) {
         ops.push({
           i: content,
@@ -37,4 +37,24 @@ module.exports = {
     }
     return ops
   },
+
+  diffAsHistoryV1EditOperation(before, after) {
+    const diffs = dmp.diff_main(before, after)
+    dmp.diff_cleanupSemantic(diffs)
+
+    const op = new TextOperation()
+    for (const diff of diffs) {
+      const [type, content] = diff
+      if (type === this.ADDED) {
+        op.insert(content)
+      } else if (type === this.REMOVED) {
+        op.remove(content.length)
+      } else if (type === this.UNCHANGED) {
+        op.retain(content.length)
+      } else {
+        throw new Error('Unknown type')
+      }
+    }
+    return op
+  },
 }