From 7c0ba713143884855dca23a91439ed0a594666d1 Mon Sep 17 00:00:00 2001
From: Andrew Pareles <andrewpareles@gmail.com>
Date: Sun, 30 Mar 2025 21:30:01 -0700
Subject: [PATCH] scaffolding for checkpoints

---
 .../contrib/void/browser/chatThreadService.ts | 31 ++++++++++++++-----
 .../void/common/chatThreadServiceTypes.ts     | 15 +++++++++
 2 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/src/vs/workbench/contrib/void/browser/chatThreadService.ts b/src/vs/workbench/contrib/void/browser/chatThreadService.ts
index 65c49a3b..dddd7d18 100644
--- a/src/vs/workbench/contrib/void/browser/chatThreadService.ts
+++ b/src/vs/workbench/contrib/void/browser/chatThreadService.ts
@@ -76,18 +76,19 @@ type ThreadType = {
 	createdAt: string; // ISO string
 	lastModified: string; // ISO string
 	messages: ChatMessage[];
+	currentHistoryIdx: number | null; // index in messages, ALWAYS points to a LLMHistoryEntry or UserHistoryEntry, or -1 if no changes. current code is inclusive of the current index's change
+
+	// this doesn't need to go in a state object, but feels right
 	state: {
 		stagingSelections: StagingSelectionItem[];
-		focusedMessageIdx: number | undefined; // index of the message that is being edited (undefined if none)
+		focusedMessageIdx: number | undefined; // index of the user message that is being edited (undefined if none)
 
 		linksOfMessageIdx: { // eg. link = linksOfMessageIdx[4]['RangeFunction']
 			[messageIdx: number]: {
 				[codespanName: string]: CodespanLocationLink
 			}
 		}
-
-		isCheckedOfSelectionId: { [selectionId: string]: boolean }; // TODO
-	}
+	};
 }
 
 type ChatThreads = {
@@ -97,7 +98,6 @@ type ChatThreads = {
 export const defaultThreadState: ThreadType['state'] = {
 	stagingSelections: [],
 	focusedMessageIdx: undefined,
-	isCheckedOfSelectionId: {},
 	linksOfMessageIdx: {},
 }
 
@@ -130,7 +130,8 @@ const newThreadObject = () => {
 		lastModified: now,
 		messages: [],
 		state: defaultThreadState,
-	} satisfies ChatThreads[string]
+		currentHistoryIdx: null,
+	} satisfies ThreadType
 }
 
 
@@ -943,6 +944,9 @@ class ChatThreadService extends Disposable implements IChatThreadService {
 	}
 
 
+	async callWhenJumpBackToIdx(toIdx: number) {
+		// TODO!!!
+	}
 
 
 
@@ -1251,7 +1255,20 @@ class ChatThreadService extends Disposable implements IChatThreadService {
 				// add the current file as a staging selection
 				const model = this._codeEditorService.getActiveCodeEditor()?.getModel()
 				if (model) {
-					this._setCurrentThreadState({ ...defaultThreadState, stagingSelections: [{ type: 'File', fileURI: model.uri, language: model.getLanguageId(), selectionStr: null, range: null, state: { isOpened: false, wasAddedAsCurrentFile: true } }] })
+					this._setCurrentThreadState({
+						...defaultThreadState,
+						stagingSelections: [{
+							type: 'File',
+							fileURI: model.uri,
+							language: model.getLanguageId(),
+							selectionStr: null,
+							range: null,
+							state: {
+								isOpened: false,
+								wasAddedAsCurrentFile: true
+							}
+						}]
+					})
 				}
 				return;
 			}
diff --git a/src/vs/workbench/contrib/void/common/chatThreadServiceTypes.ts b/src/vs/workbench/contrib/void/common/chatThreadServiceTypes.ts
index c4893d6c..7dfe39e5 100644
--- a/src/vs/workbench/contrib/void/common/chatThreadServiceTypes.ts
+++ b/src/vs/workbench/contrib/void/common/chatThreadServiceTypes.ts
@@ -24,6 +24,18 @@ export type ToolRequestApproval<T extends ToolName> = {
 	id: string; // proposed tool's id
 }
 
+
+// checkpoints
+export type LLMHistoryEntry = { // ALWAYS comes right after a {role:'tool', name:'edit'} message
+	role: 'LLM_changes';
+	afterStrOfURI: { [fsPath: string]: string };
+}
+export type UserHistoryEntry = { // ALWAYS comes right before a {role:'user'} message, or if it's the last message (w/o a user message yet)
+	role: 'user_changes';
+	afterStrOfURI: { [fsPath: string]: string };
+}
+
+
 // WARNING: changing this format is a big deal!!!!!! need to migrate old format to new format on users' computers so people don't get errors.
 export type ChatMessage =
 	| {
@@ -44,6 +56,8 @@ export type ChatMessage =
 	}
 	| ToolMessage<ToolName>
 	| ToolRequestApproval<ToolName>
+	| LLMHistoryEntry // invisible
+	| UserHistoryEntry // invisible
 
 
 // one of the square items that indicates a selection in a chat bubble (NOT a file, a Selection of text)
@@ -75,6 +89,7 @@ export type StagingSelectionItem = CodeSelection | FileSelection
 
 
 
+// a link to a symbol (an underlined link to a piece of code)
 export type CodespanLocationLink = {
 	uri: URI, // we handle serialization for this
 	displayText: string,