add response versioning support in messages for regeneration improvements

src/db/repositories.js

@@ -871,6 +871,10 @@ export function createRepositories(db, config) {
                 if (message.sourceId != null) importedMessageIds.set(message.sourceId, Number(result.lastInsertRowid));
                 if (message.sources) statements.updateChatMessageSources.run(JSON.stringify(message.sources), result.lastInsertRowid, chatId);
                 if (message.thinking) statements.updateChatMessageThinking.run(message.thinking, result.lastInsertRowid, chatId);
+                for (const version of message.responseVersions || []) {
+                    db.prepare("INSERT INTO chat_message_versions (message_id, content, thinking, sources, model_name, created_at) VALUES (?, ?, ?, ?, ?, COALESCE(?, CURRENT_TIMESTAMP))")
+                        .run(result.lastInsertRowid, version.content, version.thinking, JSON.stringify(version.sources), version.modelName, version.createdAt);
+                }
                 for (const [position, attachment] of (message.attachments || []).slice(0, config.uploadMaxFiles || 5).entries()) {
                     // JSON backups contain references, not files. Only restore existing, owned images.
                     db.prepare("INSERT OR IGNORE INTO message_attachments(message_id,attachment_id,position) SELECT ?,id,? FROM attachments WHERE id=? AND username=? AND status='attached'")
@@ -1046,6 +1050,29 @@ export function createRepositories(db, config) {
             username
         ),
         updateChatPreferredModel: (chatId, username, model) => statements.updateChatPreferredModel.run(model || null, chatId, username),
+        listMessageVersions: (messageId) => db.prepare("SELECT * FROM chat_message_versions WHERE message_id = ? ORDER BY id").all(messageId),
+        saveMessageVersion: (chatId, messageId, version = null, selectedIndex = null) => db.transaction(() => {
+            const row = statements.getChatMessageById.get(messageId, chatId);
+            if (!row) throw new Error("Message not found");
+            let versions = db.prepare("SELECT * FROM chat_message_versions WHERE message_id = ? ORDER BY id").all(messageId);
+            const insert = db.prepare("INSERT INTO chat_message_versions (message_id, content, thinking, sources, model_name) VALUES (?, ?, ?, ?, ?)");
+            if (!versions.length) {
+                db.prepare("INSERT INTO chat_message_versions (message_id, content, thinking, sources, model_name, created_at) VALUES (?, ?, ?, ?, ?, ?)")
+                    .run(messageId, row.content, row.thinking, row.sources, row.model_name, row.created_at);
+            } else {
+                // Edits keep their existing semantics: update the selected answer.
+                db.prepare("UPDATE chat_message_versions SET content = ?, thinking = ?, sources = ?, model_name = ? WHERE id = ?")
+                    .run(row.content, row.thinking, row.sources, row.model_name, versions[row.retry_active_index]?.id ?? versions[0].id);
+            }
+            if (version) insert.run(messageId, version.content, version.thinking || null, JSON.stringify(version.sources ?? null), version.modelName);
+            versions = db.prepare("SELECT * FROM chat_message_versions WHERE message_id = ? ORDER BY id").all(messageId);
+            const index = version ? versions.length - 1 : selectedIndex;
+            if (!Number.isInteger(index) || !versions[index]) throw new Error("Version is out of range");
+            const active = versions[index];
+            db.prepare(`UPDATE chat_messages SET content = ?, thinking = ?, sources = ?, model_name = ?,
+                retry_variants = ?, retry_active_index = ?, retry_retries_used = ? WHERE id = ? AND chat_id = ?`)
+                .run(active.content, active.thinking, active.sources, active.model_name, JSON.stringify(versions.map(item => item.content)), index, versions.length - 1, messageId, chatId);
+        })(),
         updateChatMessage: (chatId, messageId, content) => statements.updateChatMessage.run(content, messageId, chatId),
         updateChatMessageRetryState: (chatId, messageId, payload) => statements.updateChatMessageWithRetryState.run(
             payload.content,
@@ -1278,6 +1305,10 @@ export function createRepositories(db, config) {
                     persona_state: this.getPersonaChatState(chat.id, username),
                     messages: this.listChatMessages(chat.id).map((message) => ({
                         ...message,
+                        responseVersions: this.listMessageVersions(message.id).map(version => ({
+                            content: version.content, thinking: version.thinking,
+                            sources: parseJsonArray(version.sources), modelName: version.model_name, createdAt: version.created_at
+                        })),
                         attachments: db.prepare("SELECT a.* FROM attachments a JOIN message_attachments m ON a.id=m.attachment_id WHERE m.message_id=? ORDER BY m.position").all(message.id).map(attachmentMetadata),
                         retryVariants: parseJsonArray(message.retry_variants)
                     }))

src/db/schema.js

@@ -236,6 +236,16 @@ export function initializeSchema(db) {
 }
 
 export function runMigrations(db, {dropLegacyChats = true} = {}) {
+    db.exec(`CREATE TABLE IF NOT EXISTS chat_message_versions (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        message_id INTEGER NOT NULL REFERENCES chat_messages(id) ON DELETE CASCADE,
+        content TEXT NOT NULL,
+        thinking TEXT,
+        sources TEXT,
+        model_name TEXT,
+        created_at DATETIME DEFAULT CURRENT_TIMESTAMP
+    );
+    CREATE INDEX IF NOT EXISTS chat_message_versions_message ON chat_message_versions(message_id);`);
     const ensureColumn = (tableName, columns, name, sql) => {
         if (!columns.some((column) => column.name === name)) {
             db.prepare(sql).run();