Add support for message history pagination, preserve scroll in rendering, and improve draft/message workflows.

src/db/chatRepository.js

@@ -0,0 +1,559 @@
+export function createChatStatements(db) {
+    return {
+        insertChatSession: db.prepare(
+            "INSERT INTO chat_sessions (username, title, assistant_persona_id, user_persona_id, folder_name, is_pinned, archived_at, scenario_prompt, scenario_summary) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)"
+        ),
+        listChatSessions: db.prepare(`
+            SELECT cs.id,
+                   CASE
+                       WHEN cs.assistant_persona_id IS NOT NULL AND cs.source_chat_id IS NULL THEN COALESCE(p.name, cs.title)
+                       ELSE cs.title
+                       END AS title,
+                   cs.title AS stored_title,
+                   cs.assistant_persona_id,
+                   p.name AS assistant_persona_name,
+                   cs.user_persona_id,
+                   up.name AS user_persona_name,
+                   cs.folder_name,
+                   cs.is_pinned,
+                   cs.archived_at,
+                   cs.scenario_prompt,
+                   cs.scenario_summary,
+                   cs.context_summary,
+                   cs.context_summary_message_id,
+                   cs.active_leaf_message_id,
+                   cs.source_chat_id,
+                   cs.branched_from_message_id,
+                   cs.preferred_model,
+                   cs.temperature,
+                   cs.context_length,
+                   cs.response_length,
+                   cs.system_instruction,
+                   cs.created_at,
+                   cs.updated_at
+            FROM chat_sessions cs
+                     LEFT JOIN personas p ON p.id = cs.assistant_persona_id
+                     LEFT JOIN personas up ON up.id = cs.user_persona_id
+            WHERE cs.username = ?
+            ORDER BY cs.is_pinned DESC, datetime(cs.updated_at) DESC
+        `),
+        countChatSessions: db.prepare("SELECT COUNT(*) as count FROM chat_sessions WHERE username = ? AND archived_at IS NULL"),
+        getChatSession: db.prepare(`
+            SELECT cs.id,
+                   CASE
+                       WHEN cs.assistant_persona_id IS NOT NULL AND cs.source_chat_id IS NULL THEN COALESCE(p.name, cs.title)
+                       ELSE cs.title
+                       END AS title,
+                   cs.title AS stored_title,
+                   cs.assistant_persona_id,
+                   p.name AS assistant_persona_name,
+                   cs.user_persona_id,
+                   up.name AS user_persona_name,
+                   cs.folder_name,
+                   cs.is_pinned,
+                   cs.archived_at,
+                   cs.scenario_prompt,
+                   cs.scenario_summary,
+                   cs.context_summary,
+                   cs.context_summary_message_id,
+                   cs.active_leaf_message_id,
+                   cs.source_chat_id,
+                   cs.branched_from_message_id,
+                   cs.preferred_model,
+                   cs.temperature,
+                   cs.context_length,
+                   cs.response_length,
+                   cs.system_instruction,
+                   cs.created_at,
+                   cs.updated_at
+            FROM chat_sessions cs
+                     LEFT JOIN personas p ON p.id = cs.assistant_persona_id
+                     LEFT JOIN personas up ON up.id = cs.user_persona_id
+            WHERE cs.id = ?
+              AND cs.username = ?
+        `),
+        getChatSessionByParticipants: db.prepare(`
+            SELECT cs.id,
+                   CASE
+                       WHEN cs.assistant_persona_id IS NOT NULL AND cs.source_chat_id IS NULL THEN COALESCE(p.name, cs.title)
+                       ELSE cs.title
+                       END AS title,
+                   cs.title AS stored_title,
+                   cs.assistant_persona_id,
+                   p.name AS assistant_persona_name,
+                   cs.user_persona_id,
+                   up.name AS user_persona_name,
+                   cs.folder_name,
+                   cs.is_pinned,
+                   cs.archived_at,
+                   cs.scenario_prompt,
+                   cs.scenario_summary,
+                   cs.context_summary,
+                   cs.context_summary_message_id,
+                   cs.active_leaf_message_id,
+                   cs.source_chat_id,
+                   cs.branched_from_message_id,
+                   cs.preferred_model,
+                   cs.temperature,
+                   cs.context_length,
+                   cs.response_length,
+                   cs.system_instruction,
+                   cs.created_at,
+                   cs.updated_at
+            FROM chat_sessions cs
+                     LEFT JOIN personas p ON p.id = cs.assistant_persona_id
+                     LEFT JOIN personas up ON up.id = cs.user_persona_id
+            WHERE cs.username = ?
+              AND cs.assistant_persona_id = ?
+              AND ((cs.user_persona_id IS NULL AND ? IS NULL) OR cs.user_persona_id = ?)
+              AND cs.source_chat_id IS NULL
+            ORDER BY cs.is_pinned DESC, datetime(cs.updated_at) DESC
+            LIMIT 1
+        `),
+        updateChatSessionTitle: db.prepare("UPDATE chat_sessions SET title = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
+        updateChatSessionScene: db.prepare("UPDATE chat_sessions SET scenario_prompt = ?, scenario_summary = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
+        updateChatContextSummary: db.prepare("UPDATE chat_sessions SET context_summary = ?, context_summary_message_id = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
+        updateChatGenerationSettings: db.prepare(`
+            UPDATE chat_sessions
+            SET preferred_model = ?, temperature = ?, context_length = ?, response_length = ?, system_instruction = ?, updated_at = CURRENT_TIMESTAMP
+            WHERE id = ? AND username = ?
+        `),
+        updateChatPreferredModel: db.prepare("UPDATE chat_sessions SET preferred_model = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
+        updateChatActiveLeaf: db.prepare("UPDATE chat_sessions SET active_leaf_message_id = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
+        updateChatBranchSource: db.prepare("UPDATE chat_sessions SET source_chat_id = ?, branched_from_message_id = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
+        setChatActiveLeafById: db.prepare("UPDATE chat_sessions SET active_leaf_message_id = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?"),
+        updateChatSessionOrganization: db.prepare(`
+            UPDATE chat_sessions
+            SET folder_name = ?,
+                is_pinned = ?,
+                archived_at = ?,
+                updated_at = CURRENT_TIMESTAMP
+            WHERE id = ?
+              AND username = ?
+        `),
+        touchChatSession: db.prepare("UPDATE chat_sessions SET updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
+        deleteChatSession: db.prepare("DELETE FROM chat_sessions WHERE id = ? AND username = ?"),
+        insertChatMessage: db.prepare("INSERT INTO chat_messages (chat_id, role, content, model_name, retry_variants, retry_active_index, retry_retries_used, retry_prompt_message_id, delivery_status, error_message, parent_message_id) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)"),
+        updateChatMessageDelivery: db.prepare("UPDATE chat_messages SET delivery_status = ?, error_message = ? WHERE id = ? AND chat_id = ?"),
+        updateChatMessageSources: db.prepare("UPDATE chat_messages SET sources = ? WHERE id = ? AND chat_id = ?"),
+        updateChatMessageThinking: db.prepare("UPDATE chat_messages SET thinking = ? WHERE id = ? AND chat_id = ?"),
+        getChatMessages: db.prepare(`
+            SELECT thinking, sources, id, role, content, model_name, retry_variants, retry_active_index, retry_retries_used, retry_prompt_message_id, delivery_status, error_message, parent_message_id, created_at
+            FROM chat_messages
+            WHERE chat_id = ?
+            ORDER BY id
+        `),
+        getRecentChatMessages: db.prepare(`
+            WITH RECURSIVE branch AS (
+                SELECT cm.* FROM chat_messages cm
+                JOIN chat_sessions cs ON cs.id = cm.chat_id
+                WHERE cm.chat_id = ?
+                  AND cm.id = COALESCE(cs.active_leaf_message_id, (SELECT MAX(id) FROM chat_messages WHERE chat_id = cm.chat_id))
+                UNION ALL
+                SELECT parent.* FROM chat_messages parent
+                JOIN branch child ON child.parent_message_id = parent.id
+            )
+            SELECT id, role, content FROM branch
+            WHERE delivery_status != 'failed'
+            ORDER BY id DESC
+            LIMIT ?
+        `),
+        getRecentChatMessagesUpToId: db.prepare(`
+            WITH RECURSIVE branch AS (
+                SELECT * FROM chat_messages WHERE chat_id = ? AND id = ?
+                UNION ALL
+                SELECT parent.* FROM chat_messages parent
+                JOIN branch child ON child.parent_message_id = parent.id
+            )
+            SELECT id, role, content FROM branch
+            WHERE delivery_status != 'failed'
+            ORDER BY id DESC
+            LIMIT ?
+        `),
+        getChatBranchThroughMessage: db.prepare(`
+            WITH RECURSIVE branch AS (
+                SELECT * FROM chat_messages WHERE chat_id = ? AND id = ?
+                UNION ALL
+                SELECT parent.* FROM chat_messages parent
+                JOIN branch child ON child.parent_message_id = parent.id
+            )
+            SELECT id, role, content, model_name, retry_variants, retry_active_index, retry_retries_used,
+                   retry_prompt_message_id, delivery_status, error_message, parent_message_id, created_at, sources, thinking
+            FROM branch
+            WHERE delivery_status = 'complete'
+            ORDER BY id
+        `),
+        getActiveBranchMessages: db.prepare(`
+            WITH RECURSIVE branch AS (
+                SELECT cm.* FROM chat_messages cm
+                JOIN chat_sessions cs ON cs.id = cm.chat_id
+                WHERE cm.chat_id = ?
+                  AND cm.id = COALESCE(cs.active_leaf_message_id, (SELECT MAX(id) FROM chat_messages WHERE chat_id = cm.chat_id))
+                UNION ALL
+                SELECT parent.* FROM chat_messages parent
+                JOIN branch child ON child.parent_message_id = parent.id
+            )
+            SELECT id, role, content, model_name, retry_variants, retry_active_index, retry_retries_used,
+                   retry_prompt_message_id, delivery_status, error_message, parent_message_id, created_at, sources, thinking
+            FROM branch ORDER BY id
+        `),
+        getSiblingChatMessages: db.prepare(`
+            SELECT id, role, content, parent_message_id
+            FROM chat_messages
+            WHERE chat_id = ? AND role = ? AND parent_message_id IS ?
+            ORDER BY id
+        `),
+        getLatestDescendantMessage: db.prepare(`
+            WITH RECURSIVE descendants AS (
+                SELECT id FROM chat_messages WHERE chat_id = ? AND id = ?
+                UNION ALL
+                SELECT child.id FROM chat_messages child JOIN descendants parent ON child.parent_message_id = parent.id
+                WHERE child.chat_id = ? AND child.delivery_status != 'failed'
+            )
+            SELECT cm.* FROM chat_messages cm JOIN descendants d ON d.id = cm.id ORDER BY cm.id DESC LIMIT 1
+        `),
+        getChatMessageById: db.prepare(`
+            SELECT thinking, sources, id, role, content, model_name, retry_variants, retry_active_index, retry_retries_used, retry_prompt_message_id, delivery_status, error_message, parent_message_id, created_at
+            FROM chat_messages
+            WHERE id = ?
+              AND chat_id = ?
+        `),
+        getChatMessageByIndex: db.prepare(`
+            SELECT thinking, sources, id, role, content, model_name, retry_variants, retry_active_index, retry_retries_used, retry_prompt_message_id, delivery_status, error_message, parent_message_id, created_at
+            FROM chat_messages
+            WHERE chat_id = ?
+            ORDER BY id
+            LIMIT 1 OFFSET ?
+        `),
+        getLatestChatMessage: db.prepare(`
+            SELECT id, role, content, model_name, retry_variants, retry_active_index, retry_retries_used, retry_prompt_message_id, delivery_status, error_message, parent_message_id, created_at
+            FROM chat_messages
+            WHERE chat_id = ?
+            ORDER BY id DESC
+            LIMIT 1
+        `),
+        getPreviousUserMessage: db.prepare(`
+            SELECT id, role, content, model_name, retry_variants, retry_active_index, retry_retries_used, retry_prompt_message_id, delivery_status, error_message, parent_message_id, created_at
+            FROM chat_messages
+            WHERE chat_id = ?
+              AND role = 'user'
+              AND id < ?
+            ORDER BY id DESC
+            LIMIT 1
+        `),
+        listChatMemories: db.prepare(`
+            SELECT id, username, chat_id, assistant_persona_id, user_persona_id, fact, created_at, updated_at
+            FROM chat_memories
+            WHERE chat_id = ?
+              AND username = ?
+            ORDER BY datetime(updated_at) DESC, id DESC
+        `),
+        getChatMemory: db.prepare(`
+            SELECT id, username, chat_id, assistant_persona_id, user_persona_id, fact, created_at, updated_at
+            FROM chat_memories
+            WHERE id = ?
+              AND chat_id = ?
+              AND username = ?
+        `),
+        insertChatMemory: db.prepare(`
+            INSERT INTO chat_memories (username, chat_id, assistant_persona_id, user_persona_id, fact)
+            VALUES (?, ?, ?, ?, ?)
+        `),
+        updateChatMemory: db.prepare(`
+            UPDATE chat_memories
+            SET fact = ?,
+                updated_at = CURRENT_TIMESTAMP
+            WHERE id = ?
+              AND chat_id = ?
+              AND username = ?
+        `),
+        deleteChatMemory: db.prepare("DELETE FROM chat_memories WHERE id = ? AND chat_id = ? AND username = ?"),
+        getPersonaChatState: db.prepare(`
+            SELECT id,
+                   username,
+                   chat_id,
+                   assistant_persona_id,
+                   user_persona_id,
+                   relationship_notes,
+                   tone,
+                   current_location,
+                   goals,
+                   unresolved_threads,
+                   boundaries,
+                   created_at,
+                   updated_at
+            FROM persona_chat_state
+            WHERE chat_id = ?
+              AND username = ?
+        `),
+        upsertPersonaChatState: db.prepare(`
+            INSERT INTO persona_chat_state (
+                username,
+                chat_id,
+                assistant_persona_id,
+                user_persona_id,
+                relationship_notes,
+                tone,
+                current_location,
+                goals,
+                unresolved_threads,
+                boundaries
+            )
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+            ON CONFLICT(chat_id) DO UPDATE SET
+                username = excluded.username,
+                assistant_persona_id = excluded.assistant_persona_id,
+                user_persona_id = excluded.user_persona_id,
+                relationship_notes = excluded.relationship_notes,
+                tone = excluded.tone,
+                current_location = excluded.current_location,
+                goals = excluded.goals,
+                unresolved_threads = excluded.unresolved_threads,
+                boundaries = excluded.boundaries,
+                updated_at = CURRENT_TIMESTAMP
+        `),
+        updateChatMessage: db.prepare("UPDATE chat_messages SET content = ? WHERE id = ? AND chat_id = ?"),
+        updateChatMessageWithRetryState: db.prepare("UPDATE chat_messages SET content = ?, retry_variants = ?, retry_active_index = ?, retry_retries_used = ?, retry_prompt_message_id = ? WHERE id = ? AND chat_id = ?"),
+        deleteChatMessage: db.prepare("DELETE FROM chat_messages WHERE id = ? AND chat_id = ?"),
+        deleteChatMessages: db.prepare("DELETE FROM chat_messages WHERE chat_id = ?"),
+        searchChats: db.prepare(`
+            SELECT cs.id,
+                            CASE
+                                WHEN cs.assistant_persona_id IS NOT NULL AND cs.source_chat_id IS NULL THEN COALESCE(p.name, cs.title)
+                                ELSE cs.title
+                                END AS title,
+                            cs.title AS stored_title,
+                            cs.assistant_persona_id,
+                            p.name AS assistant_persona_name,
+                            cs.user_persona_id,
+                            up.name AS user_persona_name,
+                            cs.folder_name,
+                            cs.is_pinned,
+                            cs.archived_at,
+                            cs.scenario_prompt,
+                            cs.scenario_summary,
+                            cs.context_summary,
+                            cs.context_summary_message_id,
+                            cs.active_leaf_message_id,
+                            cs.source_chat_id,
+                            cs.branched_from_message_id,
+                            cs.preferred_model,
+                            cs.temperature,
+                            cs.context_length,
+                            cs.response_length,
+                            cs.system_instruction,
+                            cs.created_at,
+                            cs.updated_at,
+                            cm.id AS matched_message_id,
+                            cm.content AS matched_content
+            FROM chat_sessions cs
+                     LEFT JOIN personas p ON p.id = cs.assistant_persona_id
+                     LEFT JOIN personas up ON up.id = cs.user_persona_id
+                     LEFT JOIN chat_messages cm ON cm.id = (
+                         SELECT m.id FROM chat_messages m
+                         WHERE m.chat_id = cs.id AND LOWER(m.content) LIKE ?
+                         ORDER BY m.id DESC LIMIT 1
+                     )
+            WHERE cs.username = ?
+              AND (
+                LOWER(CASE
+                          WHEN cs.assistant_persona_id IS NOT NULL AND cs.source_chat_id IS NULL THEN COALESCE(p.name, cs.title)
+                          ELSE cs.title
+                    END) LIKE ?
+                    OR cm.id IS NOT NULL
+              )
+            ORDER BY cs.is_pinned DESC, datetime(cs.updated_at) DESC
+        `)
+    };
+}
+
+export function createChatRepository(db, config, statements) {
+    const completeChatTurnTransaction = db.transaction((chatId, userMessageId, assistantContent, retryState, modelName, sources, thinking) => {
+        const assistantResult = statements.insertChatMessage.run(
+            chatId,
+            "bot",
+            String(assistantContent || ""),
+            modelName || null,
+            JSON.stringify(retryState.retryVariants),
+            retryState.retryActiveIndex,
+            retryState.retryRetriesUsed,
+            retryState.retryPromptMessageId ?? null,
+            "complete",
+            null,
+            userMessageId
+        );
+        statements.updateChatMessageDelivery.run("complete", null, userMessageId, chatId);
+        if (sources) statements.updateChatMessageSources.run(JSON.stringify(sources), assistantResult.lastInsertRowid, chatId);
+        if (thinking) statements.updateChatMessageThinking.run(thinking, assistantResult.lastInsertRowid, chatId);
+        statements.setChatActiveLeafById.run(assistantResult.lastInsertRowid, chatId);
+        return assistantResult;
+    });
+
+const insertBranchChatMessageTransaction = db.transaction((chatId, role, content, retryState, modelName, deliveryStatus, errorMessage, parentMessageId) => {
+        const result = statements.insertChatMessage.run(
+            chatId, role, String(content || ""), modelName || null,
+            retryState ? JSON.stringify(retryState.retryVariants) : null,
+            retryState?.retryActiveIndex ?? 0,
+            retryState?.retryRetriesUsed ?? 0,
+            retryState?.retryPromptMessageId ?? null,
+            deliveryStatus,
+            errorMessage,
+            parentMessageId ?? null
+        );
+        statements.setChatActiveLeafById.run(result.lastInsertRowid, chatId);
+        return result;
+    });
+
+const failChatTurnTransaction = db.transaction((chatId, userMessageId, errorMessage, parentMessageId) => {
+        statements.updateChatMessageDelivery.run("failed", errorMessage, userMessageId, chatId);
+        statements.setChatActiveLeafById.run(parentMessageId ?? null, chatId);
+    });
+    return {
+        listChats: (username) => statements.listChatSessions.all(username),
+        searchChats(username, query) {
+            const like = `%${String(query || "").trim().toLowerCase()}%`;
+            return statements.searchChats.all(like, username, like);
+        },
+        countChats: (username) => statements.countChatSessions.get(username).count,
+        getChat: (chatId, username) => statements.getChatSession.get(chatId, username),
+        getChatByParticipants: (username, assistantPersonaId, userPersonaId) => statements.getChatSessionByParticipants.get(username, assistantPersonaId, userPersonaId, userPersonaId),
+        createChat(username, title, assistantPersonaId = null, userPersonaId = null, scenarioPrompt = null, scenarioSummary = null, organization = {}) {
+            const chatId = statements.insertChatSession.run(
+                username,
+                title,
+                assistantPersonaId,
+                userPersonaId,
+                organization.folderName ?? null,
+                organization.isPinned ? 1 : 0,
+                organization.archivedAt ?? null,
+                scenarioPrompt,
+                scenarioSummary
+            ).lastInsertRowid;
+            return statements.getChatSession.get(chatId, username);
+        },
+        updateChatTitle: (chatId, username, title) => statements.updateChatSessionTitle.run(title, chatId, username),
+        updateChatScene: (chatId, username, scenarioPrompt, scenarioSummary) => statements.updateChatSessionScene.run(scenarioPrompt, scenarioSummary, chatId, username),
+        updateChatContextSummary: (chatId, username, summary, messageId) => statements.updateChatContextSummary.run(summary, Number(messageId || 0), chatId, username),
+        getPersonaChatState: (chatId, username) => statements.getPersonaChatState.get(chatId, username) || null,
+        updatePersonaChatState(username, chat, state) {
+            statements.upsertPersonaChatState.run(
+                username,
+                chat.id,
+                chat.assistant_persona_id ?? null,
+                chat.user_persona_id ?? null,
+                state.relationship_notes ?? null,
+                state.tone ?? null,
+                state.current_location ?? null,
+                state.goals ?? null,
+                state.unresolved_threads ?? null,
+                state.boundaries ?? null
+            );
+            return statements.getPersonaChatState.get(chat.id, username);
+        },
+        updateChatOrganization(chatId, username, {folderName = null, isPinned = false, archivedAt = null}) {
+            return statements.updateChatSessionOrganization.run(folderName, isPinned ? 1 : 0, archivedAt, chatId, username);
+        },
+        touchChat: (chatId, username) => statements.touchChatSession.run(chatId, username),
+        deleteChat: (chatId, username) => statements.deleteChatSession.run(chatId, username),
+        listChatMessages: (chatId) => statements.getChatMessages.all(chatId),
+        listActiveBranchMessages: (chatId) => statements.getActiveBranchMessages.all(chatId),
+        listChatBranchThroughMessage: (chatId, messageId) => statements.getChatBranchThroughMessage.all(chatId, messageId),
+        listSiblingChatMessages: (chatId, role, parentMessageId) => statements.getSiblingChatMessages.all(chatId, role, parentMessageId ?? null),
+        getLatestDescendantMessage: (chatId, messageId) => statements.getLatestDescendantMessage.get(chatId, messageId, chatId),
+        getRecentChatMessages: (chatId) => statements.getRecentChatMessages.all(chatId, config.chatHistoryLimit),
+        getRecentChatMessagesUpToId: (chatId, messageId) => statements.getRecentChatMessagesUpToId.all(chatId, messageId, config.chatHistoryLimit),
+        getChatMessage: (chatId, messageId) => statements.getChatMessageById.get(messageId, chatId),
+        getChatMessageByIndex: (chatId, index) => statements.getChatMessageByIndex.get(chatId, index),
+        getLatestChatMessage: (chatId) => statements.getLatestChatMessage.get(chatId),
+        getPreviousUserMessage: (chatId, messageId) => statements.getPreviousUserMessage.get(chatId, messageId),
+        listChatMemories: (chatId, username) => statements.listChatMemories.all(chatId, username),
+        getChatMemory: (chatId, memoryId, username) => statements.getChatMemory.get(memoryId, chatId, username),
+        createChatMemory(username, chat, fact) {
+            const result = statements.insertChatMemory.run(
+                username,
+                chat.id,
+                chat.assistant_persona_id ?? null,
+                chat.user_persona_id ?? null,
+                String(fact || "").trim()
+            );
+            return statements.getChatMemory.get(result.lastInsertRowid, chat.id, username);
+        },
+        updateChatMemory: (chatId, memoryId, username, fact) => statements.updateChatMemory.run(String(fact || "").trim(), memoryId, chatId, username),
+        deleteChatMemory: (chatId, memoryId, username) => statements.deleteChatMemory.run(memoryId, chatId, username),
+        insertChatMessage(chatId, role, content, retryState = null, modelName = null, deliveryStatus = "complete", errorMessage = null, parentMessageId = null) {
+            return statements.insertChatMessage.run(
+                chatId,
+                role,
+                String(content || ""),
+                modelName || null,
+                retryState ? JSON.stringify(retryState.retryVariants) : null,
+                retryState?.retryActiveIndex ?? 0,
+                retryState?.retryRetriesUsed ?? 0,
+                retryState?.retryPromptMessageId ?? null,
+                deliveryStatus,
+                errorMessage,
+                parentMessageId
+            );
+        },
+        insertBranchChatMessage: (chatId, role, content, retryState = null, modelName = null, deliveryStatus = "complete", errorMessage = null, parentMessageId = null) =>
+            insertBranchChatMessageTransaction(chatId, role, content, retryState, modelName, deliveryStatus, errorMessage, parentMessageId),
+        updateChatMessageDelivery: (chatId, messageId, deliveryStatus, errorMessage = null) =>
+            statements.updateChatMessageDelivery.run(deliveryStatus, errorMessage, messageId, chatId),
+        completeChatTurn: (chatId, userMessageId, assistantContent, retryState, modelName = null, sources = null, thinking = null) =>
+            completeChatTurnTransaction(chatId, userMessageId, assistantContent, retryState, modelName, sources, thinking),
+        updateChatMessageThinking: (chatId, messageId, thinking) =>
+            statements.updateChatMessageThinking.run(thinking, messageId, chatId),
+        updateChatMessageSources: (chatId, messageId, sources) =>
+            statements.updateChatMessageSources.run(JSON.stringify(sources), messageId, chatId),
+        failChatTurn: (chatId, userMessageId, errorMessage, parentMessageId = null) =>
+            failChatTurnTransaction(chatId, userMessageId, errorMessage, parentMessageId),
+        updateChatActiveLeaf: (chatId, username, messageId) => statements.updateChatActiveLeaf.run(messageId, chatId, username),
+        updateChatBranchSource: (chatId, username, sourceChatId, messageId) =>
+            statements.updateChatBranchSource.run(sourceChatId, messageId ?? null, chatId, username),
+        updateChatGenerationSettings: (chatId, username, settings) => statements.updateChatGenerationSettings.run(
+            settings.preferredModel ?? null,
+            settings.temperature ?? null,
+            settings.contextLength ?? null,
+            settings.responseLength ?? null,
+            settings.systemInstruction ?? null,
+            chatId,
+            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,
+            JSON.stringify(payload.retryVariants),
+            payload.retryActiveIndex,
+            payload.retryRetriesUsed,
+            payload.retryPromptMessageId ?? null,
+            messageId,
+            chatId
+        ),
+        deleteChatMessage: (chatId, messageId) => statements.deleteChatMessage.run(messageId, chatId),
+        clearChatMessages: (chatId) => statements.deleteChatMessages.run(chatId)
+    };
+}