feat: add database support, conversation sidebar, and improve chat streaming

- Update .gitignore to exclude database files, extensions, and .cursor directory
- Enhance chat streaming API with safe enqueue and close functions to prevent errors
- Integrate ConversationSidebar component into ClientHome for better UI
- Add dependencies like better-sqlite3 and esbuild packages for database functionality

This commit introduces database persistence for conversations, improves error handling in streaming responses, and adds a sidebar for managing chats, enhancing overall app robustness and user experience.

app/api/conversations/[id]/messages/route.ts

@@ -0,0 +1,68 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getDatabase } from "@/database/client";
+import { MessageRepository } from "@/database/repositories/message";
+import { ConversationRepository } from "@/database/repositories/conversation";
+import { addMessageEmbedding } from "@/lib/vector-search";
+
+export async function GET(
+  request: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const { id } = await params;
+    const db = getDatabase();
+    const messageRepo = new MessageRepository(db);
+
+    const messages = messageRepo.findByConversation(id);
+
+    return NextResponse.json(messages);
+  } catch (error) {
+    console.error("Erro ao buscar mensagens:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function POST(
+  request: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const { id } = await params;
+    const { role, content } = await request.json();
+
+    if (!role || !content) {
+      return NextResponse.json(
+        { error: "Role e content são obrigatórios" },
+        { status: 400 }
+      );
+    }
+
+    const db = getDatabase();
+    const messageRepo = new MessageRepository(db);
+    const conversationRepo = new ConversationRepository(db);
+
+    // Criar mensagem
+    const messageId = messageRepo.create(id, role, content);
+
+    // Atualizar timestamp da conversa
+    conversationRepo.updateTimestamp(id);
+
+    // Gerar embedding em background (apenas para mensagens do usuário e assistente)
+    if (role === "user" || role === "assistant") {
+      addMessageEmbedding(messageId, content).catch((error) => {
+        console.error("Erro ao gerar embedding:", error);
+      });
+    }
+
+    return NextResponse.json({ id: messageId });
+  } catch (error) {
+    console.error("Erro ao criar mensagem:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}

app/api/conversations/[id]/route.ts

@@ -0,0 +1,58 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getDatabase } from "@/database/client";
+import { ConversationRepository } from "@/database/repositories/conversation";
+import { MessageRepository } from "@/database/repositories/message";
+
+export async function GET(
+  request: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const { id } = await params;
+    const db = getDatabase();
+    const conversationRepo = new ConversationRepository(db);
+    const messageRepo = new MessageRepository(db);
+
+    const conversation = conversationRepo.findById(id);
+    if (!conversation) {
+      return NextResponse.json(
+        { error: "Conversa não encontrada" },
+        { status: 404 }
+      );
+    }
+
+    const messages = messageRepo.findByConversation(id);
+
+    return NextResponse.json({
+      conversation,
+      messages,
+    });
+  } catch (error) {
+    console.error("Erro ao buscar conversa:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function DELETE(
+  request: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const { id } = await params;
+    const db = getDatabase();
+    const conversationRepo = new ConversationRepository(db);
+
+    conversationRepo.delete(id);
+
+    return NextResponse.json({ success: true });
+  } catch (error) {
+    console.error("Erro ao deletar conversa:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}

app/api/conversations/route.ts

@@ -0,0 +1,54 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getDatabase } from "@/database/client";
+import { ConversationRepository } from "@/database/repositories/conversation";
+import { MessageRepository } from "@/database/repositories/message";
+import { generateChatTitle } from "@/lib/embeddings";
+
+export async function GET() {
+  try {
+    const db = getDatabase();
+    const conversationRepo = new ConversationRepository(db);
+
+    const conversations = conversationRepo.findAll();
+
+    return NextResponse.json(conversations);
+  } catch (error) {
+    console.error("Erro ao buscar conversas:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}
+
+export async function POST(request: NextRequest) {
+  try {
+    const { model, firstMessage } = await request.json();
+
+    if (!model) {
+      return NextResponse.json(
+        { error: "Modelo é obrigatório" },
+        { status: 400 }
+      );
+    }
+
+    const db = getDatabase();
+    const conversationRepo = new ConversationRepository(db);
+
+    // Gerar título se primeira mensagem fornecida
+    let title = "Nova conversa";
+    if (firstMessage) {
+      title = await generateChatTitle(firstMessage);
+    }
+
+    const conversationId = conversationRepo.create(model, title);
+
+    return NextResponse.json({ id: conversationId, title });
+  } catch (error) {
+    console.error("Erro ao criar conversa:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}

app/api/ollama/chat/route.ts

@@ -14,6 +14,30 @@ export async function POST(req: NextRequest) {
 
     const stream = new ReadableStream({
       async start(controller) {
+        let isClosed = false;
+
+        const safeEnqueue = (data: string) => {
+          if (!isClosed) {
+            try {
+              controller.enqueue(new TextEncoder().encode(data));
+            } catch (error) {
+              console.error("Error enqueuing data:", error);
+              isClosed = true;
+            }
+          }
+        };
+
+        const safeClose = () => {
+          if (!isClosed) {
+            try {
+              controller.close();
+              isClosed = true;
+            } catch (error) {
+              console.error("Error closing controller:", error);
+            }
+          }
+        };
+
         try {
           const ollamaMessages = convertToOllamaMessages(messages);
           const response = await chatWithStream(
@@ -26,24 +50,18 @@ export async function POST(req: NextRequest) {
           for await (const chunk of response) {
             const token = chunk.message?.content || "";
             if (token) {
-              controller.enqueue(
-                new TextEncoder().encode(JSON.stringify({ token }) + "\n")
-              );
+              safeEnqueue(JSON.stringify({ token }) + "\n");
             }
           }
 
-          controller.enqueue(
-            new TextEncoder().encode(JSON.stringify({ done: true }) + "\n")
-          );
-          controller.close();
+          safeEnqueue(JSON.stringify({ done: true }) + "\n");
+          safeClose();
         } catch (error) {
           console.error("Chat streaming error:", error);
-          controller.enqueue(
-            new TextEncoder().encode(
-              JSON.stringify({ error: "Failed to generate response" }) + "\n"
-            )
+          safeEnqueue(
+            JSON.stringify({ error: "Failed to generate response" }) + "\n"
           );
-          controller.close();
+          safeClose();
         }
       },
     });

app/api/preferences/route.ts

@@ -0,0 +1,42 @@
+import { NextRequest, NextResponse } from "next/server";
+import { getPreferences, setPreferences } from "@/lib/preferences";
+
+// Estrutura de preferências
+type UserPreferences = {
+  selectedModel: string | null;
+  systemPrompt: string;
+  device: "auto" | "cpu" | "gpu";
+  gpuIndex: number;
+  numGpu: number;
+};
+
+// GET - Buscar preferências
+export async function GET(request: NextRequest) {
+  try {
+    const userId = "default"; // Pode ser expandido para multi-usuário
+    const prefs = await getPreferences(userId);
+    return NextResponse.json(prefs);
+  } catch (error) {
+    console.error("Erro ao buscar preferências:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}
+
+// POST - Salvar preferências
+export async function POST(request: NextRequest) {
+  try {
+    const userId = "default";
+    const prefs = await request.json();
+    await setPreferences(userId, prefs);
+    return NextResponse.json({ success: true });
+  } catch (error) {
+    console.error("Erro ao salvar preferências:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}

app/api/search/route.ts

@@ -0,0 +1,25 @@
+import { NextRequest, NextResponse } from "next/server";
+import { semanticSearch } from "@/lib/vector-search";
+
+export async function POST(request: NextRequest) {
+  try {
+    const { query, limit = 5 } = await request.json();
+
+    if (!query) {
+      return NextResponse.json(
+        { error: "Query é obrigatória" },
+        { status: 400 }
+      );
+    }
+
+    const results = await semanticSearch(query, limit);
+
+    return NextResponse.json(results);
+  } catch (error) {
+    console.error("Erro na busca semântica:", error);
+    return NextResponse.json(
+      { error: "Erro interno do servidor" },
+      { status: 500 }
+    );
+  }
+}