Session-Level Conversation History Management (#1113)

packages/cli/src/acp-integration/session/emitters/MessageEmitter.ts

@@ -0,0 +1,67 @@
+/**
+ * @license
+ * Copyright 2025 Qwen
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { BaseEmitter } from './BaseEmitter.js';
+
+/**
+ * Handles emission of text message chunks (user, agent, thought).
+ *
+ * This emitter is responsible for sending message content to the ACP client
+ * in a consistent format, regardless of whether the message comes from
+ * normal flow, history replay, or other sources.
+ */
+export class MessageEmitter extends BaseEmitter {
+  /**
+   * Emits a user message chunk.
+   */
+  async emitUserMessage(text: string): Promise<void> {
+    await this.sendUpdate({
+      sessionUpdate: 'user_message_chunk',
+      content: { type: 'text', text },
+    });
+  }
+
+  /**
+   * Emits an agent message chunk.
+   */
+  async emitAgentMessage(text: string): Promise<void> {
+    await this.sendUpdate({
+      sessionUpdate: 'agent_message_chunk',
+      content: { type: 'text', text },
+    });
+  }
+
+  /**
+   * Emits an agent thought chunk.
+   */
+  async emitAgentThought(text: string): Promise<void> {
+    await this.sendUpdate({
+      sessionUpdate: 'agent_thought_chunk',
+      content: { type: 'text', text },
+    });
+  }
+
+  /**
+   * Emits a message chunk based on role and thought flag.
+   * This is the unified method that handles all message types.
+   *
+   * @param text - The message text content
+   * @param role - Whether this is a user or assistant message
+   * @param isThought - Whether this is an assistant thought (only applies to assistant role)
+   */
+  async emitMessage(
+    text: string,
+    role: 'user' | 'assistant',
+    isThought: boolean = false,
+  ): Promise<void> {
+    if (role === 'user') {
+      return this.emitUserMessage(text);
+    }
+    return isThought
+      ? this.emitAgentThought(text)
+      : this.emitAgentMessage(text);
+  }
+}