refactor: Optimize the display information of "/chat list" and "/chat resume" (#2857)

Co-authored-by: Ben Guo <hundunben@gmail.com>

packages/cli/src/ui/commands/chatCommand.ts

@@ -0,0 +1,197 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fsPromises from 'fs/promises';
+import { CommandContext, SlashCommand, MessageActionReturn } from './types.js';
+import path from 'path';
+import { HistoryItemWithoutId, MessageType } from '../types.js';
+
+interface ChatDetail {
+  name: string;
+  mtime: Date;
+}
+
+const getSavedChatTags = async (
+  context: CommandContext,
+  mtSortDesc: boolean,
+): Promise<ChatDetail[]> => {
+  const geminiDir = context.services.config?.getProjectTempDir();
+  if (!geminiDir) {
+    return [];
+  }
+  try {
+    const file_head = 'checkpoint-';
+    const file_tail = '.json';
+    const files = await fsPromises.readdir(geminiDir);
+    const chatDetails: Array<{ name: string; mtime: Date }> = [];
+
+    for (const file of files) {
+      if (file.startsWith(file_head) && file.endsWith(file_tail)) {
+        const filePath = path.join(geminiDir, file);
+        const stats = await fsPromises.stat(filePath);
+        chatDetails.push({
+          name: file.slice(file_head.length, -file_tail.length),
+          mtime: stats.mtime,
+        });
+      }
+    }
+
+    chatDetails.sort((a, b) =>
+      mtSortDesc
+        ? b.mtime.getTime() - a.mtime.getTime()
+        : a.mtime.getTime() - b.mtime.getTime(),
+    );
+
+    return chatDetails;
+  } catch (_err) {
+    return [];
+  }
+};
+
+const listCommand: SlashCommand = {
+  name: 'list',
+  description: 'List saved conversation checkpoints',
+  action: async (context): Promise<MessageActionReturn> => {
+    const chatDetails = await getSavedChatTags(context, false);
+    if (chatDetails.length === 0) {
+      return {
+        type: 'message',
+        messageType: 'info',
+        content: 'No saved conversation checkpoints found.',
+      };
+    }
+
+    let message = 'List of saved conversations:\n\n';
+    for (const chat of chatDetails) {
+      message += `  - \u001b[36m${chat.name}\u001b[0m\n`;
+    }
+    message += `\n\u001b[90mNote: Newest last, oldest first\u001b[0m`;
+    return {
+      type: 'message',
+      messageType: 'info',
+      content: message,
+    };
+  },
+};
+
+const saveCommand: SlashCommand = {
+  name: 'save',
+  description:
+    'Save the current conversation as a checkpoint. Usage: /chat save <tag>',
+  action: async (context, args): Promise<MessageActionReturn> => {
+    const tag = args.trim();
+    if (!tag) {
+      return {
+        type: 'message',
+        messageType: 'error',
+        content: 'Missing tag. Usage: /chat save <tag>',
+      };
+    }
+
+    const { logger, config } = context.services;
+    await logger.initialize();
+    const chat = await config?.getGeminiClient()?.getChat();
+    if (!chat) {
+      return {
+        type: 'message',
+        messageType: 'error',
+        content: 'No chat client available to save conversation.',
+      };
+    }
+
+    const history = chat.getHistory();
+    if (history.length > 0) {
+      await logger.saveCheckpoint(history, tag);
+      return {
+        type: 'message',
+        messageType: 'info',
+        content: `Conversation checkpoint saved with tag: ${tag}.`,
+      };
+    } else {
+      return {
+        type: 'message',
+        messageType: 'info',
+        content: 'No conversation found to save.',
+      };
+    }
+  },
+};
+
+const resumeCommand: SlashCommand = {
+  name: 'resume',
+  altName: 'load',
+  description:
+    'Resume a conversation from a checkpoint. Usage: /chat resume <tag>',
+  action: async (context, args) => {
+    const tag = args.trim();
+    if (!tag) {
+      return {
+        type: 'message',
+        messageType: 'error',
+        content: 'Missing tag. Usage: /chat resume <tag>',
+      };
+    }
+
+    const { logger } = context.services;
+    await logger.initialize();
+    const conversation = await logger.loadCheckpoint(tag);
+
+    if (conversation.length === 0) {
+      return {
+        type: 'message',
+        messageType: 'info',
+        content: `No saved checkpoint found with tag: ${tag}.`,
+      };
+    }
+
+    const rolemap: { [key: string]: MessageType } = {
+      user: MessageType.USER,
+      model: MessageType.GEMINI,
+    };
+
+    const uiHistory: HistoryItemWithoutId[] = [];
+    let hasSystemPrompt = false;
+    let i = 0;
+
+    for (const item of conversation) {
+      i += 1;
+      const text =
+        item.parts
+          ?.filter((m) => !!m.text)
+          .map((m) => m.text)
+          .join('') || '';
+      if (!text) {
+        continue;
+      }
+      if (i === 1 && text.match(/context for our chat/)) {
+        hasSystemPrompt = true;
+      }
+      if (i > 2 || !hasSystemPrompt) {
+        uiHistory.push({
+          type: (item.role && rolemap[item.role]) || MessageType.GEMINI,
+          text,
+        } as HistoryItemWithoutId);
+      }
+    }
+    return {
+      type: 'load_history',
+      history: uiHistory,
+      clientHistory: conversation,
+    };
+  },
+  completion: async (context, partialArg) => {
+    const chatDetails = await getSavedChatTags(context, true);
+    return chatDetails
+      .map((chat) => chat.name)
+      .filter((name) => name.startsWith(partialArg));
+  },
+};
+
+export const chatCommand: SlashCommand = {
+  name: 'chat',
+  description: 'Manage conversation history.',
+  subCommands: [listCommand, saveCommand, resumeCommand],
+};