const dmThreadId = await adapter.openDM(userId);

// Post to the DM
const thread = chat.thread(dmThreadId);
await thread.post("Hello! This is a private message.");

interface Adapter {
  /**
   * Open a direct message conversation with a user.
   *
   * @param userId - The platform-specific user ID
   * @returns The thread ID for the DM conversation
   */
  openDM?(userId: string): Promise<string>;
}

import { Chat, Card, Text, Actions, Button } from "chat";

const chat = new Chat({ /* ... */ });

chat.onAction("send_dm", async (event) => {
  // Open DM with the user who clicked
  const dmThreadId = await event.adapter.openDM(event.user.userId);
  const dmThread = chat.thread(dmThreadId);
  
  await dmThread.post(
    <Card title="Private Message">
      <Text>This is just for you, {event.user.fullName}!</Text>
    </Card>
  );
  
  // Confirm in the original thread
  await event.thread.post("Check your DMs!");
});

chat.onNewMention(async (thread, message) => {
  // Open DM with the user who mentioned the bot
  const dmThreadId = await thread.adapter.openDM(message.author.userId);
  const dmThread = chat.thread(dmThreadId);
  
  await dmThread.post(
    "Thanks for mentioning me! How can I help?"
  );
});

interface Thread {
  readonly isDM: boolean;
}

// In a handler
chat.onNewMention(async (thread, message) => {
  if (thread.isDM) {
    await thread.post("This is a private conversation.");
  } else {
    await thread.post("This is a public channel.");
  }
});

if (adapter.openDM) {
  // Adapter supports opening DMs
  const dmThreadId = await adapter.openDM(userId);
} else {
  // Adapter doesn't support DMs
  console.log("This platform doesn't support opening DMs");
}

const userId = "U123ABC456";
await slackAdapter.openDM(userId);

chat.onNewMessage(/@(U[A-Z0-9]+)/, async (thread, message) => {
  const match = message.text.match(/@(U[A-Z0-9]+)/);
  if (match) {
    const mentionedUserId = match[1];
    const dmThreadId = await thread.adapter.openDM(mentionedUserId);
    // ...
  }
});

const userId = "29:1AbcDefGhIjKlMnOpQrStUvWxYz";
await teamsAdapter.openDM(userId);

const userId = "users/123456789012345678901";
await gchatAdapter.openDM(userId);

interface Author {
  userId: string;    // Platform-specific user ID
  userName: string;  // Username/handle
  fullName: string;  // Display name
  isBot: boolean | "unknown";
  isMe: boolean;     // Whether this is the bot itself
}

chat.onNewMention(async (thread, message) => {
  const userId = message.author.userId;
  const dmThreadId = await thread.adapter.openDM(userId);
  // ...
});

import { Chat, Card, Text, Fields, Field, Actions, LinkButton, emoji } from "chat";

const chat = new Chat({ /* ... */ });

chat.onMemberJoinedChannel(async (event) => {
  const userId = event.user.userId;
  
  // Open DM with the new member
  const dmThreadId = await event.adapter.openDM(userId);
  const dmThread = chat.thread(dmThreadId);
  
  await dmThread.post(
    <Card title={`${emoji.wave} Welcome to the team!`}>
      <Text>
        Hi {event.user.fullName}, welcome! Here's what you need to know:
      </Text>
      
      <Fields>
        <Field label="Team Size" value="42 members" />
        <Field label="Channels" value="#general, #dev, #random" />
        <Field label="Time Zone" value="PST (UTC-8)" />
      </Fields>
      
      <Text style="bold">Quick Start:</Text>
      <Text>
        • Read our handbook\n
        • Introduce yourself in #general\n
        • Join your team channels
      </Text>
      
      <Actions>
        <LinkButton 
          url="https://handbook.example.com" 
          label="View Handbook"
          style="primary"
        />
        <LinkButton 
          url="https://example.com/slack-guide" 
          label="Slack Guide"
        />
      </Actions>
    </Card>
  );
});

try {
  const dmThreadId = await adapter.openDM(userId);
  const dmThread = chat.thread(dmThreadId);
  await dmThread.post("Hello!");
} catch (error) {
  console.error("Failed to open DM:", error);
  // Fall back to posting in the original thread
  await thread.post(
    `@${userName} I couldn't send you a DM. Please check your privacy settings.`
  );
}