Feature Request : Develop Discord Channel

[marrouchi]

Summary

Implement a new channel handler for Discord, similar to the existing Facebook/Messenger Channel Handler, allowing Hexabot to integrate with Discord for messaging, events, and interaction capabilities. This feature will extend Hexabot's multi-channel capabilities to Discord, enabling a seamless chatbot experience across Discord servers.

Example : https://github.com/KevinNovak/Discord-Bot-TypeScript-Template

Objectives

• Develop a channel handler for Discord that will manage events and messages between Hexabot and Discord users.
• Utilize a structure similar to the existing MessengerHandler to maintain consistency in how channels are handled in Hexabot.
• Ensure compatibility with Discord API, handle events such as messages, reactions, user join/leave, and command invocations.
• Maintain the plugin architecture to allow easy extension and integration with other Hexabot features.

Key Requirements

1. Channel Initialization

   • Create a new channel handler (e.g., DiscordHandler) that inherits from ChannelHandler.
   • Initialize the Discord API client, utilizing the necessary credentials from the settings (similar to Graph API for Messenger).

2. Settings Management

   • Define and manage channel-specific settings such as bot token, server ID, channel IDs, command prefixes, etc.
   • Use SettingService to add/update/remove settings for Discord integration.

3. Event Handlers

   • Implement event handlers for key Discord events including:
     • Message Received: Handle direct messages and messages in server channels.
     • User Joined/Left: Track users joining or leaving a server.
     • Reaction Added/Removed: Handle emoji reactions to messages.
     • Commands: Define and handle bot commands using a command prefix (e.g., !).

4. Incoming and Outgoing Messages

   • Implement a method to format incoming Discord messages into a standard format used by Hexabot (StdIncomingMessage).
   • Implement a method to format outgoing messages into a Discord-compatible format, supporting text, embeds, attachments, and mentions.
   • Handle different types of outgoing messages such as quick replies, buttons, and attachments, similar to the methods (_textFormat, _buttonsFormat, etc.) in MessengerHandler.

5. Webhook Subscription

   • Create methods to subscribe/unsubscribe to Discord events using the Discord Gateway.
   • Implement necessary middleware for validating events from Discord to ensure secure communication.

6. User Data Fetching

   • Implement a function to fetch and store user profile data (e.g., username, discriminator, avatar URL) when interacting with Discord users.
   • Store this information in a similar manner as getUserData from MessengerHandler.

7. Logging and Debugging

   • Add proper logging at key steps to facilitate debugging, using the existing LoggerService.
   • Ensure error handling is implemented for all API interactions with Discord.

Technical Considerations

• Use discord.js or a similar library to interact with the Discord API.
• Ensure compliance with Discord's rate limits to avoid API bans.
• Make use of the EventEmitter to trigger events for received messages, commands, and other interactions.

Testing and Validation

• Implement unit tests for the DiscordHandler methods, including event handling, message formatting, and API interaction.
• Perform integration testing with a Discord server to ensure events and commands are properly handled.

Documentation

• Update the README.md with instructions on configuring Discord as a channel.
• Add documentation for new settings fields required for the Discord channel.
• Provide examples of common commands and messages that can be used with Discord.

References

• Existing MessengerHandler implementation.
• Discord Developer API documentation: https://discord.com/developers/docs/intro

Expected Outcome

Upon completion, Hexabot should support Discord as a messaging channel, allowing users to interact with Hexabot on Discord servers. This feature will add value by extending Hexabot's capabilities to one of the most popular communication platforms.