This is a Slack bot that allows users to play the cooperative card game Hanabi with one another.

$ cargo run --bin stdio
1: help
@1 Welcome to the game Hanabi!
@1
@1 All gameplay happens through your interactions with this bot.
@1 To indicate your interest in joining a game, type `join`.
@1 Once you've done so, you can type `help` again to get game-specific help.
@1
@1 If you want more information, try <https://en.wikipedia.org/wiki/Hanabi_(card_game)> or <https://github.com/jonhoo/hanabot>.

1: join
user 1 joined game
@1 Welcome! I'll get you started with a game as soon as there are some other players available.

2: join
user 2 joined game
@2 Welcome! I'll get you started with a game as soon as there are some other players available.
@2 I have 1 other available players, so we can start a game.
@2 Use `start` to do so. You can optionally pass the number of players to include.
@1 I have 1 other available players, so we can start a game.
@1 Use `start` to do so. You can optionally pass the number of players to include.

1: start
starting game #1 with 2 users: [SlackUserId("1"), SlackUserId("2")]
@1 You are now in a game with 1 other players: <@2>
@1 :hourglass: It's *your* turn; *8* :information_source: and 3 :bomb: remain.

0. Download and install Rust.

1. Create a new Slack App here. When it asks you how you want it to create the app, select "From Manifest", and paste in the JSON from slack-manifest.json.

2. Go to the "App Home" tab, and under "Show Tabs", check the box that says "Allow users to send ..." so that users can DM the bot.

3. Go to the "Basic Information" tab, and generate an "App-Level Token". Give it connections:write access so that it can be used for socket communication. Copy that token.

4. While you're on that page, go ahead and add icon.png as the app's icon and fiddle with its colors (if you want).

5. Next, open the "Install App" tab and hit "Install to ". If you're an admin for the workspace, this step will take you to the workspace to approve the bot, otherwise, it'll request the bot to be installed by your admins.

6. When the bot is approved, this page will show a "Bot User OAuth Token". Copy that token as well.

7. Finally, run the bot with

   $ env "SLACK_APP_TOKEN=XXX" "SLACK_API_TOKEN=YYY" cargo run

   where XXX is the "App-Level Token" and YYY is the "Bot User OAuth Token". Note that the app persists its state to state.json every time a game progresses, and loads that file on startup, so you'll want to run the bot from the same persistent storage each time.

At this point, players should be able to join by messaging the Hanabi app with the word "join"!

Players must first notify the Hanabi bot that they wish to play. They do so by sending the bot join in a direct message. If you no longer wish to participate in games, use leave.

The bot will try to construct games of five players. Once there are two or more players, any player can instruct the bot to start, which causes it to start a game with however many players are available. A player can only be in one game at any given point in time.

During play, a player can play, clue, and discard:

• To play, use play <card>, where <card> is the index of the card you wish to play from the left, starting at 1
• To discard, use discard <card>, where <card> is the same as for play.
• To clue, use clue @player <specifier> where @player is the user to clue, and <specifier> is either a color (e.g., red), or a number (e.g., two). The leading clue keyword is optional.

In addition, use hands to show all players' hands, and what each player knows about their hand, discards to show the discard pile, deck to show the number of cards left in the deck, and ping to remind the current player that it's their turn. You can also terminate the current game using quit.

When new cards are drawn, they appear on the right-hand side of your hand.

• No spectator mode.
• No support for playing with the rainbow suit.
• No support for playing with character cards.
• No long-term statistics tracking.

All of these are fixable. PRs are welcome.