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730//! Mattermost channel adapter for the OpenFang channel bridge.
//!
//! Uses the Mattermost WebSocket API v4 for real-time message reception and the
//! REST API v4 for sending messages. No external Mattermost crate — just
//! `tokio-tungstenite` + `reqwest`.
use crate::types::{
split_message, ChannelAdapter, ChannelContent, ChannelMessage, ChannelType, ChannelUser,
};
use async_trait::async_trait;
use chrono::Utc;
use futures::{SinkExt, Stream, StreamExt};
use std::collections::HashMap;
use std::pin::Pin;
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::{mpsc, watch, RwLock};
use tracing::{debug, info, warn};
use zeroize::Zeroizing;
/// Maximum Mattermost message length (characters). The server limit is 16383.
const MAX_MESSAGE_LEN: usize = 16383;
const MAX_BACKOFF: Duration = Duration::from_secs(60);
const INITIAL_BACKOFF: Duration = Duration::from_secs(1);
/// Mattermost WebSocket + REST API v4 adapter.
///
/// Inbound messages arrive via WebSocket events (`posted`).
/// Outbound messages are sent via `POST /api/v4/posts`.
pub struct MattermostAdapter {
/// Mattermost server URL (e.g., `"https://mattermost.example.com"`).
server_url: String,
/// SECURITY: Auth token is zeroized on drop to prevent memory disclosure.
token: Zeroizing<String>,
/// Restrict to specific channel IDs (empty = all channels the bot is in).
allowed_channels: Vec<String>,
/// HTTP client for outbound REST API calls.
client: reqwest::Client,
/// Shutdown signal.
shutdown_tx: Arc<watch::Sender<bool>>,
shutdown_rx: watch::Receiver<bool>,
/// Bot's own user ID (populated after /api/v4/users/me).
bot_user_id: Arc<RwLock<Option<String>>>,
}
impl MattermostAdapter {
/// Create a new Mattermost adapter.
///
/// * `server_url` — Base Mattermost server URL (no trailing slash).
/// * `token` — Personal access token or bot token.
/// * `allowed_channels` — Channel IDs to listen on (empty = all).
pub fn new(server_url: String, token: String, allowed_channels: Vec<String>) -> Self {
let (shutdown_tx, shutdown_rx) = watch::channel(false);
Self {
server_url: server_url.trim_end_matches('/').to_string(),
token: Zeroizing::new(token),
allowed_channels,
client: reqwest::Client::new(),
shutdown_tx: Arc::new(shutdown_tx),
shutdown_rx,
bot_user_id: Arc::new(RwLock::new(None)),
}
}
/// Validate the token by calling `GET /api/v4/users/me`.
async fn validate_token(&self) -> Result<String, Box<dyn std::error::Error>> {
let url = format!("{}/api/v4/users/me", self.server_url);
let resp = self
.client
.get(&url)
.bearer_auth(self.token.as_str())
.send()
.await?;
if !resp.status().is_success() {
let status = resp.status();
let body = resp.text().await.unwrap_or_default();
return Err(format!("Mattermost auth failed {status}: {body}").into());
}
let body: serde_json::Value = resp.json().await?;
let user_id = body["id"].as_str().unwrap_or("unknown").to_string();
let username = body["username"].as_str().unwrap_or("unknown");
info!("Mattermost authenticated as {username} ({user_id})");
Ok(user_id)
}
/// Build the WebSocket URL for the Mattermost API v4.
fn ws_url(&self) -> String {
let base = if self.server_url.starts_with("https://") {
self.server_url.replacen("https://", "wss://", 1)
} else if self.server_url.starts_with("http://") {
self.server_url.replacen("http://", "ws://", 1)
} else {
format!("wss://{}", self.server_url)
};
format!("{base}/api/v4/websocket")
}
/// Send a text message to a Mattermost channel via REST API.
async fn api_send_message(
&self,
channel_id: &str,
text: &str,
) -> Result<(), Box<dyn std::error::Error>> {
let url = format!("{}/api/v4/posts", self.server_url);
let chunks = split_message(text, MAX_MESSAGE_LEN);
for chunk in chunks {
let body = serde_json::json!({
"channel_id": channel_id,
"message": chunk,
});
let resp = self
.client
.post(&url)
.bearer_auth(self.token.as_str())
.json(&body)
.send()
.await?;
if !resp.status().is_success() {
let status = resp.status();
let resp_body = resp.text().await.unwrap_or_default();
warn!("Mattermost sendMessage failed {status}: {resp_body}");
}
}
Ok(())
}
/// Check whether a channel ID is allowed (empty list = allow all).
#[allow(dead_code)]
fn is_allowed_channel(&self, channel_id: &str) -> bool {
self.allowed_channels.is_empty() || self.allowed_channels.iter().any(|c| c == channel_id)
}
}
/// Parse a Mattermost WebSocket `posted` event into a `ChannelMessage`.
///
/// The `data` field of a `posted` event contains a JSON string under `post`
/// which holds the actual post payload.
fn parse_mattermost_event(
event: &serde_json::Value,
bot_user_id: &Option<String>,
allowed_channels: &[String],
) -> Option<ChannelMessage> {
let event_type = event["event"].as_str().unwrap_or("");
if event_type != "posted" {
return None;
}
// The `data.post` field is a JSON string that needs a second parse
let post_str = event["data"]["post"].as_str()?;
let post: serde_json::Value = serde_json::from_str(post_str).ok()?;
let user_id = post["user_id"].as_str().unwrap_or("");
let channel_id = post["channel_id"].as_str().unwrap_or("");
let message = post["message"].as_str().unwrap_or("");
let post_id = post["id"].as_str().unwrap_or("").to_string();
// Skip messages from the bot itself
if let Some(ref bid) = bot_user_id {
if user_id == bid {
return None;
}
}
// Filter by allowed channels
if !allowed_channels.is_empty() && !allowed_channels.iter().any(|c| c == channel_id) {
return None;
}
if message.is_empty() {
return None;
}
// Determine if group conversation from channel_type in event data
let channel_type = event["data"]["channel_type"].as_str().unwrap_or("");
let is_group = channel_type != "D"; // "D" = direct message
// Extract thread root id if this is a threaded reply
let root_id = post["root_id"].as_str().unwrap_or("");
let thread_id = if root_id.is_empty() {
None
} else {
Some(root_id.to_string())
};
// Extract sender display name from event data
let sender_name = event["data"]["sender_name"].as_str().unwrap_or(user_id);
// Parse commands (messages starting with /)
let content = if message.starts_with('/') {
let parts: Vec<&str> = message.splitn(2, ' ').collect();
let cmd_name = &parts[0][1..];
let args = if parts.len() > 1 {
parts[1].split_whitespace().map(String::from).collect()
} else {
vec![]
};
ChannelContent::Command {
name: cmd_name.to_string(),
args,
}
} else {
ChannelContent::Text(message.to_string())
};
Some(ChannelMessage {
channel: ChannelType::Mattermost,
platform_message_id: post_id,
sender: ChannelUser {
platform_id: channel_id.to_string(),
display_name: sender_name.to_string(),
openfang_user: None,
},
content,
target_agent: None,
timestamp: Utc::now(),
is_group,
thread_id,
metadata: HashMap::new(),
})
}
#[async_trait]
impl ChannelAdapter for MattermostAdapter {
fn name(&self) -> &str {
"mattermost"
}
fn channel_type(&self) -> ChannelType {
ChannelType::Mattermost
}
async fn start(
&self,
) -> Result<Pin<Box<dyn Stream<Item = ChannelMessage> + Send>>, Box<dyn std::error::Error>>
{
// Validate token and get bot user ID
let user_id = self.validate_token().await?;
*self.bot_user_id.write().await = Some(user_id);
let (tx, rx) = mpsc::channel::<ChannelMessage>(256);
let ws_url = self.ws_url();
let token = self.token.clone();
let bot_user_id = self.bot_user_id.clone();
let allowed_channels = self.allowed_channels.clone();
let mut shutdown_rx = self.shutdown_rx.clone();
tokio::spawn(async move {
let mut backoff = INITIAL_BACKOFF;
loop {
if *shutdown_rx.borrow() {
break;
}
info!("Connecting to Mattermost WebSocket at {ws_url}...");
let ws_result = tokio_tungstenite::connect_async(&ws_url).await;
let ws_stream = match ws_result {
Ok((stream, _)) => stream,
Err(e) => {
warn!(
"Mattermost WebSocket connection failed: {e}, retrying in {backoff:?}"
);
tokio::time::sleep(backoff).await;
backoff = (backoff * 2).min(MAX_BACKOFF);
continue;
}
};
backoff = INITIAL_BACKOFF;
info!("Mattermost WebSocket connected");
let (mut ws_tx, mut ws_rx) = ws_stream.split();
// Authenticate over WebSocket with the token
let auth_msg = serde_json::json!({
"seq": 1,
"action": "authentication_challenge",
"data": {
"token": token.as_str()
}
});
if let Err(e) = ws_tx
.send(tokio_tungstenite::tungstenite::Message::Text(
serde_json::to_string(&auth_msg).unwrap(),
))
.await
{
warn!("Mattermost WebSocket auth send failed: {e}");
tokio::time::sleep(backoff).await;
backoff = (backoff * 2).min(MAX_BACKOFF);
continue;
}
// Inner message loop — returns true if we should reconnect
let should_reconnect = 'inner: loop {
let msg = tokio::select! {
msg = ws_rx.next() => msg,
_ = shutdown_rx.changed() => {
if *shutdown_rx.borrow() {
info!("Mattermost adapter shutting down");
let _ = ws_tx.close().await;
return;
}
continue;
}
};
let msg = match msg {
Some(Ok(m)) => m,
Some(Err(e)) => {
warn!("Mattermost WebSocket error: {e}");
break 'inner true;
}
None => {
info!("Mattermost WebSocket closed");
break 'inner true;
}
};
let text = match msg {
tokio_tungstenite::tungstenite::Message::Text(t) => t,
tokio_tungstenite::tungstenite::Message::Close(_) => {
info!("Mattermost WebSocket closed by server");
break 'inner true;
}
_ => continue,
};
let payload: serde_json::Value = match serde_json::from_str(&text) {
Ok(v) => v,
Err(e) => {
warn!("Mattermost: failed to parse message: {e}");
continue;
}
};
// Check for auth response
if payload.get("status").is_some() {
let status = payload["status"].as_str().unwrap_or("");
if status == "OK" {
debug!("Mattermost WebSocket authentication successful");
} else {
warn!("Mattermost WebSocket auth response: {status}");
}
continue;
}
// Parse events
let bot_id_guard = bot_user_id.read().await;
if let Some(channel_msg) =
parse_mattermost_event(&payload, &bot_id_guard, &allowed_channels)
{
debug!(
"Mattermost message from {}: {:?}",
channel_msg.sender.display_name, channel_msg.content
);
drop(bot_id_guard);
if tx.send(channel_msg).await.is_err() {
return;
}
}
};
if !should_reconnect || *shutdown_rx.borrow() {
break;
}
warn!("Mattermost: reconnecting in {backoff:?}");
tokio::time::sleep(backoff).await;
backoff = (backoff * 2).min(MAX_BACKOFF);
}
info!("Mattermost WebSocket loop stopped");
});
Ok(Box::pin(tokio_stream::wrappers::ReceiverStream::new(rx)))
}
async fn send(
&self,
user: &ChannelUser,
content: ChannelContent,
) -> Result<(), Box<dyn std::error::Error>> {
let channel_id = &user.platform_id;
match content {
ChannelContent::Text(text) => {
self.api_send_message(channel_id, &text).await?;
}
_ => {
self.api_send_message(channel_id, "(Unsupported content type)")
.await?;
}
}
Ok(())
}
async fn send_typing(&self, user: &ChannelUser) -> Result<(), Box<dyn std::error::Error>> {
// Mattermost supports typing indicators via the WebSocket, but since we
// only hold a WebSocket reader in the spawn loop, we use the REST API
// userTyping action via a POST to /api/v4/users/me/typing.
let url = format!("{}/api/v4/users/me/typing", self.server_url);
let body = serde_json::json!({
"channel_id": user.platform_id,
});
let _ = self
.client
.post(&url)
.bearer_auth(self.token.as_str())
.json(&body)
.send()
.await;
Ok(())
}
async fn send_in_thread(
&self,
user: &ChannelUser,
content: ChannelContent,
thread_id: &str,
) -> Result<(), Box<dyn std::error::Error>> {
let channel_id = &user.platform_id;
let text = match content {
ChannelContent::Text(t) => t,
_ => "(Unsupported content type)".to_string(),
};
let url = format!("{}/api/v4/posts", self.server_url);
let chunks = split_message(&text, MAX_MESSAGE_LEN);
for chunk in chunks {
let body = serde_json::json!({
"channel_id": channel_id,
"message": chunk,
"root_id": thread_id,
});
let resp = self
.client
.post(&url)
.bearer_auth(self.token.as_str())
.json(&body)
.send()
.await?;
if !resp.status().is_success() {
let status = resp.status();
let resp_body = resp.text().await.unwrap_or_default();
warn!("Mattermost send_in_thread failed {status}: {resp_body}");
}
}
Ok(())
}
async fn stop(&self) -> Result<(), Box<dyn std::error::Error>> {
let _ = self.shutdown_tx.send(true);
Ok(())
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_mattermost_adapter_creation() {
let adapter = MattermostAdapter::new(
"https://mattermost.example.com".to_string(),
"test-token".to_string(),
vec![],
);
assert_eq!(adapter.name(), "mattermost");
assert_eq!(adapter.channel_type(), ChannelType::Mattermost);
}
#[test]
fn test_mattermost_ws_url_https() {
let adapter = MattermostAdapter::new(
"https://mm.example.com".to_string(),
"token".to_string(),
vec![],
);
assert_eq!(adapter.ws_url(), "wss://mm.example.com/api/v4/websocket");
}
#[test]
fn test_mattermost_ws_url_http() {
let adapter = MattermostAdapter::new(
"http://localhost:8065".to_string(),
"token".to_string(),
vec![],
);
assert_eq!(adapter.ws_url(), "ws://localhost:8065/api/v4/websocket");
}
#[test]
fn test_mattermost_ws_url_trailing_slash() {
let adapter = MattermostAdapter::new(
"https://mm.example.com/".to_string(),
"token".to_string(),
vec![],
);
// Constructor trims trailing slash
assert_eq!(adapter.ws_url(), "wss://mm.example.com/api/v4/websocket");
}
#[test]
fn test_mattermost_allowed_channels() {
let adapter = MattermostAdapter::new(
"https://mm.example.com".to_string(),
"token".to_string(),
vec!["ch1".to_string(), "ch2".to_string()],
);
assert!(adapter.is_allowed_channel("ch1"));
assert!(adapter.is_allowed_channel("ch2"));
assert!(!adapter.is_allowed_channel("ch3"));
let open = MattermostAdapter::new(
"https://mm.example.com".to_string(),
"token".to_string(),
vec![],
);
assert!(open.is_allowed_channel("any-channel"));
}
#[test]
fn test_parse_mattermost_event_basic() {
let post = serde_json::json!({
"id": "post-1",
"user_id": "user-456",
"channel_id": "ch-789",
"message": "Hello from Mattermost!",
"root_id": ""
});
let event = serde_json::json!({
"event": "posted",
"data": {
"post": serde_json::to_string(&post).unwrap(),
"channel_type": "O",
"sender_name": "alice"
}
});
let bot_id = Some("bot-123".to_string());
let msg = parse_mattermost_event(&event, &bot_id, &[]).unwrap();
assert_eq!(msg.channel, ChannelType::Mattermost);
assert_eq!(msg.sender.display_name, "alice");
assert_eq!(msg.sender.platform_id, "ch-789");
assert!(msg.is_group);
assert!(msg.thread_id.is_none());
assert!(
matches!(msg.content, ChannelContent::Text(ref t) if t == "Hello from Mattermost!")
);
}
#[test]
fn test_parse_mattermost_event_dm() {
let post = serde_json::json!({
"id": "post-1",
"user_id": "user-456",
"channel_id": "ch-789",
"message": "DM message",
"root_id": ""
});
let event = serde_json::json!({
"event": "posted",
"data": {
"post": serde_json::to_string(&post).unwrap(),
"channel_type": "D",
"sender_name": "bob"
}
});
let msg = parse_mattermost_event(&event, &None, &[]).unwrap();
assert!(!msg.is_group);
}
#[test]
fn test_parse_mattermost_event_threaded() {
let post = serde_json::json!({
"id": "post-2",
"user_id": "user-456",
"channel_id": "ch-789",
"message": "Thread reply",
"root_id": "post-1"
});
let event = serde_json::json!({
"event": "posted",
"data": {
"post": serde_json::to_string(&post).unwrap(),
"channel_type": "O",
"sender_name": "alice"
}
});
let msg = parse_mattermost_event(&event, &None, &[]).unwrap();
assert_eq!(msg.thread_id, Some("post-1".to_string()));
}
#[test]
fn test_parse_mattermost_event_skips_bot() {
let post = serde_json::json!({
"id": "post-1",
"user_id": "bot-123",
"channel_id": "ch-789",
"message": "Bot message",
"root_id": ""
});
let event = serde_json::json!({
"event": "posted",
"data": {
"post": serde_json::to_string(&post).unwrap(),
"channel_type": "O",
"sender_name": "openfang-bot"
}
});
let bot_id = Some("bot-123".to_string());
let msg = parse_mattermost_event(&event, &bot_id, &[]);
assert!(msg.is_none());
}
#[test]
fn test_parse_mattermost_event_channel_filter() {
let post = serde_json::json!({
"id": "post-1",
"user_id": "user-456",
"channel_id": "ch-789",
"message": "Hello",
"root_id": ""
});
let event = serde_json::json!({
"event": "posted",
"data": {
"post": serde_json::to_string(&post).unwrap(),
"channel_type": "O",
"sender_name": "alice"
}
});
// Not in allowed channels
let msg =
parse_mattermost_event(&event, &None, &["ch-111".to_string(), "ch-222".to_string()]);
assert!(msg.is_none());
// In allowed channels
let msg = parse_mattermost_event(&event, &None, &["ch-789".to_string()]);
assert!(msg.is_some());
}
#[test]
fn test_parse_mattermost_event_command() {
let post = serde_json::json!({
"id": "post-1",
"user_id": "user-456",
"channel_id": "ch-789",
"message": "/agent hello-world",
"root_id": ""
});
let event = serde_json::json!({
"event": "posted",
"data": {
"post": serde_json::to_string(&post).unwrap(),
"channel_type": "O",
"sender_name": "alice"
}
});
let msg = parse_mattermost_event(&event, &None, &[]).unwrap();
match &msg.content {
ChannelContent::Command { name, args } => {
assert_eq!(name, "agent");
assert_eq!(args, &["hello-world"]);
}
other => panic!("Expected Command, got {other:?}"),
}
}
#[test]
fn test_parse_mattermost_event_non_posted() {
let event = serde_json::json!({
"event": "typing",
"data": {}
});
let msg = parse_mattermost_event(&event, &None, &[]);
assert!(msg.is_none());
}
#[test]
fn test_parse_mattermost_event_empty_message() {
let post = serde_json::json!({
"id": "post-1",
"user_id": "user-456",
"channel_id": "ch-789",
"message": "",
"root_id": ""
});
let event = serde_json::json!({
"event": "posted",
"data": {
"post": serde_json::to_string(&post).unwrap(),
"channel_type": "O",
"sender_name": "alice"
}
});
let msg = parse_mattermost_event(&event, &None, &[]);
assert!(msg.is_none());
}
}