3 files changed, 440 insertions, 0 deletions
diff --git a/src/mattermost/client.rs b/src/mattermost/client.rs
new file mode 100644
index 0000000..abdf1ba
--- /dev/null
+++ b/src/mattermost/client.rs
@@ -0,0 +1,137 @@
+use anyhow::anyhow;
+use async_tungstenite::{tokio::connect_async, tungstenite::Message};
+use futures_util::{SinkExt, StreamExt};
+use serde_json::json;
+use tracing::{debug, warn};
+
+use super::WebsocketMessage;
+pub struct AuthData {
+    pub(crate) login: String,
+    pub(crate) password: String,
+}
+pub struct Client {
+    pub(crate) auth: AuthData,
+    pub(crate) url: String,
+    bearer_token: Option<String>,
+    client: reqwest::Client,
+}
+
+#[async_trait::async_trait]
+pub trait Handler {
+    async fn handle(
+        &self,
+        message: super::model::WebsocketUpdate,
+        client: &Client,
+    ) -> Result<(), anyhow::Error>;
+}
+
+impl Client {
+    pub(crate) fn new(auth: AuthData, url: &str) -> Self {
+        Self {
+            auth,
+            url: url.to_owned(),
+            bearer_token: None,
+            client: reqwest::Client::new(),
+        }
+    }
+    pub(crate) async fn update_bearer_token(&mut self) -> Result<(), anyhow::Error> {
+        debug!("Fetching bearer token from api");
+        let response = self
+            .client
+            .post(format!("{}/api/v4/users/login", self.url))
+            .json(&json!({
+                "login_id":self.auth.login,
+                "password":self.auth.password,
+            }))
+            .send()
+            .await?;
+        let token = response
+            .headers()
+            .get("token")
+            .ok_or(anyhow!("Haven't received bearer token in headers"))?
+            .to_str()?;
+        self.bearer_token = Some(token.to_owned());
+        debug!("Successfully updated bearer token");
+        Ok(())
+    }
+    pub(crate) async fn handle_websocket_stream<T: Handler>(
+        &mut self,
+        handler: T,
+    ) -> Result<(), anyhow::Error> {
+        let url = format!("{}/api/v4/websocket", self.url.replacen("http", "ws", 1));
+        let (mut ws_stream, _) = connect_async(url).await?;
+        let token = self
+            .bearer_token
+            .clone()
+            .ok_or(anyhow!("Missing bearer token"))?;
+        ws_stream
+            .send(Message::Text(
+                json!({"seq":1,"action":"authentication_challenge","data":{"token":token}})
+                    .to_string(),
+            ))
+            .await?;
+        while let Some(message) = ws_stream.next().await {
+            match message {
+                Ok(message) => match message {
+                    Message::Text(text) => {
+                        let json: Result<WebsocketMessage, _> = serde_json::from_str(&text);
+                        match json {
+                            Ok(websocketmessage) => {
+                                if let WebsocketMessage::Update(update) = websocketmessage {
+                                    if let Err(err) = handler.handle(update, &self).await {
+                                        warn!("Handler returned error: {err}");
+                                    }
+                                } else {
+                                    debug!("Got only websocket reply. {websocketmessage:?}");
+                                }
+                            }
+                            Err(err) => warn!("Error while deserializing: {err} {text}"),
+                        }
+                    }
+                    Message::Close(_) => break,
+                    _ => {
+                        debug!("Message: {message:?}");
+                    }
+                },
+                Err(err) => warn!("Error {err} while reading message"),
+            }
+        }
+        Ok(())
+    }
+    #[allow(unreachable_code, unused_variables)] //NOCOMMIT: remove
+    pub(crate) async fn reply_to(
+        &self,
+        post: super::model::Post,
+        reply: String,
+    ) -> Result<(), anyhow::Error> {
+        let token = self
+            .bearer_token
+            .clone()
+            .ok_or(anyhow!("Missing bearer token"))?;
+        let id = post.id;
+        let root_id = post.root_id;
+        let post_id = if root_id == "" { id } else { root_id };
+        let channel_id = post.channel_id;
+
+        debug!("Sending response");
+        let response = self
+            .client
+            .post(format!("{}/api/v4/posts", self.url))
+            .json(&json!({
+                "channel_id":channel_id,
+                "root_id":post_id,
+                "message":&reply,
+            }))
+            .header("Authorization", format!("Bearer {token}"))
+            .send()
+            .await?;
+        let status = response.status();
+        let resp = response.text().await;
+        if !status.is_success() {
+            warn!("{:?}", resp);
+            return Err(anyhow!("Error {}", status));
+        }
+        debug!("Sent response");
+        Ok(())
+    }
+}
diff --git a/src/mattermost/mod.rs b/src/mattermost/mod.rs
new file mode 100644
index 0000000..68c4465
--- /dev/null
+++ b/src/mattermost/mod.rs
@@ -0,0 +1,4 @@
+pub mod client;
+pub mod model;
+pub use client::{AuthData, Client, Handler};
+pub use model::WebsocketMessage;
diff --git a/src/mattermost/model.rs b/src/mattermost/model.rs
new file mode 100644
index 0000000..9d4d78e
--- /dev/null
+++ b/src/mattermost/model.rs
@@ -0,0 +1,299 @@
+use serde::Deserialize;
+type PostId = String;
+type UserId = String;
+
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+#[serde(untagged)]
+pub enum WebsocketMessage {
+    Update(WebsocketUpdate),
+    Reply(WebsocketReply),
+}
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+pub struct WebsocketReply {
+    pub status: String,
+    pub seq_reply: u32,
+}
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+pub struct Broadcast {
+    pub channel_id: String,
+    pub connection_id: String,
+    pub omit_connection_id: String,
+    // omit_users:
+    pub team_id: String,
+    pub user_id: String,
+}
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+pub struct WebsocketUpdateStuff {
+    pub broadcast: Broadcast,
+    pub seq: u32,
+}
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+pub struct WebsocketUpdate {
+    #[serde(flatten)]
+    pub stuff: WebsocketUpdateStuff,
+    #[serde(flatten)]
+    pub update: Update,
+}
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+#[serde(tag = "event", content = "data")]
+pub enum Update {
+    #[serde(rename = "posted")]
+    Posted(Posted),
+    #[serde(rename = "hello")]
+    Hello(Hello),
+    #[serde(rename = "status_change")]
+    StatusChange {},
+    #[serde(rename = "typing")]
+    Typing {},
+    #[serde(rename = "channel_viewed")]
+    ChannelViewed {},
+    #[serde(other)]
+    Other,
+}
+
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+pub struct Posted {
+    pub channel_display_name: String,
+    pub channel_name: String,
+    pub channel_type: String,
+    #[serde(deserialize_with = "deserialize_json_field")]
+    pub mentions: Vec<String>,
+    #[serde(deserialize_with = "deserialize_json_field")]
+    pub post: Post,
+}
+fn deserialize_json_field<'de, D, T>(deserializer: D) -> Result<T, D::Error>
+where
+    D: serde::Deserializer<'de>,
+    T: serde::de::DeserializeOwned,
+{
+    let buf: String = String::deserialize(deserializer)?;
+    serde_json::from_str(&buf).map_err(|x| {
+        serde::de::Error::custom(format!("Error while deserializing json encoded field {x}"))
+    })
+}
+
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+pub struct Post {
+    pub id: String,
+    pub create_at: u64,
+    pub update_at: u64,
+    pub edit_at: u64,
+    pub delete_at: u64,
+    pub is_pinned: bool,
+    pub user_id: String,
+    pub channel_id: String,
+    // pub hashtags: String,
+    // pub last_reply_at: u64,
+    pub message: String,
+    // pub metadata:,
+    // pub original_id: String,
+    // pub participants:,
+    // pub pending_post_id: String,
+    // pub preops
+    // pub reply_count: u64,
+    pub root_id: String,
+    #[serde(rename = "type")]
+    pub ttype: String,
+}
+
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+pub struct Hello {
+    pub connection_id: String,
+    pub server_version: String,
+}
+#[cfg(test)]
+mod tests {
+    use serde_json::Value;
+
+    use crate::mattermost::model::{
+        Broadcast, Post, Update, WebsocketUpdate, WebsocketUpdateStuff,
+    };
+    #[test]
+    fn parse_post() {
+        let post = Post {
+            id: "a".to_owned(),
+            create_at: 1,
+            update_at: 2,
+            edit_at: 3,
+            delete_at: 4,
+            is_pinned: true,
+            user_id: "b".to_owned(),
+            channel_id: "c".to_owned(),
+            message: "d".to_owned(),
+            root_id: "e".to_owned(),
+            ttype: "f".to_owned(),
+        };
+        let post_str = r#"{
+                    "id":"a",
+                    "create_at":1,
+                    "update_at":2,
+                    "edit_at":3,
+                    "delete_at":4,
+                    "is_pinned":true,
+                    "user_id":"b",
+                    "channel_id":"c",
+                    "message":"d",
+                    "root_id":"e",
+                    "type":"f"
+                }"#;
+        let d: Result<Post, _> = serde_json::from_str(post_str);
+        assert_eq!(d.unwrap(), post);
+        let data = format!(
+            "\"{}\"",
+            post_str.replace('\n', "\\n").replace('\"', "\\\"")
+        );
+        let x: Value = serde_json::from_str(&data).unwrap();
+        let s = x.as_str().unwrap();
+        let d: Result<Post, _> = serde_json::from_str(s);
+        assert_eq!(d.unwrap(), post);
+    }
+
+    #[test]
+    fn parse_update() {
+        let post = Post {
+            id: "a".to_owned(),
+            create_at: 1,
+            update_at: 2,
+            edit_at: 3,
+            delete_at: 4,
+            is_pinned: true,
+            user_id: "b".to_owned(),
+            channel_id: "c".to_owned(),
+            message: "d".to_owned(),
+            root_id: "e".to_owned(),
+            ttype: "f".to_owned(),
+        };
+        let data = r#"
+        {
+            "data":{
+                "connection_id":  "aaaa",
+                "server_version": "2137"
+            },
+            "event":"hello"
+        }"#;
+        let update: Result<Update, _> = serde_json::from_str(data);
+        assert_eq!(
+            update.unwrap(),
+            Update::Hello(super::Hello {
+                connection_id: "aaaa".to_owned(),
+                server_version: "2137".to_owned()
+            })
+        );
+        let data = r#"
+        {
+            "data":{
+                "channel_display_name":"a",
+                "channel_name":"b",
+                "channel_type":"c",
+                "mentions":"[\"d\"]",
+                "post": "{\"id\":\"a\",\"create_at\":1,\"update_at\":2,\"edit_at\":3,\"delete_at\":4,\"is_pinned\":true,\"user_id\":\"b\",\"channel_id\":\"c\",\"message\":\"d\",\"root_id\":\"e\",\"type\":\"f\"}"
+            },
+            "event":"posted"
+        }"#;
+        let update: Result<Update, _> = serde_json::from_str(&data);
+        assert_eq!(
+            update.unwrap(),
+            Update::Posted(super::Posted {
+                channel_display_name: "a".to_owned(),
+                channel_name: "b".to_owned(),
+                channel_type: "c".to_owned(),
+                mentions: vec!["d".to_owned()],
+                post: post
+            })
+        );
+    }
+    #[test]
+    fn parse_websocketupdate() {
+        let post = Post {
+            id: "a".to_owned(),
+            create_at: 1,
+            update_at: 2,
+            edit_at: 3,
+            delete_at: 4,
+            is_pinned: true,
+            user_id: "b".to_owned(),
+            channel_id: "c".to_owned(),
+            message: "d".to_owned(),
+            root_id: "e".to_owned(),
+            ttype: "f".to_owned(),
+        };
+        let data = r#"
+        {
+            "broadcast":{
+                "channel_id":"a",
+                "connection_id":"b",
+                "omit_connection_id":"c",
+                "team_id":"d",
+                "user_id":"e"
+            },
+            "data":{
+                "connection_id":  "aaaa",
+                "server_version": "2137"
+            },
+            "event":"hello",
+            "seq":2137
+        }"#;
+        let update: Result<WebsocketUpdate, _> = serde_json::from_str(data);
+        assert_eq!(
+            update.unwrap(),
+            WebsocketUpdate {
+                stuff: WebsocketUpdateStuff {
+                    broadcast: Broadcast {
+                        channel_id: "a".to_owned(),
+                        connection_id: "b".to_owned(),
+                        omit_connection_id: "c".to_owned(),
+                        team_id: "d".to_owned(),
+                        user_id: "e".to_owned()
+                    },
+                    seq: 2137,
+                },
+                update: Update::Hello(super::Hello {
+                    connection_id: "aaaa".to_owned(),
+                    server_version: "2137".to_owned()
+                })
+            }
+        );
+        let data = r#"
+        {
+            "broadcast":{
+                "channel_id":"a",
+                "connection_id":"b",
+                "omit_connection_id":"c",
+                "team_id":"d",
+                "user_id":"e"
+            },
+            "data":{
+                "channel_display_name":"a",
+                "channel_name":"b",
+                "channel_type":"c",
+                "mentions":"[\"d\"]",
+                "post": "{\"id\":\"a\",\"create_at\":1,\"update_at\":2,\"edit_at\":3,\"delete_at\":4,\"is_pinned\":true,\"user_id\":\"b\",\"channel_id\":\"c\",\"message\":\"d\",\"root_id\":\"e\",\"type\":\"f\"}"
+            },
+            "event":"posted",
+            "seq": 2137
+        }"#;
+        let update: Result<WebsocketUpdate, _> = serde_json::from_str(&data);
+        assert_eq!(
+            update.unwrap(),
+            WebsocketUpdate {
+                stuff: WebsocketUpdateStuff {
+                    broadcast: Broadcast {
+                        channel_id: "a".to_owned(),
+                        connection_id: "b".to_owned(),
+                        omit_connection_id: "c".to_owned(),
+                        team_id: "d".to_owned(),
+                        user_id: "e".to_owned()
+                    },
+                    seq: 2137,
+                },
+                update: Update::Posted(super::Posted {
+                    channel_display_name: "a".to_owned(),
+                    channel_name: "b".to_owned(),
+                    channel_type: "c".to_owned(),
+                    mentions: vec!["d".to_owned()],
+                    post: post
+                })
+            }
+        );
+    }
+}