feat: persist and restore Discord member roles on rejoin

src/graphql/queries.rs

@@ -146,4 +146,63 @@ impl GraphQLClient {
         );
         Ok(attendance)
     }
+
+    pub async fn save_member_roles( &self, discord_id: String, roles: Vec<String>,) -> anyhow::Result<()> {
+
+        let query = r#"
+        mutation($discordId: String!, $roles: [String!]!) {
+            saveMemberRoles(discordId: $discordId, roles: $roles)
+        }"#;
+
+        let variables = serde_json::json!({
+            "discordId": discord_id,
+            "roles": roles
+        });
+
+        let res = self.http()
+        .post(self.root_url())
+        .bearer_auth(self.api_key())
+        .json(&serde_json::json!({
+            "query": query,
+            "variables": variables
+        }))
+        .send()
+        .await?;        
+        Ok(())
+    }
+
+    pub async fn get_member_roles( &self, discord_id: String,) -> anyhow::Result<Vec<String>> {
+        let query = r#"
+        query($discordId: String!) {
+            memberRoles(discordId: $discordId)
+        }"#;
+
+        let variables = serde_json::json!({
+            "discordId": discord_id
+        });
+
+        let response = self.http()
+            .post(self.root_url())
+            .bearer_auth(self.api_key())
+            .json(&serde_json::json!({
+                "query": query,
+                "variables": variables
+            }))
+            .send()
+            .await?
+            .json::<serde_json::Value>()
+            .await?;
+
+        //remove @everyone role, a defult role that every member has and is not useful for our purposes. It has the same ID as the guild, so we can filter it out by comparing with the guild ID.
+        let roles = response["data"]["memberRoles"]
+            .as_array()
+            .unwrap_or(&vec![])
+            .iter()
+            .filter_map(|v| v.as_str()) 
+            .map(|s| s.to_string())
+            .collect();
+
+        Ok(roles)
+    }
+
 }

src/main.rs

@@ -107,7 +107,7 @@ fn prepare_data(config: &Config, reload_handle: ReloadHandle) -> Data {
 async fn build_client(config: &Config, data: Data) -> Result<Client, anyhow::Error> {
     ClientBuilder::new(
         config.discord_token.clone(),
-        GatewayIntents::non_privileged() | GatewayIntents::MESSAGE_CONTENT,
+        GatewayIntents::non_privileged() | GatewayIntents::MESSAGE_CONTENT | GatewayIntents::GUILD_MEMBERS,
     )
     .framework(build_framework(
         config.owner_id,
@@ -160,6 +160,37 @@ async fn event_handler(
         FullEvent::ReactionRemove { removed_reaction } => {
             handle_reaction(ctx, removed_reaction, data, false).await?;
         }
+
+        FullEvent::GuildMemberRemoval { guild_id: _, user, member_data_if_available } => {
+
+            if let Some(member) = member_data_if_available {
+
+                let roles: Vec<String> = member.roles
+                    .iter()
+                    .filter(|r| r.get() != member.guild_id.get())
+                    .map(|r| r.get().to_string())
+                    .collect();
+
+                if !roles.is_empty() {
+                    data.graphql_client
+                        .save_member_roles(user.id.to_string(), roles)
+                        .await?;
+                }
+            }
+        }
+        FullEvent::GuildMemberAddition { new_member } => {
+
+            let roles = data
+                .graphql_client
+                .get_member_roles(new_member.user.id.to_string())
+                .await?;
+
+            for role in roles {
+                if let Ok(role_id) = role.parse::<u64>() {
+                    let _ = new_member.add_role(ctx, RoleId::new(role_id)).await;
+                }
+            }
+        }
         _ => {}
     }