feat(gateway): add cache event handler stubs

gateway/src/cache.rs

@@ -0,0 +1,73 @@
+use twilight_gateway::Event;
+
+pub async fn handle_event<'a>(
+    event: Event,
+    rconn: redis::Client
+) -> anyhow::Result<()> {
+    match event {
+        // todo: SaveDMChannelStub (?)
+        // todo: save user profiles for some reason (from message create, etc)
+        // todo(dotnet): remove relying on cache.OwnUserId
+
+        Event::GuildCreate(guild) => {
+            // save guild itself
+            // save all roles in guild
+            // save guild-role map
+            // save all channels in guild
+            // save all threads in guild (as channels lol)
+            // save guild-channel map
+            // save self guild member
+            
+            // c# code also saves users in guildCreate.Members, but I'm pretty sure that doesn't have anything now because intents
+        }
+        Event::GuildUpdate(guild) => {
+            // save guild itself
+        }
+        Event::GuildDelete(guild) => {
+            // delete guild
+            // this probably should also delete all channels/roles/etc of the guild
+        }
+        Event::MemberUpdate(member) => {
+            // save self guild member
+        }
+        Event::ChannelCreate(channel) => {
+            // save channel
+            // update guild-channel map
+        }
+        Event::ChannelUpdate(channel) => {
+            // save channel
+        }
+        Event::ChannelDelete(channel) => {
+            // delete channel
+            // update guild-channel map
+        }
+        Event::RoleCreate(role) => {
+            // save role
+            // update guild-role map
+        }
+        Event::RoleUpdate(role) => {
+            // save role
+        }
+        Event::RoleDelete(role) => {
+            // delete role
+            // update guild-role map
+        }
+        Event::ThreadCreate(thread) => {
+            // save channel
+            // update guild-channel map
+        }
+        Event::ThreadUpdate(thread) => {
+            // save thread
+        }
+        Event::ThreadDelete(thread) => {
+            // delete channel
+            // update guild-channel map
+        }
+        Event::ThreadListSync(tls) => {
+            // save channels
+        }
+        _ => {}
+    }
+
+    Ok(())
+}

gateway/src/evt.rs

@@ -7,6 +7,8 @@ use tracing::info;
 use twilight_gateway::Event;
 use twilight_http::Client as HttpClient;
 
+use crate::cache;
+
 lazy_static::lazy_static! {
     static ref ALLOWED_EVENTS: Vec<&'static str> = [
         "INTERACTION_CREATE",
@@ -25,6 +27,8 @@ pub async fn handle_event<'a>(
     _db: Pool,
     rconn: redis::Client
 ) -> anyhow::Result<()> {
+    cache::handle_event(event.clone(), rconn.clone()).await?;
+
     match event {
         Event::GatewayInvalidateSession(resumable) => {
             info!("shard {} session invalidated, resumable? {}", shard_id, resumable);

gateway/src/main.rs

@@ -9,6 +9,7 @@ use twilight_gateway::{
 };
 use twilight_http::Client as HttpClient;
 
+mod cache;
 mod config;
 mod evt;
 mod db;
@@ -81,7 +82,7 @@ async fn init_gateway(
     if shard_count < 16 {
         scheme = ShardScheme::Auto;
     } else {
-        let cluster_id = env::var("NOMAD_ALLOC_INDEX").or("0").parse::<u64>().unwrap();
+        let cluster_id = env::var("NOMAD_ALLOC_INDEX").or::<String>(Result::Ok("0".to_string())).unwrap().parse::<u64>().unwrap();
         let first_shard_id = 16 * cluster_id;
 
         scheme = ShardScheme::try_from((first_shard_id..first_shard_id+16, shard_count)).unwrap();