fix(api): allow hids in uppercase and with dashes; document this

crates/api/src/middleware/params.rs

@@ -13,6 +13,15 @@ use crate::auth::AuthState;
 use crate::{util::json_err, ApiContext};
 use pluralkit_models::PKSystem;
 
+// move this somewhere else
+fn parse_hid(hid: &str) -> String {
+    if hid.len() > 7 || hid.len() < 5 {
+        hid.to_string()
+    } else {
+        hid.to_lowercase().replace("-", "")
+    }
+}
+
 pub async fn params(State(ctx): State<ApiContext>, mut req: Request, next: Next) -> Response {
     let pms = match req.extensions().get::<UrlParams>() {
         None => Vec::new(),
@@ -86,7 +95,7 @@ pub async fn params(State(ctx): State<ApiContext>, mut req: Request, next: Next)
                         Err(_) => sqlx::query_as::<Postgres, PKSystem>(
                             "select * from systems where hid = $1",
                         )
-                        .bind(id),
+                        .bind(parse_hid(id)),
                     }
                     .fetch_optional(&ctx.db)
                     .await

docs/content/api/models.md

@@ -16,6 +16,8 @@ Privacy objects (`privacy` key in models) contain values "private" or "public".
 
 Every PluralKit entity has two IDs: a short (5 or 6 character) ID and a longer UUID. The short ID is unique across the resource (a member can have the same short ID as a system, for example), while the UUID is consistent for the lifetime of the entity and globally unique across the bot.
 
+The PluralKit Discord bot can be configured to display short IDs in uppercase, or (in the case of 6-character IDs) as two parts of 3 characters separated by a dash (for example, `EXA-MPL`). For convenience, IDs are accepted by the API in any format displayable by the bot.
+
 ### System model
 
 |key|type|notes|