add initial crates and apps

crates/chattyness-user-ui/src/api/realms.rs

@@ -0,0 +1,80 @@
+//! Realm API handlers for user UI (READ-ONLY).
+
+use axum::{
+    extract::{Path, Query, State},
+    Json,
+};
+use serde::{Deserialize, Serialize};
+use sqlx::PgPool;
+
+use chattyness_db::{
+    models::{RealmSummary, RealmWithUserRole},
+    queries::{memberships, realms},
+};
+use chattyness_error::AppError;
+
+use crate::auth::OptionalAuthUser;
+
+/// List query params.
+#[derive(Debug, Deserialize)]
+pub struct ListParams {
+    pub include_nsfw: Option<bool>,
+    pub page: Option<i64>,
+    pub limit: Option<i64>,
+}
+
+/// List response.
+#[derive(Debug, Serialize)]
+pub struct ListResponse {
+    pub realms: Vec<RealmSummary>,
+}
+
+/// List public realms.
+pub async fn list_realms(
+    State(pool): State<PgPool>,
+    Query(params): Query<ListParams>,
+) -> Result<Json<ListResponse>, AppError> {
+    let limit = params.limit.unwrap_or(20).min(100);
+    let offset = params.page.unwrap_or(0) * limit;
+    let include_nsfw = params.include_nsfw.unwrap_or(false);
+
+    let realm_list = realms::list_public_realms(&pool, include_nsfw, limit, offset).await?;
+
+    Ok(Json(ListResponse { realms: realm_list }))
+}
+
+/// Get a realm by slug with user role.
+pub async fn get_realm(
+    State(pool): State<PgPool>,
+    OptionalAuthUser(maybe_user): OptionalAuthUser,
+    Path(slug): Path<String>,
+) -> Result<Json<RealmWithUserRole>, AppError> {
+    let realm = realms::get_realm_by_slug(&pool, &slug)
+        .await?
+        .ok_or_else(|| AppError::NotFound(format!("Realm '{}' not found", slug)))?;
+
+    // Get the user's role if authenticated
+    let user_role = if let Some(user) = maybe_user {
+        let membership = memberships::get_user_membership(&pool, user.id, realm.id).await?;
+        membership.map(|m| m.role)
+    } else {
+        None
+    };
+
+    Ok(Json(RealmWithUserRole { realm, user_role }))
+}
+
+/// Check slug availability response.
+#[derive(Debug, Serialize)]
+pub struct SlugAvailableResponse {
+    pub available: bool,
+}
+
+/// Check if a realm slug is available.
+pub async fn check_slug_available(
+    State(pool): State<PgPool>,
+    Path(slug): Path<String>,
+) -> Result<Json<SlugAvailableResponse>, AppError> {
+    let available = realms::is_slug_available(&pool, &slug).await?;
+    Ok(Json(SlugAvailableResponse { available }))
+}