feat(admin,api): restrict community creation on self-hosted (#3055)

fluxer_admin/src/templates/components/mod.rs

@@ -21,6 +21,7 @@ pub mod resource_link;
 pub mod section_card;
 pub mod stack;
 pub mod table;
+pub mod tooltip;
 pub mod typography;
 pub mod user_display;
 pub mod user_profile_badges;

fluxer_admin/src/templates/components/tooltip.rs

@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use super::icons::paperclip_icon;
+use maud::{Markup, html};
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+static HINT_TOGGLE_ID: AtomicUsize = AtomicUsize::new(0);
+
+pub struct HintLink<'a> {
+    href: &'a str,
+    label: &'a str,
+}
+
+impl<'a> HintLink<'a> {
+    pub fn new(href: &'a str, label: &'a str) -> Self {
+        debug_assert!(
+            href.starts_with('/'),
+            "hint link href must be admin-absolute: {href:?}"
+        );
+        debug_assert!(
+            href.contains('#'),
+            "hint link href should point at an anchor: {href:?}"
+        );
+        debug_assert!(!label.trim().is_empty(), "hint link needs a label");
+        Self { href, label }
+    }
+}
+
+pub struct Hint<'a> {
+    pub name: Option<&'a str>,
+    pub body: &'a str,
+    pub link: Option<HintLink<'a>>,
+}
+
+pub fn info(base: &str, hint: &Hint<'_>) -> Markup {
+    let aria_label = match hint.name {
+        Some(name) => format!("About {name}"),
+        None => "More information".to_owned(),
+    };
+    let toggle_id = format!(
+        "hint-toggle-{}",
+        HINT_TOGGLE_ID.fetch_add(1, Ordering::Relaxed)
+    );
+    html! {
+        span class="group relative inline-flex items-center" {
+            input type="checkbox" id=(toggle_id) class="peer sr-only";
+            label for=(toggle_id) tabindex="0" aria-label=(aria_label)
+                class="flex h-4 w-4 shrink-0 cursor-pointer items-center justify-center rounded-full \
+                       font-semibold text-brand-primary leading-none active:scale-97 \
+                       hover:text-brand-primary-dark" {
+                "?"
+            }
+            label for=(toggle_id) aria-hidden="true"
+                class="invisible fixed inset-0 z-20 cursor-default peer-checked:visible" {}
+            div class="invisible absolute bottom-full left-2 z-30 w-64 pb-3 pl-2 opacity-0 \
+                      transition-[opacity,visibility] duration-200 ease-out motion-reduce:transition-none \
+                      group-hover:visible group-hover:opacity-100 \
+                      group-focus-within:visible group-focus-within:opacity-100 \
+                      peer-checked:visible peer-checked:opacity-100" {
+                div class="rounded-lg border border-neutral-200 bg-white p-3 text-neutral-600 \
+                          text-xs shadow-lg" {
+                    @if let Some(name) = hint.name {
+                        p class="font-semibold text-neutral-900" { (name) }
+                    }
+                    p class=[hint.name.is_some().then_some("mt-1")] { (hint.body) }
+                    @if let Some(link) = &hint.link {
+                        a href={(base) (link.href)} hx-boost="false"
+                            class="mt-2 inline-flex items-center gap-1 text-blue-600 hover:underline" {
+                            (paperclip_icon(""))(link.label)
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::HintLink;
+
+    #[test]
+    #[should_panic(expected = "anchor")]
+    fn rejects_a_link_that_points_at_no_anchor() {
+        let _ = HintLink::new("/instance-config", "Instance policy");
+    }
+
+    #[test]
+    #[should_panic(expected = "label")]
+    fn rejects_a_link_with_no_label() {
+        let _ = HintLink::new("/instance-config#community-creation", "  ");
+    }
+}

fluxer_admin/src/templates/pages/instance_config.rs

@@ -245,6 +245,7 @@ fn policy_config_section(
                 (single_community_form(base, csrf_token, policy))
                 (direct_messages_form(base, csrf_token, policy))
                 (premium_mode_form(base, csrf_token, policy, premium_name))
+                (community_creation_form(base, csrf_token, policy))
                 (services_form(base, csrf_token, policy))
             }
         },
@@ -364,6 +365,37 @@ fn premium_mode_form(
     }
 }
 
+fn community_creation_form(
+    base: &str,
+    csrf_token: &str,
+    policy: &InstancePolicyResponse,
+) -> Markup {
+    html! {
+        div id="community-creation" class="space-y-4 border-t border-neutral-200 pt-6" {
+            h3 class="text-sm font-semibold text-neutral-900" { "Community creation" }
+            form method="post" action={(base) "/instance-config?action=update_policy"} {
+                (csrf_input(csrf_token))
+                div class="space-y-4" {
+                    (select_input("policy_guild_create_access", "Who can create communities", &[
+                        ("true", "Everyone"),
+                        ("false", "Restricted"),
+                    ], if policy.guild_create_access { "true" } else { "false" }))
+                    p class="text-xs text-neutral-500" {
+                        "When restricted, only admins with the wildcard ACL and users matched by a "
+                        a href={(base) "/limit-config"} class="text-blue-600 hover:underline" {
+                            "limit rule"
+                        }
+                        " that grants Community Creation Access can create communities."
+                    }
+                    (form_actions(html! {
+                        (submit_button("Save community creation policy"))
+                    }))
+                }
+            }
+        }
+    }
+}
+
 fn service_select(name: &str, label: &str, override_value: Option<bool>, resolved: bool) -> Markup {
     let selected = match override_value {
         None => "inherit",

fluxer_admin/src/templates/pages/limit_config.rs

@@ -2,6 +2,7 @@
 
 use crate::{
     acl::{self, INSTANCE_LIMIT_CONFIG_UPDATE},
+    admin_hints,
     api::types::{LimitConfigResponse, LimitKeyMetadata, LimitRule},
     config::AdminConfig,
     middleware::auth::AuthContext,
@@ -9,6 +10,7 @@ use crate::{
         components::{
             form::{FORM_INPUT_CLASS, csrf_input, danger_button, form_actions, submit_button},
             page_container::{card_with_header, page_header},
+            tooltip,
         },
         layout::admin_layout,
     },
@@ -208,7 +210,7 @@ fn rule_editor(
                 @for category in CATEGORY_ORDER {
                     @let keys = keys_for_category(response, category);
                     @if !keys.is_empty() {
-                        (category_section(response, rule, category, &keys, can_update))
+                        (category_section(&config.base_path, response, rule, category, &keys, can_update))
                     }
                 }
                 @if can_update {
@@ -274,6 +276,7 @@ fn keys_for_category(response: &LimitConfigResponse, category: &str) -> Vec<Stri
 }
 
 fn category_section(
+    base: &str,
     response: &LimitConfigResponse,
     rule: &LimitRule,
     category: &str,
@@ -292,7 +295,7 @@ fn category_section(
             div class="space-y-4" {
                 @for key in keys {
                     @if let Some(metadata) = response.metadata.get(key) {
-                        (limit_field(response, rule, key, metadata, can_update))
+                        (limit_field(base, response, rule, key, metadata, can_update))
                     }
                 }
             }
@@ -301,6 +304,7 @@ fn category_section(
 }
 
 fn limit_field(
+    base: &str,
     response: &LimitConfigResponse,
     rule: &LimitRule,
     key: &str,
@@ -319,9 +323,10 @@ fn limit_field(
         .as_ref()
         .is_some_and(|fields| fields.iter().any(|field| field == key));
     if metadata.is_toggle {
-        toggle_field(key, metadata, current_value, modified, can_update)
+        toggle_field(base, key, metadata, current_value, modified, can_update)
     } else {
         numeric_field(
+            base,
             key,
             metadata,
             current_value,
@@ -333,6 +338,7 @@ fn limit_field(
 }
 
 fn toggle_field(
+    base: &str,
     key: &str,
     metadata: &LimitKeyMetadata,
     current_value: Option<u64>,
@@ -343,7 +349,7 @@ fn toggle_field(
     html! {
         div class={(field_class(modified, false))} {
             div class="flex-1 space-y-1" {
-                (field_label_row(key, metadata, modified))
+                (field_label_row(base, key, metadata, modified))
                 p class="text-xs text-neutral-500" { (metadata.description) }
             }
             div class="shrink-0" {
@@ -369,6 +375,7 @@ fn toggle_field(
 }
 
 fn numeric_field(
+    base: &str,
     key: &str,
     metadata: &LimitKeyMetadata,
     current_value: Option<u64>,
@@ -385,7 +392,7 @@ fn numeric_field(
     html! {
         div class={(field_class(modified, true))} {
             div class="flex flex-wrap items-center justify-between gap-2" {
-                (field_label_row(key, metadata, modified))
+                (field_label_row(base, key, metadata, modified))
             }
             p class="text-xs text-neutral-500" {
                 (metadata.description)
@@ -417,10 +424,13 @@ fn numeric_field(
     }
 }
 
-fn field_label_row(key: &str, metadata: &LimitKeyMetadata, modified: bool) -> Markup {
+fn field_label_row(base: &str, key: &str, metadata: &LimitKeyMetadata, modified: bool) -> Markup {
     html! {
         div class="flex flex-wrap items-center gap-2" {
             label for=(key) class="font-medium text-neutral-900 text-sm" { (metadata.label) }
+            @if let Some(hint) = admin_hints::limit_key_hint(key) {
+                (tooltip::info(base, &hint))
+            }
             span class=(scope_class(&metadata.scope)) { (scope_label(&metadata.scope)) }
             @if modified {
                 span class="rounded bg-neutral-100 px-1.5 py-0.5 text-neutral-700 text-xs" { "Modified" }