Add permission checks to p.prefix command

src/groups/servers/commands.rs

@@ -8,7 +8,9 @@ use crate::{
         Command, CommandError,
         arguments::{Argument, GreedyString, ParseArguments},
         context::CommandContext,
+        permissions::Permission,
     },
+    groups::servers::permissions::{GuildOnlyPermission, ServerModeratorPermission},
     state::State,
 };
 
@@ -37,6 +39,13 @@ impl Command<State> for PrefixCommand {
         }]
     }
 
+    fn permissions(&self) -> Vec<Box<dyn Permission<State> + Send + Sync + 'static>> {
+        vec![
+            Box::new(GuildOnlyPermission),
+            Box::new(ServerModeratorPermission),
+        ]
+    }
+
     async fn execute(
         &self,
         ctx: CommandContext<'_, State>,

src/groups/servers/permissions.rs

@@ -1,4 +1,5 @@
 use async_trait::async_trait;
+use twilight_model::guild::Permissions;
 
 use crate::{
     framework::commands::{CommandError, context::CommandContext, permissions::Permission},
@@ -11,7 +12,15 @@ pub struct GuildOnlyPermission;
 #[async_trait]
 impl Permission<State> for GuildOnlyPermission {
     async fn check(&self, ctx: &CommandContext<State>) -> Result<bool, CommandError> {
-        Ok(ctx.event.guild_id.is_none())
+        Ok(ctx.event.guild_id.is_some())
+    }
+
+    async fn on_handle_denied(&self, ctx: &CommandContext<State>) -> Result<(), CommandError> {
+        ctx.send()
+            .content("❌ This command can only be used in a server.")
+            .await?;
+
+        Ok(())
     }
 }
 
@@ -20,7 +29,37 @@ pub struct ServerModeratorPermission;
 
 #[async_trait]
 impl Permission<State> for ServerModeratorPermission {
-    async fn check(&self, _ctx: &CommandContext<State>) -> Result<bool, CommandError> {
-        Ok(true)
+    async fn check(&self, ctx: &CommandContext<State>) -> Result<bool, CommandError> {
+        if let Some(guild_id) = ctx.event.guild_id {
+            let permissions = ctx
+                .rt
+                .cache
+                .permissions()
+                .root(ctx.event.author.id, guild_id);
+
+            if let Ok(permissions) = permissions {
+                let guild = ctx
+                    .rt
+                    .cache
+                    .guild(guild_id)
+                    .ok_or(CommandError::CacheStateInconsistent)?;
+
+                Ok(permissions
+                    .contains(Permissions::MANAGE_CHANNELS | Permissions::MANAGE_MESSAGES)
+                    || guild.owner_id() == ctx.event.author.id)
+            } else {
+                Err(CommandError::CacheStateInconsistent)
+            }
+        } else {
+            Ok(true)
+        }
+    }
+
+    async fn on_handle_denied(&self, ctx: &CommandContext<State>) -> Result<(), CommandError> {
+        ctx.send()
+            .content("❌ This command can only be run by a server moderator.\n-# 🛈 Moderators must have permission to manage messages and to manage channels.")
+            .await?;
+
+        Ok(())
     }
 }