First commit in rust

backchannel-server/src/handlers/channels.rs

@@ -0,0 +1,107 @@
+use std::sync::Arc;
+
+use backchannel_common::protocol::ServerMessage;
+use backchannel_common::types::{has_permission, PermissionFlags};
+use uuid::Uuid;
+
+use crate::db::{channels, messages, roles};
+use crate::error::{Result, ServerError};
+use crate::state::{AppState, ChannelBroadcast};
+use crate::ws::session::Session;
+
+pub async fn handle_send(
+    session: &Session,
+    state: &Arc<AppState>,
+    channel_id: Uuid,
+    content: String,
+) -> Result<()> {
+    let user_id  = session.require_auth()?;
+    let username = session.require_username()?.to_string();
+
+    channels::find_by_id(&state.db, channel_id)
+        .await?
+        .ok_or_else(|| ServerError::NotFound("Channel not found".into()))?;
+
+    let perms = roles::get_user_permissions(&state.db, user_id).await?;
+    if !has_permission(perms, PermissionFlags::SEND_MESSAGES) {
+        return Err(ServerError::Forbidden);
+    }
+
+    let (message_id, timestamp) =
+        messages::insert_channel_message(&state.db, channel_id, user_id, &content).await?;
+
+    let _ = state.channel_broadcast.send(ChannelBroadcast {
+        message: ServerMessage::ChannelMessage {
+            message_id,
+            channel_id,
+            author_id: user_id,
+            author_username: username,
+            content,
+            timestamp,
+        },
+    });
+
+    Ok(())
+}
+
+pub async fn handle_history(
+    session: &Session,
+    state: &Arc<AppState>,
+    channel_id: Uuid,
+    before_message_id: Option<Uuid>,
+    limit: u32,
+) -> Result<()> {
+    let user_id = session.require_auth()?;
+    let perms   = roles::get_user_permissions(&state.db, user_id).await?;
+    if !has_permission(perms, PermissionFlags::READ_MESSAGES) {
+        return Err(ServerError::Forbidden);
+    }
+
+    let msgs = messages::fetch_channel_history(&state.db, channel_id, before_message_id, limit).await?;
+    session.send(ServerMessage::ChannelHistory { channel_id, messages: msgs })
+}
+
+pub async fn handle_create(
+    session: &Session,
+    state: &Arc<AppState>,
+    name: String,
+    topic: Option<String>,
+) -> Result<()> {
+    let user_id = session.require_auth()?;
+    let perms   = roles::get_user_permissions(&state.db, user_id).await?;
+    if !has_permission(perms, PermissionFlags::MANAGE_CHANNELS) {
+        return Err(ServerError::Forbidden);
+    }
+    if channels::name_exists(&state.db, &name).await? {
+        return Err(ServerError::BadRequest("Channel name already exists".into()));
+    }
+
+    let channel_id = channels::create(&state.db, &name, topic.as_deref(), user_id).await?;
+
+    let _ = state.channel_broadcast.send(ChannelBroadcast {
+        message: ServerMessage::ChannelCreated { channel_id, name, topic },
+    });
+
+    Ok(())
+}
+
+pub async fn handle_delete(
+    session: &Session,
+    state: &Arc<AppState>,
+    channel_id: Uuid,
+) -> Result<()> {
+    let user_id = session.require_auth()?;
+    let perms   = roles::get_user_permissions(&state.db, user_id).await?;
+    if !has_permission(perms, PermissionFlags::MANAGE_CHANNELS) {
+        return Err(ServerError::Forbidden);
+    }
+    if !channels::delete(&state.db, channel_id).await? {
+        return Err(ServerError::NotFound("Channel not found".into()));
+    }
+
+    let _ = state.channel_broadcast.send(ChannelBroadcast {
+        message: ServerMessage::ChannelDeleted { channel_id },
+    });
+
+    Ok(())
+}