feat: delete a chat

chat-cli/README.md

@@ -6,7 +6,8 @@ A terminal chat application built with [ratatui](https://ratatui.rs/) using the
 
 - 💬 End-to-end encrypted messaging using the Double Ratchet algorithm
 - 📁 File-based transport for local simulation (no network required)
-- 💾 Persistent storage (SQLite)
+- 💾 Persistent storage (SQLite + JSON state)
+- 🔄 Multiple chat support with chat switching
 - 🖥️ Beautiful terminal UI with ratatui
 
 ## Usage
@@ -40,11 +41,19 @@ cargo run -p chat-cli -- bob
 | `/help` | Show available commands |
 | `/intro` | Generate and display your introduction bundle |
 | `/connect <user> <bundle>` | Connect to a user using their introduction bundle |
-| `/peers` | List available peers |
+| `/chats` | List all your established chats |
+| `/switch <user>` | Switch to a different chat |
+| `/delete <user>` | Delete a chat (removes session and crypto state) |
+| `/peers` | List transport-level peers (users with inbox directories) |
 | `/status` | Show connection status and your address |
-| `/clear` | Clear message history |
+| `/clear` | Clear current chat's message history |
 | `/quit` or `Esc` or `Ctrl+C` | Exit the application |
 
+#### `/peers` vs `/chats`
+
+- **`/peers`**: Shows users whose CLI has been started (have inbox directories). These are potential contacts you *could* message.
+- **`/chats`**: Shows users you have an **encrypted session** with (via `/connect`). These are active conversations.
+
 ### Sending Messages
 
 Simply type your message and press Enter. Messages are automatically encrypted and delivered via file-based transport.
@@ -62,8 +71,13 @@ Messages are passed between users via files in a shared directory:
 
 ### Storage
 
-User data (identity keys, chat state) is stored in SQLite databases at:
-- `chat-cli-data/<username>.db`
+Data is stored in the `chat-cli-data/` directory:
+
+| File | Purpose |
+|------|---------|
+| `<username>.db` | SQLite database for identity keys, inbox keys, chat metadata, and Double Ratchet state |
+| `<username>_state.json` | CLI state: username↔chat mappings, message history, active chat |
+| `transport/<username>/` | Inbox directory for receiving messages |
 
 ### Encryption
 
@@ -88,6 +102,13 @@ $ cargo run -p chat-cli -- bob
 # Connected! Bob sends "Hello!" automatically
 
 # Now type messages in either terminal to chat!
+
+# To see your chats:
+/chats
+# Output: alice (active)
+
+# To switch between chats (if you have multiple):
+/switch alice
 ```
 
 ## Architecture

chat-cli/src/app.rs

@@ -206,6 +206,32 @@ impl ChatApp {
         }
     }
 
+    /// Delete a chat session.
+    pub fn delete_chat(&mut self, remote_user: &str) -> Result<()> {
+        if let Some(session) = self.state.sessions.remove(remote_user) {
+            // Also delete from the library's storage
+            if let Err(e) = self.manager.delete_chat(&session.chat_id) {
+                // Log but don't fail - the CLI state is already updated
+                self.status = format!("Warning: failed to delete crypto state: {}", e);
+            }
+
+            // If we deleted the active chat, clear it
+            if self.state.active_chat.as_deref() == Some(remote_user) {
+                // Switch to another chat if available, otherwise clear
+                self.state.active_chat = self.state.sessions.keys().next().cloned();
+            }
+
+            self.save_state()?;
+            self.status = format!("Deleted chat with {}", remote_user);
+            Ok(())
+        } else {
+            Err(anyhow::anyhow!(
+                "No chat with {}. Use /chats to list available chats.",
+                remote_user
+            ))
+        }
+    }
+
     /// Send a message in the current chat.
     pub fn send_message(&mut self, content: &str) -> Result<()> {
         let active = self
@@ -324,6 +350,8 @@ impl ChatApp {
                 self.add_system_message("/connect <user> <bundle> - Connect to a user");
                 self.add_system_message("/chats - List all chats");
                 self.add_system_message("/switch <user> - Switch to chat with user");
+                self.add_system_message("/delete <user> - Delete chat with user");
+                self.add_system_message("/peers - List transport peers");
                 self.add_system_message("/status - Show connection status");
                 self.add_system_message("/clear - Clear current chat messages");
                 self.add_system_message("/quit or Esc or Ctrl+C - Exit");
@@ -370,6 +398,13 @@ impl ChatApp {
                 self.switch_chat(args)?;
                 Ok(Some(format!("Switched to {}", args)))
             }
+            "/delete" => {
+                if args.is_empty() {
+                    return Ok(Some("Usage: /delete <username>".to_string()));
+                }
+                self.delete_chat(args)?;
+                Ok(Some(format!("Deleted chat with {}", args)))
+            }
             "/peers" => {
                 let peers = self.transport.list_peers();
                 if peers.is_empty() {