Add SSO login support

Changes:
1. Updated Cargo.toml
Added "sso-login" feature to the matrix-sdk dependency

2. Updated connection.rs
Added a local HTTP server to automatically capture the SSO callback
Added SsoLoginUrl(String) variant to ClientMessage enum
Added LoginType import from ruma::api::client::session::get_login_types::v3
Updated response_receiver to handle SsoLoginUrl messages
Modified sync_loop to:
Query available login flows using get_login_types()
Check if SSO is available
Generate and display SSO URL when SSO is available and credentials are empty
Fall back to password login when credentials are provided
Added login_with_token() method to complete SSO login with a token

3. Updated server.rs
Added receive_sso_url() method to display SSO URL and optionally open browser
Added complete_sso_login() method to complete SSO login with a token
Added use_sso parameter (defaults to False)

4. Updated commands/matrix.rs
Added sso-complete command to the command structure
Added handler method sso_complete_command()
Added subcommand to argparse

How to use:
* Connect with empty username/password:
   /matrix connect myserver

The plugin will:
Check if SSO is available on matrix.org
Display the SSO login URL
Optionally open it in your browser

* After completing SSO in the browser:
Copy the loginToken from the callback URL (the parameter after loginToken=)

* Run:
     /matrix sso-complete m <login-token>
The plugin will complete the login and you'll be connected.

The implementation follows the same pattern as the matrix-rust-sdk
examples and should work with matrix.org and other homeservers that
support SSO.

Assisted-by: Cursor AI agent (Claude 4.5 Opus)
Signed-off-by: Bogdan Dobrelya <bogdando@yahoo.com>

Author: bogdando

Cargo.lock

@@ -38,7 +38,7 @@ features = ["async", "config_macro"]
 version = "0.14.0"
 # git = "https://github.com/matrix-org/matrix-rust-sdk.git"
 # rev = "92192c549b3f53889c23954386743867a73b31b1"
-features = ["markdown", "socks", "qrcode"]
+features = ["markdown", "socks", "qrcode", "sso-login"]
 
 [profile.dev.package]
 sha2 = { opt-level = 2 }

Cargo.toml

@@ -36,12 +36,14 @@ impl MatrixCommand {
             .add_argument("keys import|export <file> <passphrase>")
             .add_argument("disconnect <server-name>")
             .add_argument("reconnect <server-name>")
+            .add_argument("sso-complete <server-name> <login-token>")
             .add_argument("help <matrix-command> [<matrix-subcommand>]")
             .arguments_description(format!(
                 "      server: List, add, or remove Matrix servers.
      connect: Connect to Matrix servers.
   disconnect: Disconnect from one or all Matrix servers.
    reconnect: Reconnect to server(s).
+ sso-complete: Complete SSO login with a token from the browser.
      devices: {}
         keys: {}
 verification: {}
@@ -61,8 +63,9 @@ Use /matrix [command] help to find out more.\n",
             .add_completion("connect %(matrix_servers)")
             .add_completion("disconnect %(matrix_servers)")
             .add_completion("reconnect %(matrix_servers)")
+            .add_completion("sso-complete %(matrix_servers)")
             .add_completion(
-                "help server|connect|disconnect|reconnect|keys|devices",
+                "help server|connect|disconnect|reconnect|sso-complete|keys|devices",
             );
 
         Command::new(
@@ -219,10 +222,31 @@ Use /matrix [command] help to find out more.\n",
         }
     }
 
+    fn sso_complete_command(&self, args: &ArgMatches) {
+        let server_name = args
+            .value_of("name")
+            .expect("Server name not set but was required");
+        let login_token = args
+            .value_of("token")
+            .expect("Login token not set but was required")
+            .to_string();
+
+        if let Some(s) = self.servers.get(server_name) {
+            let server = s.clone();
+            Weechat::spawn(async move {
+                server.complete_sso_login(login_token).await;
+            })
+            .detach();
+        } else {
+            self.server_not_found(server_name)
+        }
+    }
+
     fn run(&self, buffer: &Buffer, args: &ArgMatches) {
         match args.subcommand() {
             ("connect", Some(subargs)) => self.connect_command(subargs),
             ("disconnect", Some(subargs)) => self.disconnect_command(subargs),
+            ("sso-complete", Some(subargs)) => self.sso_complete_command(subargs),
             ("server", Some(subargs)) => self.server_command(subargs),
             ("devices", Some(subargs)) => {
                 DevicesCommand::run(buffer, &self.servers, subargs)
@@ -323,6 +347,22 @@ impl CommandCallback for MatrixCommand {
                             .value_name("server-name")
                             .required(true),
                     ),
+            )
+            .subcommand(
+                SubCommand::with_name("sso-complete")
+                    .about("Complete SSO login with a token from the browser.")
+                    .arg(
+                        Arg::with_name("name")
+                            .value_name("server-name")
+                            .required(true)
+                            .index(1),
+                    )
+                    .arg(
+                        Arg::with_name("token")
+                            .value_name("login-token")
+                            .required(true)
+                            .index(2),
+                    ),
             );
 
         parse_and_run(argparse, arguments, |args| self.run(buffer, args));