From 40a909c991a9e08f44faa8a7e38423b2332ccfd2 Mon Sep 17 00:00:00 2001
From: ghost <ma-koenig@gmx.net>
Date: Tue, 30 Sep 2025 14:19:50 +0200
Subject: [PATCH] webrtc: add runtime config README example; provider/consumer
 docs; minor fixes

---
 Cargo.lock                 |  1 +
 Cargo.toml                 |  3 ++
 README.md                  | 90 ++++++++++++++++++++++++++++++++++++++
 src/config.rs              | 63 +++++++++++++++++++++++++-
 src/lib.rs                 | 10 +++++
 src/main.rs                | 65 +++++++++++++++------------
 src/utils/media_manager.rs | 19 +++-----
 tests/config_sync_tests.rs | 19 ++++++++
 tests/config_tests.rs      | 17 +++++++
 9 files changed, 246 insertions(+), 41 deletions(-)
 create mode 100644 src/lib.rs
 create mode 100644 tests/config_sync_tests.rs
 create mode 100644 tests/config_tests.rs

diff --git a/Cargo.lock b/Cargo.lock
index 3562cc6..e3eeb7e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2686,6 +2686,7 @@ dependencies = [
  "log",
  "serde",
  "serde_json",
+ "tempfile",
  "tracing",
  "wasm-bindgen",
  "wasm-bindgen-futures",
diff --git a/Cargo.toml b/Cargo.toml
index 9634a70..1cc776f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -53,6 +53,9 @@ serde_json = "1.0.100"
 futures = "0.3.31"
 gloo-net = "0.6"
 
+[dev-dependencies]
+tempfile = "3.6"
+
 [features]
 default = ["web"]
 web = ["dioxus/web"]
diff --git a/README.md b/README.md
index 1e629b6..129fad2 100644
--- a/README.md
+++ b/README.md
@@ -23,3 +23,93 @@ To run for a different platform, use the `--platform platform` flag. E.g.
 dx serve --platform desktop
 ```
 
+## Configuration (appsettings.json and WASM fast-path)
+
+This project supports an `appsettings.json`-style configuration that is loaded at runtime.
+
+- Native (desktop/server): the app tries to read `appsettings.json` from the working directory.
+- WASM (web): the loader will first try a small HTML-injection fast-path (see below). If that
+	is not present it will fetch `appsettings.json` from the hosting origin.
+
+Example `appsettings.json`:
+
+```json
+{
+	"server": {
+		"stun_server": "stun:stun.l.google.com:19302"
+	}
+}
+```
+
+HTML injection fast-path (for embedding a small config directly in `index.html`):
+
+```html
+<script id="app-config" type="application/json">{
+	"server": { "stun_server": "stun:stun.l.google.com:19302" }
+}</script>
+```
+
+This is useful for static hosting scenarios where you want to provide a different runtime
+configuration without rebuilding the WASM artifact.
+
+## Consuming the Config in the UI (Dioxus)
+
+The Dioxus app provides a `Signal<Config>` via the hooks context. Child components can consume
+it with:
+
+```rust
+let cfg_signal = use_context::<Signal<niom_webrtc::config::Config>>();
+let cfg = cfg_signal.get(); // or cfg_signal.read()/() depending on the signal API
+// use cfg.server.stun_server
+```
+
+The app uses an async loader (via `use_resource`) and overwrites the initial default config when
+the runtime-loaded config becomes available. This gives instant sensible defaults while still
+allowing runtime overrides.
+
+### Example: Provider + Consumer (Dioxus)
+
+Below is a minimal example showing how the app creates a `Signal<Config>` provider and how a
+child component consumes it. This pattern gives children an immediately-available default
+config while an async fetch can replace it at runtime.
+
+```rust
+use dioxus::prelude::*;
+use dioxus_hooks::use_resource;
+use niom_webrtc::config;
+
+#[allow(non_snake_case)]
+fn ConfigProvider(cx: Scope) -> Element {
+	// synchronous immediate default
+	let default_cfg = config::load_config_sync_or_default();
+
+	// a reactive signal holding the current config
+	let cfg_signal = use_state(cx, || default_cfg.clone());
+
+	// async resource that loads runtime config (WASM fetch or native file)
+	let resource = use_resource(cx, (), |_| async move { config::load_config_or_default().await });
+
+	// when resource completes, update the signal so children react
+	if let Some(cfg) = resource.value() {
+		cfg_signal.set(cfg.clone());
+	}
+
+	// provide the signal to descendants
+	use_context_provider(cx, || cfg_signal.clone());
+
+	cx.render(rsx! { children(&cx) })
+}
+
+fn SomeChild(cx: Scope) -> Element {
+	let cfg_signal = use_context::<UseStateHandle<config::Config>>(cx);
+	let cfg = cfg_signal.get();
+
+	cx.render(rsx!(div { "STUN: {cfg.server.stun_server}" }))
+}
+```
+
+Notes:
+- `load_config_sync_or_default()` returns a sensible default immediately (plus HTML fast-path on WASM).
+- `load_config_or_default()` is async and will perform a network fetch on WASM if the HTML fast-path wasn't present.
+
+
diff --git a/src/config.rs b/src/config.rs
index ea9114f..7a3493b 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -26,13 +26,74 @@ impl Config {
 // WASM runtime loader: fetch `appsettings.json` from the hosting origin
 #[cfg(target_arch = "wasm32")]
 pub async fn load_config_from_server() -> Result<Config, Box<dyn std::error::Error>> {
-    // lazy import gloo-net to avoid non-wasm compile errors
+    // First try HTML-injection fast-path: look for a <script id="app-config"> element
+    if let Ok(Some(cfg)) = load_config_from_html().await {
+        return Ok(cfg);
+    }
+
+    // Fallback to fetching appsettings.json from the hosting origin
     let resp = gloo_net::http::Request::get("appsettings.json").send().await?;
     let text = resp.text().await?;
     let cfg: Config = serde_json::from_str(&text)?;
     Ok(cfg)
 }
 
+// Try to read a JSON config injected into index.html inside a script tag
+#[cfg(target_arch = "wasm32")]
+async fn load_config_from_html() -> Result<Option<Config>, Box<dyn std::error::Error>> {
+    use wasm_bindgen::JsCast;
+    use web_sys::window;
+
+    let win = window().ok_or("no window")?;
+    let doc = win.document().ok_or("no document")?;
+    if let Some(elem) = doc.get_element_by_id("app-config") {
+        if let Some(text) = elem.text_content() {
+            let cfg: Config = serde_json::from_str(&text)?;
+            return Ok(Some(cfg));
+        }
+    }
+    Ok(None)
+}
+
+// Synchronous HTML fast-path for WASM: read script#app-config synchronously if present.
+#[cfg(target_arch = "wasm32")]
+pub fn load_config_from_html_sync() -> Option<Config> {
+    use wasm_bindgen::JsCast;
+    use web_sys::window;
+
+    let win = window().ok()?;
+    let doc = win.document()?;
+    let elem = doc.get_element_by_id("app-config")?;
+    if let Some(text) = elem.text_content() {
+        if let Ok(cfg) = serde_json::from_str::<Config>(&text) {
+            return Some(cfg);
+        }
+    }
+    None
+}
+
+/// Synchronous loader that prefers the HTML-injection fast-path on WASM, otherwise reads file on native.
+pub fn load_config_sync_or_default() -> Config {
+    // WASM: try HTML-injection first
+    #[cfg(target_arch = "wasm32")]
+    {
+        if let Some(cfg) = load_config_from_html_sync() {
+            return cfg;
+        }
+    }
+
+    // Native: try reading appsettings.json from file
+    #[cfg(not(target_arch = "wasm32"))]
+    {
+        if let Ok(cfg) = Config::from_file("appsettings.json") {
+            return cfg;
+        }
+    }
+
+    // Fallback default
+    Config { server: ServerOptions { stun_server: crate::constants::DEFAULT_STUN_SERVER.to_string() } }
+}
+
 // Native loader convenience wrapper (blocking-friendly)
 #[cfg(not(target_arch = "wasm32"))]
 pub async fn load_config_from_server() -> Result<Config, Box<dyn std::error::Error>> {
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..b73686e
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,10 @@
+// Library root for niom-webrtc so integration tests and other crates can depend on the modules.
+pub mod components;
+pub mod models;
+pub mod utils;
+pub mod config;
+pub mod constants;
+
+// Re-export commonly used items if needed in the future
+// pub use config::*;
+// pub use constants::*;
diff --git a/src/main.rs b/src/main.rs
index 456d237..6a70b81 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,16 +1,11 @@
 #![allow(non_snake_case)]
 
-mod components;
-mod models;
-mod utils;
-mod config;
-mod constants;
-
 use dioxus::prelude::*;
 use log::Level;
 use console_log::init_with_level;
-use components::{ConnectionPanel, CallControls, StatusDisplay};
+use niom_webrtc::components::{ConnectionPanel, CallControls, StatusDisplay};
 use web_sys::{RtcPeerConnection, WebSocket as BrowserWebSocket, MediaStream};
+// config functions used via fully-qualified paths below
 
 const FAVICON: Asset = asset!("/assets/favicon.ico");
 const MAIN_CSS: Asset = asset!("/assets/main.css");
@@ -22,31 +17,47 @@ fn main() {
 }
 
 #[component]
-fn App(cx: Scope) -> Element {
-    // Component state for loaded config
-    let cfg_state = use_state(cx, || None::<crate::config::Config>);
-
-    // Kick off async config load once
-    use_future(cx, (), |_| {
-        let cfg_state = cfg_state.clone();
-        async move {
-            let cfg = crate::config::load_config_or_default().await;
-            cfg_state.set(Some(cfg));
-        }
-    });
-
-    match cfg_state.get().as_ref() {
-        None => rsx!( div { "Lade Konfiguration…" } ),
-        Some(_cfg) => rsx! {
-            document::Link { rel: "icon", href: FAVICON }
-            document::Link { rel: "stylesheet", href: MAIN_CSS }
-            Content {}
-        }
+fn App() -> Element {
+    rsx! {
+        document::Link { rel: "icon", href: FAVICON }
+        document::Link { rel: "stylesheet", href: MAIN_CSS }
+        ConfigProvider {}
     }
 }
 
+#[component]
+fn ConfigProvider() -> Element {
+    // Start with a synchronous default so the UI has a sensible config immediately.
+    let default_cfg = niom_webrtc::config::load_config_sync_or_default();
+
+    // A signal holding the active config; children will consume a Signal<Config> via use_context.
+    let mut cfg_signal = use_signal(|| default_cfg.clone());
+
+    // Spawn an async resource to load the config at runtime (WASM fetch / native file). When it
+    // finishes, overwrite the signal so the rest of the app sees the updated config.
+    let resource = use_resource(|| async move {
+        // load_config_or_default is async and returns a Config
+        niom_webrtc::config::load_config_or_default().await
+    });
+
+    // When the resource value becomes available, update the cfg_signal. This effect will run
+    // reactively whenever the resource's value changes.
+    // If the async resource has produced a value, apply it to the signal immediately so
+    // downstream consumers see the updated configuration.
+    if let Some(cfg) = resource.value().read_unchecked().as_ref() {
+        cfg_signal.set(cfg.clone());
+    }
+
+    // Provide the Signal<Config> to downstream components.
+    use_context_provider(|| cfg_signal.clone());
+
+    rsx! { Content {} }
+}
+
 #[component]
 pub fn Content() -> Element {
+    // Config is provided by ConfigProvider via provide_context; components can use use_context to read it.
+
     let peer_id = use_signal(|| "peer-loading...".to_string());
     let remote_id = use_signal(|| String::new());
     let connected = use_signal(|| false);
diff --git a/src/utils/media_manager.rs b/src/utils/media_manager.rs
index ddea916..a43f9e7 100644
--- a/src/utils/media_manager.rs
+++ b/src/utils/media_manager.rs
@@ -2,11 +2,9 @@ use wasm_bindgen::prelude::*;
 use wasm_bindgen::JsCast;
 use wasm_bindgen_futures::JsFuture;
 use web_sys::{
-    MediaStream, MediaStreamConstraints, Navigator, Window,
+    MediaStream, MediaStreamConstraints,
     RtcPeerConnection, RtcConfiguration, RtcIceServer,
-    // SDP-Types
-    RtcSignalingState,
-    RtcSessionDescription, RtcSessionDescriptionInit, RtcSdpType,
+    RtcSessionDescriptionInit, RtcSdpType,
 };
 use js_sys::Reflect;
 use crate::models::MediaState;
@@ -100,17 +98,12 @@ impl MediaManager {
         log::info!("📨 Handling received answer...");
         
         // **DEBUG:** State vor Answer-Verarbeitung
+        // Use the signaling_state() result for debug but avoid importing the enum type locally.
         let state = pc.signaling_state();
         log::info!("🔍 PeerConnection state before answer: {:?}", state);
-        
-        // **NUR** verarbeiten wenn im korrekten State
-        match state {
-            web_sys::RtcSignalingState::HaveLocalOffer => {
-                log::info!("✅ Korrekter State - verarbeite Answer");
-            }
-            _ => {
-                return Err(format!("❌ Falscher State für Answer: {:?}", state));
-            }
+        // Only proceed if in HaveLocalOffer
+        if state != web_sys::RtcSignalingState::HaveLocalOffer {
+            return Err(format!("❌ Falscher State für Answer: {:?}", state));
         }
         
     let init = RtcSessionDescriptionInit::new(RtcSdpType::Answer);
diff --git a/tests/config_sync_tests.rs b/tests/config_sync_tests.rs
new file mode 100644
index 0000000..a7e82ea
--- /dev/null
+++ b/tests/config_sync_tests.rs
@@ -0,0 +1,19 @@
+use niom_webrtc::config::load_config_sync_or_default;
+use std::fs;
+
+#[test]
+fn sync_loader_returns_default_when_no_file() {
+    // Ensure there's no appsettings.json in CWD for this test
+    let _ = fs::remove_file("appsettings.json");
+    let cfg = load_config_sync_or_default();
+    assert_eq!(cfg.server.stun_server, niom_webrtc::constants::DEFAULT_STUN_SERVER.to_string());
+}
+
+// This test ensures the function compiles and returns a Config; on native it will use the file-path,
+// on wasm it would read the HTML-injection. We call it to assert the API surface.
+#[test]
+fn sync_loader_api_callable() {
+    let cfg = load_config_sync_or_default();
+    // At minimum we have a non-empty stun_server
+    assert!(!cfg.server.stun_server.is_empty());
+}
diff --git a/tests/config_tests.rs b/tests/config_tests.rs
new file mode 100644
index 0000000..45770f5
--- /dev/null
+++ b/tests/config_tests.rs
@@ -0,0 +1,17 @@
+use niom_webrtc::constants::DEFAULT_STUN_SERVER;
+use niom_webrtc::config::Config;
+
+#[test]
+fn default_stun_server_present() {
+    assert!(DEFAULT_STUN_SERVER.contains("stun:"));
+}
+
+#[test]
+fn config_from_file_roundtrip() {
+    // Create a temporary JSON in /tmp and read it via Config::from_file
+    let tmp = tempfile::NamedTempFile::new().expect("tempfile");
+    let cfg_json = r#"{ "server": { "stun_server": "stun:example.org:3478" } }"#;
+    std::fs::write(tmp.path(), cfg_json).expect("write");
+    let cfg = Config::from_file(tmp.path()).expect("load");
+    assert_eq!(cfg.server.stun_server, "stun:example.org:3478");
+}