# Agent Guide: marstemedia

This document is for AI agents working on this codebase. Read it before touching anything.

---

## What is this project?

**marstemedia** is a cross-platform desktop (+ Android) news reader app built with:
- **Tauri v2** as the native shell
- **Yew** (Rust → WebAssembly) for the UI
- **Rust** for all backend logic (networking, file I/O, cryptography)

It has three features:
1. **Nostr feed** — anonymous browsing of decentralized social posts, filterable by hashtag
2. **RSS reader** — fetches and displays articles from a user-configurable list of RSS/Atom feeds
3. **AI news** — one-click tech news summary from Groq (Llama 3) or OpenRouter

---

## Repository Layout

```
marstemedia/
├── src/                        # Frontend (Yew/Wasm)
│   ├── main.rs                 # Wasm bootstrap
│   ├── app.rs                  # Router + top-level layout
│   ├── navbar/
│   │   ├── mod.rs
│   │   └── navbar.rs           # Bottom navigation dock
│   └── pages/
│       ├── mod.rs
│       ├── home.rs             # Nostr feed page
│       ├── news.rs             # RSS + AI news page
│       └── greet.rs            # Placeholder/demo page
│
├── src-tauri/                  # Backend (native Rust)
│   ├── Cargo.toml
│   ├── tauri.conf.json         # App config (window size, build commands)
│   ├── capabilities/
│   │   └── default.json        # Tauri capability permissions
│   └── src/
│       ├── main.rs             # Desktop executable entry
│       ├── lib.rs              # Tauri setup, command registration
│       ├── home.rs             # Nostr: fetch_nostr_posts command
│       └── news.rs             # RSS + AI: all news commands + NewsState
│   └── easy-nostr/             # Local path-dependency (nostr-sdk wrapper)
│
├── Cargo.toml                  # Frontend workspace root
├── styles.css                  # All CSS for the app
├── index.html                  # Trunk entry point
├── Trunk.toml                  # Trunk (Wasm bundler) config
├── justfile                    # Dev shortcuts
└── .gitea/workflows/
    └── android.yaml            # CI: builds Android APK
```

---

## How to Add a New Page

1. Create `src/pages/yourpage.rs` as a Yew `#[function_component]`.
2. Export it in `src/pages/mod.rs`: `pub mod yourpage;`
3. Add a variant to the `Route` enum in `src/app.rs`:
   ```rust
   #[at("/yourpage")]
   YourPage,
   ```
4. Add a match arm in the `switch` function in `src/app.rs`:
   ```rust
   Route::YourPage => html! { <YourPage /> },
   ```
5. Add a `<Link<Route>>` in `src/navbar/navbar.rs`.

---

## How to Add a New Backend Command

1. Write your async function in the appropriate module (`src-tauri/src/home.rs`, `news.rs`, or a new file).
2. Annotate it with `#[tauri::command]`.
3. If you need shared state, add a field to `NewsState` in `src-tauri/src/news.rs`, or create a new state struct and call `.manage()` in `lib.rs`.
4. Register the command in `src-tauri/src/lib.rs` inside `tauri::generate_handler![...]`.
5. In the frontend, call it with `invoke("your_command_name", args)`.

---

## How to Call a Backend Command from the Frontend

Every page that needs backend calls declares this extern at the top:

```rust
#[wasm_bindgen]
extern "C" {
    #[wasm_bindgen(js_namespace = ["window", "__TAURI__", "core"], catch)]
    async fn invoke(cmd: &str, args: JsValue) -> Result<JsValue, JsValue>;
}
```

Serialize args with `serde_wasm_bindgen::to_value(...)`, deserialize results with `serde_wasm_bindgen::from_value(...)`. Use `spawn_local` to run async calls inside Yew callbacks.

---

## Key Patterns to Know

### State management (frontend)
Yew uses `use_state` hooks. There is no global store — state lives inside components. If two pages need to share data, consider lifting state to `app.rs` or using Tauri's managed state on the backend.

### State management (backend)
`NewsState` in `src-tauri/src/news.rs` is registered with `.manage()` and injected into commands via `State<'_, NewsState>`. All fields are `Mutex<T>` — always lock, read/write, and drop the lock quickly. **API keys are in-memory only** (not saved to disk).

### Config persistence
RSS feeds are saved to `<app_config_dir>/rss.ron` using the `ron` crate. Access the config path via `app.path().app_config_dir()`. Pattern is: read on load, write on save, keep in-memory state in sync.

### Markdown rendering
The `News` page renders article content as Markdown using `pulldown-cmark`. The output is injected with `Html::from_html_unchecked`. Only use this for content you control or have sanitized.

### Privacy pattern (Nostr)
A new random keypair is generated on every `fetch_nostr_posts` call. This is intentional — do not change this to a persistent key without understanding the privacy implications.

---

## CSS

`styles.css` in the project root is the single entry point — it only contains `@import` statements. All actual styles are split into files under `assets/`:

| File | What's inside |
|---|---|
| `assets/variables.css` | CSS custom properties (colors, fonts), reset, `body`/`html` |
| `assets/layout.css` | `.feed-container`, responsive media queries |
| `assets/navbar.css` | `.navbar-dock`, `.nav-link` |
| `assets/header.css` | `.feed-header`, `.mode-toggle`, `.toggle-btn`, `.action-btn`, `.provider-switch` |
| `assets/cards.css` | `.post-card`, `.markdown-body`, `.post-category-badge` |
| `assets/config.css` | `.config-panel`, RSS list, inputs, `.add-btn`, `.delete-btn`, `.save-master-btn` |
| `assets/filters.css` | Hashtag chips (Home), `.category-bar`, `.cat-btn` (News) |
| `assets/animations.css` | `@keyframes float`, `slideIn`, `pulse-subtle` |
| `assets/utils.css` | `.reload-btn-large`, `.error-box`, `.loading-spinner`, `.status-msg` |
| `assets/greet.css` | `.robot-container`, `.robot-icon`, `.bubble` |

When adding styles for a new page, create a new file in `assets/` and add an `@import` line to `styles.css`. There is no CSS framework — vanilla CSS with custom classes.

---

## Build & Dev

```bash
# Start dev server (hot reload)
cargo tauri dev

# Build for desktop release
cargo tauri build

# Build for Android (requires Android SDK + NDK)
cargo tauri android build

# Frontend only (no Tauri shell)
trunk serve
```

The `justfile` may contain additional shortcuts — check it first.

---

## Dependencies Worth Knowing

| Crate | Used for |
|---|---|
| `yew` | UI components |
| `yew-router` | Client-side routing |
| `wasm-bindgen` / `wasm-bindgen-futures` | Wasm ↔ JS bridge |
| `serde-wasm-bindgen` | Serialize/deserialize across the Tauri IPC |
| `pulldown-cmark` | Markdown → HTML in the frontend |
| `nostr-sdk` | Nostr protocol (via `easy-nostr` wrapper) |
| `reqwest` | HTTP client (rustls, no OpenSSL) |
| `feed-rs` | RSS/Atom feed parsing |
| `ron` | Config file serialization |
| `tauri-plugin-opener` | Open URLs in system browser |

---

## What to Watch Out For

- **`easy-nostr`** is a local path dependency at `src-tauri/easy-nostr/`. It is also a private Git repo cloned by CI. If you need to update it, clone it manually into that path.
- **No OpenSSL** — both `reqwest` usages (frontend and backend) use `rustls-tls` with `default-features = false`. Keep it that way to avoid cross-compilation pain on Android/CI.
- **`wasm32-unknown-unknown`** target is required for the frontend. `aarch64-linux-android` and friends are required for Android CI.
- The `Greet` page (`src/pages/greet.rs`) appears to be a leftover demo page from the Tauri template. It is still linked in the navbar — decide whether to keep or remove it.
- API keys entered by the user are held in `Mutex<String>` fields in `NewsState`. They are lost when the app restarts. There is no persistence for keys by design.
