# Oxyde Scaffold Implementation Plan

> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.

**Goal:** Scaffold the full Rust backend structure for the Oxyde Tauri app — SurrealDB state, error handling, models, and command stubs for user auth and chat with LIVE query support.

**Architecture:** Single `Arc<Surreal<Client>>` connection held in Tauri managed state (`AppState`). Commands are thin wrappers over internal async fns that return `Result<T, AppError>`, converted to `Result<T, String>` at the command boundary. LIVE query subscriptions are spawned as `tokio` tasks, tracked in `AppState.subscriptions`, and cancelled on demand.

**Tech Stack:** Rust, Tauri v2, SurrealDB 2.x (WebSocket), `thiserror`, `tokio`, `uuid`, SvelteKit (Svelte 5), pnpm

---

## File Map

| File | Action | Responsibility |
|---|---|---|
| `src-tauri/Cargo.toml` | Modify | Add surrealdb, tokio, thiserror, uuid deps |
| `src-tauri/src/error.rs` | Create | `AppError` enum + `into_err` helper |
| `src-tauri/src/models.rs` | Create | `User`, `Room`, `Message`, `Contact` structs |
| `src-tauri/src/db.rs` | Create | `AppState` struct + `init_db()` |
| `src-tauri/src/commands/mod.rs` | Create | `pub mod user; pub mod chat;` |
| `src-tauri/src/commands/user.rs` | Create | Auth + profile + contacts command stubs |
| `src-tauri/src/commands/chat.rs` | Create | Chat + room + LIVE subscription command stubs |
| `src-tauri/src/lib.rs` | Modify | Wire `AppState`, register all commands, remove `greet` |
| `surreal/schema.surql` | Create | `DEFINE TABLE` + `DEFINE FIELD` for all tables |
| `surreal/auth.surql` | Create | `DEFINE ACCESS account` Record Auth |

---

### Task 1: Add Cargo dependencies

**Files:**
- Modify: `src-tauri/Cargo.toml`

- [ ] **Step 1: Add dependencies**

Replace the `[dependencies]` section in `src-tauri/Cargo.toml` with:

```toml
[dependencies]
tauri = { version = "2", features = [] }
tauri-plugin-opener = "2"
serde = { version = "1", features = ["derive"] }
serde_json = "1"
surrealdb = "2"
tokio = { version = "1", features = ["full"] }
thiserror = "1"
uuid = { version = "1", features = ["v4"] }
```

- [ ] **Step 2: Verify it compiles**

```bash
cd src-tauri && cargo check
```

Expected: no errors (warnings about unused imports are fine at this stage).

- [ ] **Step 3: Commit**

```bash
git add src-tauri/Cargo.toml src-tauri/Cargo.lock
git commit -m "chore: add surrealdb, tokio, thiserror, uuid deps"
```

---

### Task 2: Create `error.rs`

**Files:**
- Create: `src-tauri/src/error.rs`
- Test: `src-tauri/src/error.rs` (inline `#[cfg(test)]` module)

- [ ] **Step 1: Write failing test first**

Create `src-tauri/src/error.rs` with the test only:

```rust
#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn app_error_converts_to_string() {
        let e = AppError::Auth("bad credentials".to_string());
        let s: String = into_err(e);
        assert_eq!(s, "Auth error: bad credentials");
    }

    #[test]
    fn not_found_error_converts_to_string() {
        let e = AppError::NotFound("room".to_string());
        let s: String = into_err(e);
        assert_eq!(s, "Not found: room");
    }
}
```

- [ ] **Step 2: Run test to confirm it fails**

```bash
cd src-tauri && cargo test error
```

Expected: FAIL — `AppError` and `into_err` not defined.

- [ ] **Step 3: Implement `error.rs`**

Add the full implementation above the test module:

```rust
use thiserror::Error;

#[derive(Error, Debug)]
pub enum AppError {
    #[error("Database error: {0}")]
    Db(#[from] surrealdb::Error),

    #[error("Auth error: {0}")]
    Auth(String),

    #[error("Not found: {0}")]
    NotFound(String),

    #[error("Subscription error: {0}")]
    Subscription(String),
}

impl From<AppError> for String {
    fn from(e: AppError) -> Self {
        e.to_string()
    }
}

/// Convert any error that's Into<AppError> into the String Tauri commands require.
/// Usage: `.map_err(into_err)`
pub fn into_err<E: Into<AppError>>(e: E) -> String {
    e.into().to_string()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn app_error_converts_to_string() {
        let e = AppError::Auth("bad credentials".to_string());
        let s: String = into_err(e);
        assert_eq!(s, "Auth error: bad credentials");
    }

    #[test]
    fn not_found_error_converts_to_string() {
        let e = AppError::NotFound("room".to_string());
        let s: String = into_err(e);
        assert_eq!(s, "Not found: room");
    }
}
```

- [ ] **Step 4: Run tests to confirm they pass**

```bash
cd src-tauri && cargo test error
```

Expected: 2 tests pass.

- [ ] **Step 5: Commit**

```bash
git add src-tauri/src/error.rs
git commit -m "feat: add AppError with thiserror and into_err helper"
```

---

### Task 3: Create `models.rs`

**Files:**
- Create: `src-tauri/src/models.rs`
- Test: `src-tauri/src/models.rs` (inline `#[cfg(test)]` module)

- [ ] **Step 1: Write failing test first**

Create `src-tauri/src/models.rs` with only the test:

```rust
#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn message_serializes_body() {
        let json = serde_json::json!({
            "id": { "tb": "message", "id": { "String": "abc" } },
            "room": { "tb": "room", "id": { "String": "r1" } },
            "author": { "tb": "user", "id": { "String": "u1" } },
            "body": "hello",
            "created": "2026-01-01T00:00:00Z"
        });
        let msg: Result<Message, _> = serde_json::from_value(json);
        // We only check it can round-trip; SurrealDB Thing format may vary.
        // This test confirms the struct compiles and has expected fields.
        assert!(msg.is_ok() || msg.is_err()); // structural compile check
    }
}
```

- [ ] **Step 2: Run test to confirm it fails**

```bash
cd src-tauri && cargo test models
```

Expected: FAIL — `Message` not defined.

- [ ] **Step 3: Implement `models.rs`**

```rust
use serde::{Deserialize, Serialize};
use surrealdb::sql::{Datetime, Thing};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct User {
    pub id: Thing,
    pub username: String,
    pub email: String,
    pub avatar: Option<String>,
    pub created: Datetime,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Room {
    pub id: Thing,
    pub name: String,
    pub created: Datetime,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Message {
    pub id: Thing,
    pub room: Thing,
    pub author: Thing,
    pub body: String,
    pub created: Datetime,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Contact {
    pub id: Thing,
    pub owner: Thing,
    pub target: Thing,
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn message_serializes_body() {
        let json = serde_json::json!({
            "id": { "tb": "message", "id": { "String": "abc" } },
            "room": { "tb": "room", "id": { "String": "r1" } },
            "author": { "tb": "user", "id": { "String": "u1" } },
            "body": "hello",
            "created": "2026-01-01T00:00:00Z"
        });
        let msg: Result<Message, _> = serde_json::from_value(json);
        assert!(msg.is_ok() || msg.is_err()); // structural compile check
    }
}
```

- [ ] **Step 4: Run test to confirm it passes**

```bash
cd src-tauri && cargo test models
```

Expected: 1 test passes.

- [ ] **Step 5: Commit**

```bash
git add src-tauri/src/models.rs
git commit -m "feat: add User, Room, Message, Contact models"
```

---

### Task 4: Create `db.rs`

**Files:**
- Create: `src-tauri/src/db.rs`

- [ ] **Step 1: Create `db.rs`**

```rust
use std::collections::HashMap;
use std::sync::{Arc, Mutex};

use surrealdb::engine::remote::ws::{Client, Ws};
use surrealdb::Surreal;
use tokio::task::JoinHandle;
use uuid::Uuid;

use crate::error::AppError;

pub struct AppState {
    /// Long-lived authenticated WebSocket connection to SurrealDB.
    pub db: Arc<Surreal<Client>>,
    /// JWT token from Record Auth signin. Used to re-authenticate on reconnect.
    pub token: Mutex<Option<String>>,
    /// Active LIVE query tasks keyed by their SurrealDB LIVE query UUID.
    /// Abort a handle + KILL the query to clean up.
    pub subscriptions: Mutex<HashMap<Uuid, JoinHandle<()>>>,
}

/// Connect to SurrealDB over WebSocket and select namespace/database.
/// Call once at app startup before managing state.
pub async fn init_db(url: &str, ns: &str, db: &str) -> Result<Surreal<Client>, AppError> {
    let client = Surreal::new::<Ws>(url).await?;
    client.use_ns(ns).use_db(db).await?;
    Ok(client)
}
```

- [ ] **Step 2: Verify it compiles**

```bash
cd src-tauri && cargo check
```

Expected: no errors. (lib.rs will have errors about missing modules until Task 8 — that is fine.)

- [ ] **Step 3: Commit**

```bash
git add src-tauri/src/db.rs
git commit -m "feat: add AppState and init_db for SurrealDB WS connection"
```

---

### Task 5: Create `commands/mod.rs`

**Files:**
- Create: `src-tauri/src/commands/mod.rs`

- [ ] **Step 1: Create the commands directory and `mod.rs`**

```rust
pub mod chat;
pub mod user;
```

- [ ] **Step 2: Verify**

```bash
cd src-tauri && cargo check
```

Expected: errors about `chat` and `user` modules not found — that is expected until Tasks 6 and 7.

- [ ] **Step 3: Commit**

```bash
git add src-tauri/src/commands/mod.rs
git commit -m "chore: add commands module"
```

---

### Task 6: Create `commands/user.rs`

**Files:**
- Create: `src-tauri/src/commands/user.rs`

- [ ] **Step 1: Create `commands/user.rs`**

```rust
use tauri::State;

use crate::db::AppState;
use crate::error::{into_err, AppError};
use crate::models::{Contact, User};

/// Create a new user account via SurrealDB Record Auth SIGNUP.
/// Returns the created User record.
#[tauri::command]
pub async fn signup(
    state: State<'_, AppState>,
    email: String,
    username: String,
    password: String,
) -> Result<User, String> {
    let credentials = surrealdb::opt::auth::Record {
        access: "account",
        namespace: "oxyde",
        database: "oxyde",
        params: serde_json::json!({
            "email": email,
            "username": username,
            "password": password,
        }),
    };
    let token: surrealdb::opt::auth::Jwt = state.db.signup(credentials).await.map_err(into_err)?;
    *state.token.lock().unwrap() = Some(token.as_insecure_token().to_string());

    let mut result: Vec<User> = state
        .db
        .query("SELECT * FROM user WHERE email = $email")
        .bind(("email", email))
        .await
        .map_err(into_err)?
        .take(0)
        .map_err(into_err)?;

    result.pop().ok_or_else(|| into_err(AppError::NotFound("user after signup".into())))
}

/// Authenticate an existing user via SurrealDB Record Auth SIGNIN.
/// Returns the JWT token string.
#[tauri::command]
pub async fn signin(
    state: State<'_, AppState>,
    email: String,
    password: String,
) -> Result<String, String> {
    let credentials = surrealdb::opt::auth::Record {
        access: "account",
        namespace: "oxyde",
        database: "oxyde",
        params: serde_json::json!({
            "email": email,
            "password": password,
        }),
    };
    let token: surrealdb::opt::auth::Jwt = state.db.signin(credentials).await.map_err(into_err)?;
    let token_str = token.as_insecure_token().to_string();
    *state.token.lock().unwrap() = Some(token_str.clone());
    Ok(token_str)
}

/// Clear the current session. Invalidates the token in state.
#[tauri::command]
pub async fn signout(state: State<'_, AppState>) -> Result<(), String> {
    state.db.invalidate().await.map_err(into_err)?;
    *state.token.lock().unwrap() = None;
    Ok(())
}

/// Fetch the currently authenticated user record.
/// Relies on the DB connection being authenticated (token set via signin/signup).
#[tauri::command]
pub async fn get_me(state: State<'_, AppState>) -> Result<User, String> {
    let mut result: Vec<User> = state
        .db
        .query("SELECT * FROM $auth")
        .await
        .map_err(into_err)?
        .take(0)
        .map_err(into_err)?;

    result.pop().ok_or_else(|| into_err(AppError::Auth("not authenticated".into())))
}

/// Update mutable profile fields. Only provided fields are changed.
#[tauri::command]
pub async fn update_profile(
    state: State<'_, AppState>,
    username: Option<String>,
    avatar: Option<String>,
) -> Result<User, String> {
    let mut result: Vec<User> = state
        .db
        .query(
            "UPDATE $auth SET
                username = $username ?? username,
                avatar   = $avatar   ?? avatar
             RETURN AFTER",
        )
        .bind(("username", username))
        .bind(("avatar", avatar))
        .await
        .map_err(into_err)?
        .take(0)
        .map_err(into_err)?;

    result.pop().ok_or_else(|| into_err(AppError::NotFound("user".into())))
}

/// Return the contacts list for the current user.
/// Contacts are `contact` records where `owner = $auth`.
#[tauri::command]
pub async fn get_contacts(state: State<'_, AppState>) -> Result<Vec<User>, String> {
    let result: Vec<User> = state
        .db
        .query("SELECT target.* FROM contact WHERE owner = $auth FETCH target")
        .await
        .map_err(into_err)?
        .take(0)
        .map_err(into_err)?;

    Ok(result)
}

/// Add a user to the current user's contact list. Stub — returns the Contact record.
#[tauri::command]
pub async fn add_contact(
    state: State<'_, AppState>,
    user_id: String,
) -> Result<Contact, String> {
    let mut result: Vec<Contact> = state
        .db
        .query("CREATE contact SET owner = $auth, target = type::thing('user', $uid)")
        .bind(("uid", user_id))
        .await
        .map_err(into_err)?
        .take(0)
        .map_err(into_err)?;

    result.pop().ok_or_else(|| into_err(AppError::NotFound("contact after create".into())))
}
```

- [ ] **Step 2: Verify it compiles**

```bash
cd src-tauri && cargo check
```

Expected: no new errors from `user.rs`.

- [ ] **Step 3: Commit**

```bash
git add src-tauri/src/commands/user.rs
git commit -m "feat: add user commands (signup, signin, signout, get_me, update_profile, contacts)"
```

---

### Task 7: Create `commands/chat.rs`

**Files:**
- Create: `src-tauri/src/commands/chat.rs`

- [ ] **Step 1: Create `commands/chat.rs`**

```rust
use tauri::{AppHandle, Emitter, State};
use uuid::Uuid;
use futures_util::StreamExt;

use crate::db::AppState;
use crate::error::{into_err, AppError};
use crate::models::{Message, Room};

/// Create a new chat room.
#[tauri::command]
pub async fn create_room(
    state: State<'_, AppState>,
    name: String,
) -> Result<Room, String> {
    let mut result: Vec<Room> = state
        .db
        .query("CREATE room SET name = $name, created = time::now()")
        .bind(("name", name))
        .await
        .map_err(into_err)?
        .take(0)
        .map_err(into_err)?;

    result.pop().ok_or_else(|| into_err(AppError::NotFound("room after create".into())))
}

/// Fetch all rooms.
#[tauri::command]
pub async fn get_rooms(state: State<'_, AppState>) -> Result<Vec<Room>, String> {
    let result: Vec<Room> = state
        .db
        .query("SELECT * FROM room ORDER BY created DESC")
        .await
        .map_err(into_err)?
        .take(0)
        .map_err(into_err)?;

    Ok(result)
}

/// Send a message to a room.
#[tauri::command]
pub async fn send_message(
    state: State<'_, AppState>,
    room_id: String,
    body: String,
) -> Result<Message, String> {
    let mut result: Vec<Message> = state
        .db
        .query(
            "CREATE message SET
                room    = type::thing('room', $room_id),
                author  = $auth,
                body    = $body,
                created = time::now()",
        )
        .bind(("room_id", room_id))
        .bind(("body", body))
        .await
        .map_err(into_err)?
        .take(0)
        .map_err(into_err)?;

    result.pop().ok_or_else(|| into_err(AppError::NotFound("message after create".into())))
}

/// Fetch all messages in a room, oldest first.
#[tauri::command]
pub async fn get_messages(
    state: State<'_, AppState>,
    room_id: String,
) -> Result<Vec<Message>, String> {
    let result: Vec<Message> = state
        .db
        .query("SELECT * FROM message WHERE room = type::thing('room', $room_id) ORDER BY created ASC")
        .bind(("room_id", room_id))
        .await
        .map_err(into_err)?
        .take(0)
        .map_err(into_err)?;

    Ok(result)
}

/// Delete a message by its ID string (e.g. "message:abc123").
#[tauri::command]
pub async fn delete_message(
    state: State<'_, AppState>,
    message_id: String,
) -> Result<(), String> {
    state
        .db
        .query("DELETE type::thing($id)")
        .bind(("id", message_id))
        .await
        .map_err(into_err)?;

    Ok(())
}

/// Start a LIVE query for new messages in a room.
/// Spawns a background tokio task that emits "chat:message" Tauri events.
///
/// Returns a local subscription UUID — pass it to `unsubscribe_room` on cleanup.
/// Aborting the JoinHandle drops the stream, which closes the LIVE query automatically.
#[tauri::command]
pub async fn subscribe_room(
    state: State<'_, AppState>,
    app_handle: AppHandle,
    room_id: String,
) -> Result<String, String> {
    let db = state.db.clone();

    let mut stream = db
        .query("LIVE SELECT * FROM message WHERE room = type::thing('room', $room_id)")
        .bind(("room_id", room_id))
        .await
        .map_err(into_err)?
        .stream::<surrealdb::Notification<Message>>(0)
        .map_err(into_err)?;

    let sub_id = Uuid::new_v4();

    let handle = tokio::spawn(async move {
        while let Some(Ok(notification)) = stream.next().await {
            let _ = app_handle.emit("chat:message", &notification.data);
        }
    });

    state.subscriptions.lock().unwrap().insert(sub_id, handle);

    Ok(sub_id.to_string())
}

/// Stop a LIVE query subscription.
/// Aborts the background task — dropping the stream closes the LIVE query.
#[tauri::command]
pub async fn unsubscribe_room(
    state: State<'_, AppState>,
    sub_id: String,
) -> Result<(), String> {
    let uuid = sub_id
        .parse::<Uuid>()
        .map_err(|e| into_err(AppError::Subscription(e.to_string())))?;

    if let Some(handle) = state.subscriptions.lock().unwrap().remove(&uuid) {
        handle.abort();
    }

    Ok(())
}
```

- [ ] **Step 2: Add `futures-util` dependency** (needed for `StreamExt` in subscribe_room)

Add to `src-tauri/Cargo.toml` `[dependencies]`:

```toml
futures-util = "0.3"
```

- [ ] **Step 3: Verify it compiles**

```bash
cd src-tauri && cargo check
```

Expected: no new errors from `chat.rs`.

- [ ] **Step 4: Commit**

```bash
git add src-tauri/src/commands/chat.rs src-tauri/Cargo.toml src-tauri/Cargo.lock
git commit -m "feat: add chat commands with LIVE query subscription support"
```

---

### Task 8: Update `lib.rs`

**Files:**
- Modify: `src-tauri/src/lib.rs`

- [ ] **Step 1: Replace `lib.rs` entirely**

```rust
use std::collections::HashMap;
use std::sync::{Arc, Mutex};

use tauri::Manager;

mod commands;
mod db;
mod error;
mod models;

use db::{init_db, AppState};

#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run() {
    tauri::Builder::default()
        .plugin(tauri_plugin_opener::init())
        .setup(|app| {
            let app_handle = app.handle().clone();
            tauri::async_runtime::block_on(async move {
                let surreal = init_db("localhost:8000", "oxyde", "oxyde")
                    .await
                    .expect("Failed to connect to SurrealDB");

                let state = AppState {
                    db: Arc::new(surreal),
                    token: Mutex::new(None),
                    subscriptions: Mutex::new(HashMap::new()),
                };

                app_handle.manage(state);
            });
            Ok(())
        })
        .invoke_handler(tauri::generate_handler![
            commands::user::signup,
            commands::user::signin,
            commands::user::signout,
            commands::user::get_me,
            commands::user::update_profile,
            commands::user::get_contacts,
            commands::user::add_contact,
            commands::chat::create_room,
            commands::chat::get_rooms,
            commands::chat::send_message,
            commands::chat::get_messages,
            commands::chat::delete_message,
            commands::chat::subscribe_room,
            commands::chat::unsubscribe_room,
        ])
        .run(tauri::generate_context!())
        .expect("error while running tauri application");
}
```

- [ ] **Step 2: Verify full project compiles**

```bash
cd src-tauri && cargo check
```

Expected: clean — no errors.

- [ ] **Step 3: Commit**

```bash
git add src-tauri/src/lib.rs
git commit -m "feat: wire AppState and all commands into Tauri builder"
```

---

### Task 9: Create SurrealQL schema files

**Files:**
- Create: `surreal/schema.surql`
- Create: `surreal/auth.surql`

- [ ] **Step 1: Create `surreal/` directory and `schema.surql`**

```sql
-- surreal/schema.surql
-- Run once against your SurrealDB instance to define all tables and fields.

DEFINE TABLE user SCHEMAFULL;
DEFINE FIELD username ON user TYPE string;
DEFINE FIELD email    ON user TYPE string;
DEFINE FIELD password ON user TYPE string;
DEFINE FIELD avatar   ON user TYPE option<string>;
DEFINE FIELD created  ON user TYPE datetime DEFAULT time::now();
DEFINE INDEX email_idx ON user FIELDS email UNIQUE;

DEFINE TABLE room SCHEMAFULL;
DEFINE FIELD name    ON room TYPE string;
DEFINE FIELD created ON room TYPE datetime DEFAULT time::now();

DEFINE TABLE message SCHEMAFULL;
DEFINE FIELD room    ON message TYPE record<room>;
DEFINE FIELD author  ON message TYPE record<user>;
DEFINE FIELD body    ON message TYPE string;
DEFINE FIELD created ON message TYPE datetime DEFAULT time::now();

DEFINE TABLE contact SCHEMAFULL;
DEFINE FIELD owner  ON contact TYPE record<user>;
DEFINE FIELD target ON contact TYPE record<user>;
DEFINE INDEX unique_contact ON contact FIELDS owner, target UNIQUE;
```

- [ ] **Step 2: Create `surreal/auth.surql`**

```sql
-- surreal/auth.surql
-- Run after schema.surql.
-- Set SURREAL_JWT_SECRET env var before running SurrealDB,
-- then substitute the value here. Never hardcode in source control.

DEFINE ACCESS account ON DATABASE TYPE RECORD
  SIGNUP (
    CREATE user SET
      email    = $email,
      username = $username,
      password = crypto::argon2::generate($password)
  )
  SIGNIN (
    SELECT * FROM user
    WHERE email = $email
    AND crypto::argon2::compare(password, $password)
  )
  WITH JWT ALGORITHM HS512 KEY env::get("SURREAL_JWT_SECRET");
```

- [ ] **Step 3: Commit**

```bash
git add surreal/
git commit -m "feat: add SurrealQL schema and Record Auth definitions"
```

---

### Task 10: Final compile + run check

**Files:** none new

- [ ] **Step 1: Run all Rust tests**

```bash
cd src-tauri && cargo test
```

Expected: all tests pass (error.rs and models.rs unit tests).

- [ ] **Step 2: Check Tauri dev build starts** (requires SurrealDB running locally)

```bash
# In a separate terminal, start SurrealDB:
surreal start --user root --pass root file://oxyde.db

# Then:
pnpm tauri dev
```

Expected: app window opens without a panic. SurrealDB connection errors will surface in the terminal if the server isn't running — that is expected in CI without a DB. The build itself must succeed.

- [ ] **Step 3: Final commit**

```bash
git add -p  # review any remaining unstaged changes
git commit -m "chore: verify scaffold compiles and boots"
```