## AI Prompt: Generate `rhai.rs` for a new Rust Model

**Objective:**
Create a `rhai.rs` file to expose the Rust model `[YourModelName]` (and any related owned sub-models like `[YourSubModelName]`) to the Rhai scripting engine. This file should allow Rhai scripts to create, manipulate, and retrieve instances of `[YourModelName]`.

**Input Requirements (Provide this information for your specific model):**

1.  **Rust Struct Definition(s):**
    ```rust
    // Example for [YourModelName]
    #[derive(Clone, Debug, Serialize, Deserialize)] // Ensure necessary derives
    pub struct [YourModelName] {
        pub base_data: BaseModelData, // Common field for ID
        pub unique_id_field: String, // Example: like flow_uuid
        pub name: String,
        pub status: String,
        // If it owns a collection of sub-models:
        pub sub_items: Vec<[YourSubModelName]>,
        // Other fields...
    }

    impl [YourModelName] {
        // Constructor
        pub fn new(id: u32, unique_id_field: String /*, other essential params */) -> Self {
            Self {
                base_data: BaseModelData::new(id),
                unique_id_field,
                name: "".to_string(), // Default or passed in
                status: "".to_string(), // Default or passed in
                sub_items: Vec::new(),
                // ...
            }
        }

        // Builder methods
        pub fn name(mut self, name: String) -> Self {
            self.name = name;
            self
        }
        pub fn status(mut self, status: String) -> Self {
            self.status = status;
            self
        }
        // Method to add sub-items
        pub fn add_sub_item(mut self, item: [YourSubModelName]) -> Self {
            self.sub_items.push(item);
            self
        }
        // Other methods to expose...
    }

    // Example for [YourSubModelName] (if applicable)
    #[derive(Clone, Debug, Serialize, Deserialize)]
    pub struct [YourSubModelName] {
        pub id: u32,
        pub description: String,
        // ...
    }

    impl [YourSubModelName] {
        pub fn new(id: u32, description: String) -> Self {
            Self { id, description }
        }
        // Builder methods for sub-model...
    }
    ```

2.  **Key ID fields that need `i64` (Rhai) to `u32` (Rust) conversion:** (e.g., `base_data.id`, `[YourSubModelName].id`, any foreign key IDs).

**Implementation Guidelines for `rhai.rs`:**

1.  **File Structure:**
    *   Start with necessary imports: `rhai::{Dynamic, Engine, EvalAltResult, NativeCallContext, Position}`, `std::sync::Arc`, your model structs, `BaseModelData`, `OurDB`.
    *   Include the `i64_to_u32` helper function.
    *   Define `pub fn register_[your_model_name]_rhai_module(engine: &mut Engine, db: Arc<OurDB>) { ... }`.

2.  **Helper Function for ID Conversion:**
    ```rust
    fn i64_to_u32(val: i64, context_pos: Position, field_name: &str, object_name: &str) -> Result<u32, Box<EvalAltResult>> {
        val.try_into().map_err(|_e| {
            Box::new(EvalAltResult::ErrorArithmetic(
                format!("Conversion error for {} in {} from i64 to u32", field_name, object_name),
                context_pos,
            ))
        })
    }
    ```

3.  **Constructors (e.g., `new_[your_model_name]`):**
    *   Use `NativeCallContext` for manual argument parsing and `i64_to_u32` conversion for ID fields.
    *   Example:
        ```rust
        engine.register_fn("new_[your_model_name]", 
            move |context: NativeCallContext, id_i64: i64, unique_id_str: String /*, other_args... */| 
            -> Result<[YourModelName], Box<EvalAltResult>> {
                let id_u32 = i64_to_u32(id_i64, context.position(), "id", "new_[your_model_name]")?;
                Ok([YourModelName]::new(id_u32, unique_id_str /*, ... */))
        });
        ```
    *   Do the same for `new_[your_sub_model_name]` if applicable.
    *   **Note on `adapter_macros`**: `adapt_rhai_i64_input_fn!` is generally NOT suitable for constructors with multiple arguments or mixed types (e.g., `u32` and `String`). Prefer `NativeCallContext`.

4.  **Builder Methods:**
    *   Register functions that take ownership of the model, modify it, and return it.
    *   Example:
        ```rust
        engine.register_fn("name", |model: [YourModelName], name_val: String| -> [YourModelName] { model.name(name_val) });
        engine.register_fn("status", |model: [YourModelName], status_val: String| -> [YourModelName] { model.status(status_val) });
        // For adding sub-items (if applicable)
        engine.register_fn("add_sub_item", |model: [YourModelName], item: [YourSubModelName]| -> [YourModelName] { model.add_sub_item(item) });
        ```

5.  **Getters:**
    *   Use `engine.register_get("field_name", |model: &mut [YourModelName]| -> Result<FieldType, Box<EvalAltResult>> { Ok(model.field.clone()) });`
    *   For `base_data.id` (u32), cast to `i64` for Rhai: `Ok(model.base_data.id as i64)`
    *   **For `Vec<[YourSubModelName]>` fields (e.g., `sub_items`):** Convert to `rhai::Array`.
        ```rust
        engine.register_get("sub_items", |model: &mut [YourModelName]| -> Result<rhai::Array, Box<EvalAltResult>> {
            let rhai_array = model.sub_items.iter().cloned().map(Dynamic::from).collect::<rhai::Array>();
            Ok(rhai_array)
        });
        ```
        (Ensure `[YourSubModelName]` is `Clone` and works with `Dynamic::from`).

6.  **Setters (Less common if using a full builder pattern, but can be useful):**
    *   Use `engine.register_set("field_name", |model: &mut [YourModelName], value: FieldType| { model.field = value; Ok(()) });`
    *   If a setter method in Rust takes an ID (e.g., `set_related_id(id: u32)`), and you want to call it from Rhai with an `i64`:
        *   You *could* use `adapter_macros::adapt_rhai_i64_input_method!(YourModelType::set_related_id, u32)` if `YourModelType::set_related_id` takes `&mut self, u32`.
        *   Or, handle manually with `NativeCallContext` if the method signature is more complex or doesn't fit the macro.

7.  **Other Custom Methods:**
    *   Register any other public methods from your Rust struct that should be callable.
    *   Example: `engine.register_fn("custom_method_name", |model: &mut [YourModelName]| model.custom_method_in_rust());`

8.  **Database Interaction (Using actual `OurDB` methods like `set` and `get_by_id`):**
    *   The `Arc<OurDB>` instance passed to `register_[your_model_name]_rhai_module` should be cloned and *captured* by the closures for DB functions.
    *   The Rhai script will call these functions without explicitly passing the DB instance (e.g., `set_my_model(my_model_instance);`, `let m = get_my_model_by_id(123);`).
    *   Ensure proper error handling, converting DB errors and `Option::None` (for getters) to `Box<EvalAltResult::ErrorRuntime(...)`.

    *   **Example for `set_[your_model_name]`:**
        ```rust
        // In register_[your_model_name]_rhai_module(engine: &mut Engine, db: Arc<OurDB>)
        let captured_db_for_set = Arc::clone(&db);
        engine.register_fn("set_[your_model_name]", 
            move |model: [YourModelName]| -> Result<(), Box<EvalAltResult>> {
                captured_db_for_set.set(&model).map_err(|e| {
                    Box::new(EvalAltResult::ErrorRuntime(
                        format!("Failed to set [YourModelName] (ID: {}): {}", model.base_data.id, e).into(),
                        Position::NONE,
                    ))
                })
        });
        ```

    *   **Example for `get_[your_model_name]_by_id`:**
        ```rust
        // In register_[your_model_name]_rhai_module(engine: &mut Engine, db: Arc<OurDB>)
        let captured_db_for_get = Arc::clone(&db);
        engine.register_fn("get_[your_model_name]_by_id", 
            move |context: NativeCallContext, id_i64: i64| -> Result<[YourModelName], Box<EvalAltResult>> {
                let id_u32 = i64_to_u32(id_i64, context.position(), "id", "get_[your_model_name]_by_id")?;
                
                captured_db_for_get.get_by_id(id_u32) // Assumes OurDB directly implements Collection<_, [YourModelName]>
                    .map_err(|e| Box::new(EvalAltResult::ErrorRuntime(
                        format!("Error getting [YourModelName] (ID: {}): {}", id_u32, e).into(),
                        Position::NONE,
                    )))?
                    .ok_or_else(|| Box::new(EvalAltResult::ErrorRuntime(
                        format!("[YourModelName] with ID {} not found", id_u32).into(),
                        Position::NONE,
                    )))
        });
        ```

**Example Output Snippet (Illustrating a few parts):**

```rust
// #[...]
// pub struct MyItem { /* ... */ }
// impl MyItem { /* ... */ }
// pub fn register_my_item_rhai_module(engine: &mut Engine, db: Arc<OurDB>) {
//     fn i64_to_u32(...) { /* ... */ }
//
//     engine.register_fn("new_my_item", |ctx: NativeCallContext, id: i64, name: String| { /* ... */ });
//     engine.register_fn("name", |item: MyItem, name: String| -> MyItem { /* ... */ });
//     engine.register_get("id", |item: &mut MyItem| Ok(item.base_data.id as i64));
//     engine.register_get("sub_elements", |item: &mut MyItem| {
//         Ok(item.sub_elements.iter().cloned().map(Dynamic::from).collect::<rhai::Array>())
//     });
//     // ... etc.
// }
```