arcature-cli 2026.1.1

//! `arc make command <name> --module <module>` — generate a command fn.
//!
//! Creates `src/<module>/<name>.rs` with a `#[command(\"<name>\")]` async
//! function, and appends `pub mod <name>;` to the module's `mod.rs`. The
//! command name may contain colons (e.g. `users:prune`); the function name is
//! snake_case (e.g. `prune_users`).

use std::path::Path;

use super::naming::{
    append_mod_declaration, mod_declaration, module_file_path, snake_case, validate_module_name,
    validate_type_name,
};
use super::write::{GeneratedFile, module_mod_rs};

pub(crate) fn generate(
    root: &Path,
    raw_name: &str,
    raw_module: &str,
) -> Result<(GeneratedFile, String), String> {
    let name = validate_type_name(raw_name)?;
    let module = validate_module_name(raw_module)?;
    let fn_name = snake_case(&name);
    let command_name = snake_case(&name).replace('_', ":");
    let path = module_file_path(root, &module, &format!("{fn_name}.rs"))?;
    let content = render(&fn_name, &command_name, &module);
    let file = GeneratedFile {
        path: path.clone(),
        content,
    };
    let mod_rs = module_mod_rs(root, &module);
    let declaration = mod_declaration(&fn_name)?;
    let mod_msg = append_mod_declaration(&mod_rs, &declaration)?;
    Ok((file, mod_msg))
}

fn render(fn_name: &str, command_name: &str, module: &str) -> String {
    format!(
        "//! `{fn_name}` — application command for the `{module}` module.\n\
         \n\
         /// A typed application command. The `#[command]` macro generates a\n\
         /// `CommandBinding` const for `arc check` and `arc run`. Register the\n\
         /// command with `CommandRegistry::register` at startup.\n\
         #[arcature::command(\"{command_name}\")]\n\
         pub async fn {fn_name}() -> Result<(), ()> {{\n\
         \x20   Ok(())\n\
         }}\n"
    )
}