smith

//! Reference system plugin: one echo tool over the smith:plugin world.
#![expect(missing_docs, reason = "wit-bindgen generates the world surface")]
#![expect(clippy::pedantic, reason = "wit-bindgen generates the world surface")]

wit_bindgen::generate!({
    path: "../../wit/smith-plugin.wit",
    world: "plugin-world",
});

use exports::smith::plugin::plugin::{Guest, ToolDeclaration};

struct EchoPlugin;

impl Guest for EchoPlugin {
    fn declare_tools() -> Vec<ToolDeclaration> {
        vec![ToolDeclaration {
            name: "echo".to_string(),
            description: "Echoes the input string back verbatim.".to_string(),
        }]
    }

    fn invoke(name: String, input_json: String) -> Result<String, String> {
        if name == "echo" {
            Ok(input_json)
        } else {
            Err(format!("unknown tool: {name}"))
        }
    }
}

export!(EchoPlugin);