use std::sync::Arc; use anyhow::{anyhow, Result};use assistant_tool::Tool;use chrono::{Local, Utc};use gpui::{App, Task, WeakEntity, Window};use schemars::JsonSchema;use serde::{Deserialize, Serialize}; #[derive(Debug, Serialize, Deserialize, JsonSchema)]#[serde(rename_all = "snake_case")]pub enum Timezone {    /// Use UTC for the datetime.    Utc,    /// Use local time for the datetime.    Local,} #[derive(Debug, Serialize, Deserialize, JsonSchema)]pub struct NowToolInput {    /// The timezone to use for the datetime.    timezone: Timezone,} pub struct NowTool; impl Tool for NowTool {    fn name(&self) -> String {        "now".into()    }     fn description(&self) -> String {        "Returns the current datetime in RFC 3339 format. Only use this tool when the user specifically asks for it or the current task would benefit from knowing the current datetime.".into()    }     fn input_schema(&self) -> serde_json::Value {        let schema = schemars::schema_for!(NowToolInput);        serde_json::to_value(&schema).unwrap()    }     fn run(        self: Arc<Self>,        input: serde_json::Value,        _workspace: WeakEntity<workspace::Workspace>,        _window: &mut Window,        _cx: &mut App,    ) -> Task<Result<String>> {        let input: NowToolInput = match serde_json::from_value(input) {            Ok(input) => input,            Err(err) => return Task::ready(Err(anyhow!(err))),        };         let now = match input.timezone {            Timezone::Utc => Utc::now().to_rfc3339(),            Timezone::Local => Local::now().to_rfc3339(),        };        let text = format!("The current datetime is {now}.");         Task::ready(Ok(text))    }}