use std::sync::Arc;
use std::sync::atomic::AtomicBool;

use anyhow::Result;
use assistant_slash_command::{
    ArgumentCompletion, SlashCommand, SlashCommandOutput, SlashCommandOutputSection,
    SlashCommandResult,
};
use chrono::Local;
use gpui::{Task, WeakEntity};
use language::{BufferSnapshot, LspAdapterDelegate};
use ui::prelude::*;
use workspace::Workspace;

pub struct NowSlashCommand;

impl SlashCommand for NowSlashCommand {
    fn name(&self) -> String {
        "now".into()
    }

    fn description(&self) -> String {
        "Insert current date and time".into()
    }

    fn menu_text(&self) -> String {
        self.description()
    }

    fn requires_argument(&self) -> bool {
        false
    }

    fn complete_argument(
        self: Arc<Self>,
        _arguments: &[String],
        _cancel: Arc<AtomicBool>,
        _workspace: Option<WeakEntity<Workspace>>,
        _window: &mut Window,
        _cx: &mut App,
    ) -> Task<Result<Vec<ArgumentCompletion>>> {
        Task::ready(Ok(Vec::new()))
    }

    fn run(
        self: Arc<Self>,
        _arguments: &[String],
        _context_slash_command_output_sections: &[SlashCommandOutputSection<language::Anchor>],
        _context_buffer: BufferSnapshot,
        _workspace: WeakEntity<Workspace>,
        _delegate: Option<Arc<dyn LspAdapterDelegate>>,
        _window: &mut Window,
        _cx: &mut App,
    ) -> Task<SlashCommandResult> {
        let now = Local::now();
        let text = format!("Today is {now}.", now = now.to_rfc2822());
        let range = 0..text.len();

        Task::ready(Ok(SlashCommandOutput {
            text,
            sections: vec![SlashCommandOutputSection {
                range,
                icon: IconName::CountdownTimer,
                label: now.to_rfc2822().into(),
                metadata: None,
            }],
            run_commands_in_text: false,
        }
        .to_event_stream()))
    }
}