use iced::{
    widget::{column, text_input},
    Element, Sandbox, Settings,
};

pub fn main() -> iced::Result {
    App::run(Settings::default())
}

#[derive(Default)]
struct App {
    displacement: f64,
    ui: UI,
}

#[derive(Default)]
struct UI {
    displacement: String,
}

impl App {
    fn set_displacement(&mut self, displacement: &str) {
        if displacement.len() == 0 {
            self.displacement = 0.;
        } else if let Ok(d) = displacement.parse::<f64>() {
            self.displacement = d;
        }
        self.ui.displacement = String::from(displacement);
    }
}

impl Sandbox for App {
    type Message = Message;

    fn new() -> Self {
        Self::default()
    }

    fn title(&self) -> String {
        String::from("volute")
    }

    fn update(&mut self, message: Message) {
        match message {
            Message::DisplacementChanged(displacement) => {
                self.set_displacement(&displacement);
            }
        }
    }

    fn view(&self) -> Element<Self::Message> {
        column![text_input(
            "placeholder",
            &self.ui.displacement,
            Message::DisplacementChanged,
        ),]
        .into()
    }
}

#[derive(Debug, Clone)]
pub enum Message {
    DisplacementChanged(String),
}