use std::process::Command;

use style;
use ui::context::Context;
use widgets::{Message, Update, Widget, WidgetParams};

pub struct Disk {
    context: Context,
    mount: String,
    space: String
}

pub fn disk(params: WidgetParams) -> Box<Widget> {
    let config: DiskConfig = params.config.try_into().unwrap();
    let widget = Disk {
        context: params.context,
        mount: config.mount,
        space: "???".to_string()
    };
    Box::new(widget)
}

impl Widget for Disk {
    fn render(&mut self, x: u16, width: u16) {
        style::render(&self.context, &self.mount, &self.space, x, width);
    }

    fn width(&mut self) -> u16 {
        style::width(&self.context, &self.mount, &self.space)
    }

    fn handle_event(&mut self, event: &Message) -> Update {
        match event {
            &Message::Update => {
                let output = Command::new("df")
                  .arg("--output=avail")
                  .arg("-h")
                  .arg(&self.mount)
                  .output()
                  .ok()
                  .expect("Could not run df");

                let output = String::from_utf8_lossy(&output.stdout);
                let space = output.lines().nth(1).expect("Could not get space");
                let space = space.trim().to_string();

                let changed = space != self.space;
                self.space = space;

                if changed {
                    Update::Relayout
                }
                else {
                    Update::Nothing
                }
            },
            _ => Update::Nothing
        }
    }
}

#[derive(Deserialize)]
struct DiskConfig {
    mount: String
}