use crate::*;

/// A plugin device.
pub struct Plugin<E> {
    _engine:      PhantomData<E>,
    /// JACK client handle (needs to not be dropped for standalone mode to work).
    pub jack:     Arc<RwLock<JackClient>>,
    pub name:     String,
    pub path:     Option<String>,
    pub plugin:   Option<PluginKind>,
    pub selected: usize,
    pub mapping:  bool,
    pub ports:    JackPorts,
}

impl<E> Plugin<E> {
    /// Create a plugin host device.
    pub fn new (
        jack: &Arc<RwLock<JackClient>>,
        name: &str,
    ) -> Usually<Self> {
        Ok(Self {
            _engine:    Default::default(),
            jack:       jack.clone(),
            name:       name.into(),
            path:       None,
            plugin:     None,
            selected:   0,
            mapping:    false,
            ports:      JackPorts::default()
        })
    }
}
impl Widget for Plugin<Tui> {
    type Engine = Tui;
    fn layout (&self, to: [u16;2]) -> Perhaps<[u16;2]> {
        Ok(Some(to))
    }
    fn render (&self, to: &mut TuiOutput) -> Usually<()> {
        let area = to.area();
        let [x, y, _, height] = area;
        let mut width = 20u16;
        match &self.plugin {
            Some(PluginKind::LV2(LV2Plugin { port_list, instance, .. })) => {
                let start = self.selected.saturating_sub((height as usize / 2).saturating_sub(1));
                let end   = start + height as usize - 2;
                //draw_box(buf, Rect { x, y, width, height });
                for i in start..end {
                    if let Some(port) = port_list.get(i) {
                        let value = if let Some(value) = instance.control_input(port.index) {
                            value
                        } else {
                            port.default_value
                        };
                        //let label = &format!("C·· M·· {:25} = {value:.03}", port.name);
                        let label = &format!("{:25} = {value:.03}", port.name);
                        width = width.max(label.len() as u16 + 4);
                        let style = if i == self.selected {
                            Some(Style::default().green())
                        } else {
                            None
                        } ;
                        to.blit(&label, x + 2, y + 1 + i as u16 - start as u16, style);
                    } else {
                        break
                    }
                }
            },
            _ => {}
        };
        draw_header(self, to, x, y, width)?;
        Ok(())
    }
}

fn draw_header <E> (state: &Plugin<E>, to: &mut TuiOutput, x: u16, y: u16, w: u16) -> Usually<Rect> {
    let style  = Style::default().gray();
    let label1 = format!(" {}", state.name);
    to.blit(&label1, x + 1, y, Some(style.white().bold()));
    if let Some(ref path) = state.path {
        let label2 = format!("{}…", &path[..((w as usize - 10).min(path.len()))]);
        to.blit(&label2, x + 2 + label1.len() as u16, y, Some(style.not_dim()));
    }
    Ok(Rect { x, y, width: w, height: 1 })
}

impl Handle<Tui> for Plugin<Tui> {
    fn handle (&mut self, from: &TuiInput) -> Perhaps<bool> {
        match from.event() {
            key!(KeyCode::Up) => {
                self.selected = self.selected.saturating_sub(1);
                Ok(Some(true))
            },
            key!(KeyCode::Down) => {
                self.selected = (self.selected + 1).min(match &self.plugin {
                    Some(PluginKind::LV2(LV2Plugin { port_list, .. })) => port_list.len() - 1,
                    _ => unimplemented!()
                });
                Ok(Some(true))
            },
            key!(KeyCode::PageUp) => {
                self.selected = self.selected.saturating_sub(8);
                Ok(Some(true))
            },
            key!(KeyCode::PageDown) => {
                self.selected = (self.selected + 10).min(match &self.plugin {
                    Some(PluginKind::LV2(LV2Plugin { port_list, .. })) => port_list.len() - 1,
                    _ => unimplemented!()
                });
                Ok(Some(true))
            },
            key!(KeyCode::Char(',')) => {
                match self.plugin.as_mut() {
                    Some(PluginKind::LV2(LV2Plugin { port_list, ref mut instance, .. })) => {
                        let index = port_list[self.selected].index;
                        if let Some(value) = instance.control_input(index) {
                            instance.set_control_input(index, value - 0.01);
                        }
                    },
                    _ => {}
                }
                Ok(Some(true))
            },
            key!(KeyCode::Char('.')) => {
                match self.plugin.as_mut() {
                    Some(PluginKind::LV2(LV2Plugin { port_list, ref mut instance, .. })) => {
                        let index = port_list[self.selected].index;
                        if let Some(value) = instance.control_input(index) {
                            instance.set_control_input(index, value + 0.01);
                        }
                    },
                    _ => {}
                }
                Ok(Some(true))
            },
            key!(KeyCode::Char('g')) => {
                match self.plugin {
                    Some(PluginKind::LV2(ref mut plugin)) => {
                        plugin.ui_thread = Some(run_lv2_ui(LV2PluginUI::new()?)?);
                    },
                    Some(_) => unreachable!(),
                    None => {}
                }
                Ok(Some(true))
            },
            _ => Ok(None)
        }
    }
}