use crate::core::*;

mod lv2;  pub use lv2::*;
mod vst2;
mod vst3;

pub struct Plugin {
    name:       String,
    path:       Option<String>,
    plugin:     Option<PluginKind>,
    selected:   usize,
    mapping:    bool,
    midi_ins:   Vec<Port<MidiIn>>,
    midi_outs:  Vec<Port<MidiOut>>,
    audio_ins:  Vec<Port<AudioIn>>,
    audio_outs: Vec<Port<AudioOut>>,
}

enum PluginKind {
    LV2(LV2Plugin),
    VST2 {
        instance: ::vst::host::PluginInstance
    },
    VST3,
}

const HELM: &'static str = "file:///nix/store/ij3sz7nqg5l7v2dygdvzy3w6cj62bd6r-helm-0.9.0/lib/lv2/helm.lv2";

impl Plugin {
    /// Load a LV2 plugin.
    pub fn lv2 (name: &str, path: &str) -> Usually<DynamicDevice<Self>> {
        let host       = Self::new(name)?;
        let plugin     = LV2Plugin::new(path)?;
        let mut state  = host.state();
        let client     = host.client.as_ref().unwrap().as_client();
        let (midi_ins, midi_outs, audio_ins, audio_outs) = (
            plugin.plugin.port_counts().atom_sequence_inputs,
            plugin.plugin.port_counts().atom_sequence_outputs,
            plugin.plugin.port_counts().audio_inputs,
            plugin.plugin.port_counts().audio_outputs,
        );
        state.midi_ins = {
            let mut ports = vec![];
            for i in 0..midi_ins {
                ports.push(client.register_port(&format!("midi-in-{i}"), MidiIn::default())?)
            }
            ports
        };
        state.midi_outs = {
            let mut ports = vec![];
            for i in 0..midi_outs {
                ports.push(client.register_port(&format!("midi-out-{i}"), MidiOut::default())?)
            }
            ports
        };
        state.audio_ins = {
            let mut ports = vec![];
            for i in 0..audio_ins {
                ports.push(client.register_port(&format!("audio-in-{i}"), AudioIn::default())?)
            }
            ports
        };
        state.audio_outs = {
            let mut ports = vec![];
            for i in 0..audio_outs {
                ports.push(client.register_port(&format!("audio-out-{i}"), AudioOut::default())?)
            }
            ports
        };
        state.plugin = Some(PluginKind::LV2(plugin));
        state.path   = Some(String::from(path));
        std::mem::drop(state);
        Ok(host)
    }
    pub fn new (name: &str) -> Usually<DynamicDevice<Self>> {
        DynamicDevice::new(render, handle, Self::process, Self {
            name:       name.into(),
            path:       None,
            plugin:     None,
            selected:   0,
            mapping:    false,
            midi_ins:   vec![],
            midi_outs:  vec![],
            audio_ins:  vec![],
            audio_outs: vec![],
        }).activate(Client::new(name, ClientOptions::NO_START_SERVER)?.0)
    }
    pub fn process (&mut self, _: &Client, scope: &ProcessScope) -> Control {
        match self.plugin.as_mut() {
            Some(PluginKind::LV2(LV2Plugin { features, ref mut instance, .. })) => {
                let urid = features.midi_urid();
                let mut inputs = vec![];
                for port in self.midi_ins.iter() {
                    let mut atom = ::livi::event::LV2AtomSequence::new(
                        &features,
                        scope.n_frames() as usize
                    );
                    for event in port.iter(scope) {
                        match event.bytes.len() {
                            3 => atom.push_midi_event::<3>(
                                event.time as i64,
                                urid,
                                &event.bytes[0..3]
                            ).unwrap(),
                            _ => {}
                        }
                    }
                    inputs.push(atom);
                }
                let mut outputs = vec![];
                for _ in self.midi_outs.iter() {
                    outputs.push(::livi::event::LV2AtomSequence::new(
                        &features,
                        scope.n_frames() as usize
                    ));
                }
                let ports = ::livi::EmptyPortConnections::new()
                    .with_atom_sequence_inputs(
                        inputs.iter()
                    )
                    .with_atom_sequence_outputs(
                        outputs.iter_mut()
                    )
                    .with_audio_inputs(
                        self.audio_ins.iter().map(|o|o.as_slice(scope))
                    )
                    .with_audio_outputs(
                        self.audio_outs.iter_mut().map(|o|o.as_mut_slice(scope))
                    );
                unsafe {
                    instance.run(scope.n_frames() as usize, ports).unwrap()
                };
            },
            _ => {}
        }
        Control::Continue
    }
}

impl PortList for Plugin {
    fn audio_ins (&self) -> Usually<Vec<String>> {
        let mut ports = vec![];
        for port in self.audio_ins.iter() {
            ports.push(port.name()?);
        }
        Ok(ports)
    }
    fn audio_outs (&self) -> Usually<Vec<String>> {
        let mut ports = vec![];
        for port in self.audio_outs.iter() {
            ports.push(port.name()?);
        }
        Ok(ports)
    }
    fn midi_ins (&self) -> Usually<Vec<String>> {
        let mut ports = vec![];
        for port in self.midi_ins.iter() {
            ports.push(port.name()?);
        }
        Ok(ports)
    }
    fn midi_outs (&self) -> Usually<Vec<String>> {
        let mut ports = vec![];
        for port in self.midi_outs.iter() {
            ports.push(port.name()?);
        }
        Ok(ports)
    }
}

pub fn render (state: &Plugin, buf: &mut Buffer, area: Rect)
    -> Usually<Rect>
{
    let Rect { x, y, height, .. } = area;
    let mut width = 20u16;
    match &state.plugin {
        Some(PluginKind::LV2(LV2Plugin { port_list, instance, .. })) => {
            let start = state.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);
                    label.blit(buf, x + 2, y + 1 + i as u16 - start as u16, if i == state.selected {
                        Some(Style::default().green())
                    } else {
                        None
                    });
                } else {
                    break
                }
            }
        },
        _ => {}
    };
    draw_header(state, buf, area.x, area.y, width)?;
    Ok(Rect { width, ..area })
}

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

pub fn handle (s: &mut Plugin, event: &AppEvent) -> Usually<bool> {
    handle_keymap(s, event, keymap!(Plugin {

        [Up,   NONE, "cursor_up",   "move cursor up",
            |s: &mut Plugin|{
                if s.selected > 0 {
                    s.selected = s.selected - 1
                } else {
                    s.selected = match &s.plugin {
                        Some(PluginKind::LV2(LV2Plugin { port_list, .. })) => port_list.len() - 1,
                        _ => 0
                    }
                }
                Ok(true)
            }],

        [Down, NONE, "cursor_down", "move cursor down",
            |s: &mut Plugin|{
                s.selected = s.selected + 1;
                match &s.plugin {
                    Some(PluginKind::LV2(LV2Plugin { port_list, .. })) => {
                        if s.selected >= port_list.len() {
                            s.selected = 0;
                        }
                    },
                    _ => {}
                }
                Ok(true)
            }],

        [Char(','), NONE, "decrement", "decrement value",
            |s: &mut Plugin|{
                match s.plugin.as_mut() {
                    Some(PluginKind::LV2(LV2Plugin { port_list, ref mut instance, .. })) => {
                        let index = port_list[s.selected].index;
                        if let Some(value) = instance.control_input(index) {
                            instance.set_control_input(index, value - 0.01);
                        }
                    },
                    _ => {}
                }
                Ok(true)
            }],

        [Char('.'), NONE, "increment", "increment value",
            |s: &mut Plugin|{
                match s.plugin.as_mut() {
                    Some(PluginKind::LV2(LV2Plugin { port_list, ref mut instance, .. })) => {
                        let index = port_list[s.selected].index;
                        if let Some(value) = instance.control_input(index) {
                            instance.set_control_input(index, value + 0.01);
                        }
                    },
                    _ => {}
                }
                Ok(true)
            }],

        [Char('m'), NONE, "toggle_midi_map", "toggle midi map mode",
            |s: &mut Plugin|{
                s.mapping = !s.mapping;
                Ok(true)
            }]

    }))
}