use crate::*;

handle!(TuiIn: |self: MidiPool, input|{
    //Ok(if let Some(command) = match self.mode() {
        //Some(PoolMode::Rename(..)) => self.keys_rename,
        //Some(PoolMode::Length(..)) => self.keys_length,
        //Some(PoolMode::Import(..)) | Some(PoolMode::Export(..)) => self.keys_file,
        //_ => self.keys
    //}.command::<Self, PoolCommand, TuiIn>(self, input) {
    Ok(if let Some(command) = self.keys.command(self, input) {
        let _undo = command.execute(self)?;
        Some(true)
    } else {
        None
    })
});

provide!(bool: |self: MidiPool| {});

provide!(MidiClip: |self: MidiPool| {
    ":new-clip"    => self.new_clip(),
    ":cloned-clip" => self.cloned_clip(),
});

provide!(PathBuf:  |self: MidiPool| {});

provide!(Arc<str>: |self: MidiPool| {});

provide!(usize: |self: MidiPool| {
    ":current"  => 0,
    ":after"    => 0,
    ":previous" => 0,
    ":next"     => 0
});

provide!(ItemColor: |self: MidiPool| {
    ":random-color" => ItemColor::random()
});

#[derive(Clone, PartialEq, Debug)] pub enum PoolCommand {
    /// Toggle visibility of pool
    Show(bool),
    /// Select a clip from the clip pool
    Select(usize),
    /// Rename a clip
    Rename(ClipRenameCommand),
    /// Change the length of a clip
    Length(ClipLengthCommand),
    /// Import from file
    Import(FileBrowserCommand),
    /// Export to file
    Export(FileBrowserCommand),
    /// Update the contents of the clip pool
    Clip(PoolClipCommand),
}

atom_command!(PoolCommand: |state: MidiPool| {
    ("show"   [a: bool]  Some(Self::Show(a.expect("no flag"))))
    ("select" [i: usize] Some(Self::Select(i.expect("no index"))))
    ("rename" [,..a] ClipRenameCommand::try_from_expr(state, a).map(Self::Rename))
    ("length" [,..a] ClipLengthCommand::try_from_expr(state, a).map(Self::Length))
    ("import" [,..a] FileBrowserCommand::try_from_expr(state, a).map(Self::Import))
    ("export" [,..a] FileBrowserCommand::try_from_expr(state, a).map(Self::Export))
    ("clip"   [,..a] PoolClipCommand::try_from_expr(state, a).map(Self::Clip))
});

command!(|self: PoolCommand, state: MidiPool|{
    use PoolCommand::*;
    match self {
        Rename(ClipRenameCommand::Begin) => { state.begin_clip_rename(); None }
        Rename(command) => command.delegate(state, Rename)?,
        Length(ClipLengthCommand::Begin) => { state.begin_clip_length(); None },
        Length(command) => command.delegate(state, Length)?,
        Import(FileBrowserCommand::Begin) => { state.begin_import()?; None },
        Import(command) => command.delegate(state, Import)?,
        Export(FileBrowserCommand::Begin) => { state.begin_export()?; None },
        Export(command) => command.delegate(state, Export)?,
        Clip(command) => command.execute(state)?.map(Clip),
        Show(visible) => { state.visible = visible; Some(Self::Show(!visible)) },
        Select(clip) => { state.set_clip_index(clip); None },
    }
});

#[derive(Clone, Debug, PartialEq)] pub enum PoolClipCommand {
    Add(usize, MidiClip),
    Delete(usize),
    Swap(usize, usize),
    Import(usize, PathBuf),
    Export(usize, PathBuf),
    SetName(usize, Arc<str>),
    SetLength(usize, usize),
    SetColor(usize, ItemColor),
}

atom_command!(PoolClipCommand: |state: MidiPool| {
    ("add"        [i: usize, c: MidiClip]
        Some(Self::Add(i.expect("no index"), c.expect("no clip"))))
    ("delete"     [i: usize]
        Some(Self::Delete(i.expect("no index"))))
    ("swap"       [a: usize, b: usize]
        Some(Self::Swap(a.expect("no index"), b.expect("no index"))))
    ("import"     [i: usize, p: PathBuf]
        Some(Self::Import(i.expect("no index"), p.expect("no path"))))
    ("export"     [i: usize, p: PathBuf]
        Some(Self::Export(i.expect("no index"), p.expect("no path"))))
    ("set-name"   [i: usize, n: Arc<str>]
        Some(Self::SetName(i.expect("no index"), n.expect("no name"))))
    ("set-length" [i: usize, l: usize]
        Some(Self::SetLength(i.expect("no index"), l.expect("no length"))))
    ("set-color"  [i: usize, c: ItemColor]
        Some(Self::SetColor(i.expect("no index"), c.expect("no color"))))
});

impl<T: HasClips> Command<T> for PoolClipCommand {
    fn execute (self, model: &mut T) -> Perhaps<Self> {
        use PoolClipCommand::*;
        Ok(match self {
            Add(mut index, clip) => {
                let clip  = Arc::new(RwLock::new(clip));
                let mut clips = model.clips_mut();
                if index >= clips.len() {
                    index = clips.len();
                    clips.push(clip)
                } else {
                    clips.insert(index, clip);
                }
                Some(Self::Delete(index))
            },
            Delete(index) => {
                let clip = model.clips_mut().remove(index).read().unwrap().clone();
                Some(Self::Add(index, clip))
            },
            Swap(index, other) => {
                model.clips_mut().swap(index, other);
                Some(Self::Swap(index, other))
            },
            Import(index, path) => {
                let bytes = std::fs::read(&path)?;
                let smf = Smf::parse(bytes.as_slice())?;
                let mut t = 0u32;
                let mut events = vec![];
                for track in smf.tracks.iter() {
                    for event in track.iter() {
                        t += event.delta.as_int();
                        if let TrackEventKind::Midi { channel, message } = event.kind {
                            events.push((t, channel.as_int(), message));
                        }
                    }
                }
                let mut clip = MidiClip::new("imported", true, t as usize + 1, None, None);
                for event in events.iter() {
                    clip.notes[event.0 as usize].push(event.2);
                }
                Self::Add(index, clip).execute(model)?
            },
            Export(_index, _path) => {
                todo!("export clip to midi file");
            },
            SetName(index, name) => {
                let clip = &mut model.clips_mut()[index];
                let old_name = clip.read().unwrap().name.clone();
                clip.write().unwrap().name = name;
                Some(Self::SetName(index, old_name))
            },
            SetLength(index, length) => {
                let clip = &mut model.clips_mut()[index];
                let old_len = clip.read().unwrap().length;
                clip.write().unwrap().length = length;
                Some(Self::SetLength(index, old_len))
            },
            SetColor(index, color) => {
                let mut color = ItemTheme::from(color);
                std::mem::swap(&mut color, &mut model.clips()[index].write().unwrap().color);
                Some(Self::SetColor(index, color.base))
            },
        })
    }
}