use crate::*;

#[derive(Debug)]
pub struct Pool {
    pub visible: bool,
    /// Collection of clips
    pub clips:   Arc<RwLock<Vec<Arc<RwLock<MidiClip>>>>>,
    /// Selected clip
    pub clip:    AtomicUsize,
    /// Mode switch
    pub mode:    Option<PoolMode>,
    /// Embedded file browser
    pub browser: Option<Browser>,
}
//take!(BrowserCommand |state: Pool, iter|Ok(state.browser.as_ref()
    //.map(|p|Take::take(p, iter))
    //.transpose()?
    //.flatten()));
impl Default for Pool {
    fn default () -> Self {
        //use PoolMode::*;
        Self {
            visible: true,
            clips:   Arc::from(RwLock::from(vec![])),
            clip:    0.into(),
            mode:    None,
            browser: None,
        }
    }
}

impl Pool {
    pub fn clip_index (&self) -> usize {
        self.clip.load(Relaxed)
    }
    pub fn set_clip_index (&self, value: usize) {
        self.clip.store(value, Relaxed);
    }
    pub fn mode (&self) -> &Option<PoolMode> {
        &self.mode
    }
    pub fn mode_mut (&mut self) -> &mut Option<PoolMode> {
        &mut self.mode
    }
    pub fn begin_clip_length (&mut self) {
        let length = self.clips()[self.clip_index()].read().unwrap().length;
        *self.mode_mut() = Some(PoolMode::Length(
            self.clip_index(),
            length,
            ClipLengthFocus::Bar
        ));
    }
    pub fn begin_clip_rename (&mut self) {
        let name = self.clips()[self.clip_index()].read().unwrap().name.clone();
        *self.mode_mut() = Some(PoolMode::Rename(
            self.clip_index(),
            name
        ));
    }
    pub fn begin_import (&mut self) -> Usually<()> {
        *self.mode_mut() = Some(PoolMode::Import(
            self.clip_index(),
            Browser::new(None)?
        ));
        Ok(())
    }
    pub fn begin_export (&mut self) -> Usually<()> {
        *self.mode_mut() = Some(PoolMode::Export(
            self.clip_index(),
            Browser::new(None)?
        ));
        Ok(())
    }
    pub fn new_clip (&self) -> MidiClip {
        MidiClip::new("Clip", true, 4 * PPQ, None, Some(ItemTheme::random()))
    }
    pub fn cloned_clip (&self) -> MidiClip {
        let index    = self.clip_index();
        let mut clip = self.clips()[index].read().unwrap().duplicate();
        clip.color   = ItemTheme::random_near(clip.color, 0.25);
        clip
    }
    pub fn add_new_clip (&self) -> (usize, Arc<RwLock<MidiClip>>) {
        let clip = Arc::new(RwLock::new(self.new_clip()));
        let index = {
            let mut clips = self.clips.write().unwrap();
            clips.push(clip.clone());
            clips.len().saturating_sub(1)
        };
        self.clip.store(index, Relaxed);
        (index, clip)
    }
    pub fn delete_clip (&mut self, clip: &MidiClip) -> bool {
        let index = self.clips.read().unwrap().iter().position(|x|*x.read().unwrap()==*clip);
        if let Some(index) = index {
            self.clips.write().unwrap().remove(index);
            return true
        }
        false
    }
}

/// Modes for clip pool
#[derive(Debug, Clone)]
pub enum PoolMode {
    /// Renaming a pattern
    Rename(usize, Arc<str>),
    /// Editing the length of a pattern
    Length(usize, usize, ClipLengthFocus),
    /// Load clip from disk
    Import(usize, Browser),
    /// Save clip to disk
    Export(usize, Browser),
}

/// Focused field of `ClipLength`
#[derive(Copy, Clone, Debug)]
pub enum ClipLengthFocus {
    /// Editing the number of bars
    Bar,
    /// Editing the number of beats
    Beat,
    /// Editing the number of ticks
    Tick,
}

impl ClipLengthFocus {
    pub fn next (&mut self) {
        use ClipLengthFocus::*;
        *self = match self { Bar => Beat, Beat => Tick, Tick => Bar, }
    }
    pub fn prev (&mut self) {
        use ClipLengthFocus::*;
        *self = match self { Bar => Tick, Beat => Bar, Tick => Beat, }
    }
}

/// Displays and edits clip length.
#[derive(Clone)]
pub struct ClipLength {
    /// Pulses per beat (quaver)
    ppq: usize,
    /// Beats per bar
    bpb: usize,
    /// Length of clip in pulses
    pulses: usize,
    /// Selected subdivision
    pub focus: Option<ClipLengthFocus>,
}

impl ClipLength {
    pub fn _new (pulses: usize, focus: Option<ClipLengthFocus>) -> Self {
        Self { ppq: PPQ, bpb: 4, pulses, focus }
    }
    pub fn bars  (&self) -> usize {
        self.pulses / (self.bpb * self.ppq)
    }
    pub fn beats (&self) -> usize {
        (self.pulses % (self.bpb * self.ppq)) / self.ppq
    }
    pub fn ticks (&self) -> usize {
        self.pulses % self.ppq
    }
    pub fn bars_string  (&self) -> Arc<str> {
        format!("{}", self.bars()).into()
    }
    pub fn beats_string (&self) -> Arc<str> {
        format!("{}", self.beats()).into()
    }
    pub fn ticks_string (&self) -> Arc<str> {
        format!("{:>02}", self.ticks()).into()
    }
}

pub type ClipPool = Vec<Arc<RwLock<MidiClip>>>;

pub trait HasClips {
    fn clips <'a> (&'a self) -> std::sync::RwLockReadGuard<'a, ClipPool>;
    fn clips_mut <'a> (&'a self) -> std::sync::RwLockWriteGuard<'a, ClipPool>;
    fn add_clip (&self) -> (usize, Arc<RwLock<MidiClip>>) {
        let clip = Arc::new(RwLock::new(MidiClip::new("Clip", true, 384, None, None)));
        self.clips_mut().push(clip.clone());
        (self.clips().len() - 1, clip)
    }
}

#[macro_export] macro_rules! has_clips {
    (|$self:ident:$Struct:ident$(<$($L:lifetime),*$($T:ident$(:$U:path)?),*>)?|$cb:expr) => {
        impl $(<$($L),*$($T $(: $U)?),*>)? HasClips for $Struct $(<$($L),*$($T),*>)? {
            fn clips <'a> (&'a $self) -> std::sync::RwLockReadGuard<'a, ClipPool>      {
                $cb.read().unwrap()
            }
            fn clips_mut <'a> (&'a $self) -> std::sync::RwLockWriteGuard<'a, ClipPool> {
                $cb.write().unwrap()
            }
        }
    }
}

has_clips!(|self: Pool|self.clips);

has_clip!(|self: Pool|self.clips().get(self.clip_index()).map(|c|c.clone()));

from!(|clip:&Arc<RwLock<MidiClip>>|Pool = {
    let model = Self::default();
    model.clips.write().unwrap().push(clip.clone());
    model.clip.store(1, Relaxed);
    model
});