use crate::{*, clock::*, sequence::*, sample::*};

def_command!(FileBrowserCommand: |sampler: Sampler|{
    //("begin"   []            Some(Self::Begin))
    //("cancel"  []            Some(Self::Cancel))
    //("confirm" []            Some(Self::Confirm))
    //("select"  [i: usize]    Some(Self::Select(i.expect("no index"))))
    //("chdir"   [p: PathBuf]  Some(Self::Chdir(p.expect("no path"))))
    //("filter"  [f: Arc<str>] Some(Self::Filter(f.expect("no filter")))))
});

/// Browses for files to load/save.
///
/// ```
/// let browse = tek::Browse::default();
/// ```
#[derive(Debug, Clone, Default, PartialEq)] pub struct Browse {
    pub cwd:    PathBuf,
    pub dirs:   Vec<(OsString, String)>,
    pub files:  Vec<(OsString, String)>,
    pub filter: String,
    pub index:  usize,
    pub scroll: usize,
    pub size:   [AtomicUsize; 2],
}

pub(crate) struct EntriesIterator<'a> {
    pub browser: &'a Browse,
    pub offset:  usize,
    pub length:  usize,
    pub index:   usize,
}

#[derive(Clone, Debug)] pub enum BrowseTarget {
    SaveProject,
    LoadProject,
    ImportSample(Arc<RwLock<Option<Sample>>>),
    ExportSample(Arc<RwLock<Option<Sample>>>),
    ImportClip(Arc<RwLock<Option<MidiClip>>>),
    ExportClip(Arc<RwLock<Option<MidiClip>>>),
}

/// A clip pool.
///
/// ```
/// let pool = tek::Pool::default();
/// ```
#[derive(Debug)] pub struct Pool {
    pub visible: bool,
    /// Selected clip
    pub clip: AtomicUsize,
    /// Mode switch
    pub mode: Option<PoolMode>,
    /// Embedded file browse
    #[cfg(feature = "browse")]  pub browse:  Option<Browse>,
    /// Collection of MIDI clips.
    #[cfg(feature = "clip")]    pub clips:   Arc<RwLock<Vec<Arc<RwLock<MidiClip>>>>>,
    /// Collection of sound samples.
    #[cfg(feature = "sampler")] pub samples: Arc<RwLock<Vec<Arc<RwLock<Sample>>>>>,
}

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

/// Some sort of wrapper again?
pub struct PoolView<'a>(pub &'a Pool);

// Commands supported by [Browse]
//#[derive(Debug, Clone, PartialEq)]
//pub enum BrowseCommand {
    //Begin,
    //Cancel,
    //Confirm,
    //Select(usize),
    //Chdir(PathBuf),
    //Filter(Arc<str>),
//}

/// 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, Browse),
    /// Save clip to disk
    Export(usize, Browse),
}

/// 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,
}
has_clip!(|self: Pool|self.clips().get(self.clip_index()).map(|c|c.clone()));
impl_has_clips!(|self: Pool|self.clips);
impl_from!(Pool: |clip:&Arc<RwLock<MidiClip>>|{
    let model = Self::default();
    model.clips.write().unwrap().push(clip.clone());
    model.clip.store(1, Relaxed);
    model
});
impl_default!(Pool: Self {
    browse:  None,
    clip:    0.into(),
    clips:   Arc::from(RwLock::from(vec![])),
    mode:    None,
    samples: Arc::from(RwLock::from(vec![])),
    visible: true,
});
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(),
            Browse::new(None)?
        ));
        Ok(())
    }
    pub fn begin_export (&mut self) -> Usually<()> {
        *self.mode_mut() = Some(PoolMode::Export(
            self.clip_index(),
            Browse::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
    }
}
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, }
    }
}
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()
    }
}

impl Pool {
    fn _todo_usize_ (&self) -> usize     { todo!() }
    fn _todo_bool_  (&self) -> bool      { todo!() }
    fn _todo_clip_  (&self) -> MidiClip  { todo!() }
    fn _todo_path_  (&self) -> PathBuf   { todo!() }
    fn _todo_color_ (&self) -> ItemColor { todo!() }
    fn _todo_str_   (&self) -> Arc<str>  { todo!() }
    fn _clip_new (&self) -> MidiClip { self.new_clip() }
    fn _clip_cloned (&self) -> MidiClip { self.cloned_clip() }
    fn _clip_index_current (&self) -> usize { 0 }
    fn _clip_index_after (&self) -> usize { 0 }
    fn _clip_index_previous (&self) -> usize { 0 }
    fn _clip_index_next (&self) -> usize { 0 }
    fn _color_random (&self) -> ItemColor { ItemColor::random() }
}

impl<'a> PoolView<'a> {
    fn tui (&self) -> impl Draw<Tui> {
        let Self(pool) = self;
        //let color  = self.1.clip().map(|c|c.read().unwrap().color).unwrap_or_else(||Tui::g(32).into());
        //let on_bg  = |x|x;//below(Repeat(" "), Tui::bg(color.darkest.term, x));
        //let border = |x|x;//Outer(Style::default().fg(color.dark.term).bg(color.darkest.term)).enclose(x);
        //let height = pool.clips.read().unwrap().len() as u16;
        w_exact(20, h_full(origin_n(iter(
            ||pool.clips().clone().into_iter(),
            move|clip: Arc<RwLock<MidiClip>>, i: usize|{
            let item_height = 1;
            let item_offset = i as u16 * item_height;
            let selected    = i == pool.clip_index();
            let MidiClip { ref name, color, length, .. } = *clip.read().unwrap();
            let bg     = if selected { color.light.term } else { color.base.term };
            let fg     = color.lightest.term;
            let name   = if false { format!(" {i:>3}") } else { format!(" {i:>3} {name}") };
            let length = if false { String::default()  } else { format!("{length}  ") };
            h_exact(1, iter_south(item_offset, item_height, Tui::bg(bg, below!(
                w_full(origin_w(Tui::fg(fg, Tui::bold(selected, name)))),
                w_full(origin_e(Tui::fg(fg, Tui::bold(selected, length)))),
                w_full(origin_w(When::new(selected, Tui::bold(true, Tui::fg(Tui::g(255), "▶"))))),
                w_full(origin_e(When::new(selected, Tui::bold(true, Tui::fg(Tui::g(255), "◀"))))),
            ))))
        }))))
    }
}
impl ClipLength {
    fn tui (&self) -> impl Draw<Tui> {
        use ClipLengthFocus::*;
        let bars  = ||self.bars_string();
        let beats = ||self.beats_string();
        let ticks = ||self.ticks_string();
        match self.focus {
            None       => east!(" ", bars(), ".", beats(), ".", ticks()),
            Some(Bar)  => east!("[", bars(), "]", beats(), ".", ticks()),
            Some(Beat) => east!(" ", bars(), "[", beats(), "]", ticks()),
            Some(Tick) => east!(" ", bars(), ".", beats(), "[", ticks()),
        }
    }
}

impl Browse {
    pub fn new (cwd: Option<PathBuf>) -> Usually<Self> {
        let cwd = if let Some(cwd) = cwd { cwd } else { std::env::current_dir()? };
        let mut dirs  = vec![];
        let mut files = vec![];
        for entry in std::fs::read_dir(&cwd)? {
            let entry   = entry?;
            let name    = entry.file_name();
            let decoded = name.clone().into_string().unwrap_or_else(|_|"<unreadable>".to_string());
            let meta    = entry.metadata()?;
            if meta.is_dir() {
                dirs.push((name, format!("📁 {decoded}")));
            } else if meta.is_file() {
                files.push((name, format!("📄 {decoded}")));
            }
        }
        Ok(Self { cwd, dirs, files, ..Default::default() })
    }
    pub fn chdir (&self) -> Usually<Self> { Self::new(Some(self.path())) }
    pub fn len (&self) -> usize { self.dirs.len() + self.files.len() }
    pub fn is_dir (&self) -> bool { self.index < self.dirs.len() }
    pub fn is_file (&self) -> bool { self.index >= self.dirs.len() }
    pub fn path (&self) -> PathBuf {
        self.cwd.join(if self.is_dir() {
            &self.dirs[self.index].0
        } else if self.is_file() {
            &self.files[self.index - self.dirs.len()].0
        } else {
            unreachable!()
        })
    }
    fn _todo_stub_path_buf (&self) -> PathBuf { todo!() }
    fn _todo_stub_usize (&self) -> usize { todo!() }
    fn _todo_stub_arc_str (&self) -> Arc<str> { todo!() }
}
impl Browse {
    fn tui (&self) -> impl Draw<Tui> {
        iter_south(1, ||EntriesIterator {
            offset:  0,
            index:   0,
            length:  self.dirs.len() + self.files.len(),
            browser: self,
        }, |entry, _index|w_full(origin_w(entry)))
    }
}
impl<'a> Iterator for EntriesIterator<'a> {
    type Item = Modify<&'a str>;
    fn next (&mut self) -> Option<Self::Item> {
        let dirs  = self.browser.dirs.len();
        let files = self.browser.files.len();
        let index = self.index;
        if self.index < dirs {
            self.index += 1;
            Some(Tui::bold(true, self.browser.dirs[index].1.as_str()))
        } else if self.index < dirs + files {
            self.index += 1;
            Some(Tui::bold(false, self.browser.files[index - dirs].1.as_str()))
        } else {
            None
        }
    }
}
impl PartialEq for BrowseTarget {
    fn eq (&self, other: &Self) -> bool {
        match self {
            Self::ImportSample(_) => false,
            Self::ExportSample(_) => false,
            Self::ImportClip(_) => false,
            Self::ExportClip(_) => false,
            #[allow(unused)] t => matches!(other, t)
        }
    }
}

def_command!(BrowseCommand: |browse: Browse| {
    SetVisible => Ok(None),
    SetPath { address: PathBuf } => Ok(None),
    SetSearch { filter: Arc<str> } => Ok(None),
    SetCursor { cursor: usize } => Ok(None),
});

def_command!(PoolCommand: |pool: Pool| {
    // Toggle visibility of pool
    Show { visible: bool } => { pool.visible = *visible; Ok(Some(Self::Show { visible: !visible })) },
    // Select a clip from the clip pool
    Select { index: usize } => { pool.set_clip_index(*index); Ok(None) },
    // Update the contents of the clip pool
    Clip { command: PoolClipCommand } => Ok(command.execute(pool)?.map(|command|Self::Clip{command})),
    // Rename a clip
    Rename { command: RenameCommand } => Ok(command.delegate(pool, |command|Self::Rename{command})?),
    // Change the length of a clip
    Length { command: CropCommand } => Ok(command.delegate(pool, |command|Self::Length{command})?),
    // Import from file
    Import { command: BrowseCommand } => Ok(if let Some(browse) = pool.browse.as_mut() {
        command.delegate(browse, |command|Self::Import{command})?
    } else {
        None
    }),
    // Export to file
    Export { command: BrowseCommand } => Ok(if let Some(browse) = pool.browse.as_mut() {
        command.delegate(browse, |command|Self::Export{command})?
    } else {
        None
    }),
});

def_command!(PoolClipCommand: |pool: Pool| {
    Delete { index: usize } => {
        let index = *index;
        let clip = pool.clips_mut().remove(index).read().unwrap().clone();
        Ok(Some(Self::Add { index, clip }))
    },
    Swap { index: usize, other: usize } => {
        let index = *index;
        let other = *other;
        pool.clips_mut().swap(index, other);
        Ok(Some(Self::Swap { index, other }))
    },
    Export { index: usize, path: PathBuf } => {
        todo!("export clip to midi file");
    },
    Add { index: usize, clip: MidiClip } => {
        let index = *index;
        let mut index = index;
        let clip = Arc::new(RwLock::new(clip.clone()));
        let mut clips = pool.clips_mut();
        if index >= clips.len() {
            index = clips.len();
            clips.push(clip)
        } else {
            clips.insert(index, clip);
        }
        Ok(Some(Self::Delete { index }))
    },
    Import { index: usize, path: PathBuf } => {
        let index = *index;
        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);
        }
        Ok(Self::Add { index, clip }.execute(pool)?)
    },
    SetName { index: usize, name: Arc<str> } => {
        let index = *index;
        let clip = &mut pool.clips_mut()[index];
        let old_name = clip.read().unwrap().name.clone();
        clip.write().unwrap().name = name.clone();
        Ok(Some(Self::SetName { index, name: old_name }))
    },
    SetLength { index: usize, length: usize } => {
        let index = *index;
        let clip = &mut pool.clips_mut()[index];
        let old_len = clip.read().unwrap().length;
        clip.write().unwrap().length = *length;
        Ok(Some(Self::SetLength { index, length: old_len }))
    },
    SetColor { index: usize, color: ItemColor } => {
        let index = *index;
        let mut color = ItemTheme::from(*color);
        std::mem::swap(&mut color, &mut pool.clips()[index].write().unwrap().color);
        Ok(Some(Self::SetColor { index, color: color.base }))
    },
});

def_command!(RenameCommand: |pool: Pool| {
    Begin => unreachable!(),
    Cancel => {
        if let Some(PoolMode::Rename(clip, ref mut old_name)) = pool.mode_mut().clone() {
            pool.clips()[clip].write().unwrap().name = old_name.clone().into();
        }
        Ok(None)
    },
    Confirm => {
        if let Some(PoolMode::Rename(_clip, ref mut old_name)) = pool.mode_mut().clone() {
            let old_name = old_name.clone(); *pool.mode_mut() = None; return Ok(Some(Self::Set { value: old_name }))
        }
        Ok(None)
    },
    Set { value: Arc<str> } => {
        if let Some(PoolMode::Rename(clip, ref mut _old_name)) = pool.mode_mut().clone() {
            pool.clips()[clip].write().unwrap().name = value.clone();
        }
        Ok(None)
    },
});

def_command!(CropCommand: |pool: Pool| {
    Begin => unreachable!(),
    Cancel => { if let Some(PoolMode::Length(..)) = pool.mode_mut().clone() { *pool.mode_mut() = None; } Ok(None) },
    Set { length: usize } => {
        if let Some(PoolMode::Length(clip, ref mut length, ref mut _focus))
            = pool.mode_mut().clone()
        {
            let old_length;
            {
                let clip = pool.clips()[clip].clone();//.write().unwrap();
                old_length = Some(clip.read().unwrap().length);
                clip.write().unwrap().length = *length;
            }
            *pool.mode_mut() = None;
            return Ok(old_length.map(|length|Self::Set { length }))
        }
        Ok(None)
    },
    Next => {
        if let Some(PoolMode::Length(_clip, ref mut _length, ref mut focus)) = pool.mode_mut().clone() { focus.next() }; Ok(None)
    },
    Prev => {
        if let Some(PoolMode::Length(_clip, ref mut _length, ref mut focus)) = pool.mode_mut().clone() { focus.prev() }; Ok(None)
    },
    Inc => {
        if let Some(PoolMode::Length(_clip, ref mut length, ref mut focus)) = pool.mode_mut().clone() {
            match focus {
                ClipLengthFocus::Bar  => { *length += 4 * PPQ },
                ClipLengthFocus::Beat => { *length += PPQ     },
                ClipLengthFocus::Tick => { *length += 1       },
            }
        }
        Ok(None)
    },
    Dec => {
        if let Some(PoolMode::Length(_clip, ref mut length, ref mut focus)) = pool.mode_mut().clone() {
            match focus {
                ClipLengthFocus::Bar  => { *length = length.saturating_sub(4 * PPQ) },
                ClipLengthFocus::Beat => { *length = length.saturating_sub(PPQ)     },
                ClipLengthFocus::Tick => { *length = length.saturating_sub(1)       },
            }
        }
        Ok(None)
    }
});