use crate::*;

#[derive(Clone, Debug, PartialEq)]
pub enum TransportCommand {
    Focus(FocusCommand),
    Clock(ClockCommand),
}

impl<T: TransportControl> Command<T> for TransportCommand {
    fn execute (self, state: &mut T) -> Perhaps<Self> {
        use TransportCommand::{Focus, Clock};
        use FocusCommand::{Next, Prev};
        use ClockCommand::{SetBpm, SetQuant, SetSync};
        Ok(match self {
            Focus(cmd)             => cmd.execute(state)?.map(Focus),
            Clock(SetBpm(bpm))     => Some(Clock(SetBpm(state.bpm().set(bpm)))),
            Clock(SetQuant(quant)) => Some(Clock(SetQuant(state.quant().set(quant)))),
            Clock(SetSync(sync))   => Some(Clock(SetSync(state.sync().set(sync)))),
            _ => return Ok(None)
        })
    }
}

#[derive(Clone, Debug, PartialEq)]
pub enum SequencerCommand {
    Focus(FocusCommand),
    Undo,
    Redo,
    Clear,
    Clock(ClockCommand),
    Phrases(PhrasesCommand),
    Editor(PhraseCommand),
}

impl Command<SequencerTui> for SequencerCommand {
    fn execute (self, state: &mut SequencerTui) -> Perhaps<Self> {
        use SequencerCommand::*;
        Ok(match self {
            Focus(cmd)   => cmd.execute(state)?.map(Focus),
            Phrases(cmd) => cmd.execute(state)?.map(Phrases),
            Editor(cmd)  => cmd.execute(state)?.map(Editor),
            Clock(cmd)   => cmd.execute(state)?.map(Clock),
            Undo  => { todo!() },
            Redo  => { todo!() },
            Clear => { todo!() },
        })
    }
}

#[derive(Clone, Debug)]
pub enum ArrangerCommand {
    Focus(FocusCommand),
    Undo,
    Redo,
    Clear,
    Color(ItemColor),
    Clock(ClockCommand),
    Scene(ArrangerSceneCommand),
    Track(ArrangerTrackCommand),
    Clip(ArrangerClipCommand),
    Select(ArrangerSelection),
    Zoom(usize),
    Phrases(PhrasesCommand),
    Editor(PhraseCommand),
    EditPhrase(Option<Arc<RwLock<Phrase>>>),
}

impl Command<ArrangerTui> for ArrangerCommand {
    fn execute (self, state: &mut ArrangerTui) -> Perhaps<Self> {
        use ArrangerCommand::*;
        Ok(match self {
            Focus(cmd)       => cmd.execute(state)?.map(Focus),
            Scene(cmd)       => cmd.execute(state)?.map(Scene),
            Track(cmd)       => cmd.execute(state)?.map(Track),
            Clip(cmd)        => cmd.execute(state)?.map(Clip),
            Phrases(cmd)     => cmd.execute(state)?.map(Phrases),
            Editor(cmd)      => cmd.execute(state)?.map(Editor),
            Clock(cmd)       => cmd.execute(state)?.map(Clock),
            Zoom(zoom)       => { todo!(); },
            Select(selected) => {
                *state.selected_mut() = selected;
                None
            },
            EditPhrase(phrase) => {
                state.edit_phrase(&phrase);
                None
            },
            _ => { todo!() }
        })
    }
}

impl Command<ArrangerTui> for ArrangerSceneCommand {
    fn execute (self, state: &mut ArrangerTui) -> Perhaps<Self> {
        todo!();
        Ok(None)
    }
}

impl Command<ArrangerTui> for ArrangerTrackCommand {
    fn execute (self, state: &mut ArrangerTui) -> Perhaps<Self> {
        todo!();
        Ok(None)
    }
}

impl Command<ArrangerTui> for ArrangerClipCommand {
    fn execute (self, state: &mut ArrangerTui) -> Perhaps<Self> {
        todo!();
        Ok(None)
    }
}

#[derive(Clone, PartialEq, Debug)]
pub enum PhrasesCommand {
    Select(usize),
    Phrase(PhrasePoolCommand),
    Rename(PhraseRenameCommand),
    Length(PhraseLengthCommand),
    Import(FileBrowserCommand),
    Export(FileBrowserCommand),
}

impl<T: PhrasesControl> Command<T> for PhrasesCommand {
    fn execute (self, state: &mut T) -> Perhaps<Self> {
        use PhrasesCommand::*;
        Ok(match self {
            Phrase(command) => command.execute(state)?.map(Phrase),
            Rename(command) => match command {
                PhraseRenameCommand::Begin => {
                    let length = state.phrases()[state.phrase_index()].read().unwrap().length;
                    *state.phrases_mode_mut() = Some(
                        PhrasesMode::Length(state.phrase_index(), length, PhraseLengthFocus::Bar)
                    );
                    None
                },
                _ => command.execute(state)?.map(Rename)
            },
            Length(command) => match command {
                PhraseLengthCommand::Begin => {
                    let name = state.phrases()[state.phrase_index()].read().unwrap().name.clone();
                    *state.phrases_mode_mut() = Some(
                        PhrasesMode::Rename(state.phrase_index(), name)
                    );
                    None
                },
                _ => command.execute(state)?.map(Length)
            },
            Import(command) => match command {
                FileBrowserCommand::Begin => {
                    *state.phrases_mode_mut() = Some(
                        PhrasesMode::Import(state.phrase_index(), FileBrowser::new(None)?)
                    );
                    None
                },
                _ => command.execute(state)?.map(Import)
            },
            Export(command) => match command {
                FileBrowserCommand::Begin => {
                    *state.phrases_mode_mut() = Some(
                        PhrasesMode::Export(state.phrase_index(), FileBrowser::new(None)?)
                    );
                    None
                },
                _ => command.execute(state)?.map(Export)
            },
            Select(phrase) => {
                state.set_phrase_index(phrase);
                None
            },
        })
    }
}

#[derive(Copy, Clone, Debug, PartialEq)]
pub enum PhraseLengthCommand {
    Begin,
    Cancel,
    Set(usize),
    Next,
    Prev,
    Inc,
    Dec,
}

impl<T: PhrasesControl> Command<T> for PhraseLengthCommand {
    fn execute (self, state: &mut T) -> Perhaps<Self> {
        use PhraseLengthFocus::*;
        use PhraseLengthCommand::*;
        match state.phrases_mode_mut().clone() {
            Some(PhrasesMode::Length(phrase, ref mut length, ref mut focus)) => match self {
                Cancel => { *state.phrases_mode_mut() = None; },
                Prev => { focus.prev() },
                Next => { focus.next() },
                Inc => match focus {
                    Bar  => { *length += 4 * PPQ },
                    Beat => { *length += PPQ },
                    Tick => { *length += 1 },
                },
                Dec => match focus {
                    Bar  => { *length = length.saturating_sub(4 * PPQ) },
                    Beat => { *length = length.saturating_sub(PPQ) },
                    Tick => { *length = length.saturating_sub(1) },
                },
                Set(length) => {
                    let mut phrase = state.phrases()[phrase].write().unwrap();
                    let old_length = phrase.length;
                    phrase.length = length;
                    std::mem::drop(phrase);
                    *state.phrases_mode_mut() = None;
                    return Ok(Some(Self::Set(old_length)))
                },
                _ => unreachable!()
            },
            _ => unreachable!()
        };
        Ok(None)
    }
}

#[derive(Clone, Debug, PartialEq)]
pub enum PhraseRenameCommand {
    Begin,
    Cancel,
    Confirm,
    Set(String),
}

impl<T: PhrasesControl> Command<T> for PhraseRenameCommand {
    fn execute (self, state: &mut T) -> Perhaps<Self> {
        use PhraseRenameCommand::*;
        match state.phrases_mode_mut().clone() {
            Some(PhrasesMode::Rename(phrase, ref mut old_name)) => match self {
                Set(s) => {
                    state.phrases()[phrase].write().unwrap().name = s.into();
                    return Ok(Some(Self::Set(old_name.clone())))
                },
                Confirm => {
                    let old_name = old_name.clone();
                    *state.phrases_mode_mut() = None;
                    return Ok(Some(Self::Set(old_name)))
                },
                Cancel => {
                    state.phrases()[phrase].write().unwrap().name = old_name.clone();
                },
                _ => unreachable!()
            },
            _ => unreachable!()
        };
        Ok(None)
    }
}

/// Commands supported by [FileBrowser]
#[derive(Debug, Clone, PartialEq)]
pub enum FileBrowserCommand {
    Begin,
    Cancel,
    Confirm,
    Select(usize),
    Chdir(PathBuf),
    Filter(String),
}

impl<T: PhrasesControl> Command<T> for FileBrowserCommand {
    fn execute (self, state: &mut T) -> Perhaps<Self> {
        use FileBrowserCommand::*;
        let mode = state.phrases_mode_mut();
        match mode {
            Some(PhrasesMode::Import(index, ref mut browser)) => match self {
                Cancel => {
                    *mode = None;
                },
                Chdir(cwd) => {
                    *mode = Some(PhrasesMode::Import(*index, FileBrowser::new(Some(cwd))?));
                },
                Select(index) => {
                    browser.index = index;
                },
                Confirm => {
                    todo!("import midi to phrase");
                },
                _ => todo!(),
                _ => unreachable!()
            },
            Some(PhrasesMode::Export(index, ref mut browser)) => match self {
                Cancel => {
                    *mode = None;
                },
                Chdir(cwd) => {
                    *mode = Some(PhrasesMode::Export(*index, FileBrowser::new(Some(cwd))?));
                },
                Select(index) => {
                    browser.index = index;
                },
                _ => unreachable!()
            },
            _ => unreachable!(),
        };
        Ok(None)
    }
}

#[derive(Clone, PartialEq, Debug)]
pub enum PhraseCommand {
    // TODO: 1-9 seek markers that by default start every 8th of the phrase
    ToggleDirection,
    EnterEditMode,
    ExitEditMode,
    NoteAppend,
    NoteSet,
    NoteCursorSet(Option<usize>),
    NoteLengthSet(usize),
    NoteScrollSet(usize),
    TimeCursorSet(Option<usize>),
    TimeScrollSet(usize),
    TimeZoomSet(usize),
}

impl<T: PhraseEditorControl + HasEnter> Command<T> for PhraseCommand {
    fn execute (self, state: &mut T) -> Perhaps<Self> {
        use PhraseCommand::*;
        Ok(match self {
            ToggleDirection => { todo!() },
            EnterEditMode => { state.focus_enter(); None },
            ExitEditMode  => { state.focus_exit(); None },
            NoteAppend => {
                if state.phrase_editor_entered() {
                    state.put_note();
                    state.time_cursor_advance();
                }
                None
            },
            NoteSet => { if state.phrase_editor_entered() { state.put_note(); } None },
            TimeCursorSet(time) => { state.time_axis().write().unwrap().point_set(time); None },
            TimeScrollSet(time) => { state.time_axis().write().unwrap().start_set(time); None },
            TimeZoomSet(zoom)   => { state.time_axis().write().unwrap().scale_set(zoom); None },
            NoteScrollSet(note) => { state.note_axis().write().unwrap().start_set(note); None },
            NoteLengthSet(time) => { *state.note_len_mut() = time; None },
            NoteCursorSet(note) => {
                let mut axis = state.note_axis().write().unwrap();
                axis.point_set(note);
                if let Some(point) = axis.point {
                    if point > 73 {
                        axis.point = Some(73);
                    }
                    if point < axis.start {
                        axis.start = (point / 2) * 2;
                    }
                }
                None
            },
            _ => unreachable!()
        })
    }
}