use crate::*;

#[derive(Clone, PartialEq)]
pub enum SequencerCommand {
    FocusNext,
    FocusPrev,
    FocusUp,
    FocusDown,
    FocusLeft,
    FocusRight,
    Transport(TransportCommand),
    Phrases(PhrasePoolCommand),
    Editor(PhraseEditorCommand),
}
#[derive(Clone, PartialEq)]
pub enum PhrasePoolCommand {
    Prev,
    Next,
    MoveUp,
    MoveDown,
    Delete,
    Append,
    Insert,
    Duplicate,
    RandomColor,
    Edit,
    Import,
    Export,
    Rename(PhraseRenameCommand),
    Length(PhraseLengthCommand),
}
#[derive(Clone, PartialEq)]
pub enum PhraseRenameCommand {
    Begin,
    Backspace,
    Append(char),
    Set(String),
    Confirm,
    Cancel,
}
#[derive(Clone, PartialEq)]
pub enum PhraseLengthCommand {
    Begin,
    Next,
    Prev,
    Inc,
    Dec,
    Set(usize),
    Confirm,
    Cancel,
}
#[derive(Clone, PartialEq)]
pub enum PhraseEditorCommand {
    // TODO: 1-9 seek markers that by default start every 8th of the phrase
    ToggleDirection,
    EnterEditMode,
    ExitEditMode,
    NoteLengthDec,
    NoteLengthInc,
    TimeZoomIn,
    TimeZoomOut,
    NoteAppend,
    NoteSet,
    NotePageUp,
    NotePageDown,
    GoUp,
    GoDown,
    GoLeft,
    GoRight,
}
impl<E: Engine> Command<Sequencer<E>> for SequencerCommand {
    fn run (&self, state: &mut Sequencer<E>) -> Perhaps<Self> {
        use SequencerCommand::*;
        match self {
            FocusNext  => { state.focus_next(); },
            FocusPrev  => { state.focus_prev(); },
            FocusUp    => { state.focus_up(); },
            FocusDown  => { state.focus_down(); },
            FocusLeft  => { state.focus_left(); },
            FocusRight => { state.focus_right(); },
            Transport(command) => if let Some(ref transport) = state.transport {
                return command.run(&mut*transport.write().unwrap()).map(|x|x.map(Transport))
            },
            Phrases(command)   => {
                return command.run(&mut*state.phrases.write().unwrap()).map(|x|x.map(Phrases))
            },
            Editor(command)    => {
                return command.run(&mut state.editor).map(|x|x.map(Editor))
            },
        }
        Ok(None)
    }
}
impl<E: Engine> Command<PhrasePool<E>> for PhrasePoolCommand {
    fn run (&self, state: &mut PhrasePool<E>) -> Perhaps<Self> {
        use PhrasePoolCommand::*;
        use PhraseRenameCommand as Rename;
        use PhraseLengthCommand as Length;
        match self {
            Prev                  => { state.select_prev() },
            Next                  => { state.select_next() },
            Delete                => { state.delete_selected() },
            Append                => { state.append_new(None, None) },
            Insert                => { state.insert_new(None, None) },
            Duplicate             => { state.insert_dup() },
            Edit                  => { todo!(); }
            RandomColor           => { state.randomize_color() },
            MoveUp                => { state.move_up() },
            MoveDown              => { state.move_down() },
            Rename(Rename::Begin) => { state.begin_rename() },
            Rename(_)             => { unreachable!() },
            Length(Length::Begin) => { state.begin_length() },
            Length(_)             => { unreachable!() },
            Import                => todo!(),
            Export                => todo!(),
        }
        Ok(None)
    }
}
impl<E: Engine> Command<PhrasePool<E>> for PhraseRenameCommand {
    fn run (&self, state: &mut PhrasePool<E>) -> Perhaps<Self> {
        use PhraseRenameCommand::*;
        if let Some(PhrasePoolMode::Rename(phrase, ref mut old_name)) = state.mode {
            match self {
                Begin => { unreachable!(); },
                Backspace => {
                    let mut phrase = state.phrases[phrase].write().unwrap();
                    let old_name = phrase.name.clone();
                    phrase.name.pop();
                    return Ok(Some(Self::Set(old_name)))
                },
                Append(c) => {
                    let mut phrase = state.phrases[phrase].write().unwrap();
                    let old_name = phrase.name.clone();
                    phrase.name.push(*c);
                    return Ok(Some(Self::Set(old_name)))
                },
                Set(s) => {
                    let mut phrase = state.phrases[phrase].write().unwrap();
                    phrase.name = s.into();
                    return Ok(Some(Self::Set(old_name.clone())))
                },
                Confirm => {
                    let old_name = old_name.clone();
                    state.mode = None;
                    return Ok(Some(Self::Set(old_name)))
                },
                Cancel => {
                    let mut phrase = state.phrases[phrase].write().unwrap();
                    phrase.name = old_name.clone();
                }
            };
            Ok(None)
        } else if *self == Begin {
            todo!()
        } else {
            unreachable!()
        }
    }
}
impl<E: Engine> Command<PhrasePool<E>> for PhraseLengthCommand {
    fn run (&self, state: &mut PhrasePool<E>) -> Perhaps<Self> {
        use PhraseLengthCommand::*;
        if let Some(PhrasePoolMode::Length(phrase, ref mut length, ref mut focus)) = state.mode {
            match self {
                Begin => { unreachable!(); },
                Cancel => { state.mode = None; },
                Confirm => { return Self::Set(*length).run(state) },
                Prev => { focus.prev() },
                Next => { focus.next() },
                Inc => {
                    use PhraseLengthFocus::*;
                    match focus {
                        Bar  => { *length += 4 * PPQ },
                        Beat => { *length += PPQ },
                        Tick => { *length += 1 },
                    }
                },
                Dec => {
                    use PhraseLengthFocus::*;
                    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;
                    state.mode = None;
                    return Ok(Some(Self::Set(old_length)))
                },
            }
            Ok(None)
        } else if *self == Begin {
            todo!()
        } else {
            unreachable!()
        }
    }
}
impl<E: Engine> Command<PhraseEditor<E>> for PhraseEditorCommand {
    fn run (&self, state: &mut PhraseEditor<E>) -> Perhaps<Self> {
        use PhraseEditorCommand::*;
        match self {
            ToggleDirection => { state.mode = !state.mode; },
            EnterEditMode => { state.entered = true; },
            ExitEditMode => { state.entered = false; },
            TimeZoomOut => { state.time_zoom_out() },
            TimeZoomIn => { state.time_zoom_in() },
            NoteLengthDec => { state.note_length_dec() },
            NoteLengthInc => { state.note_length_inc() },
            NotePageUp => { state.note_page_up() },
            NotePageDown => { state.note_page_down() },
            NoteAppend => if state.entered {
                state.put();
                state.time_cursor_advance();
            },
            NoteSet => if state.entered { state.put(); },
            GoUp => match state.entered {
                true  => state.note_cursor_inc(),
                false => state.note_scroll_inc(),
            },
            GoDown => match state.entered {
                true  => state.note_cursor_dec(),
                false => state.note_scroll_dec(),
            },
            GoLeft => match state.entered {
                true  => state.time_cursor_dec(),
                false => state.time_scroll_dec(),
            },
            GoRight => match state.entered {
                true  => state.time_cursor_inc(),
                false => state.time_scroll_inc(),
            },
        }
        Ok(None)
    }
}