use crate::*;
use opener::open;

macro_rules! press {
    (Shift-$($key:tt)+) => {
        Event::Key(KeyEvent {
            code:      KeyCode::$($key)+,
            kind:      KeyEventKind::Press,
            modifiers: KeyModifiers::SHIFT,
            state:     KeyEventState::NONE
        })
    };
    ($($key:tt)+) => {
        Event::Key(KeyEvent {
            code:      KeyCode::$($key)+,
            kind:      KeyEventKind::Press,
            modifiers: KeyModifiers::NONE,
            state:     KeyEventState::NONE
        })
    };
}

mod edit;
mod save;
mod quit;
mod help;

impl Handle<TuiIn> for Perch {
    fn handle (&mut self, input: &TuiIn) -> Perhaps<bool> {
        let min = self.offset;
        let max = self.offset + self.display.h().saturating_sub(1);
        let event = &*input.event();
        match &self.mode {
            Some(Mode::Edit { .. })     => self.handle_edit(event),
            Some(Mode::Help { page })   => self.handle_help(event, *page),
            Some(Mode::Save { choice }) => self.handle_save(event, *choice)?,
            Some(Mode::Quit { choice }) => self.handle_quit(input, *choice)?,
            None => match event {
                press!(F(1))      => { self.help_begin() },
                press!(Char('q')) => { self.quit_begin(&input) },
                press!(Char('w')) => { self.save_begin() },
                press!(Up)        => { self.cursor_select(-1); },
                press!(Down)      => { self.cursor_select( 1); },
                press!(PageUp)    => { self.cursor_select(-(PAGE_SIZE as isize)); },
                press!(PageDown)  => { self.cursor_select(  PAGE_SIZE as isize);  },
                press!(Left)      => { self.column_select(-1); },
                press!(Right)     => { self.column_select( 1); },
                press!(Char('[')) => { self.column_resize(-1); },
                press!(Char(']')) => { self.column_resize( 1); },
                press!(Char('{')) => { self.column_collapse(true);  self.column_select( 1); },
                press!(Char('}')) => { self.column_collapse(false); self.column_select(-1); },
                press!(Delete)    => { self.edit_clear() },
                press!(Enter)     => { self.edit_begin() },
                press!(Char(' ')) => { self.open_in_player()?; },
                _ => {}
            },
        }
        self.clamp(min, max);
        Ok(None)
    }
}

impl Perch {
    fn open_in_player (&self) -> Usually<()> {
        open(self.entries[self.cursor].path.as_ref())?;
        Ok(())
    }
    fn cursor_select (&mut self, amount: isize) {
        self.cursor = ((self.cursor as isize) + amount).max(0) as usize;
    }
    fn column_select (&mut self, amount: isize) {
        self.column = ((self.column as isize) + amount).max(0) as usize;
    }
    fn column_resize (&mut self, amount: isize) {
        let column = &mut self.columns.0[self.column];
        column.width = ((column.width as isize) + amount).max(0) as usize;
    }
    fn column_collapse (&mut self, value: bool) {
        let column = &mut self.columns.0[self.column];
        column.collapsed = value;
    }
}