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
        })
    };
}

impl Handle<TuiIn> for Taggart {
    fn handle (&mut self, input: &TuiIn) -> Perhaps<bool> {
        let x_min = self.offset;
        let x_max = self.offset + self.size.h().saturating_sub(1);
        let event = &*input.event();
        match &self.editing {
            None => match event {
                press!(Up)        => { self.cursor = self.cursor.saturating_sub(1); },
                press!(Down)      => { self.cursor = self.cursor + 1; },
                press!(PageUp)    => { self.cursor = self.cursor.saturating_sub(PAGE_SIZE); },
                press!(PageDown)  => { self.cursor += PAGE_SIZE; },
                press!(Left)      => { self.column = self.column.saturating_sub(1); },
                press!(Right)     => { self.column = self.column + 1; },
                press!(Enter)     => { self.edit_begin() },
                press!(Char(' ')) => { open(&self.paths[self.cursor].path)?; }
                press!(Char(']')) => { self.columns.0[self.column].width += 1; }
                press!(Char('[')) => { self.columns.0[self.column].width =
                    self.columns.0[self.column].width.saturating_sub(1).max(5); }
                _ => {}
            },
            Some(_value) => match event {
                press!(Char(c))       => self.edit_insert(*c),
                press!(Shift-Char(c)) => self.edit_insert(c.to_uppercase().next().unwrap()),
                press!(Backspace)     => self.edit_backspace(),
                press!(Delete)        => self.edit_delete(),
                press!(Enter)         => self.edit_cancel(),
                press!(Esc)           => self.edit_confirm(),
                _ => {}
            },
        }
        if self.cursor < x_min {
            self.offset = self.cursor;
        }
        if self.cursor > x_max {
            self.offset += self.cursor - x_max;
        }
        if self.cursor >= self.paths.len() {
            self.cursor = self.paths.len().saturating_sub(1)
        }
        if self.column + 1 > self.columns.0.len() {
            self.column = self.columns.0.len().saturating_sub(1)
        }
        Ok(None)
    }
}