use {
    std::sync::Arc,
    std::sync::RwLock,
    termion::event::{Key, Event},
    cgmath::Point2,
    crate::{
        core::{ViewPort, OuterViewPort, Observer},
        singleton::{SingletonView, SingletonBuffer},
        sequence::{SequenceView, SequenceViewExt},
        vec::VecBuffer,
        terminal::{TerminalAtom, TerminalStyle, TerminalView, TerminalEvent, TerminalEditor, TerminalEditorResult},
        tree_nav::{TreeNav, TreeNavResult, TerminalTreeEditor, TreeCursor},
        list::{ListEditor, ListEditorStyle, sexpr::ListDecoration}
    }
};

//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>

pub struct DigitEditor {
    radix: u32,
    data: SingletonBuffer<Option<char>>,
    data_port: ViewPort<dyn SingletonView<Item = Option<char>>>,
}

impl DigitEditor {
    pub fn new(radix: u32) -> Self {
        let mut data_port = ViewPort::new();
        DigitEditor {
            radix,
            data: SingletonBuffer::new(None, data_port.inner()),
            data_port
        }
    }

    pub fn get_data_port(&self) -> OuterViewPort<dyn SingletonView<Item = Option<u32>>> {
        let radix = self.radix;
        self.data_port.outer().map(
            move |c| c?.to_digit(radix)
        )
    }
}

impl TreeNav for DigitEditor {}
impl TerminalEditor for DigitEditor {
    fn get_term_view(&self) -> OuterViewPort<dyn TerminalView> {
        let radix = self.radix;
        self.data_port.outer().map(
            move |c| TerminalAtom::new(
                c.unwrap_or('?'),
                if c.unwrap_or('?').to_digit(radix).is_some() {
                    TerminalStyle::fg_color((100, 140, 100))
                } else {
                    //TerminalStyle::bg_color((90, 10, 10))
                    TerminalStyle::fg_color((200, 40, 40))
                }
            )
        ).to_grid()
    }

    fn handle_terminal_event(&mut self, event: &TerminalEvent) -> TerminalEditorResult {
        match event {
            TerminalEvent::Input(Event::Key(Key::Char(' '))) |
            TerminalEvent::Input(Event::Key(Key::Char('\n'))) =>
                TerminalEditorResult::Exit,
            TerminalEvent::Input(Event::Key(Key::Char(c))) => {
                self.data.set(Some(*c));
                TerminalEditorResult::Exit
            }
            TerminalEvent::Input(Event::Key(Key::Backspace)) |
            TerminalEvent::Input(Event::Key(Key::Delete)) => {
                self.data.set(None);
                TerminalEditorResult::Exit
            }
            _ => TerminalEditorResult::Continue
        }
    }
}

pub struct PosIntEditor {
    radix: u32,
    digits_editor: ListEditor< DigitEditor,
                               Box<dyn Fn() -> Arc<RwLock<DigitEditor>> + Send + Sync + 'static> >
}

impl PosIntEditor {
    pub fn new(radix: u32) -> Self {
        PosIntEditor {
            radix,
            digits_editor: ListEditor::new(
                Box::new(
                    move || {
                        Arc::new(RwLock::new(DigitEditor::new(radix)))
                    }
                ),
                crate::list::ListEditorStyle::Hex
            )
        }
    }

    pub fn get_data_port(&self) -> OuterViewPort<dyn SequenceView<Item = u32>> {
        let radix = self.radix;
        self.digits_editor.get_data_port()
            .filter_map(move |digit_editor| digit_editor.read().unwrap().data.get()?.to_digit(radix))
    }

    pub fn get_value(&self) -> u32 {
        let mut value = 0;
        let mut weight = 1;
        for digit_value in self.get_data_port().get_view().unwrap().iter().collect::<Vec<_>>().into_iter().rev() {
            value += digit_value * weight;
            weight *= self.radix;
        }

        value
    }
}

impl TreeNav for PosIntEditor {
    fn get_cursor(&self) -> TreeCursor { self.digits_editor.get_cursor() }
    fn goto(&mut self, cur: TreeCursor) -> TreeNavResult  { self.digits_editor.goto(cur) }
    fn goto_home(&mut self) -> TreeNavResult  { self.digits_editor.goto_home() }
    fn goto_end(&mut self) -> TreeNavResult  { self.digits_editor.goto_end() }
    fn pxev(&mut self) -> TreeNavResult  { self.digits_editor.pxev() }
    fn nexd(&mut self) -> TreeNavResult  { self.digits_editor.nexd() }
    fn up(&mut self) -> TreeNavResult { self.digits_editor.up() }
    fn dn(&mut self) -> TreeNavResult { self.digits_editor.dn() }
}

impl TerminalEditor for PosIntEditor {
    fn get_term_view(&self) -> OuterViewPort<dyn TerminalView> {
        self.digits_editor
            .get_seg_seq_view()
            .decorate(
                match self.radix {
                    2 => "0b",
                    8 => "0o",
                    10 => "0d",
                    16 => "0x",
                    _ => ""
                },
                "",
                "",
                0
            )
            .to_grid_horizontal()
            .flatten()
    }

    fn handle_terminal_event(&mut self, event: &TerminalEvent) -> TerminalEditorResult {
        match event {
            TerminalEvent::Input(Event::Key(Key::Char(' '))) |
            TerminalEvent::Input(Event::Key(Key::Char('\n'))) => {
                self.digits_editor.up();
                TerminalEditorResult::Exit
            }

            event => self.digits_editor.handle_terminal_event(event)
        }
    }
}