extern crate termion;
extern crate tui;

use std::io;
use std::sync::mpsc;
use std::thread;
use std::time;

use termion::event;
use termion::input::TermRead;

use tui::backend::MouseBackend;
use tui::layout::{Constraint, Direction, Layout, Rect};
use tui::style::{Color, Modifier, Style};
use tui::widgets::{BarChart, Block, Borders, Widget};
use tui::Terminal;

struct App<'a> {
    size: Rect,
    data: Vec<(&'a str, u64)>,
}

impl<'a> App<'a> {
    fn new() -> App<'a> {
        App {
            size: Rect::default(),
            data: vec![
                ("B1", 9),
                ("B2", 12),
                ("B3", 5),
                ("B4", 8),
                ("B5", 2),
                ("B6", 4),
                ("B7", 5),
                ("B8", 9),
                ("B9", 14),
                ("B10", 15),
                ("B11", 1),
                ("B12", 0),
                ("B13", 4),
                ("B14", 6),
                ("B15", 4),
                ("B16", 6),
                ("B17", 4),
                ("B18", 7),
                ("B19", 13),
                ("B20", 8),
                ("B21", 11),
                ("B22", 9),
                ("B23", 3),
                ("B24", 5),
            ],
        }
    }

    fn advance(&mut self) {
        let value = self.data.pop().unwrap();
        self.data.insert(0, value);
    }
}

enum Event {
    Input(event::Key),
    Tick,
}

fn main() {
    // Terminal initialization
    let backend = MouseBackend::new().unwrap();
    let mut terminal = Terminal::new(backend).unwrap();

    // Channels
    let (tx, rx) = mpsc::channel();
    let input_tx = tx.clone();
    let clock_tx = tx.clone();

    // Input
    thread::spawn(move || {
        let stdin = io::stdin();
        for c in stdin.keys() {
            let evt = c.unwrap();
            input_tx.send(Event::Input(evt)).unwrap();
            if evt == event::Key::Char('q') {
                break;
            }
        }
    });

    // Tick
    thread::spawn(move || loop {
        clock_tx.send(Event::Tick).unwrap();
        thread::sleep(time::Duration::from_millis(500));
    });

    // App
    let mut app = App::new();

    // First draw call
    terminal.clear().unwrap();
    terminal.hide_cursor().unwrap();
    app.size = terminal.size().unwrap();
    draw(&mut terminal, &app).unwrap();

    loop {
        let size = terminal.size().unwrap();
        if app.size != size {
            terminal.resize(size).unwrap();
            app.size = size;
        }

        let evt = rx.recv().unwrap();
        match evt {
            Event::Input(input) => if input == event::Key::Char('q') {
                break;
            },
            Event::Tick => {
                app.advance();
            }
        }
        draw(&mut terminal, &app).unwrap();
    }

    terminal.show_cursor().unwrap();
}

fn draw(t: &mut Terminal<MouseBackend>, app: &App) -> Result<(), io::Error> {
    t.draw(|mut f| {
        let chunks = Layout::default()
            .direction(Direction::Vertical)
            .margin(2)
            .constraints([Constraint::Percentage(50), Constraint::Percentage(50)].as_ref())
            .split(app.size);
        BarChart::default()
            .block(Block::default().title("Data1").borders(Borders::ALL))
            .data(&app.data)
            .bar_width(9)
            .style(Style::default().fg(Color::Yellow))
            .value_style(Style::default().fg(Color::Black).bg(Color::Yellow))
            .render(&mut f, chunks[0]);
        {
            let chunks = Layout::default()
                .direction(Direction::Horizontal)
                .constraints([Constraint::Percentage(50), Constraint::Percentage(50)].as_ref())
                .split(chunks[1]);
            BarChart::default()
                .block(Block::default().title("Data2").borders(Borders::ALL))
                .data(&app.data)
                .bar_width(5)
                .bar_gap(3)
                .style(Style::default().fg(Color::Green))
                .value_style(Style::default().bg(Color::Green).modifier(Modifier::Bold))
                .render(&mut f, chunks[0]);
            BarChart::default()
                .block(Block::default().title("Data3").borders(Borders::ALL))
                .data(&app.data)
                .style(Style::default().fg(Color::Red))
                .bar_width(7)
                .bar_gap(0)
                .value_style(Style::default().bg(Color::Red))
                .label_style(Style::default().fg(Color::Cyan).modifier(Modifier::Italic))
                .render(&mut f, chunks[1]);
        }
    })
}
