use anki_bridge::{AnkiClient, AnkiRequestable, prelude::*};
use crossterm::{
    cursor,
    event::{self, Event, KeyCode},
    execute,
    style::*,
    terminal::*,
};
use nanohtml2text::html2text;
use std::{
    io::stdout,
    process::{Command, Stdio},
    thread,
    time::Duration,
};

const GOOD: char = '3';
const AGAIN: char = '1';

fn main() {
    let anki = AnkiClient::default();
    init(&anki);
    loop {
        prompt(&anki);
    }
}

fn init(anki: &AnkiClient) {
    clear_screen();
    let mut decks = anki.request(DeckNamesRequest {});
    if let Err(_) = decks {
        clear_screen();
        display_text("initializing headless anki...");
        Command::new("bash")
            .arg("-c")
            .arg("QT_QPA_PLATFORM=xcb xvfb-run -a anki")
            .stdin(Stdio::null())
            .stdout(Stdio::null())
            .stderr(Stdio::null())
            .spawn()
            .unwrap();
        loop {
            thread::sleep(Duration::from_secs(1));
            display_text(".");
            decks = anki.request(DeckNamesRequest {});
            if let Ok(_) = decks {
                clear_screen();
                break;
            }
        }
    }
    let decks = decks.unwrap();
    for (index, title) in decks.clone().into_iter().enumerate() {
        // 0th index is Default, which is not predictable
        if index > 0 {
            println!("{:?}: {}", index, title);
        }
    }
    display_prompt_text("deck index:");
    let mut input = "".to_string();
    loop {
        match event::read().unwrap() {
            Event::Key(e) => match e.code {
                KeyCode::Char(c) => input = input + &c.to_string(),
                KeyCode::Enter => break,
                _ => (),
            },
            _ => (),
        }
    }
    clear_screen();
    display_text("loading...");
    anki.request(GuiDeckReviewRequest {
        name: decks[input.parse::<usize>().unwrap()].clone(),
    })
    .unwrap();
}

fn prompt(anki: &AnkiClient) {
    flush_read();
    // needs to be done twice to account for lag on the other end
    anki.request(GuiCurrentCardRequest {}).unwrap();
    let card = anki.request(GuiCurrentCardRequest {}).unwrap();
    clear_with_bar(&anki, &card);
    display_html(&card.question);
    loop {
        match event::read().unwrap() {
            Event::Key(e) => match e.code {
                KeyCode::Enter => break,
                KeyCode::Char('u') => {
                    anki.request(GuiUndoRequest {}).unwrap();
                    return;
                }
                _ => (),
            },
            _ => (),
        };
    }
    anki.request(GuiShowAnswerRequest {}).unwrap();
    clear_with_bar(&anki, &card);
    {
        let length = html2text(&card.question).len();
        let text = &html2text(&card.answer)[(2 + length)..];
        display_text(&text);
    }
    display_prompt_text(":");
    let ease = loop {
        match event::read().unwrap() {
            Event::Key(e) => match e.code {
                KeyCode::Char(AGAIN) => break Ease::Again,
                KeyCode::Char(GOOD) => break Ease::Good,
                KeyCode::Char('u') => {
                    anki.request(GuiUndoRequest {}).unwrap();
                    return;
                }
                _ => (),
            },
            _ => (),
        };
    };
    anki.request(GuiAnswerCardRequest { ease: ease }).unwrap();
}

fn flush_read() {
    loop {
        if event::poll(Duration::from_secs(0)).unwrap() {
            event::read().unwrap();
        } else {
            break;
        }
    }
}

fn clear_with_bar(anki: &AnkiClient, current_card: &GuiCurrentCardResponse) {
    let deck_name = &current_card.deck_name;
    let deck_stats = anki
        .request(GetDeckStatsRequest {
            decks: vec![deck_name.to_string()],
        })
        .unwrap()
        .into_iter()
        .next()
        .unwrap()
        .1;
    clear_screen();
    execute!(
        stdout(),
        SetForegroundColor(Color::Blue),
        Print(&format!("{:?} ", deck_stats.new_count)),
        SetForegroundColor(Color::Red),
        Print(&format!("{:?} ", deck_stats.learn_count)),
        SetForegroundColor(Color::Green),
        Print(&format!("{:?}\n", deck_stats.review_count)),
        ResetColor
    )
    .unwrap();
}

fn clear_screen() {
    execute!(
        stdout(),
        Clear(ClearType::All),
        cursor::MoveTo(0, 0),
        cursor::Hide
    )
    .unwrap();
}

fn display_prompt_text(text: &str) {
    execute!(
        stdout(),
        SetForegroundColor(Color::Blue),
        Print(text),
        ResetColor
    )
    .unwrap();
}

fn display_html(html: &str) {
    let text = html2text(html);
    display_text(&text);
}

fn display_text(text: &str) {
    execute!(
        stdout(),
        SetForegroundColor(Color::DarkYellow),
        Print(text),
        ResetColor
    )
    .unwrap();
}