pub mod message;
pub mod question;
pub mod util;

use crate::{db, space_repetition, util::event::Events, util::time};
use anyhow::Result;
use rusqlite::Connection;
use std::io;
use termion::{raw::IntoRawMode, raw::RawTerminal, screen::AlternateScreen};
use tui::{backend::TermionBackend, Terminal};

pub type Term = Terminal<TermionBackend<AlternateScreen<RawTerminal<io::Stdout>>>>;

pub fn terminal() -> Result<Term> {
    let stdout = io::stdout().into_raw_mode()?;
    let stdout = AlternateScreen::from(stdout);
    let backend = TermionBackend::new(stdout);
    Ok(Terminal::new(backend)?)
}

pub fn start(conn: &Connection, term: &mut Term, events: &Events, deck_name: &str) -> Result<()> {
    let mut answers = 0;

    loop {
        let now = time::seconds_since_unix_epoch()?;
        let title = title(deck_name, answers, db::count_available(conn).unwrap_or(0));

        match db::pick_random_ready(conn) {
            Some(card) => match question::ask(term, events, &title, &card)? {
                question::Response::Aborted => break,
                question::Response::Answered { difficulty } => {
                    answers += 1;
                    db::update(
                        conn,
                        &card.question,
                        &space_repetition::update(card.state, difficulty),
                    )?;
                }
            },
            None => {
                let message = match db::next_ready(conn) {
                    Some(ready) => {
                        let duration = time::pp_duration(ready - now);
                        format!("Prochaine carte disponible dans {duration}.")
                    }
                    None => "Aucune carte n’est disponible. Votre deck est-il vide ?".to_string(),
                };
                let _ = message::show(term, events, &title, &message, true);
                break;
            }
        }
    }

    Ok(())
}

fn title(deck_name: &str, answers: i32, available_cards: i32) -> String {
    if answers == 0 && available_cards == 0 {
        deck_name.to_string()
    } else if available_cards == 0 {
        let from = answers;
        let to = answers + available_cards;
        format!("{deck_name} ({from} / {to})")
    } else {
        let from = answers + 1;
        let to = answers + available_cards;
        format!("{deck_name} ({from} / {to})")
    }
}