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

use crate::{db, space_repetition, util::time};
use anyhow::Result;
use rusqlite::Connection;
use std::io::Stdout;
use tui::{backend::CrosstermBackend, Terminal};
use crossterm::{terminal};

pub type Term = Terminal<CrosstermBackend<Stdout>>;

pub fn setup_terminal() -> Result<Term> {
    terminal::enable_raw_mode()?;
    let mut stdout = std::io::stdout();
    crossterm::execute!(stdout, terminal::EnterAlternateScreen)?;
    let backend = CrosstermBackend::new(stdout);
    Ok(Terminal::new(backend)?)
}

pub fn restore_terminal(term: &mut Term) -> Result<()> {
    terminal::disable_raw_mode()?;
    crossterm::execute!(term.backend_mut(), terminal::LeaveAlternateScreen)?;
    term.show_cursor()?;
    Ok(())
}

pub fn start(
    conn: &Connection,
    term: &mut Term,
    deck_name: &str,
    hide_progress: bool,
) -> 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), hide_progress);

        match db::pick_random_ready(conn) {
            Some(card) => match question::ask(term, &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, &title, &message, true);
                break;
            }
        }
    }

    Ok(())
}

fn title(deck_name: &str, answers: i32, available_cards: i32, hide_progress: bool) -> String {
    if answers == 0 && available_cards == 0 || hide_progress {
        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})")
    }
}