/*
Program: Bibliofile
Language: Rustc 1.71.0
ide: CLion
Operating system: POP_OS
Purpose: TUI-based ereader and library manager for Linux terminal environments.
Last edited: 10/14/23
*/

mod html_module;
use cursive::views::{Dialog, TextView};
use cursive::backends::termion::termion;
use cursive::event;
use epub::doc::EpubDoc; //library for navigating epubs
use std::*;
use std::i32;
use std::io::stdin;
use std::path::Path;
use termion::event::{Event, Key};
use termion::input::TermRead;
use termion::scroll;



//this function will determine if Bibliofile has been opened before. If it has not, it will create a library folder under /opt/bibliofile.
fn library_exists(){


    //if /var/lib/bibliofile/library does not exist, create it.
    let library_exist_var = Path::exists("/var/lib/bibliofile/library".as_ref());

    if library_exist_var == false{
        fs::create_dir_all("/var/lib/bibliofile/library").expect("Error...could not create library. If this is your first time running Bibliofile, try running with sudo.\n\
        Keep in mind, this program was designed with *nix systems in mind. Running this on Windows will result in unexpected behavior, as it uses a different file system.");
    }

}

//initial function. Reads the ebook passed by argument.
//TODO: add visual library to pull up ebooks.
fn main() {
    //library_exists();
    if env::args().len() == 1 {
        println!("You need to enter a book! \n\
        context: bibliofile book.epub\n\
        Closing program.");
    }
    else {
        let args: Vec<String> = env::args().collect();
        let filename = &args[1];

        screen_func(filename);
    }
}


//this function manages the screen
fn screen_func(epub_file: &str){
    let mut page_num = 1;
    let textinfo = get_text(epub_file, &page_num, "next");
    let text = textinfo.0;
    let title = textinfo.1;
    page_num = textinfo.2;
    // Creates the cursive root - required for every application.
    let mut siv = cursive::default();

    // Creates a dialog with a single "Quit" button
    siv.add_layer(Dialog::around(TextView::new(text))
        .title(title)
        .button("Quit", |s| s.quit()));

    // Starts the event loop.
    siv.run();

    let c = stdin();
    for c in stdin().events() {
        let evt = c.unwrap();
        match evt {
            Event::Key(Key::Up) => scroll::Up(1),

            _ => {}
        }
    }

}




fn get_text(epub_file: &str, mut page_num: &i32, direction: &str) -> (String, String, i32){
    let doc = EpubDoc::new(&epub_file);
    assert!(doc.is_ok());
    let mut doc = doc.unwrap();
    let mut usize_num = *page_num as usize;

    return if direction == "next" {
        usize_num = usize_num + 1;
        let title = doc.mdata("title");

        doc.set_current_page(usize_num);
        let content = doc.get_current_str();
        let str_content = content.unwrap();
        let text = html_module::main(str_content.0);

        (text, title.unwrap(), usize_num as i32)
    } else if direction == "last" {
        usize_num = usize_num - 1;
        let title = doc.mdata("title");

        doc.set_current_page(usize_num);
        let content = doc.get_current_str();
        let str_content = content.unwrap();
        let text = html_module::main(str_content.0);

        (text, title.unwrap(), usize_num as i32)
    } else {
        let title = doc.mdata("title");

        doc.set_current_page(usize_num);
        let content = doc.get_current_str();
        let str_content = content.unwrap();
        let text = html_module::main(str_content.0);

        (text, title.unwrap(), usize_num as i32)
    }

}