#[macro_use]
extern crate lazy_static;

use std::process::exit;

use async_std::stream;
use async_std::task;
use comfy_table::presets::{UTF8_FULL, UTF8_HORIZONTAL_BORDERS_ONLY};
use comfy_table::{ContentArrangement, Table};
use futures::stream::StreamExt;
use indicatif::{ProgressBar, ProgressStyle};
use log::{debug, warn};
use url::Url;

mod cli;
mod epub;
mod errors;
mod extractor;
/// This module is responsible for async HTTP calls for downloading
/// the HTML content and images
mod http;
mod logs;
mod moz_readability;

use cli::AppConfig;
use epub::generate_epubs;
use extractor::Extractor;
use http::{download_images, fetch_html};
use logs::display_summary;

fn main() {
    let app_config = match cli::AppConfig::init_with_cli() {
        Ok(app_config) => app_config,
        Err(err) => {
            eprintln!("{}", err);
            exit(1);
        }
    };

    if !app_config.urls.is_empty() {
        download(app_config);
    }
}

fn download(app_config: AppConfig) {
    let mut errors = Vec::new();
    let mut partial_download_count: usize = 0;
    let bar = if app_config.can_disable_progress_bar {
        ProgressBar::hidden()
    } else {
        let enabled_bar = ProgressBar::new(app_config.urls.len() as u64);
        let style = ProgressStyle::default_bar().template(
        "{spinner:.cyan} [{elapsed_precise}] {bar:40.white} {:>8} link {pos}/{len:7} {msg:.yellow/white}",
    );
        enabled_bar.set_style(style);
        enabled_bar.enable_steady_tick(500);
        enabled_bar
    };
    let articles = task::block_on(async {
        let urls_iter = app_config.urls.iter().map(|url| fetch_html(url));
        let mut responses = stream::from_iter(urls_iter).buffered(app_config.max_conn);
        let mut articles = Vec::new();
        while let Some(fetch_result) = responses.next().await {
            match fetch_result {
                Ok((url, html)) => {
                    debug!("Extracting {}", &url);
                    let mut extractor = Extractor::from_html(&html, &url);
                    bar.set_message("Extracting...");
                    match extractor.extract_content() {
                        Ok(_) => {
                            extractor.extract_img_urls();
                            if let Err(img_errors) =
                                download_images(&mut extractor, &Url::parse(&url).unwrap(), &bar)
                                    .await
                            {
                                partial_download_count += 1;
                                warn!(
                                    "{} image{} failed to download for {}",
                                    img_errors.len(),
                                    if img_errors.len() > 1 { "s" } else { "" },
                                    url
                                );
                                for img_error in img_errors {
                                    warn!(
                                        "{}\n\t\tReason {}",
                                        img_error.url().as_ref().unwrap(),
                                        img_error
                                    );
                                }
                            }
                            articles.push(extractor);
                        }
                        Err(mut e) => {
                            e.set_article_source(&url);
                            errors.push(e);
                        }
                    }
                }
                Err(e) => errors.push(e),
            }
            bar.inc(1);
        }
        articles
    });
    bar.finish_with_message("Downloaded articles");

    let mut succesful_articles_table = Table::new();
    succesful_articles_table
        .load_preset(UTF8_FULL)
        .load_preset(UTF8_HORIZONTAL_BORDERS_ONLY)
        .set_content_arrangement(ContentArrangement::Dynamic);
    match generate_epubs(articles, &app_config, &mut succesful_articles_table) {
        Ok(_) => (),
        Err(gen_epub_errors) => {
            errors.extend(gen_epub_errors);
        }
    };
    let has_errors = !errors.is_empty();
    display_summary(
        app_config.urls.len(),
        succesful_articles_table,
        partial_download_count,
        errors,
    );
    if app_config.is_logging_to_file {
        println!(
            "Log written to paperoni_{}.log\n",
            app_config.start_time.format("%Y-%m-%d_%H-%M-%S")
        );
    }
    if has_errors {
        std::process::exit(1);
    }
}