use glib;
use gtk;
use gtk::prelude::*;

use failure::Error;
use humansize::FileSize;
use open;
use rayon;
use take_mut;

use hammond_data::{EpisodeWidgetQuery, Podcast};
use hammond_data::dbqueries;
use hammond_data::utils::get_download_folder;

use app::Action;
use manager;
use utils::lazy_load;
use widgets::episode_states::*;

use std::cell::RefCell;
use std::ops::DerefMut;
use std::path::Path;
use std::rc::Rc;
use std::sync::{Arc, Mutex};
use std::sync::mpsc::Sender;

#[derive(Debug)]
pub struct EpisodeWidget {
    pub container: gtk::Box,
    date: DateMachine,
    duration: DurationMachine,
    title: Rc<RefCell<TitleMachine>>,
    media: Arc<Mutex<MediaMachine>>,
}

impl Default for EpisodeWidget {
    fn default() -> Self {
        let builder = gtk::Builder::new_from_resource("/org/gnome/hammond/gtk/episode_widget.ui");

        let container: gtk::Box = builder.get_object("episode_container").unwrap();
        let progress: gtk::ProgressBar = builder.get_object("progress_bar").unwrap();

        let download: gtk::Button = builder.get_object("download_button").unwrap();
        let play: gtk::Button = builder.get_object("play_button").unwrap();
        let cancel: gtk::Button = builder.get_object("cancel_button").unwrap();

        let title: gtk::Label = builder.get_object("title_label").unwrap();
        let date: gtk::Label = builder.get_object("date_label").unwrap();
        let duration: gtk::Label = builder.get_object("duration_label").unwrap();
        let local_size: gtk::Label = builder.get_object("local_size").unwrap();
        let total_size: gtk::Label = builder.get_object("total_size").unwrap();

        let separator1: gtk::Label = builder.get_object("separator1").unwrap();
        let separator2: gtk::Label = builder.get_object("separator2").unwrap();
        let prog_separator: gtk::Label = builder.get_object("prog_separator").unwrap();

        let date_machine = DateMachine::new(date, 0);
        let dur_machine = DurationMachine::new(duration, separator1, None);
        let title_machine = Rc::new(RefCell::new(TitleMachine::new(title, false)));
        let media = MediaMachine::new(
            play,
            download,
            progress,
            cancel,
            total_size,
            local_size,
            separator2,
            prog_separator,
        );
        let media_machine = Arc::new(Mutex::new(media));

        EpisodeWidget {
            container,
            title: title_machine,
            duration: dur_machine,
            date: date_machine,
            media: media_machine,
        }
    }
}

impl EpisodeWidget {
    pub fn new(episode: EpisodeWidgetQuery, sender: Sender<Action>) -> EpisodeWidget {
        let mut widget = EpisodeWidget::default();
        widget.init(episode, sender);
        widget
    }

    fn init(&mut self, episode: EpisodeWidgetQuery, sender: Sender<Action>) {
        WidgetExt::set_name(&self.container, &episode.rowid().to_string());

        // Set the date label.
        self.set_date(episode.epoch());

        // Set the title label state.
        self.set_title(&episode);

        // Set the duaration label.
        self.set_duration(episode.duration());

        // Determine what the state of the media widgets should be.
        if let Err(err) = self.determine_media_state(&episode) {
            error!("Something went wrong determining the Media State.");
            error!("Error: {}", err);
        }

        let episode = Arc::new(Mutex::new(episode));
        self.connect_buttons(episode, sender);
    }

    fn connect_buttons(&self, episode: Arc<Mutex<EpisodeWidgetQuery>>, sender: Sender<Action>) {
        let title = self.title.clone();
        if let Ok(media) = self.media.lock() {
            media.play_connect_clicked(clone!(episode, sender => move |_| {
                if let Ok(mut ep) = episode.lock() {
                    if let Err(err) = on_play_bttn_clicked(&mut ep, title.clone(), sender.clone()){
                        error!("Error: {}", err);
                    };
                }
            }));

            media.download_connect_clicked(clone!(episode, sender => move |dl| {
                dl.set_sensitive(false);
                if let Ok(ep) = episode.lock() {
                    if let Err(err) = on_download_clicked(&ep, sender.clone())  {
                        error!("Download failed to start.");
                        error!("Error: {}", err);
                    } else {
                        info!("Donwload started succesfully.");
                    }
                }
            }));
        }
    }

    /// Determine the title state.
    fn set_title(&mut self, episode: &EpisodeWidgetQuery) {
        let mut machine = self.title.borrow_mut();
        machine.set_title(episode.title());
        take_mut::take(machine.deref_mut(), |title| {
            title.determine_state(episode.played().is_some())
        });
    }

    /// Set the date label depending on the current time.
    fn set_date(&mut self, epoch: i32) {
        let machine = &mut self.date;
        take_mut::take(machine, |date| date.determine_state(i64::from(epoch)));
    }

    /// Set the duration label.
    fn set_duration(&mut self, seconds: Option<i32>) {
        let machine = &mut self.duration;
        take_mut::take(machine, |duration| duration.determine_state(seconds));
    }

    fn determine_media_state(&self, episode: &EpisodeWidgetQuery) -> Result<(), Error> {
        let id = WidgetExt::get_name(&self.container)
            .ok_or_else(|| format_err!("Failed to get widget Name"))?
            .parse::<i32>()?;

        let active_dl = || -> Result<Option<_>, Error> {
            let m = manager::ACTIVE_DOWNLOADS
                .read()
                .map_err(|_| format_err!("Failed to get a lock on the mutex."))?;

            Ok(m.get(&id).cloned())
        }()?;

        let mut lock = self.media.lock().map_err(|err| format_err!("{}", err))?;
        take_mut::take(lock.deref_mut(), |media| {
            media.determine_state(
                episode.length(),
                active_dl.is_some(),
                episode.local_uri().is_some(),
            )
        });

        // Show or hide the play/delete/download buttons upon widget initialization.
        if let Some(prog) = active_dl {
            lock.cancel_connect_clicked(prog.clone());
            drop(lock);

            // Setup a callback that will update the progress bar.
            update_progressbar_callback(prog.clone(), self.media.clone(), id);

            // Setup a callback that will update the total_size label
            // with the http ContentLength header number rather than
            // relying to the RSS feed.
            update_total_size_callback(prog.clone(), self.media.clone());
        }

        Ok(())
    }
}

#[inline]
fn on_download_clicked(ep: &EpisodeWidgetQuery, sender: Sender<Action>) -> Result<(), Error> {
    let pd = dbqueries::get_podcast_from_id(ep.podcast_id())?;
    let download_fold = get_download_folder(&pd.title())?;

    // Start a new download.
    manager::add(ep.rowid(), download_fold, sender.clone())?;

    // Update Views
    sender.send(Action::RefreshEpisodesView)?;
    sender.send(Action::RefreshWidgetIfVis)?;

    Ok(())
}

#[inline]
fn on_play_bttn_clicked(
    episode: &mut EpisodeWidgetQuery,
    title: Rc<RefCell<TitleMachine>>,
    sender: Sender<Action>,
) -> Result<(), Error> {
    open_uri(episode.rowid())?;
    episode.set_played_now()?;

    let mut machine = title.try_borrow_mut()?;
    take_mut::take(machine.deref_mut(), |title| {
        title.determine_state(episode.played().is_some())
    });

    sender.send(Action::RefreshEpisodesViewBGR)?;
    Ok(())
}

fn open_uri(rowid: i32) -> Result<(), Error> {
    let uri = dbqueries::get_episode_local_uri_from_id(rowid)?
        .ok_or_else(|| format_err!("Expected Some found None."))?;

    if Path::new(&uri).exists() {
        info!("Opening {}", uri);
        open::that(&uri)?;
    } else {
        bail!("File \"{}\" does not exist.", uri);
    }

    Ok(())
}

// Setup a callback that will update the progress bar.
#[inline]
#[cfg_attr(feature = "cargo-clippy", allow(if_same_then_else))]
fn update_progressbar_callback(
    prog: Arc<Mutex<manager::Progress>>,
    media: Arc<Mutex<MediaMachine>>,
    episode_rowid: i32,
) {
    timeout_add(
        400,
        clone!(prog, media => move || {
            progress_bar_helper(prog.clone(), media.clone(), episode_rowid)
                .unwrap_or(glib::Continue(false))
        }),
    );
}

#[inline]
#[allow(if_same_then_else)]
fn progress_bar_helper(
    prog: Arc<Mutex<manager::Progress>>,
    media: Arc<Mutex<MediaMachine>>,
    episode_rowid: i32,
) -> Result<glib::Continue, Error> {
    let (fraction, downloaded) = {
        let m = prog.lock()
            .map_err(|_| format_err!("Failed to get a lock on the mutex."))?;
        (m.get_fraction(), m.get_downloaded())
    };

    // I hate floating points.
    // Update the progress_bar.
    if (fraction >= 0.0) && (fraction <= 1.0) && (!fraction.is_nan()) {
        // Update local_size label
        let size = downloaded
            .file_size(SIZE_OPTS.clone())
            .map_err(|err| format_err!("{}", err))?;

        let mut m = media.lock().unwrap();
        m.update_progress(&size, fraction);
    }

    // info!("Fraction: {}", progress_bar.get_fraction());
    // info!("Fraction: {}", fraction);

    // Check if the download is still active
    let active = {
        let m = manager::ACTIVE_DOWNLOADS
            .read()
            .map_err(|_| format_err!("Failed to get a lock on the mutex."))?;
        m.contains_key(&episode_rowid)
    };

    if (fraction >= 1.0) && (!fraction.is_nan()) {
        Ok(glib::Continue(false))
    } else if !active {
        Ok(glib::Continue(false))
    } else {
        Ok(glib::Continue(true))
    }
}

// Setup a callback that will update the total_size label
// with the http ContentLength header number rather than
// relying to the RSS feed.
#[inline]
fn update_total_size_callback(
    prog: Arc<Mutex<manager::Progress>>,
    media: Arc<Mutex<MediaMachine>>,
) {
    timeout_add(
        500,
        clone!(prog, media => move || {
            total_size_helper(prog.clone(), media.clone()).unwrap_or(glib::Continue(true))
        }),
    );
}

#[inline]
fn total_size_helper(
    prog: Arc<Mutex<manager::Progress>>,
    media: Arc<Mutex<MediaMachine>>,
) -> Result<glib::Continue, Error> {
    // Get the total_bytes.
    let total_bytes = {
        let m = prog.lock()
            .map_err(|_| format_err!("Failed to get a lock on the mutex."))?;
        m.get_total_size()
    };

    debug!("Total Size: {}", total_bytes);
    if total_bytes != 0 {
        // Update the total_size label
        if let Ok(mut m) = media.lock() {
            take_mut::take(m.deref_mut(), |machine| {
                machine.set_size(Some(total_bytes as i32))
            });
        }

        // Do not call again the callback
        Ok(glib::Continue(false))
    } else {
        Ok(glib::Continue(true))
    }
}

// fn on_delete_bttn_clicked(episode_id: i32) -> Result<(), Error> {
//     let mut ep = dbqueries::get_episode_from_rowid(episode_id)?.into();
//     delete_local_content(&mut ep).map_err(From::from).map(|_| ())
// }

pub fn episodes_listbox(pd: Arc<Podcast>, sender: Sender<Action>) -> Result<gtk::ListBox, Error> {
    use crossbeam_channel::TryRecvError::*;
    use crossbeam_channel::bounded;

    let count = dbqueries::get_pd_episodes_count(&pd)?;

    let (sender_, receiver) = bounded(1);
    rayon::spawn(move || {
        let episodes = dbqueries::get_pd_episodeswidgets(&pd).unwrap();
        sender_
            .send(episodes)
            .expect("Something terrible happened to the channnel");
    });

    let list = gtk::ListBox::new();
    list.set_visible(true);
    list.set_selection_mode(gtk::SelectionMode::None);

    if count == 0 {
        let builder = gtk::Builder::new_from_resource("/org/gnome/hammond/gtk/empty_show.ui");
        let container: gtk::Box = builder.get_object("empty_show").unwrap();
        list.add(&container);
        return Ok(list);
    }

    gtk::idle_add(clone!(list => move || {
        let episodes = match receiver.try_recv() {
            Ok(e) => e,
            Err(Empty) => return glib::Continue(true),
            Err(Disconnected) => return glib::Continue(false),
        };

        lazy_load(episodes, list.clone(), clone!(sender => move |ep| {
            EpisodeWidget::new(ep, sender.clone()).container
        }));

        glib::Continue(false)
    }));

    Ok(list)
}