use dbus::arg;
use dbus::blocking::stdintf::org_freedesktop_dbus::PropertiesPropertiesChanged;
use dbus::blocking::Connection;
use dbus::message::Message;
use std::collections::HashMap;
use std::process::Command;
use std::sync::{Arc, Mutex};
use std::thread;
use std::time::Duration;

// Custom signal type impl
// Mostly copied from library examples
#[derive(Debug)]
pub struct ComJacobCasperMailUnreadCount {
    pub count: u32,
}

impl arg::AppendAll for ComJacobCasperMailUnreadCount {
    fn append(&self, iter: &mut arg::IterAppend) {
        arg::RefArg::append(&self.count, iter);
    }
}

impl arg::ReadAll for ComJacobCasperMailUnreadCount {
    fn read(iter: &mut arg::Iter) -> Result<Self, arg::TypeMismatchError> {
        Ok(ComJacobCasperMailUnreadCount {
            count: iter.read()?,
        })
    }
}

impl dbus::message::SignalArgs for ComJacobCasperMailUnreadCount {
    const NAME: &'static str = "UnreadCount";
    const INTERFACE: &'static str = "com.jacobcasper.Mail";
}

fn get_local_time_string() -> std::string::String {
    use chrono::prelude::*;
    let local_time = chrono::prelude::Local::now();
    return format!(
        "{}-{}-{:02} {}:{:02}",
        local_time.year(),
        local_time.month(),
        local_time.day(),
        local_time.hour(),
        local_time.minute(),
    );
}

fn update_map(arc_map: Arc<Mutex<HashMap<String, String>>>, key: &str, val: &str) {
    let clone_arc = arc_map.clone();
    let mut map = clone_arc.lock().unwrap();
    map.insert(String::from(key), String::from(val));
}

fn update_xsetroot(arc_map: Arc<Mutex<HashMap<String, String>>>) {
    let clone_arc = arc_map.clone();
    let map = clone_arc.lock().unwrap();
    let _ = Command::new("xsetroot")
        .arg("-name")
        .arg(format!(
            "[{playback_status} {title} - {artist}] | ✉ {unread_count} | {date_time}",
            playback_status = map.get("playback_status").unwrap_or(&String::from("🔈")),
            title = map.get("title").unwrap_or(&String::from("")),
            artist = map.get("artist").unwrap_or(&String::from("")),
            unread_count = map.get("unread_count").unwrap_or(&String::from("?")),
            date_time = map.get("date_time").unwrap_or(&get_local_time_string()),
        ))
        .spawn();
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let arc_locked_xset_map = Arc::new(Mutex::new(HashMap::new()));
    let conn = Connection::new_session()?;

    let mail_proxy = conn.with_proxy(
        "com.jacobcasper.Mail",
        "/com/jacobcasper/Mail/Unread",
        Duration::from_millis(5000),
    );

    let mail_match_map = arc_locked_xset_map.clone();
    let _ = mail_proxy.match_signal(
        move |m: ComJacobCasperMailUnreadCount, _: &Connection, _: &Message| {
            update_map(
                mail_match_map.clone(),
                "unread_count",
                m.count.to_string().as_str(),
            );
            update_xsetroot(mail_match_map.clone());
            true
        },
    );

    let spotify_proxy = conn.with_proxy(
        "org.mpris.MediaPlayer2.spotify",
        "/org/mpris/MediaPlayer2",
        Duration::from_millis(5000),
    );

    let spotify_match_map = arc_locked_xset_map.clone();
    let _ = spotify_proxy.match_signal(
        move |pc: PropertiesPropertiesChanged, _: &Connection, _: &Message| {
            match pc.changed_properties.get("Metadata") {
                Some(variant) => {
                    variant.0.as_iter().and_then(|mut iter| {
                        // Iterating over a RefArg goes key, value, key, value... Insane honestly.
                        while let Some(key) = iter.next() {
                            let key_str = key.as_str()?;
                            let value = iter.next();

                            match key_str {
                                "xesam:artist" => {
                                    // Variant holding a variant that should just be a Vec<&str> I
                                    // believe. This is _the recommended_ way to do this by the author.
                                    let inner_value =
                                        value?.as_iter()?.next()?.as_iter()?.next()?;
                                    let artist = inner_value.as_str()?;
                                    update_map(spotify_match_map.clone(), "artist", artist);
                                }
                                "xesam:title" => {
                                    let title = value?.as_iter()?.next()?.as_str()?;
                                    update_map(spotify_match_map.clone(), "title", title);
                                }
                                _ => (),
                            }
                        }
                        update_xsetroot(spotify_match_map.clone());
                        Some(())
                    });
                }
                None => (),
            }
            match &pc.changed_properties.get("PlaybackStatus") {
                Some(variant) => {
                    let playback_status = &variant.0;
                    update_map(
                        spotify_match_map.clone(),
                        "playback_status",
                        match &*playback_status.as_str().unwrap_or("") {
                            "Playing" => "🔊",
                            _ => "🔈",
                        },
                    );
                    update_xsetroot(spotify_match_map.clone());
                }
                None => (),
            }
            true
        },
    );

    let date_time_map = arc_locked_xset_map.clone();
    let _ = thread::spawn(move || -> Result<(), std::time::SystemTimeError> {
        let mut last_run_at = std::time::SystemTime::now();
        loop {
            let sys_time = std::time::SystemTime::now();
            let elapsed_time = sys_time.duration_since(last_run_at)?;
            if elapsed_time.as_secs() > 60 {
                last_run_at = sys_time;
                update_map(
                    date_time_map.clone(),
                    "date_time",
                    get_local_time_string().as_str(),
                );
                update_xsetroot(date_time_map.clone());
            }
            thread::sleep(Duration::from_millis(5000));
        }
    });

    loop {
        conn.process(Duration::from_millis(1000))?;
    }
}