use std::fs::File;
use std::io::{BufReader};
use std::process::Command;

use gio::prelude::*;
use gtk::prelude::*;
use gtk::Orientation;
use rodio::{Sink, Source};

const SPACING: i32 = 16;

fn popup(title: &str, message: &str) -> gtk::Window {
    let popup = gtk::Window::new(gtk::WindowType::Toplevel);
    popup.set_title(title);
    popup.set_border_width(SPACING as u32);
    popup.set_position(gtk::WindowPosition::Center);
    popup.set_default_size(256, 64);
    popup.set_type_hint(gdk::WindowTypeHint::Dialog);
    popup.set_resizable(false);

    let message = gtk::Label::new(Some(message));
    popup.add(&message);

    popup
}

fn build_ui(application: &gtk::Application) {
    let window = gtk::ApplicationWindow::new(application);

    window.set_title("lull");
    window.set_border_width(SPACING as u32);
    window.set_position(gtk::WindowPosition::Center);
    window.set_default_size(256, 128);

    if let Some(config) = crate::config::load_config() {
        window.move_(config.position.0, config.position.1);
        window.resize(config.size.0, config.size.1);
    }

    let button_manage_sounds = gtk::Button::with_label("open sounds folder");

    button_manage_sounds.connect_clicked(|_| {
        popup(
            "info",
            concat!(
                "after changing the sounds in this folder, ",
                "you will need to restart lull to see your changes."
            )
        );

        let mut file_manager = Command::new(crate::file_manager());
        file_manager.arg(crate::get_sounds_dir());
        file_manager.output().unwrap();
    });

    let sounds_manage  = gtk::Box::new(Orientation::Vertical,   SPACING);
    let columns        = gtk::Box::new(Orientation::Horizontal, SPACING);
    let column_labels  = gtk::Box::new(Orientation::Vertical,   SPACING);
    let column_sliders = gtk::Box::new(Orientation::Vertical,   SPACING);

    columns.set_homogeneous(false);
    column_labels.set_homogeneous(true);
    column_sliders.set_homogeneous(true);
    column_labels.set_expand(false);
    column_sliders.set_expand(true);
    column_sliders.set_width_request(128);

    window.add(&sounds_manage);
    sounds_manage.add(&columns);
    sounds_manage.add(&button_manage_sounds);
    columns.add(&column_labels);
    columns.add(&column_sliders);

    let device = rodio::default_output_device().unwrap();

    let mut paths = std::fs::read_dir(crate::get_sounds_dir())
        .expect("Couldn't read lull sounds directory")
        .map(|res| res.map(|e| e.path()))
        .collect::<Result<Vec<_>, std::io::Error>>()
        .expect("Couldn't read files from lull sounds directory");

    paths.sort();

    for path in paths {
        let name      = path.file_stem().unwrap().to_str().unwrap();
        let extension = path.extension().unwrap().to_str().unwrap();

        // on Windows the data dir and config dir are the same,
        // so avoid parsing the config file as an audio file
        if extension == "toml" {
            continue;
        }

        let file = File::open(&path)
            .expect("Couldn't open audio file");

        let source = rodio::Decoder::new(
            BufReader::new(file)
        );

        if source.is_err() {
            popup("error", &format!(
                "Couldn't parse file {}. \n{}.",
                path.to_str().unwrap(),
                source.err().unwrap()
            )).show_all();

            continue;
        }

        let source = source.unwrap().repeat_infinite();

        let sink = Sink::new(&device);
        sink.append(source);
        sink.pause();

        let label = gtk::Label::new(Some(name));
        label.set_halign(gtk::Align::End);
        column_labels.add(&label);

        let adjustment = gtk::Adjustment::new(
            0.0,
            0.0,
            1.0,
            0.0,
            0.0,
            0.0
        );

        let slider = gtk::Scale::new(
            Orientation::Horizontal,
            Some(&adjustment)
        );

        slider.set_draw_value(false);

        slider.connect_value_changed(move |scale| {
            let volume = scale.value();

            if volume == 0. {
                sink.pause();
            } else {
                sink.play();
                sink.set_volume(volume as f32);
            }
        });

        column_sliders.add(&slider);
    }

    window.show_all();

    window.connect_delete_event(|window, _event| {
        crate::config::save_config(crate::config::Config {
            position: window.position(),
            size:     window.size()
        });

        Inhibit(false)
    });
}

pub(crate) fn instantiate() {
    #[cfg(target_os = "windows")] {
        // instantiate rodio before gtk and don't do anything with it
        // this is silly but it's the easiest way to prevent cpal crashing on windows
        rodio::default_output_device().unwrap();
    }

    let application = gtk::Application::new(
        Some("dev.tinybird.max.lull"),
        Default::default()
    );

    application.connect_activate(|app| {
        build_ui(app);
    });

    application.run();
}