/*
Copyright 2023, Savanni D'Gerinel <savanni@luminescent-dreams.com>

This file is part of Screenplay.

Screenplay is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Screenplay is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Lumeto. If not, see <https://www.gnu.org/licenses/>.
*/

use gtk::prelude::*;

#[derive(Clone, Debug)]
pub enum Action {
    SelectPage(usize),
    Deselect,
}

#[derive(Clone, Debug)]
pub struct Error;

#[derive(Clone)]
pub struct Screen {
    pub title: String,
    pub widget: gtk::Widget,
    pub adjustments: Vec<gtk::Widget>,
}

#[derive(Clone)]
pub struct Screenplay {
    frame: gtk::Frame,
    screens: Vec<Screen>,
}

impl Screenplay {
    pub fn new(gtk_app: &gtk::Application, screens: Vec<Screen>) -> Result<Self, Error> {
        let window = gtk::ApplicationWindow::new(gtk_app);
        window.show();

        let (sender, receiver) = gtk::glib::MainContext::channel(gtk::glib::PRIORITY_DEFAULT);

        let layout = gtk::Box::builder()
            .orientation(gtk::Orientation::Horizontal)
            .build();
        window.set_child(Some(&layout));

        let listbox = gtk::ListBox::builder()
            .activate_on_single_click(true)
            .show_separators(true)
            .focusable(false)
            .build();

        let frame = gtk::Frame::builder()
            .height_request(500)
            .width_request(500)
            .build();

        layout.append(&listbox);
        layout.append(&frame);

        listbox.connect_row_activated(move |_, row| {
            match row.index() {
                -1 => sender.send(Action::Deselect),
                idx => sender.send(Action::SelectPage(idx as usize)),
            }
            .unwrap()
        });

        screens.iter().for_each(|Screen { title, .. }| {
            listbox.append(
                &gtk::ListBoxRow::builder()
                    .child(&gtk::Label::new(Some(title.as_ref())))
                    .build(),
            );
        });

        let storybook = Self { frame, screens };

        {
            let mut storybook = storybook.clone();
            receiver.attach(None, move |message| storybook.process_action(message));
        }

        Ok(storybook)
    }

    fn process_action(&mut self, message: Action) -> Continue {
        let nothing: Option<&gtk::Widget> = None;
        match message {
            Action::SelectPage(index) => match self.screens.get(index) {
                Some(Screen {
                    widget,
                    adjustments,
                    ..
                }) => {
                    let b = gtk::Box::new(gtk::Orientation::Vertical, 0);
                    let control_box = gtk::Box::new(gtk::Orientation::Vertical, 0);
                    b.append(widget);
                    b.append(&control_box);

                    adjustments
                        .iter()
                        .for_each(|control| control_box.append(control));

                    self.frame.set_child(Some(&b));
                }
                None => self.frame.set_child(nothing),
            },
            Action::Deselect => self.frame.set_child(nothing),
        }

        Continue(true)
    }
}