use iced::widget::{column, container, responsive};
use iced::{Element, Fill, Font, color, font, padding};
use iced_selection::{rich_text, selectable, span};

fn main() -> iced::Result {
    iced::application(State::default, State::update, State::view)
        .theme(iced::Theme::Dark)
        .run()
}

#[derive(Default)]
struct State {
    clicked: Option<String>,
    hovered: Option<String>,
}

#[derive(Debug, Clone)]
enum Message {
    LinkClicked(String),
    LinkHovered(String),
    HoverLost,
}

impl State {
    fn update(&mut self, message: Message) {
        match message {
            Message::LinkClicked(link) => {
                let _ = open::that_in_background(&link);
                self.clicked = Some(link);
            }
            Message::LinkHovered(link) => {
                self.hovered = Some(link);
            }
            Message::HoverLost => self.hovered = None,
        };
    }

    fn view(&self) -> Element<'_, Message> {
        responsive(|size| {
            selectable(
                container(
                    column![
                        rich_text![
                            span("iced")
                                .color(color!(0x2b79a2))
                                .link("https://iced.rs"),
                            " is a cross-platform GUI library for ",
                            span("Rust")
                                .color(color!(0x2b79a2))
                                .link("https://rust-lang.org"),
                            ". It is inspired by ",
                            span("Elm")
                                .color(color!(0x2b79a2))
                                .link("https://elm-lang.org"),
                            ", a delightful functional language for building web applications.\n\n",
                            "As a GUI library, iced helps you build ",
                            span("graphical user interfaces")
                                .color(color!(0x2b79a2))
                                .link("https://en.wikipedia.org/wiki/Graphical_user_interface")
                                .font(Font {
                                    style: font::Style::Italic,
                                    ..Font::DEFAULT
                                }),
                            " for your Rust applications.\n\n",
                            "iced is strongly focused on ",
                            span("simplicity")
                                .font(Font {
                                    weight: font::Weight::Bold,
                                    ..Font::DEFAULT
                                }),
                            " and ",
                            span("type-safety")
                                .font(Font {
                                    weight: font::Weight::Bold,
                                    ..Font::DEFAULT
                                }),
                            ". As a result, iced tries to provide simple building blocks that can be put together with strong typing to reduce the chance of ",
                            span("runtime errors")
                                .font(Font {
                                    weight: font::Weight::Bold,
                                    ..Font::DEFAULT
                                }),
                            "."
                        ]
                        .on_link_click(Message::LinkClicked)
                        .on_link_hover(Message::LinkHovered)
                        .on_hover_lost(Message::HoverLost),
                        self.clicked.as_deref().map(|link| rich_text![
                            "Last clicked link: ",
                            span(link).color(color!(0x2b79a2)).link(link)
                        ]
                        .on_link_click(Message::LinkClicked)
                        .on_link_hover(Message::LinkHovered)
                        .on_hover_lost(Message::HoverLost)),
                        self.hovered.as_deref().map(|link| rich_text![
                            "Currently hovered link: ",
                            span(link).color(color!(0x2b79a2)).link(link)
                        ]
                        .on_link_click(Message::LinkClicked)),
                    ]
                    .spacing(10)
                    .max_width(size.width * 0.8),
                )
                .padding(padding::top(size.height * 0.4))
                .center_x(Fill)
            )
            .into()
        })
        .into()
    }
}