use iced::widget::{operation, row, scrollable, text_editor};
use iced::{Element, Fill, Font, Theme, highlighter};
use iced_selection::markdown;

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

#[derive(Default)]
struct State {
    content: markdown::Content,
    raw: text_editor::Content,
}

#[derive(Debug, Clone)]
enum Message {
    Edit(text_editor::Action),
    LinkClicked(markdown::Url),
}

impl State {
    fn new() -> (Self, iced::Task<Message>) {
        const INITIAL_CONTENT: &str = include_str!("../overview.md");

        (
            Self {
                content: markdown::Content::parse(INITIAL_CONTENT),
                raw: text_editor::Content::with_text(INITIAL_CONTENT),
            },
            operation::focus_next(),
        )
    }

    fn update(&mut self, message: Message) {
        match message {
            Message::Edit(action) => {
                let is_edit = action.is_edit();

                self.raw.perform(action);

                if is_edit {
                    self.content = markdown::Content::parse(&self.raw.text());
                }
            }
            Message::LinkClicked(link) => {
                let _ = open::that_in_background(link.to_string());
            }
        }
    }

    fn view(&self) -> Element<'_, Message> {
        let editor = text_editor(&self.raw)
            .placeholder("Type your Markdown here...")
            .on_action(Message::Edit)
            .height(Fill)
            .padding(10)
            .font(Font::MONOSPACE)
            .highlight("markdown", highlighter::Theme::Base16Ocean);

        let preview =
            markdown::view(self.content.items(), &Theme::CatppuccinMocha)
                .map(Message::LinkClicked);

        row![
            editor,
            scrollable(preview).spacing(10).width(Fill).height(Fill)
        ]
        .spacing(10)
        .padding(10)
        .into()
    }
}