//! The smallest ltk app in a browser: a counter and a text field on a canvas over the whole page, on the default theme the page serves under `ltk/`. `make web-example` builds it and its resources into `target/web/`, `make web-serve` serves it at <http://localhost:8000/>.
//!
//! A web app is a library the page loads, so this example builds as a `cdylib` whose entry point is the `start` function wasm-bindgen runs when the module is loaded.

use ltk::{ App, ButtonVariant, Element, button, column, spacer, text, text_edit };
use wasm_bindgen::prelude::wasm_bindgen;

#[ derive( Clone ) ]
enum Msg
{
	Press,
	Edit( String ),
	Submit,
	Fullscreen,
}

#[ derive( Default ) ]
struct Hello
{
	presses:    u32,
	typed:      String,
	submitted:  String,
	fullscreen: bool,
}

impl App for Hello
{
	type Message = Msg;

	fn app_id( &self ) -> &str { "net.liberux.ltk.Hello" }
	fn save_state( &self ) -> Option<Vec<u8>> { None }
	fn restore_state( &mut self, _state: Vec<u8> ) {}
	fn fullscreen( &self ) -> Option<bool> { Some( self.fullscreen ) }

	fn view( &self ) -> Element<Msg>
	{
		let palette = ltk::theme_palette();
		column::<Msg>()
			.spacing( 16.0 )
			.push( spacer() )
			.push( text( "ltk in a browser" ).size( 28.0 ).color( palette.text_primary ) )
			.push( text( format!( "Pressed {} times", self.presses ) ).size( 18.0 ).color( palette.text_secondary ) )
			.push( button::<Msg>( "Press" ).variant( ButtonVariant::Secondary ).on_press( Msg::Press ) )
			.push( text_edit::<Msg>( "Type and press Enter", &self.typed ).fixed_width( 320.0 ).on_change( Msg::Edit ).on_submit( Msg::Submit ) )
			.push( text( format!( "Submitted: {}", self.submitted ) ).size( 18.0 ).color( palette.text_secondary ) )
			.push( button::<Msg>( if self.fullscreen { "Leave fullscreen" } else { "Fullscreen" } ).variant( ButtonVariant::Secondary ).on_press( Msg::Fullscreen ) )
			.push( spacer() )
			.into()
	}

	fn update( &mut self, msg: Msg )
	{
		match msg
		{
			Msg::Press         => self.presses += 1,
			Msg::Edit( value ) => self.typed = value,
			Msg::Submit        => self.submitted = std::mem::take( &mut self.typed ),
			Msg::Fullscreen    => self.fullscreen = !self.fullscreen,
		}
	}
}

#[ wasm_bindgen( start ) ]
pub async fn start()
{
	if let Err( e ) = ltk::web::load_resources( "ltk" ).await
	{
		web_sys::console::warn_1( &format!( "ltk resources: {e}" ).into() );
	}
	ltk::run( Hello::default() );
}