#![ cfg( feature = "test-support" ) ]

// End-to-end coverage for the `text_edit` ↔ event-loop contract: the layout
// pass snapshots the widget's `on_change` / `on_submit` / `value` into a
// `WidgetHandlers::TextEdit` entry, and the runtime drives keystrokes through
// `text_change_msg` / `submit_msg` / `current_value`. These tests skip the
// Wayland loop and exercise that contract directly through `UiSurface`.

use ltk::core::{ RenderOptions, UiSurface };
use ltk::test_support::WidgetHandlers;
use ltk::{ column, text_edit, Color, Element };

#[ derive( Clone, Debug, PartialEq, Eq ) ]
enum Msg
{
	Username( String ),
	Password( String ),
	UsernameSubmit,
	PasswordSubmit,
}

fn login_view() -> Element<Msg>
{
	column::<Msg>()
		.padding( 16.0 )
		.spacing( 8.0 )
		.push(
			text_edit( "Username", "alice" )
				.on_change( |s| Msg::Username( s ) )
				.on_submit( Msg::UsernameSubmit ),
		)
		.push(
			text_edit::<Msg>( "Password", "" )
				.secure( true )
				.on_change( |s| Msg::Password( s ) )
				.on_submit( Msg::PasswordSubmit ),
		)
		.into()
}

fn render_login() -> UiSurface<Msg>
{
	let mut surface = UiSurface::<Msg>::new( 320, 240 );
	let _ = surface.render(
		&login_view(),
		RenderOptions::full_canvas( 320, 240 ).background( Color::rgb( 0.1, 0.1, 0.1 ) ),
	);
	surface
}

#[ test ]
fn layout_records_two_text_edit_widgets()
{
	let surface = render_login();
	assert_eq!( surface.widget_rects().len(), 2 );
	for w in surface.widget_rects()
	{
		assert!( w.handlers.is_text_input() );
	}
}

#[ test ]
fn text_change_msg_carries_new_value_through_user_callback()
{
	let surface = render_login();
	let username_idx = surface.widget_rects()[ 0 ].flat_idx;

	let h = surface.handlers( username_idx ).expect( "text edit handler should exist" );
	let msg = h.text_change_msg( "alic" );  // user pressed backspace once
	assert_eq!( msg, Some( Msg::Username( "alic".into() ) ) );
}

#[ test ]
fn text_change_msg_passes_unicode_unchanged()
{
	let surface = render_login();
	let username_idx = surface.widget_rects()[ 0 ].flat_idx;
	let h = surface.handlers( username_idx ).unwrap();

	let msg = h.text_change_msg( "café 🦀" );
	assert_eq!( msg, Some( Msg::Username( "café 🦀".into() ) ) );
}

#[ test ]
fn submit_msg_returns_configured_message()
{
	let surface = render_login();
	let password_idx = surface.widget_rects()[ 1 ].flat_idx;
	let h = surface.handlers( password_idx ).unwrap();
	assert_eq!( h.submit_msg(), Some( Msg::PasswordSubmit ) );
}

#[ test ]
fn each_text_edit_dispatches_to_its_own_callback()
{
	// The two fields share the same `Msg` enum but differ in which variant
	// they wrap the new value in — confirms the handler snapshot captured
	// the right closure for the right widget.
	let surface = render_login();
	let username_h = surface.handlers( surface.widget_rects()[ 0 ].flat_idx ).unwrap();
	let password_h = surface.handlers( surface.widget_rects()[ 1 ].flat_idx ).unwrap();

	assert_eq!( username_h.text_change_msg( "x" ), Some( Msg::Username( "x".into() ) ) );
	assert_eq!( password_h.text_change_msg( "x" ), Some( Msg::Password( "x".into() ) ) );
}

#[ test ]
fn current_value_reflects_initial_state()
{
	let surface = render_login();
	let username_h = surface.handlers( surface.widget_rects()[ 0 ].flat_idx ).unwrap();
	let password_h = surface.handlers( surface.widget_rects()[ 1 ].flat_idx ).unwrap();

	assert_eq!( username_h.current_value(), Some( "alice" ) );
	assert_eq!( password_h.current_value(), Some( "" ) );
}

#[ test ]
fn current_value_reflects_state_after_app_update()
{
	// User types into the username field. The app updates state and the next
	// render must snapshot the new value into the handler.
	let mut surface = UiSurface::<Msg>::new( 320, 240 );
	let mut username = String::from( "alice" );

	let view = |val: &str| -> Element<Msg>
	{
		column::<Msg>()
			.padding( 16.0 )
			.push(
				text_edit( "Username", val.to_string() )
					.on_change( |s| Msg::Username( s ) ),
			)
			.into()
	};

	let opts = RenderOptions::full_canvas( 320, 240 );
	let _ = surface.render( &view( &username ), opts );
	assert_eq!(
		surface.handlers( surface.widget_rects()[ 0 ].flat_idx ).unwrap().current_value(),
		Some( "alice" ),
	);

	username.push_str( "_2" );
	let _ = surface.render( &view( &username ), opts );
	assert_eq!(
		surface.handlers( surface.widget_rects()[ 0 ].flat_idx ).unwrap().current_value(),
		Some( "alice_2" ),
	);
}

#[ test ]
fn is_text_input_distinguishes_text_edit_from_other_handlers()
{
	use ltk::button;
	let mut surface = UiSurface::<Msg>::new( 240, 200 );
	let view: Element<Msg> = column()
		.push( text_edit::<Msg>( "p", "" ) )
		.push( button( "go" ).on_press( Msg::UsernameSubmit ) )
		.into();
	let _ = surface.render( &view, RenderOptions::full_canvas( 240, 200 ) );

	let h0 = surface.handlers( surface.widget_rects()[ 0 ].flat_idx ).unwrap();
	let h1 = surface.handlers( surface.widget_rects()[ 1 ].flat_idx ).unwrap();
	assert!(  h0.is_text_input() );
	assert!( !h1.is_text_input() );
}

#[ test ]
fn submit_msg_returns_none_for_non_text_edit_handlers()
{
	use ltk::button;
	let mut surface = UiSurface::<Msg>::new( 240, 100 );
	let view: Element<Msg> = column()
		.push( button( "go" ).on_press( Msg::UsernameSubmit ) )
		.into();
	let _ = surface.render( &view, RenderOptions::full_canvas( 240, 100 ) );

	let h = surface.handlers( surface.widget_rects()[ 0 ].flat_idx ).unwrap();
	assert!( h.submit_msg().is_none() );
}

#[ test ]
fn text_change_msg_returns_none_when_no_callback_configured()
{
	let mut surface = UiSurface::<Msg>::new( 240, 100 );
	let view: Element<Msg> = column()
		.push( text_edit::<Msg>( "no callback", "x" ) )
		.into();
	let _ = surface.render( &view, RenderOptions::full_canvas( 240, 100 ) );

	let h = surface.handlers( surface.widget_rects()[ 0 ].flat_idx ).unwrap();
	assert!( h.text_change_msg( "y" ).is_none() );
}

#[ test ]
fn handler_variant_for_text_edit_carries_value_field()
{
	// Confirm the layout pass populates the `value` field of the
	// `WidgetHandlers::TextEdit` snapshot — input dispatch reads it for cursor
	// placement / backspace rebuild.
	let surface = render_login();
	let h = surface.handlers( surface.widget_rects()[ 0 ].flat_idx ).unwrap();
	match h
	{
		WidgetHandlers::TextEdit { value, .. } => assert_eq!( value, "alice" ),
		_ => panic!( "expected TextEdit handler variant" ),
	}
}