// SPDX-License-Identifier: LGPL-2.1-only
// Copyright (C) 2026 Liberux Labs, S. L. <info@liberux.net>

// `cfg( backend )` marks the runtime behind `ltk::run`, which builds when some platform backend does. Each backend defines `ltk::run` and the native platform types, so only one may be enabled. `cfg( queued_sources )` marks the targets whose run loop cannot wait on calloop, so the runtime's timers and channels go through its own queue.
fn main()
{
	println!( "cargo::rustc-check-cfg=cfg(backend)" );
	println!( "cargo::rustc-check-cfg=cfg(queued_sources)" );
	let wayland = std::env::var_os( "CARGO_FEATURE_WAYLAND" ).is_some();
	let android = std::env::var_os( "CARGO_FEATURE_ANDROID" ).is_some();
	let web     = std::env::var_os( "CARGO_FEATURE_WEB" ).is_some();
	let windows = std::env::var_os( "CARGO_FEATURE_WINDOWS" ).is_some();
	if [ wayland, android, web, windows ].iter().filter( |on| **on ).count() > 1
	{
		panic!( "ltk: the `wayland`, `android`, `web` and `windows` features are exclusive; build another backend with `default-features = false, features = [ \"android\" ]`, `[ \"web\" ]` or `[ \"windows\" ]`" );
	}
	if web && std::env::var( "CARGO_CFG_TARGET_ARCH" ).as_deref() != Ok( "wasm32" )
	{
		panic!( "ltk: the `web` feature builds only for `wasm32-unknown-unknown`" );
	}
	if windows && std::env::var( "CARGO_CFG_TARGET_OS" ).as_deref() != Ok( "windows" )
	{
		panic!( "ltk: the `windows` feature builds only for Windows targets, such as `x86_64-pc-windows-gnu` or `x86_64-pc-windows-msvc`" );
	}
	if wayland || android || web || windows
	{
		println!( "cargo::rustc-cfg=backend" );
	}
	if std::env::var( "CARGO_CFG_TARGET_ARCH" ).as_deref() == Ok( "wasm32" ) || windows
	{
		println!( "cargo::rustc-cfg=queued_sources" );
	}
}