export module runtime;

import app;

import core;
import core.files;
import core.math;
import core.sequence;

import kym;
import kym.environment;

extern "C" int main(int argc, char const * const * argv) {
	return app::display("Ona Runtime", [](app::system & system, app::graphics & graphics) -> int {
		constexpr core::path config_path{"config.kym"};
		bool is_config_loaded{false};

		if ((system.res_fs().read_file(config_path, [&](core::readable const & file) {
			kym::vm vm{&system.thread_safe_allocator(),
				[&system](core::slice<char const> const & error_message) {
					system.log(app::log_level::error, error_message);
				}};

			if (!vm.init({
				.datastack_size = 64,
				.callstack_size = 64,
			})) {
				system.log(app::log_level::error, "failed to allocate memory for config vm");

				return;
			}

			core::stack<core::u8> script_source{&system.thread_safe_allocator()};
			core::u8 stream_buffer[1024]{0};

			if (!core::stream(core::sequence_writer{&script_source}, file, stream_buffer).is_ok())
				return;

			vm.with_object(vm.compile(core::slice{script_source.begin(), script_source.end()}.as_chars()), [&](kym::bound_object & script) {
				vm.with_object(script.call({}), [&](kym::bound_object & config) {
					core::u16 const width{config.get_field("width").as_u16().value_or(0)};

					if (width == 0) return system.log(app::log_level::error,
						"failed to decode `width` property of config");

					core::u16 const height{config.get_field("height").as_u16().value_or(0)};

					if (height == 0) return system.log(app::log_level::error,
						"failed to decode `height` property of config");

					if (graphics.show(width, height) != app::graphics::show_result::ok)
						return system.log(app::log_level::error, "failed to initialize window");

					vm.with_object(config.get_field("title"), [&](kym::bound_object & title) {
						core::stack<core::u8, 128> title_buffer{&system.thread_safe_allocator()};

						if (!title.stringify(core::sequence_writer(&title_buffer)).is_ok()) {
							system.log(app::log_level::error,
								"failed to decode `title` property of config");

							return;
						}

						is_config_loaded = true;
					});
				});
			});
		}) != core::fs::access_result::ok) || (!is_config_loaded)) return core::u8_max;

		// app::canvas canvas_2d();

		while (system.poll()) {
			// canvas_2d.render(graphics);
			graphics.present();
		}

		return 0;
	});
}