export module renderer.factory;
import renderer.frontend;
import assets.shader;
import renderer.backend.vk.device;
import renderer.vk.pass;
import renderer.backend.vk.instance;
import renderer.backend.vk.swapchain;
import renderer.backend.vk.buffer;
import renderer.backend.vk.gpu;
import renderer.backend.vk.surface;
import memory.scope;
import debug.assertions;
import ecs.entity;
import std;

export namespace lt::renderer {

[[nodiscard]] auto get_instance(Api target_api) -> IInstance *;

[[nodiscard]] auto create_surface(
    Api target_api,
    IInstance *instance,
    const ecs::Entity &surface_entity
);

[[nodiscard]] auto create_gpu(Api target_api, IInstance *instance) -> memory::Scope<IGpu>;

[[nodiscard]] auto create_swapchain(Api target_api, ISurface *surface, IGpu *gpu, IDevice *device)
    -> memory::Scope<ISwapchain>;

[[nodiscard]] auto create_pass(
    lt::renderer::Api target_api,
    IDevice *device,
    const lt::assets::ShaderAsset &vertex_shader,
    const lt::assets::ShaderAsset &fragment_shader
) -> memory::Scope<IPass>;

} // namespace lt::renderer

module :private;
using namespace lt;
using namespace lt::renderer;

[[nodiscard]] auto get_instance(Api target_api) -> IInstance *
{
	switch (target_api)
	{
	case Api::vulkan: return vkb::Instance::get();
	case Api::none:
	case Api::metal:
	case Api::direct_x: throw std::runtime_error { "Invalid API" };
	}
}

[[nodiscard]] auto create_surface(
    Api target_api,
    class IInstance *instance,
    const lt::ecs::Entity &surface_entity
) -> memory::Scope<ISurface>
{
	debug::ensure(instance, "Failed to create renderer::ISurface: null instance");

	switch (target_api)
	{
	case Api::vulkan: return memory::create_scope<vkb::Surface>(instance, surface_entity);
	case Api::none:
	case Api::metal:
	case Api::direct_x: throw std::runtime_error { "Invalid API" };
	}
}

[[nodiscard]] auto create_gpu(Api target_api, IInstance *instance) -> memory::Scope<IGpu>
{
	switch (target_api)
	{
	case Api::vulkan: return memory::create_scope<vkb::Gpu>(instance);
	case Api::none:
	case Api::metal:
	case Api::direct_x: throw std::runtime_error { "Invalid API" };
	}
}

[[nodiscard]] auto create_device(Api target_api, IGpu *gpu, ISurface *surface)
    -> memory::Scope<IDevice>
{
	debug::ensure(gpu, "Failed to create renderer::IDevice: null gpu");
	debug::ensure(surface, "Failed to create renderer::IDevice: null surface");

	switch (target_api)
	{
	case Api::vulkan: return memory::create_scope<vkb::Device>(gpu, surface);
	case Api::none:
	case Api::metal:
	case Api::direct_x: throw std::runtime_error { "Invalid API" };
	}
}

[[nodiscard]] auto create_swapchain(Api target_api, ISurface *surface, IGpu *gpu, IDevice *device)
    -> memory::Scope<ISwapchain>
{
	switch (target_api)
	{
	case Api::vulkan: return memory::create_scope<vkb::Swapchain>(surface, gpu, device);
	case Api::none:
	case Api::metal:
	case Api::direct_x: throw std::runtime_error { "Invalid API" };
	}
}

[[nodiscard]] auto create_buffer(
    Api target_api,
    class IDevice *device,
    class IGpu *gpu,
    const IBuffer::CreateInfo &info
) -> memory::Scope<IBuffer>
{
	debug::ensure(device, "Failed to create renderer::IBuffer: null device");
	debug::ensure(gpu, "Failed to create renderer::IBuffer: null gpu");
	debug::ensure(info.size > 0, "Failed to create renderer::IBuffer: null size");

	switch (target_api)
	{
	case Api::vulkan: return memory::create_scope<vkb::Buffer>(device, gpu, info);
	case Api::none:
	case Api::metal:
	case Api::direct_x: throw std::runtime_error { "Invalid API" };
	}
}


[[nodiscard]] auto create_pass(
    lt::renderer::Api target_api,
    IDevice *device,
    const lt::assets::ShaderAsset &vertex_shader,
    const lt::assets::ShaderAsset &fragment_shader
) -> memory::Scope<IPass>
{
	debug::ensure(device, "Failed to create renderer::IPass: null device");

	switch (target_api)
	{
	case Api::vulkan:
		return memory::create_scope<vkb::Pass>(device, vertex_shader, fragment_shader);
	case Api::none:
	case Api::metal:
	case Api::direct_x: throw std::runtime_error { "Invalid API" };
	}
}

// [[nodiscard]] /* static */ auto IRenderer::create(
//     Api target_api,
//     IGpu *gpu,
//     IDevice *device,
//     ISwapchain *swapchain,
//     uint32_t max_frames_in_flight
// ) -> memory::Scope<IRenderer>
// {
// 	ensure(gpu, "Failed to create renderer::IRenderer: null gpu");
// 	ensure(device, "Failed to create renderer::IRenderer: null device");
// 	ensure(swapchain, "Failed to create renderer::IRenderer: null swapchain");
// 	ensure(
// 	    std::clamp(max_frames_in_flight, frames_in_flight_lower_limit, frames_in_flight_upper_limit)
// 	        == max_frames_in_flight,
// 	    "Failed to initialize renderer::System: max_frames_in_flight ({}) not within bounds ({} -> "
// 	    "{}) ",
// 	    max_frames_in_flight,
// 	    frames_in_flight_lower_limit,
// 	    frames_in_flight_upper_limit
// 	);
//
//
// 	switch (target_api)
// 	{
// 	case Api::vulkan:
// 		return memory::create_scope<vk::Renderer>(gpu, device, swapchain, max_frames_in_flight);
// 	case Api::none:
// 	case Api::metal:
// 	case Api::direct_x: throw std::runtime_error { "Invalid API" };
// 	}
// }


// [[nodiscard]] /* static */ auto IDebugger::create(
//     Api target_api,
//     IInstance *instance,
//     CreateInfo info
// ) -> memory::Scope<IDebugger>
// {
// 	debug::ensure(
// 	    info.severities != MessageSeverity::none,
// 	    "Failed to create vk::Messenger: severities == none"
// 	);
//
// 	debug::ensure(info.types != MessageType::none, "Failed to create vk::Messenger: types == none");
//
// 	debug::ensure(info.callback, "Failed to create vk::Messenger: null callback");
//
// 	switch (target_api)
// 	{
// 	case Api::vulkan: return memory::create_scope<vk::Messenger>(instance, std::move(info));
// 	case Api::none:
// 	case Api::metal:
// 	case Api::direct_x: throw std::runtime_error { "Invalid API" };
// 	}
// }