#include "externals.hh"
#include "window.hh"
#include "imgui_impl_sdl.h"
#include <imgui_internal.h>


/*= A_ModalDialog ============================================================*/

A_ModalDialog::A_ModalDialog(
		char const* const id ) noexcept
	: id_{ id , uint32_t( strlen( id ) + 1 ) }
{}

A_ModalDialog::~A_ModalDialog( )
{ }

void A_ModalDialog::initDialog( ) noexcept
{}

void A_ModalDialog::onCancel( ) noexcept
{ }

bool A_ModalDialog::draw( ) noexcept
{
	using namespace ImGui;
	if ( !open_ ) {
		OpenPopup( id_.data( ) );
		open_ = true;
	}

	initDialog( );
	if ( initialSize_ ) {
		SetNextWindowSize( *initialSize_ , ImGuiCond_Appearing );
	}

	bool ok{ false };
	bool keep{ BeginPopupModal( id_.data( ) , nullptr , ImGuiWindowFlags_NoResize ) };
	if ( keep ) {
		const bool canUseOK{ drawDialog( ) };

		const ImVec2 ws( GetWindowContentRegionMax( ) );
		auto const& style( GetStyle( ) );
		const float innerWidth{ ws.x - 2 * style.FramePadding.x };
		constexpr float nButtons{ 2.f };
		const ImVec2 buttonSize{ std::max( 40.f ,
				( innerWidth - nButtons * style.FramePadding.x ) / nButtons ) ,
		      0.f
		};

		if ( !canUseOK ) {
			PushItemFlag( ImGuiItemFlags_Disabled , true );
			PushStyleVar( ImGuiStyleVar_Alpha ,
					GetStyle( ).Alpha * .5f );
		}
		if ( Button( "OK" , buttonSize ) ) {
			ok = true;
			keep = false;
		}
		if ( !canUseOK ) {
			PopItemFlag( );
			PopStyleVar( );
		}
		SameLine( 0 );
		keep = !Button( "Cancel" , buttonSize ) && keep;

		if ( !keep ) {
			CloseCurrentPopup( );
		}
		EndPopup( );
	}
	if ( !keep ) {
		if ( ok ) {
			onOK( );
		} else {
			onCancel( );
		}
	}
	return keep;
}


/*= T_Window =================================================================*/

namespace {
#include "font-awesome.inl"

static const ImWchar IconsRanges_[] = {
	ICON_MIN_FA ,
	ICON_MAX_FA ,
	0
};
} // namespace <anon>

T_Window::T_Window( )
{
	SDL_Init( SDL_INIT_VIDEO | SDL_INIT_TIMER );

	SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER , 1 );
	SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE , 24 );
	SDL_GL_SetAttribute( SDL_GL_STENCIL_SIZE , 8 );
	SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION , 2 );
	SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION , 2 );

	SDL_DisplayMode current;
	SDL_GetCurrentDisplayMode( 0 , &current );
	window = SDL_CreateWindow( "DEMO",
			SDL_WINDOWPOS_CENTERED , SDL_WINDOWPOS_CENTERED ,
			1280 , 720 ,
			SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE );
	gl = SDL_GL_CreateContext( window );
	glewInit( );
	if ( !GLEW_VERSION_4_5 ) {
		fprintf( stderr , "OpenGL 4.5 required\n" );
		exit( 1 );
	}

	ImGui_ImplSdl_Init( window );

	using namespace ImGui;
	StyleColorsDark( );
	ImGuiIO& io{ GetIO( ) };
	io.IniFilename = nullptr;
	{
		ImFontConfig cfg;
		cfg.SizePixels = 13.0f;
		defaultFont_ = io.Fonts->AddFontDefault( &cfg );

		ImFontConfig icons;
		icons.MergeMode = true;
		icons.PixelSnapH = true;
		io.Fonts->AddFontFromMemoryCompressedBase85TTF(
				FontAwesome__compressed_data_base85 , 13.f ,
				&icons , IconsRanges_ );
	}
	{
		ImFontConfig cfg;
		cfg.SizePixels = 9.0f;
		smallFont_ = io.Fonts->AddFontDefault( &cfg );

		ImFontConfig icons;
		icons.MergeMode = true;
		icons.PixelSnapH = true;
		icons.DstFont = smallFont_;
		io.Fonts->AddFontFromMemoryCompressedBase85TTF(
				FontAwesome__compressed_data_base85 , 9.f ,
				&icons , IconsRanges_ );
	}
}

T_Window::~T_Window( )
{
	ImGui_ImplSdl_Shutdown( );
	SDL_GL_DeleteContext( gl );
	SDL_DestroyWindow( window );
	SDL_Quit( );
}

void T_Window::startFrame(
		const bool capture ,
		ImVec2 const& mouseInitial ) const
{
	ImGui_ImplSdl_NewFrame( window , capture , mouseInitial );
}

void T_Window::warpMouse(
		ImVec2 const& pos ) const
{
	SDL_WarpMouseInWindow( window , pos.x , pos.y );
}

void T_Window::swap( ) const
{
	SDL_GL_SwapWindow( window );
}

void T_Window::handleDialogs( ) noexcept
{
	const auto nDialogs{ modals_.size( ) };
	for ( auto i = 0u ; i < nDialogs ; i ++ ) {
		const bool keep{ modals_[ i ]->draw( ) };
		assert( keep || i + 1 == nDialogs );
		if ( !keep ) {
			modals_.removeLast( );
		}
	}
}