#include "externals.hh"

#include "imgui_impl_sdl.h"
#include "demo.hh"
#include "globals.hh"
#include "profiling.hh"
#include "window.hh"
#include "shaders.hh"
#include "odbg.hh"


/*= T_Main ===================================================================*/

struct T_Main
{
	static constexpr uint32_t ResizeDelay = 50;

	T_Main( );
	~T_Main( );

	void mainLoop( );

    private:
	bool done = false;
	bool capture = false;
	ImVec2 mouseInitial;
	ImVec2 mouseMove;

	uint32_t stopResize = 0;
	ImVec2 prevSize;

	bool demoCtrl_ = true;
	std::unique_ptr< T_Demo > demo;

	void initDemo( );

	void startIteration( );
	void handleCapture( );
	void makeUI( );
	void render( );
};

/*----------------------------------------------------------------------------*/

T_Main::T_Main( )
{
	Globals::Init( );
	prevSize = ImVec2( 1280 , 720 );
}

void T_Main::mainLoop( )
{
	auto& p( Globals::Profiler( ) );
	while ( !done ) {
		if ( demo ) {
			auto const& dspSize( ImGui::GetIO( ).DisplaySize );
			if ( prevSize.x != dspSize.x || prevSize.y != dspSize.y ) {
				stopResize = ResizeDelay;
				prevSize = dspSize;
			}
		}
		if ( stopResize > 0 ) {
			stopResize --;
			if ( stopResize == 0 ) {
				demo.reset( );
			}
		}
		if ( !demo ) {
			initDemo( );
		}

		Globals::Watcher( ).check( );
		Globals::Shaders( ).update( );

		glFinish( );
		p.startFrame( );
		p.start( "Full frame" );
		startIteration( );
		if ( !done ) {
			handleCapture( );
			makeUI( );
			render( );
			p.end( "Full frame" );
			Globals::Window( ).swap( );
			p.endFrame( );
		}
	}
}

T_Main::~T_Main( )
{
	demo.reset( );
	Globals::Shutdown( );
}

/*----------------------------------------------------------------------------*/

void T_Main::initDemo( )
{
	assert( !demo );
	auto const& dspSize( ImGui::GetIO( ).DisplaySize );
	if ( dspSize.x < 0 || dspSize.y < 0 ) {
		return;
	}

	printf( "init w/ dspsize %dx%d\n" , int( dspSize.x ) , int( dspSize.y ) );
	demo = std::make_unique< T_Demo >( dspSize.x , dspSize.y );
	if ( demo->initialise( ) ) {
		Globals::Profiler( ).clear( );
	} else {
		demo.reset( );
	}
}

void T_Main::startIteration( )
{
	SDL_Event event;
	mouseMove = ImVec2( );
	while ( SDL_PollEvent( &event ) ) {
		ImGui_ImplSdl_ProcessEvent( &event );
		if ( event.type == SDL_QUIT ) {
			done = true;
			return;
		}

		if ( capture && event.type == SDL_MOUSEMOTION ) {
			mouseMove.x += event.motion.xrel;
			mouseMove.y += event.motion.yrel;
		}
	}

	Globals::Window( ).startFrame( capture , mouseInitial );
	ImGui::GetIO( ).MouseDrawCursor = true;
}

void T_Main::handleCapture( )
{
	auto const& io( ImGui::GetIO( ) );
	const bool lmb( ImGui::IsMouseDown( 0 ) );
	const bool mb( lmb || ImGui::IsMouseDown( 1 ) );
	const bool appCanGrab( !( ImGui::IsMouseHoveringAnyWindow( )
				|| io.WantCaptureMouse
				|| io.WantCaptureKeyboard ) );
	const bool shift( io.KeyShift );
	const bool ctrl( io.KeyCtrl );

	if ( capture && !mb ) {
		capture = false;
		ImGui::CaptureMouseFromApp( false );
		SDL_SetRelativeMouseMode( SDL_FALSE );
		Globals::Window( ).warpMouse( mouseInitial );
		ImGui::SetMouseCursor( ImGuiMouseCursor_Arrow );
	} else if ( capture ) {
		ImGui::SetMouseCursor( ImGuiMouseCursor_Move );
		if ( demo ) {
			demo->handleDND( mouseMove , ctrl , shift , lmb );
		}
	} else if ( appCanGrab && mb ) {
		capture = true;
		mouseInitial = ImGui::GetMousePos( );
		ImGui::CaptureMouseFromApp( true );
		SDL_SetRelativeMouseMode( SDL_TRUE );
		ImGui::SetMouseCursor( ImGuiMouseCursor_Move );
	}

	if ( ( appCanGrab || capture ) && io.MouseWheel && demo ) {
		demo->handleWheel( io.MouseWheel , ctrl , shift );
	}
}

void T_Main::makeUI( )
{
	ImGui::SetNextWindowSize( ImVec2( 300 , 150 ) ,
			ImGuiSetCond_Once );
	ImGui::SetNextWindowPos( ImVec2( ) , ImGuiSetCond_Once );
	ImGui::Begin( "Tools" );

	ImGui::Checkbox( "Demo controls" , &demoCtrl_ );
	ImGui::Checkbox( "Profiler" , &Globals::Profiler( ).uiEnabled( ) );
	ImGui::Checkbox( "Output debugger" ,
			&Globals::ODbg( ).uiEnabled( ) );

	ImGui::End( );

	if ( demo && demoCtrl_ ) {
		demo->makeUI( );
	}

	Globals::Profiler( ).makeUI( );
	Globals::ODbg( ).makeUI( );
}

void T_Main::render( )
{
	if ( demo ) {
		Globals::Profiler( ).start( "Render" );
		demo->render( );
		glFinish( ); Globals::Profiler( ).end( "Render" );

		Globals::Profiler( ).start( "Debug" );
		T_Rendertarget::MainOutput( );
		if ( Globals::ODbg( ).isActive( ) ) {
			Globals::ODbg( ).debugOutput( );
		}
		glFinish( ); Globals::Profiler( ).end( "Debug" );

	} else {
		T_Rendertarget::MainOutput( );
		glClearColor( 0 , 0 , 0 , 1 );
		glClear( GL_COLOR_BUFFER_BIT );
	}

	glUseProgram( 0 );
	glBindProgramPipeline( 0 );
	Globals::Textures( ).reset( );
	glClearColor( 0 , 0 , 0 , 1 );
	ImGui::Render( );
}


/*============================================================================*/

int main( int , char** )
{
	T_Main m;
	m.mainLoop( );
	return 0;
}