#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"
#include "ops.hh"
#include "rendertarget.hh"
#include "sync.hh"
#include "syncview.hh"
#include "undo.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;

	T_Optional< T_Demo > demo;
	T_Optional< T_SyncView > sequencer;

	void initDemo( );

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

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

T_Main::T_Main( )
{
	Globals::Init( );
	prevSize = ImVec2( -1 , -1 );
}

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

		bool needInit( !demo );
		if ( stopResize > 0 ) {
			stopResize --;
			if ( stopResize == 0 ) {
				needInit = true;
			}
		}
		if ( needInit ) {
			initDemo( );
		}
#warning FIXME remove this
		if ( !sequencer ) {
			sequencer.setNew( );
		}

		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.clear( );
	Globals::Shutdown( );
}

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

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

	if ( !demo ) {
		demo.setNew( );
	}

	printf( "init w/ dspsize %dx%d\n" , int( dspSize.x ) , int( dspSize.y ) );
	if ( demo->initialise( (uint32_t) dspSize.x , (uint32_t) dspSize.y ) ) {
		Globals::Profiler( ).clear( );
	}
}

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( )
{
	using namespace ImGui;
	auto const& io( GetIO( ) );
	const T_MouseButtons mb( ([]() {;
			T_MouseButtons mb;
			if ( IsMouseDown( 0 ) ) {
				mb |= E_MouseButton::LEFT;
			}
			if ( IsMouseDown( 1 ) ) {
				mb |= E_MouseButton::RIGHT;
			}
			if ( IsMouseDown( 2 ) ) {
				mb |= E_MouseButton::MIDDLE;
			}
			return mb;
		})() );
	const T_KeyboardModifiers kb( ([&io]() {
			T_KeyboardModifiers kb;
			if ( io.KeyCtrl ) {
				kb |= E_KeyboardModifier::CTRL;
			}
			if ( io.KeyShift ) {
				kb |= E_KeyboardModifier::SHIFT;
			}
			if ( io.KeyAlt ) {
				kb |= E_KeyboardModifier::ALT;
			}
			return kb;
		})() );
	const bool appCanGrab( !( ImGui::IsMouseHoveringAnyWindow( )
				|| io.WantCaptureMouse
				|| io.WantCaptureKeyboard ) );

	if ( capture && !mb ) {
		capture = false;
		CaptureMouseFromApp( false );
		SDL_SetRelativeMouseMode( SDL_FALSE );
		Globals::Window( ).warpMouse( mouseInitial );
		SetMouseCursor( ImGuiMouseCursor_Arrow );
	} else if ( capture ) {
		SetMouseCursor( ImGuiMouseCursor_Move );
		Globals::Sync( ).handleDragAndDrop( mouseMove , kb , mb );
	} else if ( appCanGrab && mb ) {
		capture = true;
		mouseInitial = GetMousePos( );
		CaptureMouseFromApp( true );
		SDL_SetRelativeMouseMode( SDL_TRUE );
		SetMouseCursor( ImGuiMouseCursor_Move );
	}

	if ( ( appCanGrab || capture ) && io.MouseWheel ) {
		Globals::Sync( ).handleWheel( io.MouseWheel , kb , mb );
	}
}

void T_Main::makeUI( )
{
	using namespace ImGui;
	auto& undo( Globals::Undo( ) );
	auto& sync( Globals::Sync( ) );
	bool eSequencer{ sequencer };
	if ( BeginMainMenuBar( ) ) {
		if ( BeginMenu( "File" ) ) {
			if ( MenuItem( "Save curves" , "C-s" , false , sync.curvesModified( ) ) ) {
				// FIXME: confirmation dialog if file changed
				sync.saveCurves( );
			}
			if ( MenuItem( "Reload curves" , "C-R" , false , sync.curvesModified( ) ) ) {
				// FIXME: confirmation dialog
				sync.loadCurves( );
			}
			Separator( );
			if ( MenuItem( "Undo" , "C-z" , false , undo.canUndo( ) ) ) {
				undo.undo( );
			}
			if ( MenuItem( "Redo" , "C-Z" , false , undo.canRedo( ) ) ) {
				undo.redo( );
			}
			Separator( );
			if ( MenuItem( "Quit" ) ) {
				done = true;
			}
			EndMenu( );
		}
		if ( BeginMenu( "Views" ) ) {
			MenuItemCheckbox( "Input overrides" ,
					&sync.overridesWindowEnabled( ) );
			MenuItemCheckbox( "Output debugger" ,
					&Globals::ODbg( ).uiEnabled( ) );
			MenuItemCheckbox( "Profiler" ,
					&Globals::Profiler( ).uiEnabled( ) );
			MenuItemCheckbox( "Sequencer" , &eSequencer );
			MenuItemCheckbox( "Shaders" ,
					&Globals::Shaders( ).uiEnabled( ) );
			EndMenu( );
		}
		EndMainMenuBar( );
	}

	if ( eSequencer && !sequencer ) {
		sequencer.setNew( );
	} else if ( !eSequencer && sequencer ) {
		sequencer.clear( );
	}

	Globals::Profiler( ).makeUI( );
	Globals::ODbg( ).makeUI( );
	Globals::Shaders( ).makeUI( );
	Globals::Sync( ).makeOverridesWindow( );
	if ( sequencer && !sequencer->display( ) ) {
		sequencer.clear( );
	}
}

void T_Main::render( )
{
	if ( demo ) {
		demo->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 );
	}

	Globals::Window( ).handleDialogs( );
	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;
}