#include <iostream>
#include <cstdlib>
#include <cmath>
#include <cstdint>
#include <cassert>

#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Input.H>
#include <FL/Fl_Multiline_Input.H>
#include <FL/Fl_Scroll.H>
#include <FL/Fl_Image.H>
#include <FL/Fl_Select_Browser.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_draw.H>

#include "flogo.h"
#include "engine.h"

using namespace std;

Fl_Window *window;
Fl_Scroll *drawscroll;
Fl_Box *drawimagebox,*turtleimagebox;
Fl_RGB_Image *drawimage,*turtleimage;
Fl_Select_Browser *histbrowser;
Fl_Input *cmdinput;
Fl_Button *evaluatebutton;

uchar *imagebuf,*turtlebuf;

Turtle turtle;


void bresenham(int x1,int y1,int x2,int y2,uchar *buf,int bufintsz,int bufcellsz,uint32_t v){
	int steep,deltax,deltay,error,ystep,x,y;
	steep=abs(y2-y1)>abs(x2-x1);
	if(steep){
		swap(x1,y1);
		swap(x2,y2);
	}
	if(x1>x2){
		swap(x1,x2);
		swap(y1,y2);
	}
	deltax=x2-x1;
	deltay=abs(y2-y1);
	error=deltax/2;
	if(y1<y2)ystep=1; else ystep=-1;
	for(x=x1,y=y1;x<=x2;x++){
		if(steep){
			switch(bufintsz){
				case 1: buf[bufcellsz*(WIDTH*x+y)]=(uchar)v; break;
				case 2: *(uint16_t*)(buf+bufcellsz*(WIDTH*x+y))=(uint16_t)v; break;
				case 4: *(uint32_t*)(buf+bufcellsz*(WIDTH*x+y))=(uint32_t)v; break;
				default: assert(false);
			}
		} else {
			switch(bufintsz){
				case 1: buf[bufcellsz*(WIDTH*y+x)]=(uchar)v; break;
				case 2: *(uint16_t*)(buf+bufcellsz*(WIDTH*y+x))=(uint16_t)v; break;
				case 4: *(uint32_t*)(buf+bufcellsz*(WIDTH*y+x))=(uint32_t)v; break;
				default: assert(false);
			}
		}
		error=error-deltay;
		if(error<0){
			y+=ystep;
			error+=deltax;
		}
	}
}

void drawline(int x1,int y1,int x2,int y2){
	bresenham(x1,y1,x2,y2,imagebuf,4,4,0xff000000);
	drawimage->uncache();
	window->redraw();
}

void drawturtle(void){
	memset(turtlebuf,0,WIDTH*HEIGHT*2*sizeof(uchar));
	const double raddir=turtle.dir*M_PI/180;
	const int x1=turtle.x-15*cos(raddir), //left-bottom
	          y1=turtle.y-15*sin(raddir),
	          x2=turtle.x+15*cos(raddir), //right-bottom
	          y2=turtle.y+15*sin(raddir),
	          x3=turtle.x+15*sin(raddir), //top
	          y3=turtle.y-15*cos(raddir);
	bresenham(x1,y1,x2,y2,turtlebuf+1,1,2,255);
	bresenham(x2,y2,x3,y3,turtlebuf+1,1,2,255);
	bresenham(x3,y3,x1,y1,turtlebuf+1,1,2,255);
	turtleimage->uncache();
	window->redraw();
}


void maincallback(Fl_Widget*,void*){
	if(Fl::event()==FL_SHORTCUT&&Fl::event_key()==FL_Escape)return;
	exit(0);
}

void evaluatebuttoncallback(Fl_Widget*){
	if(cmdinput->value()[0]=='\0')return;
	histbrowser->insert(histbrowser->size(),cmdinput->value());
	histbrowser->bottomline(histbrowser->size());
	logocommand(cmdinput->value());
	cmdinput->value(NULL);
}

void histcallback(Fl_Widget *wid){
	Fl_Select_Browser *br=(Fl_Select_Browser*)wid;
	cmdinput->value(br->text(br->value()));
}

int main(int argc,char **argv){
	window=new Fl_Window(1016,700,"FLogo");

	imagebuf=new uchar[WIDTH*HEIGHT*4]; //RGB(A)
	memset(imagebuf,255,WIDTH*HEIGHT*4*sizeof(uchar));
	turtlebuf=new uchar[WIDTH*HEIGHT*2]; //GA
	memset(turtlebuf,0,WIDTH*HEIGHT*2*sizeof(uchar));

	drawscroll=new Fl_Scroll(0,0,window->w(),window->h()-150);
		drawimagebox=new Fl_Box(0,0,WIDTH,HEIGHT);
			drawimage=new Fl_RGB_Image(imagebuf,WIDTH,HEIGHT,4);
			drawimagebox->image(drawimage);
		turtleimagebox=new Fl_Box(0,0,WIDTH,HEIGHT);
			turtleimage=new Fl_RGB_Image(turtlebuf,WIDTH,HEIGHT,2);
			turtleimagebox->image(turtleimage);
	drawscroll->end();
	drawscroll->scroll_to(max(0,WIDTH-drawscroll->w())/2,max(0,HEIGHT-drawscroll->h())/2);
	drawturtle();

	cmdinput=new Fl_Input(0,window->h()-25,window->w()-150,25);
		cmdinput->when(FL_WHEN_ENTER_KEY|FL_WHEN_NOT_CHANGED);
		cmdinput->callback(evaluatebuttoncallback);

	evaluatebutton=new Fl_Button(cmdinput->x()+cmdinput->w(),cmdinput->y(),80,cmdinput->h(),"Evaluate");
		evaluatebutton->callback(evaluatebuttoncallback);
	window->add(evaluatebutton);

	histbrowser=new Fl_Select_Browser(0,drawscroll->y()+drawscroll->h(),cmdinput->w(),cmdinput->y()-(drawscroll->y()+drawscroll->h()));
		histbrowser->callback(histcallback);
	histbrowser->add(""); //add blank line

	window->resizable(drawscroll);

	window->end();
	Fl::visual(FL_RGB);
	//window->callback(maincallback); //disable esc window closing
	window->show(argc,argv);
	return Fl::run();
}