// MIT License

// Copyright (c) 2017 Vadim Grigoruk @nesbox // grigoruk@gmail.com

// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

#include "machine.h"

#if defined(TIC_BUILD_WITH_SQUIRREL)

//#define USE_FOREIGN_POINTER
//#define CHECK_FORCE_EXIT

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <squirrel.h>
#include <sqstdmath.h>
#include <sqstdstring.h>
#include <sqstdblob.h>
#include <ctype.h>

static const char TicMachine[] = "_TIC80";


// !TODO: get rid of this wrap
static s32 getSquirrelNumber(HSQUIRRELVM vm, s32 index)
{
	SQInteger i;
	if (SQ_SUCCEEDED(sq_getinteger(vm, index, &i)))
		return (s32)i;
	
	SQFloat f;
	if (SQ_SUCCEEDED(sq_getfloat(vm, index, &f)))
		return (s32)f;
	
	return 0;
}

static void registerSquirrelFunction(tic_machine* machine, SQFUNCTION func, const char *name)
{
	sq_pushroottable(machine->squirrel);
	sq_pushstring(machine->squirrel, name, -1);
	sq_newclosure(machine->squirrel, func, 0);
	sq_newslot(machine->squirrel, -3, SQTrue);
	sq_poptop(machine->squirrel); // remove root table.
}

static tic_machine* getSquirrelMachine(HSQUIRRELVM vm)
{
#if USE_FOREIGN_POINTER
	return (tic_machine*)sq_getforeignpointer(vm);
#else
	sq_pushregistrytable(vm);
	sq_pushstring(vm, TicMachine, -1);
	if (SQ_FAILED(sq_get(vm, -2)))
	{
		fprintf(stderr, "FATAL ERROR: TicMachine not found!\n");
		abort();
	}
	SQUserPointer ptr;
	if (SQ_FAILED(sq_getuserpointer(vm, -1, &ptr)))
	{
		fprintf(stderr, "FATAL ERROR: Cannot get user pointer for TicMachine!\n");
		abort();
	}
	tic_machine* machine = (tic_machine*)ptr;
	sq_pop(vm, 2); // user pointer and registry table.
	return machine;
#endif
}

static SQInteger squirrel_errorHandler(HSQUIRRELVM vm)
{
	tic_machine* machine = getSquirrelMachine(vm);

	SQStackInfos si;
	SQInteger level = 0;
	while (SQ_SUCCEEDED(sq_stackinfos(vm, level, &si)))
	{
		char buffer[100];
		snprintf(buffer, 99, "%.40s %.40s %.6d\n", si.funcname, si.source, (int)si.line);
		
		machine->data->error(machine->data->data, buffer);
		++level;
	}

	return 0;
}


static SQInteger squirrel_peek(HSQUIRRELVM vm)
{
	tic_machine* machine = getSquirrelMachine(vm);

	// check number of args
	if (sq_gettop(vm) != 2)
		return sq_throwerror(vm, "invalid parameters, peek(address)");
	s32 address = getSquirrelNumber(vm, 2);

	if(address >=0 && address < sizeof(tic_ram))
	{
		sq_pushinteger(vm, *((u8*)&machine->memory.ram + address));
		return 1;
	}

	return 0;
}

static SQInteger squirrel_poke(HSQUIRRELVM vm)
{
	tic_machine* machine = getSquirrelMachine(vm);

	if (sq_gettop(vm) != 3)
		return sq_throwerror( vm, "invalid parameters, poke(address,value)" );
	s32 address = getSquirrelNumber(vm, 2);
	u8 value = getSquirrelNumber(vm, 3) & 0xff;

	if(address >=0 && address < sizeof(tic_ram))
	{
		*((u8*)&machine->memory.ram + address) = value;
	}

	return 0;
}

static SQInteger squirrel_peek4(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 2)
	{
		s32 address = getSquirrelNumber(vm, 2);

		if(address >= 0 && address < sizeof(tic_ram)*2)
		{
			sq_pushinteger(vm, tic_tool_peek4((u8*)&getSquirrelMachine(vm)->memory.ram, address));
			return 1;
		}		
	}
	else return sq_throwerror(vm, "invalid parameters, peek4(addr)\n");

	return 0;
}

static SQInteger squirrel_poke4(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 3)
	{
		s32 address = getSquirrelNumber(vm, 2);
		u8 value = getSquirrelNumber(vm, 3);

		if(address >= 0 && address < sizeof(tic_ram)*2)
		{
			tic_tool_poke4((u8*)&getSquirrelMachine(vm)->memory.ram, address, value);
		}
	}
	else return sq_throwerror(vm, "invalid parameters, poke4(addr,value)\n");

	return 0;
}

static SQInteger squirrel_cls(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

	memory->api.clear(memory, top == 2 ? getSquirrelNumber(vm, 2) : 0);

	return 0;
}

static SQInteger squirrel_pix(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top >= 3)
	{
		s32 x = getSquirrelNumber(vm, 2);
		s32 y = getSquirrelNumber(vm, 3);
		
		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		if(top >= 4)
		{
			s32 color = getSquirrelNumber(vm, 4);
			memory->api.pixel(memory, x, y, color);
		}
		else
		{
			sq_pushinteger(vm, memory->api.get_pixel(memory, x, y));
			return 1;
		}

	}
	else return sq_throwerror(vm, "invalid parameters, pix(x y [color])\n");

	return 0;
}



static SQInteger squirrel_line(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 6)
	{
		s32 x0 = getSquirrelNumber(vm, 2);
		s32 y0 = getSquirrelNumber(vm, 3);
		s32 x1 = getSquirrelNumber(vm, 4);
		s32 y1 = getSquirrelNumber(vm, 5);
		s32 color = getSquirrelNumber(vm, 6);

		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		memory->api.line(memory, x0, y0, x1, y1, color);
	}
	else return sq_throwerror(vm, "invalid parameters, line(x0,y0,x1,y1,color)\n");

	return 0;
}

static SQInteger squirrel_rect(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 6)
	{
		s32 x = getSquirrelNumber(vm, 2);
		s32 y = getSquirrelNumber(vm, 3);
		s32 w = getSquirrelNumber(vm, 4);
		s32 h = getSquirrelNumber(vm, 5);
		s32 color = getSquirrelNumber(vm, 6);

		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		memory->api.rect(memory, x, y, w, h, color);
	}
	else return sq_throwerror(vm, "invalid parameters, rect(x,y,w,h,color)\n");

	return 0;
}

static SQInteger squirrel_rectb(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 6)
	{
		s32 x = getSquirrelNumber(vm, 2);
		s32 y = getSquirrelNumber(vm, 3);
		s32 w = getSquirrelNumber(vm, 4);
		s32 h = getSquirrelNumber(vm, 5);
		s32 color = getSquirrelNumber(vm, 6);

		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		memory->api.rect_border(memory, x, y, w, h, color);
	}
	else return sq_throwerror(vm, "invalid parameters, rectb(x,y,w,h,color)\n");

	return 0;
}

static SQInteger squirrel_circ(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 5)
	{
		s32 radius = getSquirrelNumber(vm, 4);
		if(radius < 0) return 0;
		
		s32 x = getSquirrelNumber(vm, 2);
		s32 y = getSquirrelNumber(vm, 3);
		s32 color = getSquirrelNumber(vm, 5);

		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		memory->api.circle(memory, x, y, radius, color);
	}
	else return sq_throwerror(vm, "invalid parameters, circ(x,y,radius,color)\n");

	return 0;
}

static SQInteger squirrel_circb(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 5)
	{
		s32 radius = getSquirrelNumber(vm, 4);
		if(radius < 0) return 0;

		s32 x = getSquirrelNumber(vm, 2);
		s32 y = getSquirrelNumber(vm, 3);
		s32 color = getSquirrelNumber(vm, 5);

		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		memory->api.circle_border(memory, x, y, radius, color);
	}
	else return sq_throwerror(vm, "invalid parameters, circb(x,y,radius,color)\n");

	return 0;
}

static SQInteger squirrel_tri(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 8)
	{
		s32 pt[6];

		for(s32 i = 0; i < COUNT_OF(pt); i++)
			pt[i] = getSquirrelNumber(vm, i+2);
		
		s32 color = getSquirrelNumber(vm, 8);

		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		memory->api.tri(memory, pt[0], pt[1], pt[2], pt[3], pt[4], pt[5], color);
	}
	else return sq_throwerror(vm, "invalid parameters, tri(x1,y1,x2,y2,x3,y3,color)\n");

	return 0;
}

static SQInteger squirrel_textri(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if (top >= 13)
	{
		float pt[12];

		for (s32 i = 0; i < COUNT_OF(pt); i++)
		{
			SQFloat f = 0.0;
			sq_getfloat(vm, i + 2, &f);
			pt[i] = (float)f;
		}

		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);
		u8 chroma = 0xff;
		bool use_map = false;

		//	check for use map 
		if (top >= 14)
		{
			SQBool b = SQFalse;
			sq_getbool(vm, 14, &b);
			use_map = (b != SQFalse);
		}
		//	check for chroma 
		if (top >= 15)
			chroma = (u8)getSquirrelNumber(vm, 15);

		memory->api.textri(memory, pt[0], pt[1],	//	xy 1
									pt[2], pt[3],	//	xy 2
									pt[4], pt[5],	//  xy 3
									pt[6], pt[7],	//	uv 1
									pt[8], pt[9],	//	uv 2
									pt[10], pt[11], //  uv 3
									use_map,		// use map
									chroma);		// chroma
	}
	else return sq_throwerror(vm, "invalid parameters, textri(x1,y1,x2,y2,x3,y3,u1,v1,u2,v2,u3,v3,[use_map=false],[chroma=off])\n");
	return 0;
}


static SQInteger squirrel_clip(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 1)
	{
		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		memory->api.clip(memory, 0, 0, TIC80_WIDTH, TIC80_HEIGHT);
	}
	else if(top == 5)
	{
		s32 x = getSquirrelNumber(vm, 2);
		s32 y = getSquirrelNumber(vm, 3);
		s32 w = getSquirrelNumber(vm, 4);
		s32 h = getSquirrelNumber(vm, 5);

		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		memory->api.clip((tic_mem*)getSquirrelMachine(vm), x, y, w, h);
	}
	else return sq_throwerror(vm, "invalid parameters, use clip(x,y,w,h) or clip()\n");

	return 0;
}

static SQInteger squirrel_btnp(HSQUIRRELVM vm)
{
	tic_machine* machine = getSquirrelMachine(vm);
	tic_mem* memory = (tic_mem*)machine;

	SQInteger top = sq_gettop(vm);

	if (top == 1)
	{
		sq_pushinteger(vm, memory->api.btnp(memory, -1, -1, -1));
	}
	else if(top == 2)
	{
		s32 index = getSquirrelNumber(vm, 2) & 0x1f;

		sq_pushbool(vm, (memory->api.btnp(memory, index, -1, -1) ? SQTrue : SQFalse));
	}
	else if (top == 4)
	{
		s32 index = getSquirrelNumber(vm, 2) & 0x1f;
		u32 hold = getSquirrelNumber(vm, 3);
		u32 period = getSquirrelNumber(vm, 4);

		sq_pushbool(vm, (memory->api.btnp(memory, index, hold, period) ? SQTrue : SQFalse));
	}
	else
	{
		return sq_throwerror(vm, "invalid params, btnp [ id [ hold period ] ]\n");
	}

	return 1;
}

static SQInteger squirrel_btn(HSQUIRRELVM vm)
{
	tic_machine* machine = getSquirrelMachine(vm);

	SQInteger top = sq_gettop(vm);

	if (top == 1)
	{
		sq_pushinteger(vm, machine->memory.ram.input.gamepads.data);
	}
	else if (top == 2)
	{
		u32 index = getSquirrelNumber(vm, 2) & 0x1f;
		bool pressed = (machine->memory.ram.input.gamepads.data & (1 << index)) != 0;
		sq_pushbool(vm, pressed ? SQTrue : SQFalse);
	}
	else
	{
		return sq_throwerror(vm, "invalid params, btn [ id ]\n");
	} 

	return 1;
}

static SQInteger squirrel_spr(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	s32 index = 0;
	s32 x = 0;
	s32 y = 0;
	s32 w = 1;
	s32 h = 1;
	s32 scale = 1;
	tic_flip flip = tic_no_flip;
	tic_rotate rotate = tic_no_rotate;
	static u8 colors[TIC_PALETTE_SIZE];
	s32 count = 0;

	if(top >= 2) 
	{
		index = getSquirrelNumber(vm, 2);

		if(top >= 4)
		{
			x = getSquirrelNumber(vm, 3);
			y = getSquirrelNumber(vm, 4);

			if(top >= 5)
			{
				if(OT_ARRAY == sq_gettype(vm, 5))
				{
					for(s32 i = 0; i < TIC_PALETTE_SIZE; i++)
					{
						sq_pushinteger(vm, (SQInteger)i);
						sq_rawget(vm, 5);
						if(sq_gettype(vm, -1) & (OT_FLOAT|OT_INTEGER))
						{
							colors[i-1] = getSquirrelNumber(vm, -1);
							count++;
							sq_poptop(vm);
						}
						else
						{
							sq_poptop(vm);
							break;
						}
					}
				}
				else 
				{
					colors[0] = getSquirrelNumber(vm, 5);
					count = 1;
				}

				if(top >= 6)
				{
					scale = getSquirrelNumber(vm, 6);

					if(top >= 7)
					{
						flip = getSquirrelNumber(vm, 7);

						if(top >= 8)
						{
							rotate = getSquirrelNumber(vm, 8);

							if(top >= 10)
							{
								w = getSquirrelNumber(vm, 9);
								h = getSquirrelNumber(vm, 10);
							}
						}
					}
				}
			}
		}
	}

	tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

	memory->api.sprite_ex(memory, &memory->ram.tiles, index, x, y, w, h, colors, count, scale, flip, rotate);

	return 0;
}

static SQInteger squirrel_mget(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 3)
	{
		s32 x = getSquirrelNumber(vm, 2);
		s32 y = getSquirrelNumber(vm, 3);

		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		u8 value = memory->api.map_get(memory, &memory->ram.map, x, y);
		sq_pushinteger(vm, value);
		return 1;
	}
	else return sq_throwerror(vm, "invalid params, mget(x,y)\n");

	return 0;
}

static SQInteger squirrel_mset(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 4)
	{
		s32 x = getSquirrelNumber(vm, 2);
		s32 y = getSquirrelNumber(vm, 3);
		u8 val = getSquirrelNumber(vm, 4);

		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		memory->api.map_set(memory, &memory->ram.map, x, y, val);
	}
	else return sq_throwerror(vm, "invalid params, mget(x,y)\n");

	return 0;
}

typedef struct
{
	HSQUIRRELVM vm;
	HSQOBJECT reg;
} RemapData;

static void remapCallback(void* data, s32 x, s32 y, RemapResult* result)
{
	RemapData* remap = (RemapData*)data;
	HSQUIRRELVM vm = remap->vm;

	SQInteger top = sq_gettop(vm);
	
	sq_pushobject(vm, remap->reg);
	sq_pushroottable(vm);
	sq_pushinteger(vm, result->index);
	sq_pushinteger(vm, x);
	sq_pushinteger(vm, y);
	//lua_pcall(lua, 3, 3, 0);

	if (SQ_SUCCEEDED(sq_call(vm, 4, SQTrue, SQTrue)))
	{
		sq_pushinteger(vm, 0);
		if (SQ_SUCCEEDED(sq_get(vm, -2)))
		{
			result->index = getSquirrelNumber(vm, -1);
			sq_poptop(vm);
			sq_pushinteger(vm, 1);
			if (SQ_SUCCEEDED(sq_get(vm, -2)))
			{
				result->flip = getSquirrelNumber(vm, -1);
				sq_poptop(vm);
				sq_pushinteger(vm, 2);
				if (SQ_SUCCEEDED(sq_get(vm, -2)))
				{
					result->rotate = getSquirrelNumber(vm, -1);
					sq_poptop(vm);
				}
			}
		}
	}

	sq_settop(vm, top);
}

static SQInteger squirrel_map(HSQUIRRELVM vm)
{
	s32 x = 0;
	s32 y = 0;
	s32 w = TIC_MAP_SCREEN_WIDTH;
	s32 h = TIC_MAP_SCREEN_HEIGHT;
	s32 sx = 0;
	s32 sy = 0;
	u8 chromakey = -1;
	s32 scale = 1;

	SQInteger top = sq_gettop(vm);

	if(top >= 3) 
	{
		x = getSquirrelNumber(vm, 2);
		y = getSquirrelNumber(vm, 3);

		if(top >= 5)
		{
			w = getSquirrelNumber(vm, 4);
			h = getSquirrelNumber(vm, 5);

			if(top >= 7)
			{
				sx = getSquirrelNumber(vm, 6);
				sy = getSquirrelNumber(vm, 7);

				if(top >= 8)
				{
					chromakey = getSquirrelNumber(vm, 8);

					if(top >= 9)
					{
						scale = getSquirrelNumber(vm, 9);

						if(top >= 10)
						{
							SQObjectType type = sq_gettype(vm, 10);
							if (type & (OT_CLOSURE|OT_NATIVECLOSURE|OT_INSTANCE))
							{
								RemapData data = {vm};
								sq_resetobject(&data.reg);
								sq_getstackobj(vm, 10, &data.reg);
								sq_addref(vm, &data.reg);

								tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

								memory->api.remap(memory, &memory->ram.map, &memory->ram.tiles, x, y, w, h, sx, sy, chromakey, scale, remapCallback, &data);

								//luaL_unref(lua, LUA_REGISTRYINDEX, data.reg);
								sq_release(vm, &data.reg);

								return 0;
							}							
						}
					}
				}
			}
		}
	}

	tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

	memory->api.map((tic_mem*)getSquirrelMachine(vm), &memory->ram.map, &memory->ram.tiles, x, y, w, h, sx, sy, chromakey, scale);

	return 0;
}

static SQInteger squirrel_music(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);
	tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

	if(top == 1) memory->api.music(memory, -1, 0, 0, false);
	else if(top >= 2)
	{
		memory->api.music(memory, -1, 0, 0, false);

		s32 track = getSquirrelNumber(vm, 2);
		s32 frame = -1;
		s32 row = -1;
		bool loop = true;

		if(top >= 3)
		{
			frame = getSquirrelNumber(vm, 3);

			if(top >= 4)
			{
				row = getSquirrelNumber(vm, 4);

				if(top >= 5)
				{
					SQBool b = SQFalse;
					sq_getbool(vm, 5, &b);
					loop = (b != SQFalse);
				}
			}
		}

		memory->api.music(memory, track, frame, row, loop);
	}
	else return sq_throwerror(vm, "invalid params, use music(track)\n");

	return 0;
}

static SQInteger squirrel_sfx(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top >= 2)
	{
		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		s32 note = -1;
		s32 octave = -1;
		s32 duration = -1;
		s32 channel = 0;
		s32 volume = MAX_VOLUME;
		s32 speed = SFX_DEF_SPEED;

		s32 index = getSquirrelNumber(vm, 2);

		if(index < SFX_COUNT)
		{
			if (index >= 0)
			{
				tic_sample* effect = memory->ram.sfx.samples.data + index;

				note = effect->note;
				octave = effect->octave;
				speed = effect->speed;
			}

			if(top >= 3)
			{
				if(sq_gettype(vm, 3) & (OT_INTEGER|OT_FLOAT))
				{
					s32 id = getSquirrelNumber(vm, 3);
					note = id % NOTES;
					octave = id / NOTES;
				}
				else if(sq_gettype(vm, 3) == OT_STRING)
				{
					const SQChar* str;
					sq_getstring(vm, 3, &str);
					const char* noteStr = (const char*)str;

					if(!tic_tool_parse_note(noteStr, &note, &octave))
					{
						return sq_throwerror(vm, "invalid note, should be like C#4\n");
					}
				}

				if(top >= 4)
				{
					duration = getSquirrelNumber(vm, 4);

					if(top >= 5)
					{
						channel = getSquirrelNumber(vm, 5);

						if(top >= 6)
						{
							volume = getSquirrelNumber(vm, 6);

							if(top >= 7)
							{
								speed = getSquirrelNumber(vm, 7);
							}
						}
					}					
				}
			}

			if (channel >= 0 && channel < TIC_SOUND_CHANNELS)
			{
				memory->api.sfx_stop(memory, channel);
				memory->api.sfx_ex(memory, index, note, octave, duration, channel, volume & 0xf, speed);
			}
			else return sq_throwerror(vm, "unknown channel\n");
		}
		else return sq_throwerror(vm, "unknown sfx index\n");
	}
	else return sq_throwerror(vm, "invalid sfx params\n");

	return 0;
}

static SQInteger squirrel_sync(HSQUIRRELVM vm)
{
	tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

	bool toCart = false;
	u32 mask = 0;
	s32 bank = 0;

	if(sq_gettop(vm) >= 2)
	{
		mask = getSquirrelNumber(vm, 2);

		if(sq_gettop(vm) >= 3)
		{
			bank = getSquirrelNumber(vm, 3);

			if(sq_gettop(vm) >= 4)
			{
				SQBool b = SQFalse;
				sq_getbool(vm, 4, &b);
				toCart = (b != SQFalse);
			}
		}
	}

	if(bank >= 0 && bank < TIC_BANKS)
		memory->api.sync(memory, mask, bank, toCart);
	else
		return sq_throwerror(vm, "sync() error, invalid bank");

	return 0;
}

static SQInteger squirrel_reset(HSQUIRRELVM vm)
{
	tic_machine* machine = getSquirrelMachine(vm);

	machine->state.initialized = false;

	return 0;
}

static SQInteger squirrel_key(HSQUIRRELVM vm)
{
	tic_machine* machine = getSquirrelMachine(vm);
	tic_mem* tic = &machine->memory;

	SQInteger top = sq_gettop(vm);

	if (top == 1)
	{
		sq_pushbool(vm, tic->api.key(tic, tic_key_unknown) ? SQTrue : SQFalse);
	}
	else if (top == 2)
	{
		tic_key key = getSquirrelNumber(vm, 2);

		if(key < tic_key_escape)
			sq_pushbool(vm, tic->api.key(tic, key) ? SQTrue : SQFalse);
		else
		{
			return sq_throwerror(vm, "unknown keyboard code\n");
		}
	}
	else
	{
		return sq_throwerror(vm, "invalid params, key [code]\n");
	} 

	return 1;
}

static SQInteger squirrel_keyp(HSQUIRRELVM vm)
{
	tic_machine* machine = getSquirrelMachine(vm);
	tic_mem* tic = &machine->memory;

	SQInteger top = sq_gettop(vm);

	if (top == 1)
	{
		sq_pushbool(vm, tic->api.keyp(tic, tic_key_unknown, -1, -1) ? SQTrue : SQFalse);
	}
	else
	{
		tic_key key = getSquirrelNumber(vm, 2);

		if(key >= tic_key_escape)
		{
			return sq_throwerror(vm, "unknown keyboard code\n");
		}
		else
		{
			if(top == 2)
			{
				sq_pushbool(vm, tic->api.keyp(tic, key, -1, -1) ? SQTrue : SQFalse);
			}
			else if(top == 4)
			{
				u32 hold = getSquirrelNumber(vm, 3);
				u32 period = getSquirrelNumber(vm, 4);

				sq_pushbool(vm, tic->api.keyp(tic, key, hold, period) ? SQTrue : SQFalse);
			}
			else
			{
				return sq_throwerror(vm, "invalid params, keyp [ code [ hold period ] ]\n");
			}
		}
	}

	return 1;
}

static SQInteger squirrel_memcpy(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 4)
	{
		s32 dest = getSquirrelNumber(vm, 2);
		s32 src = getSquirrelNumber(vm, 3);
		s32 size = getSquirrelNumber(vm, 4);
		s32 bound = sizeof(tic_ram) - size;

		if(size >= 0 && size <= sizeof(tic_ram) && dest >= 0 && src >= 0 && dest <= bound && src <= bound)
		{
			u8* base = (u8*)&getSquirrelMachine(vm)->memory;
			memcpy(base + dest, base + src, size);
			return 0;
		}
	}

	return sq_throwerror(vm, "invalid params, memcpy(dest,src,size)\n");
}

static SQInteger squirrel_memset(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top == 4)
	{
		s32 dest = getSquirrelNumber(vm, 2);
		u8 value = getSquirrelNumber(vm, 3);
		s32 size = getSquirrelNumber(vm, 4);
		s32 bound = sizeof(tic_ram) - size;

		if(size >= 0 && size <= sizeof(tic_ram) && dest >= 0 && dest <= bound)
		{
			u8* base = (u8*)&getSquirrelMachine(vm)->memory;
			memset(base + dest, value, size);
			return 0;
		}
	}

	return sq_throwerror(vm, "invalid params, memset(dest,val,size)\n");
}

// NB we leave the string on the stack so that the char* pointer remains valid.
static const char* printString(HSQUIRRELVM vm, s32 index)
{
	const SQChar* text = "";
	if (SQ_SUCCEEDED(sq_tostring(vm, index)))
	{
		sq_getstring(vm, -1, &text);
	}
	
	return (const char*)text;
}

static SQInteger squirrel_font(HSQUIRRELVM vm)
{
	tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);
	SQInteger top = sq_gettop(vm);

	if(top >= 2)
	{
		const char* text = printString(vm, 2);
		s32 x = 0;
		s32 y = 0;
		s32 width = TIC_SPRITESIZE;
		s32 height = TIC_SPRITESIZE;
		u8 chromakey = 0;
		bool fixed = false;
		s32 scale = 1;

		if(top >= 4)
		{
			x = getSquirrelNumber(vm, 3);
			y = getSquirrelNumber(vm, 4);

			if(top >= 5)
			{
				chromakey = getSquirrelNumber(vm, 5);

				if(top >= 7)
				{
					width = getSquirrelNumber(vm, 6);
					height = getSquirrelNumber(vm, 7);

					if(top >= 8)
					{
						SQBool b = SQFalse;
						sq_getbool(vm, 8, &b);
						fixed = (b != SQFalse);

						if(top >= 9)
						{
							scale = getSquirrelNumber(vm, 9);
						}
					}
				}
			}
		}

		if(scale == 0)
		{
			sq_pushinteger(vm, 0);
			return 1;
		}

		s32 size = drawText(memory, text, x, y, width, height, chromakey, scale, fixed ? drawSpriteFont : drawFixedSpriteFont);

		sq_pushinteger(vm, size);
		return 1;
	}

	return 0;
}

static SQInteger squirrel_print(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);

	if(top >= 2) 
	{
		tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);

		s32 x = 0;
		s32 y = 0;
		s32 color = TIC_PALETTE_SIZE-1;
		bool fixed = false;
		s32 scale = 1;

		const char* text = printString(vm, 2);

		if(top >= 4)
		{
			x = getSquirrelNumber(vm, 3);
			y = getSquirrelNumber(vm, 4);

			if(top >= 5)
			{
				color = getSquirrelNumber(vm, 5) % TIC_PALETTE_SIZE;

				if(top >= 6)
				{
					SQBool b = SQFalse;
					sq_getbool(vm, 5, &b);
					fixed = (b != SQFalse);

					if(top >= 7)
					{
						scale = getSquirrelNumber(vm, 7);
					}
				}
			}
		}

		if(scale == 0)
		{
			sq_pushinteger(vm, 0);
			return 1;
		}

		s32 size = memory->api.text_ex(memory, text ? text : "nil", x, y, color, fixed, scale);

		sq_pushinteger(vm, size);

		return 1;
	}

	return 0;
}

static SQInteger squirrel_trace(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);
	tic_machine* machine = getSquirrelMachine(vm);

	if(top >= 2)
	{
		const char* text = printString(vm, 2);
		u8 color = tic_color_white;

		if(top >= 3)
		{
			color = getSquirrelNumber(vm, 3);
		}

		machine->data->trace(machine->data->data, text ? text : "nil", color);
	}

	return 0;
}

static SQInteger squirrel_pmem(HSQUIRRELVM vm)
{
	SQInteger top = sq_gettop(vm);
	tic_machine* machine = getSquirrelMachine(vm);
	tic_mem* memory = &machine->memory;

	if(top >= 2)
	{
		u32 index = getSquirrelNumber(vm, 2);

		if(index < TIC_PERSISTENT_SIZE)
		{
			u32 val = memory->persistent.data[index];

			if(top >= 3)
			{
				SQInteger i = 0;
				sq_getinteger(vm, 3, &i);
				memory->persistent.data[index] = (u32)i;
				machine->data->syncPMEM = true;
			}

			sq_pushinteger(vm, val);

			return 1;			
		}
		return sq_throwerror(vm, "invalid persistent memory index\n");
	}
	else return sq_throwerror(vm, "invalid params, pmem(index [val]) -> val\n");

	return 0;
}

static SQInteger squirrel_time(HSQUIRRELVM vm)
{
	tic_mem* memory = (tic_mem*)getSquirrelMachine(vm);
	
	sq_pushfloat(vm, (SQFloat)(memory->api.time(memory)));

	return 1;
}

static SQInteger squirrel_exit(HSQUIRRELVM vm)
{
	tic_machine* machine = getSquirrelMachine(vm);

	machine->data->exit(machine->data->data);
	
	return 0;
}

static SQInteger squirrel_mouse(HSQUIRRELVM vm)
{
	tic_machine* machine = getSquirrelMachine(vm);

	const tic80_mouse* mouse = &machine->memory.ram.input.mouse;

	sq_newarray(vm, 5);
	sq_pushinteger(vm, mouse->x);
	sq_arrayappend(vm, -2);
	sq_pushinteger(vm, mouse->y);
	sq_arrayappend(vm, -2);
	sq_pushbool(vm, mouse->left ? SQTrue : SQFalse);
	sq_arrayappend(vm, -2);
	sq_pushbool(vm, mouse->middle ? SQTrue : SQFalse);
	sq_arrayappend(vm, -2);
	sq_pushbool(vm, mouse->right ? SQTrue : SQFalse);
	sq_arrayappend(vm, -2);

	return 1;
}

static SQInteger squirrel_dofile(HSQUIRRELVM vm)
{
	return sq_throwerror(vm, "unknown method: \"dofile\"\n");
}

static SQInteger squirrel_loadfile(HSQUIRRELVM vm)
{
	return sq_throwerror(vm, "unknown method: \"loadfile\"\n");
}

static void squirrel_open_builtins(HSQUIRRELVM vm)
{
	sq_pushroottable(vm);
	sqstd_register_mathlib(vm);
	sqstd_register_stringlib(vm);
	sqstd_register_bloblib(vm);
	sq_poptop(vm);
}

static const char* const ApiKeywords[] = API_KEYWORDS;
static const SQFUNCTION ApiFunc[] = 
{
	NULL, NULL, NULL, squirrel_print, squirrel_cls, squirrel_pix, squirrel_line, squirrel_rect, 
	squirrel_rectb, squirrel_spr, squirrel_btn, squirrel_btnp, squirrel_sfx, squirrel_map, squirrel_mget, 
	squirrel_mset, squirrel_peek, squirrel_poke, squirrel_peek4, squirrel_poke4, squirrel_memcpy, 
	squirrel_memset, squirrel_trace, squirrel_pmem, squirrel_time, squirrel_exit, squirrel_font, squirrel_mouse, 
	squirrel_circ, squirrel_circb, squirrel_tri, squirrel_textri, squirrel_clip, squirrel_music, squirrel_sync, squirrel_reset,
	squirrel_key, squirrel_keyp
};

STATIC_ASSERT(api_func, COUNT_OF(ApiKeywords) == COUNT_OF(ApiFunc));

static void checkForceExit(HSQUIRRELVM vm, SQInteger type, const SQChar* sourceName, SQInteger line, const SQChar* functionName)
{
	tic_machine* machine = getSquirrelMachine(vm);
	tic_tick_data* tick = machine->data;

	if(tick->forceExit && tick->forceExit(tick->data))
		sq_throwerror(vm, "script execution was interrupted");
}

static void initAPI(tic_machine* machine)
{
	//lua_pushlightuserdata(machine->lua, machine);
	//lua_setglobal(machine->lua, TicMachine);
	HSQUIRRELVM vm = machine->squirrel;
	
	sq_pushregistrytable(vm);
	sq_pushstring(vm, TicMachine, -1);
	sq_pushuserpointer(machine->squirrel, machine);
	sq_newslot(vm, -3, SQTrue);
	sq_poptop(vm);

#if USE_FOREIGN_POINTER
	sq_setforeignptr(vm, machine);
#endif

	for (s32 i = 0; i < COUNT_OF(ApiFunc); i++)
		if (ApiFunc[i])
			registerSquirrelFunction(machine, ApiFunc[i], ApiKeywords[i]);

	registerSquirrelFunction(machine, squirrel_dofile, "dofile");
	registerSquirrelFunction(machine, squirrel_loadfile, "loadfile");

#if CHECK_FORCE_EXIT
	sq_setnativedebughook(vm, checkForceExit);
#endif
	sq_enabledebuginfo(vm, SQTrue);

}

static void closeSquirrel(tic_mem* tic)
{
	tic_machine* machine = (tic_machine*)tic;

	if(machine->squirrel)
	{
		sq_close(machine->squirrel);
		machine->squirrel = NULL;
	}
}

static bool initSquirrel(tic_mem* tic, const char* code)
{
	tic_machine* machine = (tic_machine*)tic;

	closeSquirrel(tic);

	HSQUIRRELVM vm = machine->squirrel = sq_open(100);
	squirrel_open_builtins(vm);

	sq_newclosure(vm, squirrel_errorHandler, 0);
	sq_seterrorhandler(vm);

	initAPI(machine);

	{
		HSQUIRRELVM vm = machine->squirrel;

		sq_settop(vm, 0);

		if((SQ_FAILED(sq_compilebuffer(vm, code, strlen(code), "squirrel", SQFalse))) || 
			(sq_pushroottable(vm), false) ||
			(SQ_FAILED(sq_call(vm, 1, SQFalse, SQTrue))))
		{
			sq_getlasterror(vm);
			sq_tostring(vm, -1);
			const SQChar* errorString = "unknown error";
			sq_getstring(vm, -1, &errorString);

			machine->data->error(machine->data->data, errorString);
			
			sq_pop(vm, 2); // error and error string

			return false;
		}
	}

	return true;
}

static void callSquirrelTick(tic_mem* tic)
{
	tic_machine* machine = (tic_machine*)tic;

	const char* TicFunc = ApiKeywords[0];

	HSQUIRRELVM vm = machine->squirrel;

	if(vm)
	{
		//lua_getglobal(lua, TicFunc);
		sq_pushroottable(vm);
		sq_pushstring(vm, TicFunc, -1);

		if (SQ_SUCCEEDED(sq_get(vm, -2)))
		{
			sq_pushroottable(vm);
			if(SQ_FAILED(sq_call(vm, 1, SQFalse, SQTrue)))
			{
				sq_getlasterror(vm);
				sq_tostring(vm, -1);
				const SQChar* errorString = "unknown error";
				sq_getstring(vm, -1, &errorString);

				machine->data->error(machine->data->data, errorString);
				sq_pop(vm, 3); // remove string, error and root table.
			}
		}
		else 
		{		
			sq_pop(vm, 1);
			machine->data->error(machine->data->data, "'function TIC()...' isn't found :(");
		}
	}
}

static void callSquirrelScanlineName(tic_mem* memory, s32 row, void* data, const char* name)
{
	tic_machine* machine = (tic_machine*)memory;
	HSQUIRRELVM vm = machine->squirrel;

	if (vm)
	{
		sq_pushroottable(vm);
		sq_pushstring(vm, name, -1);
		if (SQ_SUCCEEDED(sq_get(vm, -2)))
		{
			sq_pushroottable(vm);
			sq_pushinteger(vm, row);

			if(SQ_FAILED(sq_call(vm, 2, SQFalse, SQTrue)))
			{
				sq_getlasterror(vm);
				sq_tostring(vm, -1);

				const SQChar* errorString = "unknown error";
				sq_getstring(vm, -1, &errorString);
				machine->data->error(machine->data->data, errorString);
				sq_pop(vm, 3); // error string, error and root table
			}
		}
		else sq_poptop(vm);
	}
}

static void callSquirrelScanline(tic_mem* memory, s32 row, void* data)
{
	callSquirrelScanlineName(memory, row, data, ApiKeywords[1]);

	// try to call old scanline
	callSquirrelScanlineName(memory, row, data, "scanline");
}

static void callSquirrelOverline(tic_mem* memory, void* data)
{
	tic_machine* machine = (tic_machine*)memory;
	HSQUIRRELVM vm = machine->squirrel;

	if (vm)
	{
		const char* OvrFunc = ApiKeywords[2];

		sq_pushroottable(vm);
		sq_pushstring(vm, OvrFunc, -1);
		
		if(SQ_SUCCEEDED(sq_get(vm, -2))) 
		{
			sq_pushroottable(vm);
			if(SQ_FAILED(sq_call(vm, 1, SQFalse, SQTrue)))
			{
				sq_getlasterror(vm);
				sq_tostring(vm, -1);
				const SQChar* errorString = "unknown error";
				sq_getstring(vm, -1, &errorString);
				machine->data->error(machine->data->data, errorString);
				sq_pop(vm, 3);
			}
		}
		else sq_poptop(vm);
	}

}

static const char* const SquirrelKeywords [] =
{
	"base", "break", "case", "catch", "class", "clone",
	"continue", "const", "default", "delete", "else", "enum",
	"extends", "for", "foreach", "function", "if", "in",
	"local", "null", "resume", "return", "switch", "this",
	"throw", "try", "typeof", "while", "yield", "constructor",
	"instanceof", "true", "false", "static", "__LINE__", "__FILE__"
};

static inline bool isalnum_(char c) {return isalnum(c) || c == '_';}

static const tic_outline_item* getSquirrelOutline(const char* code, s32* size)
{
	enum{Size = sizeof(tic_outline_item)};

	*size = 0;

	static tic_outline_item* items = NULL;

	if(items)
	{
		free(items);
		items = NULL;
	}

	const char* ptr = code;

	while(true)
	{
		static const char FuncString[] = "function ";

		ptr = strstr(ptr, FuncString);

		if(ptr)
		{
			ptr += sizeof FuncString - 1;

			const char* start = ptr;
			const char* end = start;

			while(*ptr)
			{
				char c = *ptr;

				if(isalnum_(c) || c == ':');
				else if(c == '(')
				{
					end = ptr;
					break;
				}
				else break;

				ptr++;
			}

			if(end > start)
			{
				items = items ? realloc(items, (*size + 1) * Size) : malloc(Size);

				items[*size].pos = (s32)(start - code);
				items[*size].size = (s32)(end - start);

				(*size)++;
			}
		}
		else break;
	}

	return items;
}

void evalSquirrel(tic_mem* tic, const char* code) {
	tic_machine* machine = (tic_machine*)tic;
	HSQUIRRELVM vm = machine->squirrel;

	sq_settop(vm, 0);

	if((SQ_FAILED(sq_compilebuffer(vm, code, strlen(code), "squirrel", SQFalse))) || 
		(sq_pushroottable(vm), false) ||
		(SQ_FAILED(sq_call(vm, 1, SQFalse, SQTrue))))
	{
		sq_getlasterror(vm);
		sq_tostring(vm, -1);
		const SQChar* errorString = "unknown error";
		sq_getstring(vm, -1, &errorString);
		machine->data->error(machine->data->data, errorString);
		sq_pop(vm, 3);
	}
}

static const tic_script_config SquirrelSyntaxConfig = 
{
	.init 				= initSquirrel,
	.close 				= closeSquirrel,
	.tick 				= callSquirrelTick,
	.scanline 			= callSquirrelScanline,
	.overline 			= callSquirrelOverline,

	.getOutline			= getSquirrelOutline,
	.parse 				= parseCode,
	.eval				= evalSquirrel,

	.blockCommentStart 	= "/*",
	.blockCommentEnd 	= "*/",
	.singleComment 		= "//",
	.blockStringStart	= "@\"",
	.blockStringEnd		= "\"",

	.keywords 			= SquirrelKeywords,
	.keywordsCount 		= COUNT_OF(SquirrelKeywords),
	
	.api 				= ApiKeywords,
	.apiCount 			= COUNT_OF(ApiKeywords),
};

const tic_script_config* getSquirrelScriptConfig()
{
	return &SquirrelSyntaxConfig;
}

#endif /* defined(TIC_BUILD_WITH_SQUIRREL) */