local gc,kb=love.graphics,love.keyboard
local setColor,rectangle=gc.setColor,gc.rectangle

local int,abs=math.floor,math.abs
local rnd,min=math.random,math.min
local format=string.format
local ins=table.insert
local setFont=setFont
local mStr=mStr

local scene={}

local blind,tapControl

local board
local startTime,time
local state,progress
local move

local nextTile,nextCD
local nextPos,prevPos
local prevSpawnTime=0
local maxTile

local skipper={
	used=false,
	cd=0,
}
local repeater={
	focus=false,
	seq={"",""},last={"X","X"},
}
local score

--[[Tiles' value:
	-1: black tile, cannot move
	0: X tile, cannot merge
	1/2/3/...: 2/4/8/... tile
]]
local tileColor={
	[-1]=COLOR.black,
	[0]={.5,.3,.3},
	{.93,.89,.85},
	{.93,.88,.78},
	{.95,.69,.47},
	{.96,.58,.39},
	{.96,.49,.37},
	{.96,.37,.23},
	{.93,.81,.45},
	{.93,.80,.38},
	{.93,.78,.31},
	{.93,.77,.25},
	{.93,.76,.18},
	{.40,.37,.33},
	{.22,.19,.17},
}
local tileFont={
	80,80,80,--2/4/8
	70,70,70,--16/32/64
	60,60,60,--128/256/512
	55,55,55,55,--1024/2048/4096/8192
	50,50,50,--16384/32768/65536
	45,45,45,--131072/262144/524288
	30,--1048576
}
local tileName={[0]="X","2","4","8","16","32","64","128","256","512","1024","2048","4096","8192","16384","32768","65536","131072","262144","524288","2^20"}
local function airExist()
	for i=1,16 do
		if not board[i]then
			return true
		end
	end
end
local function newTile()
	--Select position & generate number
	nextPos=(nextPos+6)%16+1
	while board[nextPos]do
		nextPos=(nextPos-4)%16+1
	end
	board[nextPos]=nextTile
	prevPos=nextPos
	prevSpawnTime=0

	--Fresh score
	score=score+2^nextTile
	TEXT.show("+"..2^nextTile,1130+rnd(-60,60),575+rnd(-30,30),30,"score",1.5)

	--Generate next number
	nextCD=nextCD-1
	if nextCD>0 then
		nextTile=1
	else
		nextTile=rnd()>.1 and 2 or rnd()>.1 and 3 or 4
		nextCD=rnd(8,12)
	end

	--Check if board is full
	if airExist()then return end

	--Check if board is locked in all-directions
	for i=1,12 do
		if board[i]==board[i+4]then
			return
		end
	end
	for i=1,13,4 do
		if
			board[i+0]==board[i+1]or
			board[i+1]==board[i+2]or
			board[i+2]==board[i+3]
		then
			return
		end
	end

	--Die.
	state=2
	SFX.play(maxTile>=10 and"win"or"fail")
end
local function freshMaxTile()
	maxTile=maxTile+1
	if maxTile==12 then skipper.cd=0 end
	SFX.play("reach")
	ins(progress,format("%s - %.3fs",tileName[maxTile],TIME()-startTime))
end
local function squash(L)
	local p1,p2=1
	local moved=false
	while true do
		p2=p1+1
		while not L[p2]do
			p2=p2+1
			if p2==5 then
				p1=p1+1
				if p1==4 then
					return L[1],L[2],L[3],L[4],moved
				end
				break
			end
		end
		if not L[p1]then--air←2
			L[p1],L[p2]=L[p2],false
			moved=true
		elseif L[p1]==L[p2]then--2←2
			L[p1],L[p2]=L[p1]+1,false
			if L[p1]>maxTile then
				freshMaxTile()
			end
			L[p2]=false
			p1=p1+1
			moved=true
		elseif p1+1~=p2 then--2←4
			L[p1+1],L[p2]=L[p2],false
			p1=p1+1
			moved=true
		else--2,4
			p1=p1+1
		end
	end
end
local function reset()
	for i=1,16 do board[i]=false end
	progress={}
	state=0
	score=0
	time=0
	move=0
	maxTile=6
	nextTile,nextPos=1,rnd(16)
	nextCD=32
	skipper.cd,skipper.used=false,false
	repeater.seq[1],repeater.seq[2]="",""
	repeater.last[1],repeater.last[2]="X","X"
	newTile()
end

local function moveUp()
	local moved
	for i=1,4 do
		local m
		board[i],board[i+4],board[i+8],board[i+12],m=squash({board[i],board[i+4],board[i+8],board[i+12]})
		if m then moved=true end
	end
	return moved
end
local function moveDown()
	local moved
	for i=1,4 do
		local m
		board[i+12],board[i+8],board[i+4],board[i],m=squash({board[i+12],board[i+8],board[i+4],board[i]})
		if m then moved=true end
	end
	return moved
end
local function moveLeft()
	local moved
	for i=1,13,4 do
		local m
		board[i],board[i+1],board[i+2],board[i+3],m=squash({board[i],board[i+1],board[i+2],board[i+3]})
		if m then moved=true end
	end
	return moved
end
local function moveRight()
	local moved
	for i=1,13,4 do
		local m
		board[i+3],board[i+2],board[i+1],board[i],m=squash({board[i+3],board[i+2],board[i+1],board[i]})
		if m then moved=true end
	end
	return moved
end
local function skip()
	if state==1 and skipper.cd==0 then
		if airExist()then
			skipper.cd=1024
			skipper.used=true
			newTile()
			SFX.play("hold")
		else
			SFX.play("finesseError")
		end
	end
end

function scene.sceneInit()
	BG.set("cubes")
	BGM.play("truth")
	board={}

	blind=false
	tapControl=false
	startTime=0
	reset()
	love.keyboard.setKeyRepeat(false)
end
function scene.sceneBack()
	love.keyboard.setKeyRepeat(true)
end

function scene.mouseDown(x,y,k)
	if tapControl then
		if k==2 then
			skip()
		else
			local dx,dy=x-640,y-360
			if abs(dx)<320 and abs(dy)<320 and(abs(dx)>60 or abs(dy)>60)then
				scene.keyDown(abs(dx)-abs(dy)>0 and
					(dx>0 and"right"or"left")or
					(dy>0 and"down"or"up")
				)
			end
		end
	end
end
function scene.touchDown(x,y)
	scene.mouseDown(x,y)
end
local moveFunc={
	up=moveUp,
	down=moveDown,
	left=moveLeft,
	right=moveRight,
}
local arrows={
	up="↑",down="↓",left="←",right="→",
	["↑"]="up",["↓"]="down",["←"]="left",["→"]="right",
}
local function setFocus(n)
	if state~=2 then
		repeater.focus=n
		repeater.seq[n]=""
	end
end
local function playRep(n)
	if state~=2 and #repeater.seq[n]>0 then
		repeater.focus=false
		local move0=move
		for i=1,#repeater.seq[n],3 do
			scene.keyDown(arrows[repeater.seq[n]:sub(i,i+2)],true)
		end
		if move~=move0 then
			if repeater.seq[n]~=repeater.last[n]then
				repeater.last[n]=repeater.seq[n]
				move=move0+#repeater.seq[n]/3+1
			else
				move=move0+1
			end
		end
	end
end
function scene.keyDown(key,auto)
	if key=="up"or key=="down"or key=="left"or key=="right"then
		if repeater.focus then
			local f=repeater.focus
			if #repeater.seq[f]<24 then
				repeater.seq[f]=repeater.seq[f]..arrows[key]
			end
		else
			if moveFunc[key]()then
				if state==0 then
					startTime=TIME()
					state=1
				end
				if skipper.cd and skipper.cd>0 then
					skipper.cd=skipper.cd-1
					if skipper.cd==0 then
						SFX.play("spin_0")
					end
				end
				newTile()
				TEXT.show(arrows[key],640,360,80,"beat",3)
				move=move+1
				if not auto then
					SFX.play("move")
				end
			end
		end
	elseif key=="space"then skip()
	elseif key=="r"then reset()
	elseif key=="q"then if state==0 then blind=not blind end
	elseif key=="w"then if state==0 then tapControl=not tapControl end
	elseif key=="1"or key=="2"then(kb.isDown("lshift","lctrl","lalt")and playRep or setFocus)(key=="1"and 1 or 2)
	elseif key=="c1"then playRep(1)
	elseif key=="c2"then playRep(2)
	elseif key=="return"then
		if repeater.focus then
			repeater.focus=false
		end
	elseif key=="escape"then
		if repeater.focus then
			repeater.focus=false
		else
			SCN.back()
		end
	end
end

function scene.update(dt)
	if state==1 then
		time=TIME()-startTime
	end
	if prevSpawnTime<1 then
		prevSpawnTime=min(prevSpawnTime+3*dt,1)
	end
end

function scene.draw()
	setFont(35)
	setColor(1,1,1)
	gc.print(format("%.3f",time),1000,10)
	gc.print(move,1000,45)

	--Progress time list
	setFont(20)
	setColor(.6,.6,.6)
	for i=1,#progress do
		gc.print(progress[i],1000,65+20*i)
	end

	--Repeater
	gc.setLineWidth(6)
	setFont(25)
	for i=1,2 do
		setColor(COLOR[
			repeater.focus==i and(
				TIME()%.5>.25 and
				"R"or
				"Y"
			)or(
				repeater.seq[i]==repeater.last[i]and
				"grey"or
				"white"
			)
		])
		rectangle("line",990,305+60*i,220,50)
		gc.print(repeater.seq[i],1000,313+60*i)
	end

	--Score
	setFont(40)
	setColor(1,.7,.7)
	mStr(score,1130,510)

	--Messages
	if state==2 then
		--Draw no-setting area
		setColor(1,0,0,.3)
		rectangle("fill",15,265,285,140)

		setColor(.9,.9,0)--win
	elseif state==1 then
		setColor(.9,.9,.9)--game
	elseif state==0 then
		setColor(.2,.8,.2)--ready
	end
	gc.setLineWidth(10)
	rectangle("line",310,30,660,660)

	--Board
	for i=1,16 do
		if board[i]then
			local x,y=1+(i-1)%4,int((i+3)/4)
			local N=board[i]
			if i~=prevPos or prevSpawnTime==1 then
				if not blind or i==prevPos then
					setColor(tileColor[N]or COLOR.black)
					rectangle("fill",x*160+163,y*160-117,154,154,15)
					if N>=0 then
						setColor(N<3 and COLOR.black or COLOR.W)
						local fontSize=tileFont[N]
						setFont(fontSize)
						mStr(tileName[N],320+(x-.5)*160,40+(y-.5)*160-fontSize*.7)
					end
				else
					setColor(COLOR.grey)
					rectangle("fill",x*160+163,y*160-117,154,154,15)
				end
			else
				local c=tileColor[N]
				setColor(c[1],c[2],c[3],prevSpawnTime)
				rectangle("fill",x*160+163,y*160-117,154,154,15)
				c=N<3 and 0 or 1
				setColor(c,c,c,prevSpawnTime)
				local fontSize=tileFont[N]
				setFont(fontSize)
				mStr(tileName[N],320+(x-.5)*160,40+(y-.5)*160-fontSize*.7)
			end
		end
	end

	--Next indicator
	setColor(1,1,1)
	if nextCD<=12 then
		for i=1,nextCD do
			rectangle("fill",140+i*16-nextCD*8,170,12,12)
		end
	end

	--Next
	setFont(40)
	gc.print("Next",50,195)
	if nextTile>1 then
		setColor(1,.5,.4)
	end
	setFont(70)
	mStr(tileName[nextTile],220,175)

	--Skip CoolDown
	if skipper.cd and skipper.cd>0 then
		setFont(50)
		setColor(1,1,.5)
		mStr(skipper.cd,155,600)
	end

	--Skip mark
	if skipper.used then
		setColor(1,1,.5)
		gc.circle("fill",280,675,10)
	end

	--New tile position
	local x,y=1+(prevPos-1)%4,int((prevPos+3)/4)
	gc.setLineWidth(8)
	setColor(.2,.8,0,prevSpawnTime)
	local d=25-prevSpawnTime*25
	rectangle("line",x*160+163-d,y*160-117-d,154+2*d,154+2*d,15)

	--Touch control boarder line
	if tapControl then
		gc.setLineWidth(6)
		setColor(1,1,1,.2)
		gc.line(310,30,580,300)
		gc.line(970,30,700,300)
		gc.line(310,690,580,420)
		gc.line(970,690,700,420)
		rectangle("line",580,300,120,120,10)
	end
end

scene.widgetList={
	WIDGET.newButton{name="reset",		x=155,y=100,w=180,h=100,color="lGreen",font=40,code=pressKey"r"},
	WIDGET.newSwitch{name="blind",		x=240,y=300,w=60,		font=40,disp=function()return blind end,	code=pressKey"q",hide=function()return state==1 end},
	WIDGET.newSwitch{name="tapControl",	x=240,y=370,w=60,		font=40,disp=function()return tapControl end,	code=pressKey"w",hide=function()return state==1 end},

	WIDGET.newKey{name="up",			x=155,y=460,w=100,fText="↑",font=50,color="yellow",code=pressKey"up",hide=function()return tapControl end},
	WIDGET.newKey{name="down",			x=155,y=660,w=100,fText="↓",font=50,color="yellow",code=pressKey"down",hide=function()return tapControl end},
	WIDGET.newKey{name="left",			x=55,y=560,w=100,fText="←",font=50,color="yellow",code=pressKey"left",hide=function()return tapControl end},
	WIDGET.newKey{name="right",			x=255,y=560,w=100,fText="→",font=50,color="yellow",code=pressKey"right",hide=function()return tapControl end},
	WIDGET.newKey{name="skip",			x=155,y=400,w=100,font=20,color="yellow",code=pressKey"space",hide=function()return state~=1 or not skipper.cd or skipper.cd>0 end},
	WIDGET.newKey{name="record1",		x=1100,y=390,w=220,h=50,fText="",color="grey",code=pressKey"1",hide=function()return state==2 end},
	WIDGET.newKey{name="record2",		x=1100,y=450,w=220,h=50,fText="",color="grey",code=pressKey"2",hide=function()return state==2 end},
	WIDGET.newKey{name="replay1",		x=1245,y=390,w=50,fText="!",color="green",code=pressKey"c1",hide=function()return state==2 or #repeater.seq[1]==0 end},
	WIDGET.newKey{name="replay2",		x=1245,y=450,w=50,fText="!",color="green",code=pressKey"c2",hide=function()return state==2 or #repeater.seq[2]==0 end},
	WIDGET.newButton{name="back",		x=1140,y=640,w=170,h=80,font=40,code=backScene},
}

return scene