local TermW,TermH = term.getSize()

local sLevelTitle
local tScreen
local oScreen
local SizeW,SizeH
local aExits
local fExit
local nSpeed
local Speed
local fSpeed
local fSpeedS
local bPaused
local Tick
local Blocks
local XOrgin,YOrgin

local function reset()
    sLevelTitle = ""
    tScreen = {}
    oScreen = {}
    SizeW,SizeH = TermW,TermH
    aExits = 0
    fExit = "nop"
    nSpeed = 0.6
    Speed = nSpeed
    fSpeed = 0.2
    fSpeedS = false
    bPaused = false
    Tick = os.startTimer(Speed)
    Blocks = 0
    XOrgin,YOrgin = 1,1

    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    term.clear()
end

local InterFace = {}
InterFace.cExit = colors.red
InterFace.cSpeedD = colors.white
InterFace.cSpeedA = colors.red
InterFace.cTitle = colors.red

local cG = colors.lightGray
local cW = colors.gray
local cS = colors.black
local cR1 = colors.blue
local cR2 = colors.red
local cR3 = colors.green
local cR4 = colors.yellow

local tArgs = { ... }

--Functions--
local function printCentred( yc, stg )
	local xc = math.floor((TermW - string.len(stg)) / 2) + 1
	term.setCursorPos(xc,yc)
	term.write( stg )
end

local function centerOrgin()
	XOrgin = math.floor((TermW/2)-(SizeW/2))
	YOrgin = math.floor((TermH/2)-(SizeH/2))
end

local function reMap()
	tScreen = nil
	tScreen = {}
	for x=1,SizeW do
		tScreen[x] = {}
		for y=1,SizeH do
			tScreen[x][y] = { space = true, wall = false, ground = false, robot = "zz", start = "zz", exit = "zz" }
		end
	end
end

local function tablecopy(t)
  local t2 = {}
  for k,v in pairs(t) do
    t2[k] = v
  end
  return t2
end

local function buMap()
	oScreen = nil
	oScreen = {}
	for x=1,SizeW do
		oScreen[x] = {}
		for y=1,SizeH do
			oScreen[x][y] = tablecopy(tScreen[x][y])
		end
	end
end

local function addRobot(x,y,side,color)
	local obj = tScreen[x][y]
	local data = side..color
	if obj.wall == nil and obj.robot == nil then
		tScreen[x][y].robot = data
	else
		obj.wall = nil
		obj.robot = "zz"
		tScreen[x][y].robot = data
	end
end

local function addStart(x,y,side,color)
	local obj = tScreen[x][y]
	local data = side..color
	if obj.wall == nil and obj.space == nil then
		tScreen[x][y].start = data
	else
		obj.wall = nil
		obj.space = nil
		tScreen[x][y].start = data
	end
	aExits = aExits+1
end

local function addGround(x,y)
	local obj = tScreen[x][y]
	if obj.space == nil and obj.exit == nil and obj.wall == nil and obj.robot == nil and obj.start == nil then
		tScreen[x][y].ground = true
	else
		obj.space = nil
		obj.exit = "zz"
		obj.wall = nil
		obj.robot = "zz"
		obj.start = "zz"
		tScreen[x][y].ground = true
	end
end

local function addExit(x,y,cl)
	local obj = tScreen[x][y]
	if obj.space == nil and obj.ground == nil and obj.wall == nil and obj.robot == nil and obj.start == nil then
		tScreen[x][y].exit = cl
	else
		obj.space = nil
		obj.ground = nil
		obj.wall = nil
		obj.robot = "zz"
		obj.start = "zz"
		tScreen[x][y].exit = cl
	end
end

local function addWall(x,y)
	local obj = tScreen[x][y]
	if obj == nil then
		return error("Here X"..x.." Y"..y)
	end
	if obj.space == nil and obj.exit == nil and obj.ground == nil and obj.robot == nil and obj.start == nil then
		tScreen[x][y].wall = true
	else
		obj.space = nil
		obj.exit = nil
		obj.ground = nil
		obj.robot = nil
		obj.start = nil
		tScreen[x][y].wall = true
	end
end

local function loadLevel(nNum)
    sLevelTitle = "Level "..nNum
	if nNum == nil then return error("nNum == nil") end
	local sDir = fs.getDir( shell.getRunningProgram() )
	local sLevelD = sDir .. "/levels/" .. tostring(nNum)
	if not ( fs.exists(sLevelD) or fs.isDir(sLevelD) ) then return error("Level Not Exists : "..sLevelD) end
	fLevel = fs.open(sLevelD,"r")
	local Line = 0
	local wl = true
	Blocks = tonumber(string.sub(fLevel.readLine(),1,1))
	local xSize = string.len(fLevel.readLine())+2
	local Lines = 3
	while wl do
		local wLine = fLevel.readLine()
		if wLine == nil then
			fLevel.close()
			wl = false
		else
    	    xSize = math.max(string.len(wLine)+2,xSize)
			Lines = Lines + 1
		end
	end
	SizeW,SizeH = xSize,Lines
	reMap()
	fLevel = fs.open(sLevelD,"r")
	fLevel.readLine()
	for Line=2,Lines-1 do
		sLine = fLevel.readLine()
		local chars = string.len(sLine)
		for char = 1, chars do
			local el = string.sub(sLine,char,char)
			if el == "8" then
				addGround(char+1,Line)
			elseif el == "0" then
				addStart(char+1,Line,"a","a")
			elseif el == "1" then
				addStart(char+1,Line,"b","a")
			elseif el == "2" then
				addStart(char+1,Line,"c","a")
			elseif el == "3" then
				addStart(char+1,Line,"d","a")
			elseif el == "4" then
				addStart(char+1,Line,"a","b")
			elseif el == "5" then
				addStart(char+1,Line,"b","b")
			elseif el == "6" then
				addStart(char+1,Line,"c","b")
			elseif el == "9" then
				addStart(char+1,Line,"d","b")
			elseif el == "b" then
				addExit(char+1,Line,"a")
			elseif el == "e" then
				addExit(char+1,Line,"b")
			elseif el == "7" then
				addWall(char+1,Line)
			end
		end
	end
	fLevel.close()
end

local function drawStars()
	--CCR Background By : RamiLego--
	local cStar,cStarG,crStar,crStarB = colors.lightGray,colors.gray,".","*"
	local DStar,BStar,nStar,gStar = 14,10,16,3
	local TermW,TermH = term.getSize()

    term.clear()
    term.setCursorPos(1,1)
	for x=1,TermW do
		for y=1,TermH do
			local StarT = math.random(1,30)
			if StarT == DStar then
				term.setCursorPos(x,y)
				term.setTextColor(cStar)
				write(crStar)
			elseif StarT == BStar then
				term.setCursorPos(x,y)
				term.setTextColor(cStar)
				write(crStarB)
			elseif StarT == nStar then
				term.setCursorPos(x,y)
				term.setTextColor(cStarG)
				write(crStar)
			elseif StarT == gStar then
				term.setCursorPos(x,y)
				term.setTextColor(cStarG)
				write(crStarB)
			end
		end
	end
end

local function drawMap()
	for x=1,SizeW do
		for y=1,SizeH do

			local obj = tScreen[x][y]
			if obj.ground == true then
				paintutils.drawPixel(XOrgin+x,YOrgin+y+1,cG)
			end
			if obj.wall == true then
				paintutils.drawPixel(XOrgin+x,YOrgin+y+1,cW)
			end

		 local ex = tostring(tScreen[x][y].exit)
			if not(ex == "zz" or ex == "nil") then
				if ex == "a" then
					ex = cR1
				elseif ex == "b" then
					ex = cR2
				elseif ex == "c" then
					ex = cR3
				elseif ex == "d" then
					ex = cR4
				else
					return error("Exit Color Out")
				end
				term.setBackgroundColor(cG)
				term.setTextColor(ex)
				term.setCursorPos(XOrgin+x,YOrgin+y+1)
				print("X")
			end

		 local st = tostring(tScreen[x][y].start)
			if not(st == "zz" or st == "nil") then
				local Cr = string.sub(st,2,2)
				if Cr == "a" then
					Cr = cR1
				elseif Cr == "b" then
					Cr = cR2
				elseif Cr == "c" then
					Cr = cR3
				elseif Cr == "d" then
					Cr = cR4
				else
					return error("Start Color Out")
				end

				term.setTextColor(Cr)
			term.setBackgroundColor(cG)
				term.setCursorPos(XOrgin+x,YOrgin+y+1)

				sSide = string.sub(st,1,1)
				if sSide == "a" then
					print("^")
				elseif sSide == "b" then
					print(">")
				elseif sSide == "c" then
					print("v")
				elseif sSide == "d" then
					print("<")
				else
					print("@")
				end
			end

			if obj.space == true then
				paintutils.drawPixel(XOrgin+x,YOrgin+y+1,cS)
			end

			local rb = tostring(tScreen[x][y].robot)
			if not(rb == "zz" or rb == "nil") then
				local Cr = string.sub(rb,2,2)
				if Cr == "a" then
					Cr = cR1
				elseif Cr == "b" then
					Cr = cR2
				elseif Cr == "c" then
					Cr = cR3
				elseif Cr == "d" then
					Cr = cR4
				else
					Cr = colors.white
				end
				term.setBackgroundColor(Cr)
				term.setTextColor(colors.white)
				term.setCursorPos(XOrgin+x,YOrgin+y+1)
				sSide = string.sub(rb,1,1)
				if sSide == "a" then
					print("^")
				elseif sSide == "b" then
					print(">")
				elseif sSide == "c" then
					print("v")
				elseif sSide == "d" then
					print("<")
				else
					print("@")
				end
			end
		end
	end
end

local function isBrick(x,y)
	local brb = tostring(tScreen[x][y].robot)
	local bobj = oScreen[x][y]
	if (brb == "zz" or brb == "nil") and not bobj.wall == true then
		return false
	else
		return true
	end
end

local function gRender(sContext)
	if sContext == "start" then
		for x=1,SizeW do
			for y=1,SizeH do
				local st = tostring(tScreen[x][y].start)
				if not(st == "zz" or st == "nil") then
					local Cr = string.sub(st,2,2)
					local sSide = string.sub(st,1,1)
					addRobot(x,y,sSide,Cr)
				end
			end
		end
	elseif sContext == "tick" then
		buMap()
        for x=1,SizeW do
            for y=1,SizeH do
                local rb = tostring(oScreen[x][y].robot)
                if not(rb == "zz" or rb == "nil") then
                    local Cr = string.sub(rb,2,2)
                    local sSide = string.sub(rb,1,1)
                    local sobj = oScreen[x][y]
                    if sobj.space == true then
                        tScreen[x][y].robot = "zz"
                        if not sSide == "g" then
                            addRobot(x,y,"g",Cr)
                        end
                    elseif sobj.exit == Cr then
                        if sSide == "a" or sSide == "b" or sSide == "c" or sSide == "d" then
                        tScreen[x][y].robot = "zz"
                        addRobot(x,y,"g",Cr)
                        aExits = aExits-1
                        end
                    elseif sSide == "a" then
                        local obj = isBrick(x,y-1)
                        tScreen[x][y].robot = "zz"
                        if not obj == true then
                            addRobot(x,y-1,sSide,Cr)
                        else
                            local obj2 = isBrick(x-1,y)
                            local obj3 = isBrick(x+1,y)
                            if not obj2 == true and not obj3 == true then
                                if Cr == "a" then
                                    addRobot(x,y,"d",Cr)
                                elseif Cr == "b" then
                                    addRobot(x,y,"b",Cr)
                                end
                            elseif obj == true and obj2 == true and obj3 == true then
                                addRobot(x,y,"c",Cr)
                            else
                                if obj3 == true then
                                    addRobot(x,y,"d",Cr)
                                elseif obj2 == true then
                                    addRobot(x,y,"b",Cr)
                                end
                            end
                        end
                    elseif sSide == "b" then
                        local obj = isBrick(x+1,y)
                        tScreen[x][y].robot = "zz"
                        if not obj == true then
                            addRobot(x+1,y,sSide,Cr)
                        else
                            local obj2 = isBrick(x,y-1)
                            local obj3 = isBrick(x,y+1)
                            if not obj2 == true and not obj3 == true then
                                if Cr == "a" then
                                    addRobot(x,y,"a",Cr)
                                elseif Cr == "b" then
                                    addRobot(x,y,"c",Cr)
                                end
                            elseif obj == true and obj2 == true and obj3 == true then
                                addRobot(x,y,"d",Cr)
                            else
                                if obj3 == true then
                                    addRobot(x,y,"a",Cr)
                                elseif obj2 == true then
                                    addRobot(x,y,"c",Cr)
                                end
                            end
                        end
                    elseif sSide == "c" then
                        local obj = isBrick(x,y+1)
                        tScreen[x][y].robot = "zz"
                        if not obj == true then
                            addRobot(x,y+1,sSide,Cr)
                        else
                            local obj2 = isBrick(x-1,y)
                            local obj3 = isBrick(x+1,y)
                            if not obj2 == true and not obj3 == true then
                                if Cr == "a" then
                                    addRobot(x,y,"b",Cr)
                                elseif Cr == "b" then
                                    addRobot(x,y,"d",Cr)
                                end
                            elseif obj == true and obj2 == true and obj3 == true then
                                addRobot(x,y,"a",Cr)
                            else
                                if obj3 == true then
                                    addRobot(x,y,"d",Cr)
                                elseif obj2 == true then
                                    addRobot(x,y,"b",Cr)
                                end
                            end
                        end
                    elseif sSide == "d" then
                        local obj = isBrick(x-1,y)
                        tScreen[x][y].robot = "zz"
                        if not obj == true then
                            addRobot(x-1,y,sSide,Cr)
                        else
                            local obj2 = isBrick(x,y-1)
                            local obj3 = isBrick(x,y+1)
                            if not obj2 == true and not obj3 == true then
                                if Cr == "a" then
                                    addRobot(x,y,"c",Cr)
                                elseif Cr == "b" then
                                    addRobot(x,y,"a",Cr)
                                end
                            elseif obj == true and obj2 == true and obj3 == true then
                                addRobot(x,y,"b",Cr)
                            else
                                if obj3 == true then
                                    addRobot(x,y,"a",Cr)
                                elseif obj2 == true then
                                    addRobot(x,y,"c",Cr)
                                end
                            end
                        end
                    else
                        addRobot(x,y,sSide,"g")
                    end
                end
            end
        end
    end
end

function InterFace.drawBar()
	term.setBackgroundColor( colors.black )
	term.setTextColor( InterFace.cTitle )
	printCentred( 1, "  "..sLevelTitle.."  " )

	term.setCursorPos(1,1)
	term.setBackgroundColor( cW )
	write( " " )
	term.setBackgroundColor( colors.black )
	write( " x "..tostring(Blocks).." " )

	term.setCursorPos( TermW-8,TermH )
	term.setBackgroundColor( colors.black )
    term.setTextColour(InterFace.cSpeedD)
	write(" <<" )
	if bPaused then
		term.setTextColour(InterFace.cSpeedA)
	else
		term.setTextColour(InterFace.cSpeedD)
	end
	write(" ||")
	if fSpeedS then
		term.setTextColour(InterFace.cSpeedA)
	else
		term.setTextColour(InterFace.cSpeedD)
	end
	write(" >>")

	term.setCursorPos( TermW-1, 1 )
	term.setBackgroundColor( colors.black )
	term.setTextColour( InterFace.cExit )
	write(" X")
	term.setBackgroundColor(colors.black)
end

function InterFace.render()
	local id,p1,p2,p3 = os.pullEvent()
	if id == "mouse_click" then
		if p3 == 1 and p2 == TermW then
            return "end"
        elseif p3 == TermH and p2 >= TermW-7 and p2 <= TermW-6 then
            return "retry"
        elseif p3 == TermH and p2 >= TermW-4 and p2 <= TermW-3 then
            bPaused = not bPaused
            fSpeedS = false
            Speed = (bPaused and 0) or nSpeed
            if Speed > 0 then
                Tick = os.startTimer(Speed)
            else
                Tick = nil
            end
            InterFace.drawBar()
        elseif p3 == TermH and p2 >= TermW-1 then
            bPaused = false
            fSpeedS = not fSpeedS
            Speed = (fSpeedS and fSpeed) or nSpeed
            Tick = os.startTimer(Speed)
            InterFace.drawBar()
		elseif p3-1 < YOrgin+SizeH+1 and p3-1 > YOrgin and
               p2 < XOrgin+SizeW+1 and p2 > XOrgin then
            local eobj = tScreen[p2-XOrgin][p3-YOrgin-1]
            local erobj = tostring(tScreen[p2-XOrgin][p3-YOrgin-1].robot)
            if (erobj == "zz" or erobj == "nil") and not eobj.wall == true and not eobj.space == true and Blocks > 0 then
                addWall(p2-XOrgin,p3-YOrgin-1)
                Blocks = Blocks-1
                InterFace.drawBar()
                drawMap()
            end
		end
	elseif id == "timer" and p1 == Tick then
		gRender("tick")
        drawMap()
        if Speed > 0 then
            Tick = os.startTimer(Speed)
        else
            Tick = nil
        end
	end
end

local function startG(LevelN)
	drawStars()
	loadLevel(LevelN)
	centerOrgin()
	local create = true
	drawMap()
	InterFace.drawBar()
	gRender("start")
	drawMap()

	local NExit = true
	if aExits == 0 then
		NExit = false
	end

	while true do
		local isExit = InterFace.render()
		if isExit == "end" then
		    return nil
		elseif isExit == "retry" then
		    return LevelN
		elseif fExit == "yes" then
			if fs.exists( fs.getDir( shell.getRunningProgram() ) .. "/levels/" .. tostring(LevelN + 1) ) then
			    return LevelN + 1
			else
			    return nil
			end
		end
		if aExits == 0 and NExit == true then
			fExit = "yes"
		end
	end
end

local ok, err = true, nil

--Menu--
local sStartLevel = tArgs[1]
if ok and not sStartLevel then
    ok, err = pcall( function()
        term.setTextColor(colors.white)
        term.setBackgroundColor( colors.black )
        term.clear()
        drawStars()
        term.setTextColor( colors.red )
        printCentred( TermH/2 - 1, "  REDIRECTION  " )
        printCentred( TermH/2 - 0, "  ComputerCraft Edition  " )
        term.setTextColor( colors.yellow )
        printCentred( TermH/2 + 2, "  Click to Begin  " )
        os.pullEvent( "mouse_click" )
    end )
end

--Game--
if ok then
    ok,err = pcall( function()
        local nLevel
        if sStartLevel then
            nLevel = tonumber( sStartLevel )
        else
            nLevel = 1
        end
        while nLevel do
            reset()
            nLevel = startG(nLevel)
        end
    end )
end

--Upsell screen--
if ok then
    ok, err = pcall( function()
        term.setTextColor(colors.white)
        term.setBackgroundColor( colors.black )
        term.clear()
        drawStars()
        term.setTextColor( colors.red )
        if TermW >= 40 then
            printCentred( TermH/2 - 1, "  Thank you for playing Redirection  " )
            printCentred( TermH/2 - 0, "  ComputerCraft Edition  " )
            printCentred( TermH/2 + 2, "  Check out the full game:  " )
            term.setTextColor( colors.yellow )
            printCentred( TermH/2 + 3, "  http://www.redirectiongame.com  " )
        else
            printCentred( TermH/2 - 2, "  Thank you for  " )
            printCentred( TermH/2 - 1, "  playing Redirection  " )
            printCentred( TermH/2 - 0, "  ComputerCraft Edition  " )
            printCentred( TermH/2 + 2, "  Check out the full game:  " )
            term.setTextColor( colors.yellow )
            printCentred( TermH/2 + 3, "  www.redirectiongame.com  " )
        end
        parallel.waitForAll(
            function() sleep(2) end,
            function() os.pullEvent( "mouse_click" ) end
        )
    end )
end

--Clear and exit--
term.setCursorPos(1,1)
term.setTextColor(colors.white)
term.setBackgroundColor(colors.black)
term.clear()
if not ok then
    if err == "Terminated" then
        print( "Check out the full version of Redirection:" )
        print( "http://www.redirectiongame.com" )
    else
        printError( err )
    end
end