[Computercraft] 2048

local running = true
local cx,cy = 0, 0
local drawx = 11
local drawy = -2
local xscale = 5
local yscale = 4
local cubexsize = 6
local cubeysize = 4
local score = 2
local function calcdragpos(sx,sy,ex,ey,dx,dy)
    if(ex < sx-dx)then return -1,0
    elseif(ex > sx+dx)then return 1,0
    elseif(ey < sy-dy)then return 0,-1
    elseif(ey > sy+dy)then return 0,1 end
end

local map = {
    {2,0,0,0},
    {0,0,0,0},
    {0,0,0,0},
    {0,0,0,0},
}
local numcols = {
    ['2'] = "white",
    ['4'] = "lightGray",
    ['8'] = "brown",
    ['16'] = "orange",
    ['32'] = "pink",
    ['64'] = "red",
    ['128'] = "yellow",
    ['256'] = "yellow",
    ['512'] = "yellow",
    ['1024'] = "yellow",
    ['2048'] = "yellow",
    ['4096'] = "magenta",
    ['8192'] = "purple",
}
local function drawtile(x,y)
        local sx = (drawx)+(x)*xscale
        local sy = (drawy)+(y)*yscale
        local ex = (drawx+x*xscale)+cubexsize
        local ey = (drawy+y*yscale)+cubeysize
        if(map[y][x] ~= 0)then
            -- drawing code form empty
            bcol = numcols[tostring(map[y][x])]
            if(bcol == nil)then col = colors.lightBlue end
            paintutils.drawFilledBox(sx+1,sy+1,ex-(cubexsize/2)+1,ey-(cubeysize/2)+1,colors[bcol])
            term.setTextColor(colors.black)
            term.setCursorPos((sx+3) - #tostring(map[y][x])/2 ,sy+2)
            write(map[y][x])
        else
            paintutils.drawFilledBox(sx+1,sy+1,ex-(cubexsize/2)+1,ey-(cubeysize/2)+1,colors.black)
        end
end
local function drawtiles()
    term.current().setVisible(false)
    --paintutils.drawBox(drawx,drawy,drawx+(#map[1]*xscale),drawy+(#map*yscale),colors.gray)
    for y = 1, #map do
       for x = 1, #map[y] do
            local tile = map[y][x]
                local sx = (drawx)+(x)*xscale
                local sy = (drawy)+(y)*yscale
                local ex = (drawx+x*xscale)+cubexsize
                local ey = (drawy+y*yscale)+cubeysize
                paintutils.drawBox(sx,sy,ex-1,ey,colors.gray)
                drawtile(x,y)
       end
    end
    term.current().setVisible(true)
end
local function setTile(x,y,n)
    if(map[y][x] ~= 0 and n ~= 0)then
        score = score + (n-map[y][x])
    elseif(map[y][x] ~= 0 and n == 0)then
        score = score - map[y][x]
    else
        score = score + n
    end
    map[y][x] = n
    drawtile(x,y)
end

local function getRandTile()
    local rx = math.ceil(math.random(1,#map[1]))
    local ry = math.ceil(math.random(1,#map))
    local rn = math.ceil(math.random(1,10))
    if(rn == 10)then
        rn = 4
    else
        rn = 2
    end
    return rx,ry,rn
end

local function slidetiles(xd,yd)
    -- 1, UP: 2, DOWN, 3: LEFT, 4: RIGHT
    local rna = math.ceil(math.random(1,2))
    local moved=false
    local cancombine = true
    for li = 1, #map[1] do
       for y = 1, #map do
          for x = 1, #map[y] do
                local to = nil
                if(y+yd < 0 or x+xd < 0)then break end
                if(map[y+yd] ~= nil)then
                    if(map[y+yd][x+xd] ~= nil)then
                        to = map[y+yd][x+xd]
                    end
                end

                if(to == 0)then
                    setTile(x+xd,y+yd,map[y][x])
                    setTile(x,y,0)
                    moved = true
                elseif(to == map[y][x] and cancombine and to ~= 8192)then
                    setTile(x+xd,y+yd,map[y+yd][x+xd]+map[y][x])
                    setTile(x,y,0)
                    cancombine = false
                end
           end
       end
    end
    local rx,ry,rn = getRandTile()
    if(map[ry][rx] == 0 and moved)then
        setTile(rx,ry,rn)
    end
    term.setCursorPos(1,1)
    term.setBackgroundColor(colors.white)
    term.setTextColor(colors.black)
    term.clearLine()
    print(score)
end
term.clear()
drawtiles()
while running do

    local e = {os.pullEvent()}
    if(e[1] == "mouse_click")then
        cx = e[3]
        cy = e[4]
    end
    if(e[1] == "mouse_drag" and cx ~= 0 and cy ~= 0)then
        local xdir,ydir = calcdragpos(cx,cy,e[3],e[4],2,1)
       if(type(xdir) == "number" and type(ydir) == "number")then
          slidetiles(tonumber(xdir),tonumber(ydir))
          cx = 0
          cy = 0
       end
    end
end