local gc=love.graphics
local kb=love.keyboard

local scene={}

local reg--register
local val--result value
local sym--symbol

function scene.sceneInit()
    BG.set('none')
    BGM.stop()
    reg,val,sym=false,"0",false
end
function scene.sceneBack()
    BGM.play()
end

scene.mouseDown=NULL
function scene.keyDown(key)
    if key:byte()>=48 and key:byte()<=57 then
        if sym=="="then
            val=key
            sym=false
        elseif sym and not reg then
            reg=val
            val=key
        else
            if #val<14 then
                if val=="0"then val=""end
                val=val..key
            end
        end
    elseif key:sub(1,2)=="kp"then
        scene.keyDown(key:sub(3))
    elseif key=="."then
        if sym=="="then
            sym,reg=false,false
            val="0."
        elseif not(val:find(".",nil,true)or val:find("e"))then
            if sym and not reg then
                reg=val
                val="0."
            else
                val=val.."."
            end
        end
    elseif key=="e"then
        if sym=="="then
            sym,reg=false
            val="0e"
        elseif not val:find("e")then
            val=val.."e"
        end
    elseif key=="backspace"then
        if sym=="="then
            val=""
        elseif sym then
            sym=false
        else
            val=val:sub(1,-2)
        end
        if val==""then val="0"end
    elseif key=="+"or key=="="and kb.isDown("lshift","rshift")then
        if reg and sym then scene.keyDown("return")else reg=false end sym="+"
    elseif key=="*"or key=="8"and kb.isDown("lshift","rshift")then
        if reg and sym then scene.keyDown("return")else reg=false end sym="*"
    elseif key=="-"then
        if reg and sym then scene.keyDown("return")else reg=false end sym="-"
    elseif key=="/"then
        if reg and sym then scene.keyDown("return")else reg=false end sym="/"
    elseif key=="return"then
        if val:sub(-1)=="e"then val=val:sub(1,-2)end
        if sym and reg then
            if reg:sub(-1)=="e"then reg=reg:sub(1,-2)end
            val=
                sym=="+"and tostring((tonumber(reg)or 0)+tonumber(val))or
                sym=="-"and tostring((tonumber(reg)or 0)-tonumber(val))or
                sym=="*"and tostring((tonumber(reg)or 0)*tonumber(val))or
                sym=="/"and tostring((tonumber(reg)or 0)/tonumber(val))or
                "-1"
        end
        sym="="
        reg=false
    elseif key=="escape"then
        if val~="0"then
            reg,sym=false,false
            val="0"
        else
            SCN.back()
        end
    elseif key=="delete"then
        val="0"
    end
end

function scene.draw()
    gc.setColor(COLOR.Z)
    gc.setLineWidth(2)
    gc.rectangle('line',100,80,650,150,5)
    setFont(45)
    if reg then gc.printf(reg,0,100,720,'right')end
    if val then gc.printf(val,0,150,720,'right')end
    if sym then setFont(50)gc.print(sym,126,150)end
end

scene.widgetList={
    WIDGET.newKey{name="_1",x=145,y=300,w=90,fText="1",font=50,code=pressKey"1"},
    WIDGET.newKey{name="_2",x=245,y=300,w=90,fText="2",font=50,code=pressKey"2"},
    WIDGET.newKey{name="_3",x=345,y=300,w=90,fText="3",font=50,code=pressKey"3"},
    WIDGET.newKey{name="_4",x=145,y=400,w=90,fText="4",font=50,code=pressKey"4"},
    WIDGET.newKey{name="_5",x=245,y=400,w=90,fText="5",font=50,code=pressKey"5"},
    WIDGET.newKey{name="_6",x=345,y=400,w=90,fText="6",font=50,code=pressKey"6"},
    WIDGET.newKey{name="_7",x=145,y=500,w=90,fText="7",font=50,code=pressKey"7"},
    WIDGET.newKey{name="_8",x=245,y=500,w=90,fText="8",font=50,code=pressKey"8"},
    WIDGET.newKey{name="_9",x=345,y=500,w=90,fText="9",font=50,code=pressKey"9"},
    WIDGET.newKey{name="_0",x=145,y=600,w=90,fText="0",font=50,code=pressKey"0"},
    WIDGET.newKey{name=".",x=245,y=600,w=90,fText=".",color='lM',font=50,code=pressKey"."},
    WIDGET.newKey{name="e",x=345,y=600,w=90,fText="e",color='lM',font=50,code=pressKey"e"},
    WIDGET.newKey{name="+",x=445,y=300,w=90,fText="+",color='lB',font=50,code=pressKey"+"},
    WIDGET.newKey{name="-",x=445,y=400,w=90,fText="-",color='lB',font=50,code=pressKey"-"},
    WIDGET.newKey{name="*",x=445,y=500,w=90,fText="*",color='lB',font=50,code=pressKey"*"},
    WIDGET.newKey{name="/",x=445,y=600,w=90,fText="/",color='lB',font=50,code=pressKey"/"},
    WIDGET.newKey{name="<",x=545,y=300,w=90,fText="<",color='lR',font=50,code=pressKey"backspace"},
    WIDGET.newKey{name="=",x=545,y=400,w=90,fText="=",color='lY',font=50,code=pressKey"return"},
    WIDGET.newKey{name="back",x=1135,y=640,w=170,h=80,fText=TEXTURE.back,code=backScene},
}

return scene