Convert this AFL to mql4 code

_SECTION_BEGIN("SMART TRADE ZONES"); 
x=BarIndex();
rightStrength=Param("Fractal Pivot Right side Strength",3,0,50,1); 
leftStrength=Param("Fractal Pivot Left side Strength",4,0,50,1); 
pk=H>Ref(HHV(H,leftStrength),-1) AND Ref(HHV(H,rightStrength),-rightStrength)<=H;
tr=L<Ref(LLV(L,leftStrength),-1) AND Ref(LLV(L,rightStrength),-rightStrength)>=L;
PHigh = PK;
PHighPrice0 = ValueWhen(PHigh,H);
PHighPrice1 = IIf(PHighPrice0 AND BarsSince(PHigh) > rightStrength,PHighPrice0,Null);
PHighPrice2 = IIf(PHighPrice0 AND BarsSince(PHigh) <= rightStrength,PHighPrice0,Null);
PLow = TR;
PLowPrice0 = ValueWhen(PLow,L); 
PLowPrice1 = IIf(PLowPrice0 AND BarsSince(Plow) > rightStrength,PLowPrice0,Null);
PLowPrice2 = IIf(PLowPrice0 AND BarsSince(Plow) <= rightStrength,PLowPrice0,Null);

//pk=ExRem(pk,tr);
//tr=ExRem(tr,pk);

px0=ValueWhen(pk,x,0); tx0=ValueWhen(tr,x,0);
px1=ValueWhen(pk,x,1); tx1=ValueWhen(tr,x,1);
px2=ValueWhen(pk,x,2); tx2=ValueWhen(tr,x,2);
ph0=ValueWhen(pk,H,0); tl0=ValueWhen(tr,L,0);
ph1=ValueWhen(pk,H,1); tl1=ValueWhen(tr,L,1);
ph2=ValueWhen(pk,H,2); tl2=ValueWhen(tr,L,2);

ll=tr AND tl1<tl2;
hl=tr AND tl1>tl2;
hh=pk AND ph1>ph2;
lh=pk AND ph1<ph2;
dt=pk AND ph1==ph2;
db=tr AND tl1==tl2;

ll_h=IIf(ll,1,0);
hl_h=IIf(hl,2,0);
hh_h=IIf(hh,3,0);
lh_h=IIf(lh,4,0);
dt_h=IIf(dt,5,0);
db_h=IIf(db,6,0);
combi=ll_h+hl_h+lh_h+hh_h;

t0=ValueWhen(combi,combi,0);
t1=ValueWhen(combi,combi,1);
t2=ValueWhen(combi,combi,2);
t3=ValueWhen(combi,combi,3);
t4=ValueWhen(combi,combi,4);

GraphXSpace = 5;
SetChartOptions(0, chartShowDates);
Plot(C,"\nLast",colorWhite,64);

Plot(PHighPrice1,"\nPHighPrice",colorOrange,styleLine);
Plot(PHighPrice2,"",colorOrange,styleDots | styleNoLine);
Plot(PLowPrice1,"\nPLowPrice",colorBrightGreen,styleLine);
Plot(PLowPrice2,"",colorBrightGreen,styleDots | styleNoLine);


PH =Phigh- Ref(Phigh,-1) != 0; 
PHprice = ValueWhen(PH, H,1);
Pvalid = C > ValueWhen(PH, PHighPrice2,1 ) ;
Pvalid = ExRem(Pvalid, PH);
Sell = Pvalid ; 

PL= Plow - Ref(Plow,-1) != 0;
PLPrice = ValueWhen(PL,L,1);
TValid = C < ValueWhen(PL, PLowPrice2,1) ;
TValid = ExRem(TValid, PL);
Buy = TValid ;


Buy = ExRem(Buy,Sell);
Sell = ExRem(Sell,Buy);



shape = Buy * shapeUpArrow + Sell * shapeDownArrow;
PlotShapes( shape, IIf( Buy, colorWhite, colorWhite ),0, IIf( Buy, Low, High ) );