var gases = [
	'O2','SO2','H2S','Cl2','NH3','N2','CO','CO2','H2S','NO','N2O','AsH3','F2','Cl2O','ClF3','PH3','SiH4','Si2H6','HF','CH4','H3CCH=CH2','HC#CH', "H2", "COCl2", "NO2"
]

function getRandomReaction() {
    var total = getTotalLength(actQuestion.reactions);
    
	var index = Math.floor(total*Math.random());
    
    var index2 = index;
    var findex = 0; 
    
    while (actQuestion.reactions[findex].length  < index2) {
        
        index2 -= actQuestion.reactions[findex].length;
        findex++;
    }
   
    
    var final = actQuestion.reactions[findex][index2]
	return reactions[findex][final];
    
    
}

function getTotalLength(field) {
    var out = 0;
    
    for (var i = 0; i < field.length; i++) {
        out += field[i].length;        
    }
    return out;
}

function getReagent(index) {
    console.log("index " + index)
    return actQuestion.reaction.reagents[index];
}


function getProduct(index) {
    return actQuestion.reaction.products[index];
}

function getSolubleProduct() {
    
    var solubles = []
    for (var i = 0; i < actQuestion.reaction.products.length; i++){
        var item = actQuestion.reaction.products[i];
        if (item.soluble == true) {
            solubles.push(i)
        }
    }
    
    var index = Math.floor(solubles.length*Math.random());
    return actQuestion.reaction.products[solubles[index]];
}

function getSolubleReagent() {
    
    var solubles = []
    for (var i = 0; i < actQuestion.reaction.reagents.length; i++){
        var item = actQuestion.reaction.reagents[i];
        if (item.soluble == true) {
            solubles.push(i)
        }
    }
    
    var index = Math.floor(solubles.length*Math.random());
    return actQuestion.reaction.reagents[solubles[index]];
}

function getGasReagent() {
    
    var gases = []
    for (var i = 0; i < actQuestion.reaction.reagents.length; i++){
        var item = actQuestion.reaction.reagents[i];
        if (item.gas == true) {
            gases.push(i)
        }
    }
    
    var index = Math.floor(gases.length*Math.random());
    return actQuestion.reaction.reagents[gases[index]];
}

function getGasProduct() {
    
    var gases = []
    for (var i = 0; i < actQuestion.reaction.products.length; i++){
        var item = actQuestion.reaction.products[i];
        if (item.gas == true) {
            gases.push(i)
        }
    }
    
    var index = Math.floor(gases.length*Math.random());
    return actQuestion.reaction.products[gases[index]];
}


function getRandomReagent(index) {
   var field = actQuestion.reaction.reagents;
	
    var index = Math.floor(field.length*Math.random());
    return field[index];
}

function getRandomProduct(index) {
	var field = actQuestion.reaction.products;
	
    var index = Math.floor(field.length*Math.random());
    return field[index];
}
/*
function getHTMLFormula(comp) {
    var text = comp.formula.replace(/(\d+)/g, "<sub>$1</sub>");
    return text;
}*/